// Package governance provides comprehensive governance plugin for Bifrost
package governance

import (
	"context"
	"errors"
	"fmt"
	"math/rand/v2"
	"net/url"
	"sort"
	"strings"
	"sync"
	"time"

	"github.com/bytedance/sonic"
	"github.com/google/uuid"
	bifrost "github.com/maximhq/bifrost/core"
	"github.com/maximhq/bifrost/core/network"
	"github.com/maximhq/bifrost/core/providers/gemini"
	"github.com/maximhq/bifrost/core/schemas"
	"github.com/maximhq/bifrost/framework/configstore"
	configstoreTables "github.com/maximhq/bifrost/framework/configstore/tables"
	"github.com/maximhq/bifrost/framework/mcpcatalog"
	"github.com/maximhq/bifrost/framework/modelcatalog"
)

// PluginName is the name of the governance plugin
const PluginName = "governance"

const (
	governanceRejectedContextKey schemas.BifrostContextKey = "bf-governance-rejected"

	VirtualKeyPrefix = "sk-bf-"
)

// Config is the configuration for the governance plugin
type Config struct {
	IsVkMandatory         *bool     `json:"is_vk_mandatory"`
	RequiredHeaders       *[]string `json:"required_headers"` // Pointer to live config slice; changes are reflected immediately without restart
	IsEnterprise          bool      `json:"is_enterprise"`
	DisableAutoToolInject *bool     `json:"disable_auto_tool_inject"`
	RoutingChainMaxDepth  *int      `json:"routing_chain_max_depth"` // Pointer to live config value; changes are reflected immediately without restart
}

type InMemoryStore interface {
	GetConfiguredProviders() map[schemas.ModelProvider]configstore.ProviderConfig
	GetMCPClientsAllowingAllVirtualKeys() map[string]string // clientID → clientName
}

type BaseGovernancePlugin interface {
	GetName() string
	EvaluateGovernanceRequest(ctx *schemas.BifrostContext, evaluationRequest *EvaluationRequest, requestType schemas.RequestType) (*EvaluationResult, *schemas.BifrostError)
	HTTPTransportPreHook(ctx *schemas.BifrostContext, req *schemas.HTTPRequest) (*schemas.HTTPResponse, error)
	HTTPTransportPostHook(ctx *schemas.BifrostContext, req *schemas.HTTPRequest, resp *schemas.HTTPResponse) error
	PreLLMHook(ctx *schemas.BifrostContext, req *schemas.BifrostRequest) (*schemas.BifrostRequest, *schemas.LLMPluginShortCircuit, error)
	PostLLMHook(ctx *schemas.BifrostContext, result *schemas.BifrostResponse, err *schemas.BifrostError) (*schemas.BifrostResponse, *schemas.BifrostError, error)
	PreMCPHook(ctx *schemas.BifrostContext, req *schemas.BifrostMCPRequest) (*schemas.BifrostMCPRequest, *schemas.MCPPluginShortCircuit, error)
	PostMCPHook(ctx *schemas.BifrostContext, resp *schemas.BifrostMCPResponse, bifrostErr *schemas.BifrostError) (*schemas.BifrostMCPResponse, *schemas.BifrostError, error)
	Cleanup() error
	GetGovernanceStore() GovernanceStore
}

// GovernancePlugin implements the main governance plugin with hierarchical budget system
type GovernancePlugin struct {
	ctx         context.Context
	cancelFunc  context.CancelFunc
	wg          sync.WaitGroup // Track active goroutines
	cleanupOnce sync.Once      // Ensure cleanup happens only once

	// Core components with clear separation of concerns
	store    GovernanceStore // Pure data access layer
	resolver *BudgetResolver // Pure decision engine for hierarchical governance
	tracker  *UsageTracker   // Business logic owner (updates, resets, persistence)
	engine   *RoutingEngine  // Routing engine for dynamic routing

	// Dependencies
	configStore  configstore.ConfigStore
	modelCatalog *modelcatalog.ModelCatalog
	mcpCatalog   *mcpcatalog.MCPCatalog
	logger       schemas.Logger

	// Transport dependencies
	inMemoryStore InMemoryStore

	cfgMutex sync.RWMutex

	isVkMandatory         *bool
	requiredHeaders       *[]string // pointer to live config slice; lowercased at check time
	isEnterprise          bool
	disableAutoToolInject *bool
}

// Init initializes and returns a governance plugin instance.
//
// It wires the core components (store, resolver, tracker), performs a best-effort
// startup reset of expired limits when a persistent `configstore.ConfigStore` is
// provided, and establishes a cancellable plugin context used by background work.
//
// Behavior and defaults:
//   - Enables all governance features with optimized defaults.
//   - If `configStore` is nil, the plugin will use an in-memory LocalGovernanceStore
//     (no persistence). Init constructs a LocalGovernanceStore internally when
//     configStore is nil.
//   - If `modelCatalog` is nil, cost calculation is skipped.
//   - `config.IsVkMandatory` controls whether `x-bf-vk` is required in PreLLMHook.
//   - `inMemoryStore` is used by TransportInterceptor to validate configured providers
//     and build provider-prefixed models; it may be nil. When nil, transport-level
//     provider validation/routing is skipped and existing model strings are left
//     unchanged. This is safe and recommended when using the plugin directly from
//     the Go SDK without the HTTP transport.
//
// Parameters:
//   - ctx: base context for the plugin; a child context with cancel is created.
//   - config: plugin flags; may be nil.
//   - logger: logger used by all subcomponents.
//   - configStore: configuration store used for persistence; may be nil.
//   - governanceConfig: initial/seed governance configuration for the store.
//   - modelCatalog: optional model catalog to compute request cost.
//   - inMemoryStore: provider registry used for routing/validation in transports.
//
// Returns:
//   - *GovernancePlugin on success.
//   - error if the governance store fails to initialize.
//
// Side effects:
//   - Logs warnings when optional dependencies are missing.
//   - May perform startup resets via the usage tracker when `configStore` is non-nil.
//
// Alternative entry point:
//   - Use InitFromStore to inject a custom GovernanceStore implementation instead
//     of constructing a LocalGovernanceStore internally.
func Init(
	ctx context.Context,
	config *Config,
	logger schemas.Logger,
	configStore configstore.ConfigStore,
	governanceConfig *configstore.GovernanceConfig,
	modelCatalog *modelcatalog.ModelCatalog,
	mcpCatalog *mcpcatalog.MCPCatalog,
	inMemoryStore InMemoryStore,
) (*GovernancePlugin, error) {
	if configStore == nil {
		logger.Warn("governance plugin requires config store to persist data, running in memory only mode")
	}
	if modelCatalog == nil {
		logger.Warn("governance plugin requires model catalog to calculate cost, all LLM cost calculations will be skipped.")
	}
	if mcpCatalog == nil {
		logger.Warn("governance plugin requires MCP catalog to calculate cost, all MCP cost calculations will be skipped.")
	}

	// Handle nil config - use safe defaults
	var isVkMandatory *bool
	var requiredHeaders *[]string
	var disableAutoToolInject *bool
	var routingChainMaxDepth *int
	if config != nil {
		isVkMandatory = config.IsVkMandatory
		requiredHeaders = config.RequiredHeaders
		disableAutoToolInject = config.DisableAutoToolInject
		routingChainMaxDepth = config.RoutingChainMaxDepth
	}
	if routingChainMaxDepth == nil {
		defaultDepth := DefaultRoutingChainMaxDepth
		routingChainMaxDepth = &defaultDepth
	}

	governanceStore, err := NewLocalGovernanceStore(ctx, logger, configStore, governanceConfig, modelCatalog)
	if err != nil {
		return nil, fmt.Errorf("failed to initialize governance store: %w", err)
	}
	// Initialize components in dependency order with fixed, optimal settings
	// Resolver (pure decision engine for hierarchical governance, depends only on store)
	resolver := NewBudgetResolver(governanceStore, modelCatalog, logger, inMemoryStore)

	// 3. Tracker (business logic owner, depends on store and resolver)
	tracker := NewUsageTracker(ctx, governanceStore, resolver, configStore, logger)

	// 4. Perform startup reset check for any expired limits from downtime
	// Use distributed lock to prevent race condition when multiple instances boot simultaneously
	if configStore != nil {
		lockManager := configstore.NewDistributedLockManager(configStore, logger, configstore.WithDefaultTTL(30*time.Second))
		lock, err := lockManager.NewLock("governance_startup_reset")
		if err != nil {
			logger.Warn("failed to create governance startup reset lock: %v", err)
		} else {
			// Acquire the lock
			lockAcquired := true
			if err := lock.LockWithRetry(ctx, 10); err != nil {
				logger.Warn("failed to acquire governance startup reset lock, skipping startup reset: %v", err)
				lockAcquired = false
			}
			// Only run startup resets if we successfully acquired the lock
			if lockAcquired {
				defer func() {
					if err := lock.Unlock(ctx); err != nil && !errors.Is(err, configstore.ErrLockNotHeld) {
						logger.Warn("failed to release governance startup reset lock: %v", err)
					}
				}()
				if err := tracker.PerformStartupResets(ctx); err != nil {
					logger.Warn("startup reset failed: %v", err)
					// Continue initialization even if startup reset fails (non-critical)
				}
			}
		}
	}

	// 5. Routing engine (dynamically routing requests based on routing rules)
	engine, err := NewRoutingEngine(governanceStore, logger, routingChainMaxDepth)
	if err != nil {
		return nil, fmt.Errorf("failed to initialize routing engine: %w", err)
	}

	ctx, cancelFunc := context.WithCancel(ctx)
	plugin := &GovernancePlugin{
		ctx:                   ctx,
		cancelFunc:            cancelFunc,
		store:                 governanceStore,
		resolver:              resolver,
		tracker:               tracker,
		engine:                engine,
		configStore:           configStore,
		modelCatalog:          modelCatalog,
		mcpCatalog:            mcpCatalog,
		logger:                logger,
		isVkMandatory:         isVkMandatory,
		cfgMutex:              sync.RWMutex{},
		requiredHeaders:       requiredHeaders,
		isEnterprise:          config != nil && config.IsEnterprise,
		disableAutoToolInject: disableAutoToolInject,
		inMemoryStore:         inMemoryStore,
	}
	return plugin, nil
}

// InitFromStore initializes and returns a governance plugin instance with a custom store.
//
// This constructor allows providing a custom GovernanceStore implementation instead of
// creating a new LocalGovernanceStore. Use this when you need to:
//   - Inject a custom store implementation for testing
//   - Use a pre-configured store instance
//   - Integrate with non-standard storage backends
//
// Parameters are the same as Init, except governanceConfig is replaced by governanceStore.
// The governanceStore must not be nil, or an error is returned.
//
// See Init documentation for details on other parameters and behavior.
func InitFromStore(
	ctx context.Context,
	config *Config,
	logger schemas.Logger,
	governanceStore GovernanceStore,
	configStore configstore.ConfigStore,
	modelCatalog *modelcatalog.ModelCatalog,
	mcpCatalog *mcpcatalog.MCPCatalog,
	inMemoryStore InMemoryStore,
) (*GovernancePlugin, error) {
	if configStore == nil {
		logger.Warn("governance plugin requires config store to persist data, running in memory only mode")
	}
	if modelCatalog == nil {
		logger.Warn("governance plugin requires model catalog to calculate cost, all cost calculations will be skipped.")
	}
	if mcpCatalog == nil {
		logger.Warn("governance plugin requires MCP catalog to calculate cost, all MCP cost calculations will be skipped.")
	}
	if governanceStore == nil {
		return nil, fmt.Errorf("governance store is nil")
	}
	// Handle nil config - use safe defaults
	var isVkMandatory *bool
	var requiredHeaders *[]string
	var disableAutoToolInject *bool
	var routingChainMaxDepth *int
	if config != nil {
		isVkMandatory = config.IsVkMandatory
		requiredHeaders = config.RequiredHeaders
		disableAutoToolInject = config.DisableAutoToolInject
		routingChainMaxDepth = config.RoutingChainMaxDepth
	}
	if routingChainMaxDepth == nil {
		defaultDepth := DefaultRoutingChainMaxDepth
		routingChainMaxDepth = &defaultDepth
	}
	resolver := NewBudgetResolver(governanceStore, modelCatalog, logger, inMemoryStore)
	tracker := NewUsageTracker(ctx, governanceStore, resolver, configStore, logger)
	engine, err := NewRoutingEngine(governanceStore, logger, routingChainMaxDepth)
	if err != nil {
		return nil, fmt.Errorf("failed to initialize routing engine: %w", err)
	}
	// Perform startup reset check for any expired limits from downtime
	// Use distributed lock to prevent race condition when multiple instances boot simultaneously
	if configStore != nil {
		lockManager := configstore.NewDistributedLockManager(configStore, logger, configstore.WithDefaultTTL(30*time.Second))
		lock, err := lockManager.NewLock("governance_startup_reset")
		if err != nil {
			logger.Warn("failed to create governance startup reset lock: %v", err)
		} else if err := lock.Lock(ctx); err != nil {
			logger.Warn("failed to acquire governance startup reset lock, skipping startup reset: %v", err)
		} else {
			defer lock.Unlock(ctx)
			if err := tracker.PerformStartupResets(ctx); err != nil {
				logger.Warn("startup reset failed: %v", err)
				// Continue initialization even if startup reset fails (non-critical)
			}
		}
	}
	ctx, cancelFunc := context.WithCancel(ctx)
	plugin := &GovernancePlugin{
		ctx:                   ctx,
		cancelFunc:            cancelFunc,
		store:                 governanceStore,
		resolver:              resolver,
		tracker:               tracker,
		engine:                engine,
		configStore:           configStore,
		modelCatalog:          modelCatalog,
		mcpCatalog:            mcpCatalog,
		logger:                logger,
		inMemoryStore:         inMemoryStore,
		isVkMandatory:         isVkMandatory,
		cfgMutex:              sync.RWMutex{},
		requiredHeaders:       requiredHeaders,
		isEnterprise:          config != nil && config.IsEnterprise,
		disableAutoToolInject: disableAutoToolInject,
	}
	return plugin, nil
}

// GetName returns the name of the plugin
func (p *GovernancePlugin) GetName() string {
	return PluginName
}

// UpdateEnforceAuthOnInference updates the enforce auth on inference config
func (p *GovernancePlugin) UpdateEnforceAuthOnInference(enforceAuthOnInference bool) {
	p.cfgMutex.Lock()
	defer p.cfgMutex.Unlock()
	p.isVkMandatory = new(enforceAuthOnInference)
}

// HTTPTransportPreHook intercepts requests before they are processed (governance decision point)
// It modifies the request in-place and returns nil to continue, or an HTTPResponse to short-circuit.
// Optimized to skip unnecessary operations: only unmarshals/marshals when needed
func (p *GovernancePlugin) HTTPTransportPreHook(ctx *schemas.BifrostContext, req *schemas.HTTPRequest) (*schemas.HTTPResponse, error) {
	virtualKeyValue := parseVirtualKeyFromHTTPRequest(req)
	hasRoutingRules := p.store.HasRoutingRules(ctx)

	// If no virtual key and no routing rules configured, skip all processing
	if virtualKeyValue == nil && !hasRoutingRules {
		return nil, nil
	}

	// If no body, check if large payload mode is active for read-only governance
	if len(req.Body) == 0 {
		isLargePayload, _ := ctx.Value(schemas.BifrostContextKeyLargePayloadMode).(bool)
		if !isLargePayload {
			return nil, nil
		}
		return p.governLargePayload(ctx, req, virtualKeyValue, hasRoutingRules)
	}

	// Only unmarshal if we have VK or routing rules
	var payload map[string]any
	var virtualKey *configstoreTables.TableVirtualKey
	var ok bool
	var needsMarshal bool

	contentType := req.CaseInsensitiveHeaderLookup("Content-Type")
	lowerCT := strings.ToLower(contentType)
	// Strip parameters (e.g., "; charset=utf-8") for clean media type comparison
	mediaType := lowerCT
	if idx := strings.IndexByte(mediaType, ';'); idx >= 0 {
		mediaType = strings.TrimSpace(mediaType[:idx])
	}
	isMultipart := strings.HasPrefix(mediaType, "multipart/form-data")
	isJSON := mediaType == "" || mediaType == "application/json" || strings.HasSuffix(mediaType, "+json")

	if !isMultipart && !isJSON {
		// Non-parseable body (e.g., application/sdp for WebRTC signaling) — skip governance
		return nil, nil
	}

	var err error
	if isMultipart {
		payload, err = network.ParseMultipartFormFields(contentType, req.Body)
		if err != nil {
			p.logger.Warn("failed to parse multipart form in governance plugin: %v", err)
			return nil, nil
		}
	} else {
		err = sonic.Unmarshal(req.Body, &payload)
		if err != nil {
			p.logger.Error("failed to unmarshal request body: %v", err)
			return nil, nil
		}
	}

	// Process virtual key if provided
	if virtualKeyValue != nil {
		virtualKey, ok = p.store.GetVirtualKey(ctx, *virtualKeyValue)
		if !ok || virtualKey == nil || !virtualKey.IsActive {
			return nil, nil
		}
	}

	// Attaching team and customer based on the virtual key
	if virtualKey != nil {
		if virtualKey.TeamID != nil {
			ctx.SetValue(schemas.BifrostContextKeyGovernanceTeamID, *virtualKey.TeamID)
		}
		if virtualKey.Team != nil {
			ctx.SetValue(schemas.BifrostContextKeyGovernanceTeamName, virtualKey.Team.Name)
		}
		if virtualKey.CustomerID != nil {
			ctx.SetValue(schemas.BifrostContextKeyGovernanceCustomerID, *virtualKey.CustomerID)
		}
		if virtualKey.Customer != nil {
			ctx.SetValue(schemas.BifrostContextKeyGovernanceCustomerName, virtualKey.Customer.Name)
		}
	}

	//1. Apply routing rules only if we have rules or matched decision
	var routingDecision *RoutingDecision
	if hasRoutingRules {
		var err error
		payload, routingDecision, err = p.applyRoutingRules(ctx, req, payload, virtualKey)
		if err != nil {
			return nil, err
		}
		// Mark for marshal if a routing rule matched
		if routingDecision != nil {
			needsMarshal = true
		}
	}

	// Process virtual key if provided
	if virtualKey != nil {
		//2. Load balance provider
		payload, err = p.loadBalanceProvider(ctx, req, payload, virtualKey)
		if err != nil {
			return nil, err
		}
		//3. Add MCP tools only when auto-inject is enabled and header not already set by the caller
		p.cfgMutex.RLock()
		autoInjectDisabled := p.disableAutoToolInject != nil && *p.disableAutoToolInject
		p.cfgMutex.RUnlock()
		if !autoInjectDisabled {
			// Treat an explicitly-present (even empty) x-bf-mcp-include-tools header as "present"
			// so that callers can block auto-injection by sending an empty header value.
			headerPresent := false
			for k := range req.Headers {
				if strings.EqualFold(k, "x-bf-mcp-include-tools") {
					headerPresent = true
					break
				}
			}
			if !headerPresent {
				req.Headers, err = p.addMCPIncludeTools(req.Headers, virtualKey)
				if err != nil {
					p.logger.Error("failed to add MCP include tools: %v", err)
					return nil, nil
				}
			}
		}
		needsMarshal = true
	}

	// Only marshal if something changed (VK processing or routing decision matched)
	if needsMarshal {
		if err := network.SerializePayloadToRequest(req, payload, isMultipart, contentType); err != nil {
			p.logger.Error("failed to serialize request body in governance plugin: %v", err)
			return nil, nil
		}
	}

	return nil, nil
}

// governLargePayload handles read-only governance for large payload requests.
// The request body is streaming and cannot be modified, so we build a synthetic payload
// from pre-extracted metadata and run VK validation, routing rules, and load balancing.
// Any model changes are propagated via the metadata in context (not body rewriting).
func (p *GovernancePlugin) governLargePayload(ctx *schemas.BifrostContext, req *schemas.HTTPRequest, virtualKeyValue *string, hasRoutingRules bool) (*schemas.HTTPResponse, error) {
	metadata, _ := ctx.Value(schemas.BifrostContextKeyLargePayloadMetadata).(*schemas.LargePayloadMetadata)
	if metadata == nil || metadata.Model == "" {
		return nil, nil
	}

	// Build synthetic payload from metadata — only the model field is needed
	payload := map[string]any{
		"model": metadata.Model,
	}
	originalModel := metadata.Model

	// Process virtual key if provided
	var virtualKey *configstoreTables.TableVirtualKey
	if virtualKeyValue != nil {
		vk, ok := p.store.GetVirtualKey(ctx, *virtualKeyValue)
		if !ok || vk == nil || !vk.IsActive {
			return nil, nil
		}
		virtualKey = vk
	}

	// Attaching team and customer based on the virtual key
	if virtualKey != nil {
		if virtualKey.TeamID != nil {
			ctx.SetValue(schemas.BifrostContextKeyGovernanceTeamID, *virtualKey.TeamID)
		}
		if virtualKey.Team != nil {
			ctx.SetValue(schemas.BifrostContextKeyGovernanceTeamName, virtualKey.Team.Name)
		}
		if virtualKey.CustomerID != nil {
			ctx.SetValue(schemas.BifrostContextKeyGovernanceCustomerID, *virtualKey.CustomerID)
		}
		if virtualKey.Customer != nil {
			ctx.SetValue(schemas.BifrostContextKeyGovernanceCustomerName, virtualKey.Customer.Name)
		}
	}

	// Apply routing rules (read-only: decisions still affect downstream evaluation)
	if hasRoutingRules {
		var err error
		payload, _, err = p.applyRoutingRules(ctx, req, payload, virtualKey)
		if err != nil {
			return nil, err
		}
	}

	// Process virtual key: load balance + MCP tool headers
	if virtualKey != nil {
		var err error
		payload, err = p.loadBalanceProvider(ctx, req, payload, virtualKey)
		if err != nil {
			return nil, err
		}
		// MCP tool headers — apply the same auto-inject guard as the normal path:
		// skip when DisableAutoToolInject is set or the caller already sent the header.
		p.cfgMutex.RLock()
		autoInjectDisabled := p.disableAutoToolInject != nil && *p.disableAutoToolInject
		p.cfgMutex.RUnlock()
		if !autoInjectDisabled {
			headerPresent := false
			for k := range req.Headers {
				if strings.EqualFold(k, "x-bf-mcp-include-tools") {
					headerPresent = true
					break
				}
			}
			if !headerPresent {
				req.Headers, err = p.addMCPIncludeTools(req.Headers, virtualKey)
				if err != nil {
					p.logger.Error("failed to add MCP include tools: %v", err)
					return nil, nil
				}
			}
		}
	}

	// Propagate model changes to metadata so downstream hydration picks up
	// the load-balanced/routed model (e.g., provider prefix added by LB).
	if newModel, ok := payload["model"].(string); ok && newModel != originalModel {
		metadata.Model = newModel
	}

	// No body serialization — large payload body streams through unchanged
	return nil, nil
}

// HTTPTransportPostHook intercepts requests after they are processed (governance decision point)
// It modifies the response in-place and returns nil to continue
func (p *GovernancePlugin) HTTPTransportPostHook(ctx *schemas.BifrostContext, req *schemas.HTTPRequest, resp *schemas.HTTPResponse) error {
	return nil
}

// HTTPTransportStreamChunkHook passes through streaming chunks unchanged
func (p *GovernancePlugin) HTTPTransportStreamChunkHook(ctx *schemas.BifrostContext, req *schemas.HTTPRequest, chunk *schemas.BifrostStreamChunk) (*schemas.BifrostStreamChunk, error) {
	return chunk, nil
}

// loadBalanceProvider loads balances the provider for the request
// Parameters:
//   - req: The HTTP request
//   - body: The request body
//   - virtualKey: The virtual key configuration
//
// Returns:
//   - map[string]any: The updated request body
//   - error: Any error that occurred during processing
func (p *GovernancePlugin) loadBalanceProvider(ctx *schemas.BifrostContext, req *schemas.HTTPRequest, body map[string]any, virtualKey *configstoreTables.TableVirtualKey) (map[string]any, error) {
	// Check if the request has a model field
	modelValue, hasModel := body["model"]
	isGeminiPath := strings.Contains(req.Path, "/genai")
	isBedrockPath := strings.Contains(req.Path, "/bedrock")
	if !hasModel {
		// For genai integration, model is present in URL path instead of the request body
		if isGeminiPath {
			// Prefer context value set by a routing rule (format: "provider/model:suffix")
			if ctxModel, ok := ctx.Value("model").(string); ok && ctxModel != "" {
				modelValue = ctxModel
			} else {
				modelValue = req.CaseInsensitivePathParamLookup("model")
			}
		} else if isBedrockPath {
			// For bedrock integration, model is present in URL path as modelId
			// Prefer context value set by a routing rule (format: "provider/model")
			if ctxModelID, ok := ctx.Value("modelId").(string); ok && ctxModelID != "" {
				modelValue = ctxModelID
			} else {
				rawModelID := req.CaseInsensitivePathParamLookup("modelId")
				if rawModelID == "" {
					return body, nil
				}
				// URL-decode the modelId (Bedrock model IDs may be URL-encoded, e.g. anthropic%2Fclaude-3-5-sonnet)
				decoded, err := url.PathUnescape(rawModelID)
				if err != nil {
					decoded = rawModelID
				}
				modelValue = decoded
			}
		} else {
			return body, nil
		}
	}
	modelStr, ok := modelValue.(string)
	if !ok || modelStr == "" {
		return body, nil
	}
	var genaiRequestSuffix string
	// Remove Google GenAI API endpoint suffixes if present
	if isGeminiPath {
		for _, sfx := range gemini.GeminiRequestSuffixPaths {
			if before, ok := strings.CutSuffix(modelStr, sfx); ok {
				modelStr = before
				genaiRequestSuffix = sfx
				break
			}
		}
	}
	// Check if model already has provider prefix (contains "/")
	if strings.Contains(modelStr, "/") {
		provider, _ := schemas.ParseModelString(modelStr, "")
		// Checking valid provider when store is available; if store is nil,
		// assume the prefixed model should be left unchanged.
		if p.inMemoryStore != nil {
			if _, ok := p.inMemoryStore.GetConfiguredProviders()[provider]; ok {
				return body, nil
			}
		} else {
			return body, nil
		}
	}

	ctx.AppendRoutingEngineLog(schemas.RoutingEngineGovernance, fmt.Sprintf("Loading balance provider for model %s", modelStr))

	// Get provider configs for this virtual key
	providerConfigs := virtualKey.ProviderConfigs
	if len(providerConfigs) == 0 {
		ctx.AppendRoutingEngineLog(schemas.RoutingEngineGovernance, fmt.Sprintf("No provider configs on virtual key %s for model %s, skipping load balancing", virtualKey.Name, modelStr))
		// No provider configs, continue without modification
		return body, nil
	}

	var configuredProviders []string
	for _, pc := range providerConfigs {
		configuredProviders = append(configuredProviders, pc.Provider)
	}
	p.logger.Debug("[Governance] Virtual key has %d provider configs: %v", len(providerConfigs), configuredProviders)
	ctx.AppendRoutingEngineLog(schemas.RoutingEngineGovernance, fmt.Sprintf("Load balancing model %s across %d configured providers: %v", modelStr, len(providerConfigs), configuredProviders))

	allowedProviderConfigs := make([]configstoreTables.TableVirtualKeyProviderConfig, 0)
	for _, config := range providerConfigs {
		// Delegate model allowance check to model catalog
		// This handles all cross-provider logic (OpenRouter, Vertex, Groq, Bedrock)
		// and provider-prefixed allowed_models entries
		isProviderAllowed := false
		if p.modelCatalog != nil && p.inMemoryStore != nil {
			provider := schemas.ModelProvider(config.Provider)
			providerConfig, ok := p.inMemoryStore.GetConfiguredProviders()[provider]
			providerConfigPtr := &providerConfig
			if !ok {
				providerConfigPtr = nil
			}
			isProviderAllowed = p.modelCatalog.IsModelAllowedForProvider(provider, modelStr, providerConfigPtr, config.AllowedModels)
		} else {
			// Fallback when model catalog is not available: simple string matching
			// ["*"] = allow all models; [] = deny all models
			isProviderAllowed = config.AllowedModels.IsAllowed(modelStr)
		}

		if isProviderAllowed {
			// Check if the provider's budget or rate limits are violated using resolver helper methods
			if p.resolver.isProviderBudgetViolated(ctx, virtualKey, config) {
				ctx.AppendRoutingEngineLog(schemas.RoutingEngineGovernance, fmt.Sprintf("Provider %s excluded: budget limit violated", config.Provider))
				continue
			}
			if p.resolver.isProviderRateLimitViolated(ctx, virtualKey, config) {
				ctx.AppendRoutingEngineLog(schemas.RoutingEngineGovernance, fmt.Sprintf("Provider %s excluded: rate limit violated", config.Provider))
				continue
			}
			allowedProviderConfigs = append(allowedProviderConfigs, config)
		} else {
			ctx.AppendRoutingEngineLog(schemas.RoutingEngineGovernance, fmt.Sprintf("Provider %s excluded: model %s not in allowed models list", config.Provider, modelStr))
		}
	}

	var allowedProviders []string
	for _, pc := range allowedProviderConfigs {
		allowedProviders = append(allowedProviders, pc.Provider)
	}
	p.logger.Debug("[Governance] Allowed providers after filtering: %v", allowedProviders)
	ctx.AppendRoutingEngineLog(schemas.RoutingEngineGovernance, fmt.Sprintf("Allowed providers after filtering: %v", allowedProviders))

	if len(allowedProviderConfigs) == 0 {
		ctx.AppendRoutingEngineLog(schemas.RoutingEngineGovernance, fmt.Sprintf("No eligible providers remaining after filtering for model %s, skipping load balancing", modelStr))
		// TODO: Send proper error if (overall VK budget/rate limit) or (all provider budgets/rate limits) are violated
		// No allowed provider configs, continue without modification
		return body, nil
	}
	// Separate providers with weight set (participate in routing) from those without (nil weight = excluded from routing)
	weightedConfigs := make([]configstoreTables.TableVirtualKeyProviderConfig, 0, len(allowedProviderConfigs))
	for _, config := range allowedProviderConfigs {
		if config.Weight != nil {
			weightedConfigs = append(weightedConfigs, config)
		}
	}

	var selectedProvider schemas.ModelProvider

	if len(weightedConfigs) > 0 {
		// Weighted random selection from providers that have weight set
		totalWeight := 0.0
		for _, config := range weightedConfigs {
			totalWeight += getWeight(config.Weight)
		}
		// Generate random number between 0 and totalWeight
		randomValue := rand.Float64() * totalWeight
		// Select provider based on weighted random selection
		currentWeight := 0.0
		for _, config := range weightedConfigs {
			currentWeight += getWeight(config.Weight)
			if randomValue <= currentWeight {
				selectedProvider = schemas.ModelProvider(config.Provider)
				break
			}
		}
		// Fallback: if no provider was selected (shouldn't happen but guard against FP issues)
		if selectedProvider == "" {
			selectedProvider = schemas.ModelProvider(weightedConfigs[0].Provider)
		}
	} else {
		// No providers have weight set
		return body, nil
	}

	p.logger.Debug("[Governance] Selected provider: %s", selectedProvider)
	ctx.AppendRoutingEngineLog(schemas.RoutingEngineGovernance, fmt.Sprintf("Selected provider %s for model %s (from %d eligible: %v)", selectedProvider, modelStr, len(allowedProviderConfigs), allowedProviders))

	// For genai integration, model is present in URL path instead of the request body
	if isGeminiPath {
		newModelWithRequestSuffix := string(selectedProvider) + "/" + modelStr + genaiRequestSuffix
		ctx.SetValue("model", newModelWithRequestSuffix)
	} else if isBedrockPath {
		// For bedrock integration, model is present in URL path as modelId
		ctx.SetValue("modelId", string(selectedProvider)+"/"+modelStr)
	} else {
		var err error
		refinedModel := modelStr
		// Refine the model for the selected provider
		if p.modelCatalog != nil {
			refinedModel, err = p.modelCatalog.RefineModelForProvider(selectedProvider, modelStr)
			if err != nil {
				return body, err
			}
		}
		// Update the model field in the request body
		body["model"] = string(selectedProvider) + "/" + refinedModel
	}
	// Append governance to routing engines used
	schemas.AppendToContextList(ctx, schemas.BifrostContextKeyRoutingEnginesUsed, schemas.RoutingEngineGovernance)

	// Check if fallbacks field is already present
	_, hasFallbacks := body["fallbacks"]
	// Use the same candidate set that was used for primary selection
	fallbackConfigs := weightedConfigs
	if !hasFallbacks && len(fallbackConfigs) > 1 {
		// Sort fallback configs by weight (descending)
		sort.Slice(fallbackConfigs, func(i, j int) bool {
			return getWeight(fallbackConfigs[i].Weight) > getWeight(fallbackConfigs[j].Weight)
		})

		// Filter out the selected provider and create fallbacks array
		fallbacks := make([]string, 0, len(fallbackConfigs)-1)
		for _, config := range fallbackConfigs {
			if config.Provider != string(selectedProvider) {
				var err error
				refinedModel := modelStr
				if p.modelCatalog != nil {
					refinedModel, err = p.modelCatalog.RefineModelForProvider(schemas.ModelProvider(config.Provider), modelStr)
					if err != nil {
						// Skip fallback if model refinement fails
						p.logger.Warn("failed to refine model for fallback, skipping fallback in governance plugin: %v", err)
						continue
					}
				}
				fallbacks = append(fallbacks, string(schemas.ModelProvider(config.Provider))+"/"+refinedModel)
			}
		}

		// Add fallbacks to request body
		body["fallbacks"] = fallbacks
		ctx.AppendRoutingEngineLog(schemas.RoutingEngineGovernance, fmt.Sprintf("Added %d fallback providers: %v", len(fallbacks), fallbacks))
	}

	return body, nil
}

// applyRoutingRules evaluates routing rules and returns both the modified payload AND the routing decision
// This allows the caller to determine if marshaling is necessary (only if decision != nil or payload changed)
// Parameters:
//   - ctx: Bifrost context
//   - req: HTTP request
//   - body: Request body (may be modified if routing rule matches)
//   - virtualKey: Virtual key configuration (may be nil)
//
// Returns:
//   - map[string]any: The potentially modified request body
//   - *RoutingDecision: The matched routing decision (nil if no rule matched)
//   - error: Any error that occurred during evaluation
func (p *GovernancePlugin) applyRoutingRules(ctx *schemas.BifrostContext, req *schemas.HTTPRequest, body map[string]any, virtualKey *configstoreTables.TableVirtualKey) (map[string]any, *RoutingDecision, error) {
	// Check if the request has a model field
	modelValue, hasModel := body["model"]
	isGeminiPath := strings.Contains(req.Path, "/genai")
	isBedrockPath := strings.Contains(req.Path, "/bedrock")
	if !hasModel {
		// For genai integration, model is present in URL path
		if isGeminiPath {
			modelValue = req.CaseInsensitivePathParamLookup("model")
		} else if isBedrockPath {
			// For bedrock integration, model is present in URL path as modelId
			rawModelID := req.CaseInsensitivePathParamLookup("modelId")
			if rawModelID == "" {
				return body, nil, nil
			}
			// URL-decode the modelId (Bedrock model IDs may be URL-encoded)
			decoded, err := url.PathUnescape(rawModelID)
			if err != nil {
				decoded = rawModelID
			}
			modelValue = decoded
		} else {
			return body, nil, nil
		}
	}

	modelStr, ok := modelValue.(string)
	if !ok || modelStr == "" {
		return body, nil, nil
	}

	var genaiRequestSuffix string
	if strings.Contains(req.Path, "/genai") {
		for _, sfx := range gemini.GeminiRequestSuffixPaths {
			if before, ok := strings.CutSuffix(modelStr, sfx); ok {
				modelStr = before
				genaiRequestSuffix = sfx
				break
			}
		}
	}

	// Parse provider and model from modelStr (format: "provider/model" or just "model")
	provider, model := schemas.ParseModelString(modelStr, "")

	// Extract normalized request type from context (set by HTTP middleware)
	requestType := ""
	if val := ctx.Value(schemas.BifrostContextKeyHTTPRequestType); val != nil {
		if requestTypeEnum, ok := val.(schemas.RequestType); ok {
			requestType = string(requestTypeEnum)
		} else if requestTypeStr, ok := val.(string); ok {
			requestType = requestTypeStr
		}
	}

	// Build routing context
	routingCtx := &RoutingContext{
		VirtualKey:               virtualKey,
		Provider:                 provider,
		Model:                    model,
		RequestType:              requestType,
		Headers:                  req.Headers,
		QueryParams:              req.Query,
		BudgetAndRateLimitStatus: p.store.GetBudgetAndRateLimitStatus(ctx, model, provider, virtualKey, nil, nil, nil),
	}

	p.logger.Debug("[HTTPTransport] Built routing context: provider=%s, model=%s, requestType=%s, vk=%v, headerCount=%d, paramCount=%d",
		provider, model, requestType, virtualKey != nil, len(req.Headers), len(req.Query))
	ctx.AppendRoutingEngineLog(schemas.RoutingEngineRoutingRule, fmt.Sprintf("Evaluating routing rules for model=%s, provider=%s, requestType=%s", model, provider, requestType))

	// Evaluate routing rules
	decision, err := p.engine.EvaluateRoutingRules(ctx, routingCtx)
	if err != nil {
		p.logger.Error("failed to evaluate routing rules: %v", err)
		ctx.AppendRoutingEngineLog(schemas.RoutingEngineRoutingRule, fmt.Sprintf("Routing rule evaluation error: %v", err))
		return body, nil, nil
	}

	// If a routing rule matched, apply the decision
	if decision != nil {
		p.logger.Debug("[Governance] Routing rule matched: %s", decision.MatchedRuleName)

		// Update model in request body
		if strings.Contains(req.Path, "/genai") {
			// For genai, model is in URL path
			newModel := decision.Model + genaiRequestSuffix
			// Add provider prefix if present (because there can be other routing rules down stream that can add the provider)
			if decision.Provider != "" {
				newModel = decision.Provider + "/" + newModel
			}
			ctx.SetValue("model", newModel)
		} else if isBedrockPath {
			// For bedrock, model is in URL path as modelId
			// Set new modelId in context so bedrockPreCallback picks it up via ctx.UserValue("modelId")
			newModel := decision.Model
			if decision.Provider != "" {
				newModel = decision.Provider + "/" + newModel
			}
			ctx.SetValue("modelId", newModel)
		} else {
			// For regular requests, update in body
			newModel := decision.Model
			// Add provider prefix if present (because there can be other routing rules down stream that can add the provider)
			if decision.Provider != "" {
				newModel = decision.Provider + "/" + newModel
			}
			body["model"] = newModel
		}
		// Append routing-rule to routing engines used
		schemas.AppendToContextList(ctx, schemas.BifrostContextKeyRoutingEnginesUsed, schemas.RoutingEngineRoutingRule)

		// Add fallbacks if present
		if len(decision.Fallbacks) > 0 {
			body["fallbacks"] = decision.Fallbacks
		}

		// Pin specific API key by ID if the routing rule specifies one
		if decision.KeyID != "" {
			ctx.SetValue(schemas.BifrostContextKeyAPIKeyID, decision.KeyID)
		}

		p.logger.Debug("[Governance] Applied routing decision: provider=%s, model=%s, keyID=%s, fallbacks=%v", decision.Provider, decision.Model, decision.KeyID, decision.Fallbacks)
	}

	return body, decision, nil
}

// addMCPIncludeTools adds the x-bf-mcp-include-tools header to the request headers
// Parameters:
//   - headers: The request headers
//   - virtualKey: The virtual key configuration
//
// Returns:
//   - map[string]string: The updated request headers
//   - error: Any error that occurred during processing
func (p *GovernancePlugin) addMCPIncludeTools(headers map[string]string, virtualKey *configstoreTables.TableVirtualKey) (map[string]string, error) {
	if headers == nil {
		headers = make(map[string]string)
	}

	executeOnlyTools := make([]string, 0)

	// Build a lookup of AllowOnAllVirtualKeys clients: clientID -> clientName
	var allowAllVKsClients map[string]string
	if p.inMemoryStore != nil {
		allowAllVKsClients = p.inMemoryStore.GetMCPClientsAllowingAllVirtualKeys()
	}
	if allowAllVKsClients == nil {
		allowAllVKsClients = make(map[string]string)
	}

	// Process VK-specific MCP configs first — explicit config always overrides AllowOnAllVirtualKeys.
	// Track which AllowOnAllVirtualKeys clients have an explicit VK config so we don't double-add them.
	handledClients := make(map[string]bool)
	for _, vkMcpConfig := range virtualKey.MCPConfigs {
		clientID := vkMcpConfig.MCPClient.ClientID
		if _, isAllowAll := allowAllVKsClients[clientID]; isAllowAll {
			// Explicit VK config exists — it takes precedence; mark as handled regardless of tool list
			handledClients[clientID] = true
		}
		if vkMcpConfig.ToolsToExecute.IsEmpty() {
			// No tools specified in virtual key config - skip this client entirely
			continue
		}
		if vkMcpConfig.ToolsToExecute.IsUnrestricted() {
			executeOnlyTools = append(executeOnlyTools, fmt.Sprintf("%s-*", vkMcpConfig.MCPClient.Name))
			continue
		}
		for _, tool := range vkMcpConfig.ToolsToExecute {
			if tool != "" {
				executeOnlyTools = append(executeOnlyTools, fmt.Sprintf("%s-%s", vkMcpConfig.MCPClient.Name, tool))
			}
		}
	}

	// For AllowOnAllVirtualKeys clients with no explicit VK config, fall back to allowing all tools
	for clientID, clientName := range allowAllVKsClients {
		if !handledClients[clientID] {
			executeOnlyTools = append(executeOnlyTools, fmt.Sprintf("%s-*", clientName))
		}
	}

	// Set even when empty to exclude tools when no tools are present in the virtual key config
	headers["x-bf-mcp-include-tools"] = strings.Join(executeOnlyTools, ",")

	return headers, nil
}

// validateRequiredHeaders checks that all configured required headers are present in the request.
// Headers are compared case-insensitively (both sides lowercased).
// Returns a BifrostError with status 400 if any required headers are missing, or nil if all present.
func (p *GovernancePlugin) validateRequiredHeaders(ctx *schemas.BifrostContext) *schemas.BifrostError {
	if p.requiredHeaders == nil || len(*p.requiredHeaders) == 0 {
		return nil
	}
	headers, _ := ctx.Value(schemas.BifrostContextKeyRequestHeaders).(map[string]string)
	if headers == nil {
		headers = map[string]string{}
	}
	var missing []string
	for _, h := range *p.requiredHeaders {
		if _, ok := headers[strings.ToLower(h)]; !ok {
			missing = append(missing, h)
		}
	}
	if len(missing) > 0 {
		return &schemas.BifrostError{
			Type:       bifrost.Ptr("missing_required_headers"),
			StatusCode: bifrost.Ptr(400),
			Error: &schemas.ErrorField{
				Message: fmt.Sprintf("missing required headers: %s", strings.Join(missing, ", ")),
			},
		}
	}
	return nil
}

// EvaluateGovernanceRequest is a common function that handles virtual key validation
// and governance evaluation logic. It returns the evaluation result and a BifrostError
// if the request should be rejected, or nil if allowed.
//
// Parameters:
//   - ctx: The Bifrost context
//   - evaluationRequest: The evaluation request with VirtualKey, Provider, Model, and RequestID
//
// Returns:
//   - *EvaluationResult: The governance evaluation result
//   - *schemas.BifrostError: The error to return if request is not allowed, nil if allowed
func (p *GovernancePlugin) EvaluateGovernanceRequest(ctx *schemas.BifrostContext, evaluationRequest *EvaluationRequest, requestType schemas.RequestType) (*EvaluationResult, *schemas.BifrostError) {
	// Check if authentication is mandatory (either VK or user auth)
	// Checking if the virtual key is valid or not
	isVirtualKeyValid := false
	if evaluationRequest.VirtualKey != "" {
		_, exists := p.store.GetVirtualKey(ctx, evaluationRequest.VirtualKey)
		if exists {
			isVirtualKeyValid = true
		} else {
			// VK was provided but does not exist in the store — reject regardless of mandatory setting
			return nil, &schemas.BifrostError{
				Type:       bifrost.Ptr("virtual_key_not_found"),
				StatusCode: bifrost.Ptr(401),
				Error: &schemas.ErrorField{
					Message: "virtual key not found. The provided virtual key does not exist or has been revoked.",
				},
			}
		}
	}
	p.cfgMutex.RLock()
	if !isVirtualKeyValid && evaluationRequest.UserID == "" && p.isVkMandatory != nil && *p.isVkMandatory {
		message := "virtual key is required. Provide a virtual key via the x-bf-vk header."
		if p.isEnterprise {
			message = "authentication is required. Provide a virtual key (x-bf-vk), API key, or user token."
		}
		p.cfgMutex.RUnlock()
		return nil, &schemas.BifrostError{
			Type:       bifrost.Ptr("virtual_key_required"),
			StatusCode: bifrost.Ptr(401),
			Error: &schemas.ErrorField{
				Message: message,
			},
		}
	}
	p.cfgMutex.RUnlock()

	// First evaluate model and provider checks (applies even when virtual keys are disabled or not present)
	result := p.resolver.EvaluateModelAndProviderRequest(ctx, evaluationRequest.Provider, evaluationRequest.Model)

	// The flow for governance checks is:
	//   VK (identity + VK-level budget/rate-limit) -> Customer -> Team -> User
	// VK identity runs FIRST so that revoked, provider-disallowed, or model-disallowed
	// keys are blocked before any hierarchy state is consulted. Running Customer/Team/
	// User ahead of VK would leak topology: a revoked key attached to an over-budget
	// team would return 429 team-budget-exceeded instead of 403 VK-blocked, telling
	// an attacker the key's team structure was validated.

	// Resolve the VK once; it feeds both the VK evaluation and hierarchy-ID extraction.
	var hierarchyVK *configstoreTables.TableVirtualKey
	if evaluationRequest.VirtualKey != "" {
		if vk, ok := p.store.GetVirtualKey(ctx, evaluationRequest.VirtualKey); ok && vk != nil {
			hierarchyVK = vk
		}
	}

	// Step 1: Evaluate virtual key (identity + VK-level budget/rate-limit hierarchy).
	// Short-circuits with VirtualKeyBlocked / ProviderBlocked / ModelBlocked before
	// we touch Customer / Team / User.
	if result.Decision == DecisionAllow && evaluationRequest.VirtualKey != "" {
		skipVKBudgetLimit := evaluationRequest.UserID != ""
		result = p.resolver.EvaluateVirtualKeyRequest(ctx, evaluationRequest.VirtualKey, evaluationRequest.Provider, evaluationRequest.Model, requestType, skipVKBudgetLimit)
	}

	// Step 2: Customer-level budget (customer attached directly to VK, or via the VK's team).
	// Fall back to the loaded relation IDs so VKs populated via joins without FK
	// pointer columns still participate in customer-level enforcement.
	if result.Decision == DecisionAllow && hierarchyVK != nil {
		var customerID string
		switch {
		case hierarchyVK.CustomerID != nil:
			customerID = *hierarchyVK.CustomerID
		case hierarchyVK.Customer != nil:
			customerID = hierarchyVK.Customer.ID
		case hierarchyVK.Team != nil && hierarchyVK.Team.CustomerID != nil:
			customerID = *hierarchyVK.Team.CustomerID
		case hierarchyVK.Team != nil && hierarchyVK.Team.Customer != nil:
			customerID = hierarchyVK.Team.Customer.ID
		}
		if customerID != "" {
			result = p.resolver.EvaluateCustomerRequest(ctx, customerID, evaluationRequest)
		}
	}

	// Step 3: Team-level budget. Fall back to vk.Team.ID when the FK pointer is nil
	// but the relation is populated.
	if result.Decision == DecisionAllow && hierarchyVK != nil {
		var teamID string
		switch {
		case hierarchyVK.TeamID != nil:
			teamID = *hierarchyVK.TeamID
		case hierarchyVK.Team != nil:
			teamID = hierarchyVK.Team.ID
		}
		if teamID != "" {
			result = p.resolver.EvaluateTeamRequest(ctx, teamID, evaluationRequest)
		}
	}

	// Step 4: User-level governance (enterprise-only).
	if result.Decision == DecisionAllow {
		result = p.resolver.EvaluateUserRequest(ctx, evaluationRequest.UserID, evaluationRequest)
	}

	// Check the actual MCP tools injected into the request against the VK MCPConfigs.
	// BifrostContextKeyMCPAddedTools is populated by AddToolsToRequest (which runs before
	// PreLLMHook), so it contains the real expanded tool names (e.g. "youtube-search") rather
	// than raw header patterns (e.g. "youtube-*"), giving us exact per-tool validation.
	if result.Decision == DecisionAllow && result.VirtualKey != nil {
		if addedTools, ok := ctx.Value(schemas.BifrostContextKeyMCPAddedTools).([]string); ok && len(addedTools) > 0 {
			// Fetch once before the loop to avoid repeated lock acquisitions per tool.
			var allowAllClients map[string]string
			if p.inMemoryStore != nil {
				allowAllClients = p.inMemoryStore.GetMCPClientsAllowingAllVirtualKeys()
			}
			var disallowed []string
			for _, tool := range addedTools {
				if !p.isMCPToolAllowedByVKWith(result.VirtualKey, tool, allowAllClients) {
					disallowed = append(disallowed, tool)
				}
			}
			if len(disallowed) > 0 {
				result = &EvaluationResult{
					Decision:   DecisionMCPToolBlocked,
					Reason:     fmt.Sprintf("MCP tools not allowed for virtual key '%s': %s", result.VirtualKey.Name, strings.Join(disallowed, ", ")),
					VirtualKey: result.VirtualKey,
				}
			}
		}
	}

	// Mark request as rejected in context if not allowed
	if result.Decision != DecisionAllow {
		if ctx != nil {
			if _, ok := ctx.Value(governanceRejectedContextKey).(bool); !ok {
				ctx.SetValue(governanceRejectedContextKey, true)
			}
		}
	}

	// Handle decision
	switch result.Decision {
	case DecisionAllow:
		return result, nil

	case DecisionVirtualKeyNotFound, DecisionVirtualKeyBlocked, DecisionModelBlocked, DecisionProviderBlocked:
		return result, &schemas.BifrostError{
			Type:       bifrost.Ptr(string(result.Decision)),
			StatusCode: bifrost.Ptr(403),
			Error: &schemas.ErrorField{
				Message: result.Reason,
			},
		}

	case DecisionRateLimited, DecisionTokenLimited, DecisionRequestLimited:
		return result, &schemas.BifrostError{
			Type:       bifrost.Ptr(string(result.Decision)),
			StatusCode: bifrost.Ptr(429),
			Error: &schemas.ErrorField{
				Message: result.Reason,
			},
		}

	case DecisionBudgetExceeded:
		return result, &schemas.BifrostError{
			Type:       bifrost.Ptr(string(result.Decision)),
			StatusCode: bifrost.Ptr(402),
			Error: &schemas.ErrorField{
				Message: result.Reason,
			},
		}

	case DecisionMCPToolBlocked:
		return result, &schemas.BifrostError{
			Type:       bifrost.Ptr(string(result.Decision)),
			StatusCode: bifrost.Ptr(403),
			Error: &schemas.ErrorField{
				Message: result.Reason,
			},
		}

	default:
		// Fallback to deny for unknown decisions
		return result, &schemas.BifrostError{
			Type: bifrost.Ptr(string(result.Decision)),
			Error: &schemas.ErrorField{
				Message: "Governance decision error",
			},
		}
	}
}

// isMCPToolAllowedByVK checks whether a tool pattern (in "clientName-toolName" or "clientName-*"
// format) is permitted by the virtual key's MCPConfigs.
//
// Priority order:
//  1. If the VK has an explicit MCP config for this client, that config is authoritative (can allow or deny).
//  2. If no explicit config exists and the client has AllowOnAllVirtualKeys=true, all tools are allowed.
//
// For wildcard patterns ("clientName-*"): allowed if VK has the client configured with any tools.
// Specific tool enforcement happens at execution time via checkVKMCPToolAllowance.
// For specific tools ("clientName-toolName"): allowed if VK has "*" or the exact tool name.
func (p *GovernancePlugin) isMCPToolAllowedByVK(vk *configstoreTables.TableVirtualKey, toolPattern string) bool {
	var allowAllClients map[string]string
	if p.inMemoryStore != nil {
		allowAllClients = p.inMemoryStore.GetMCPClientsAllowingAllVirtualKeys()
	}
	return p.isMCPToolAllowedByVKWith(vk, toolPattern, allowAllClients)
}

// isMCPToolAllowedByVKWith checks whether a tool pattern is allowed by the virtual key,
// using a pre-fetched allowAllClients map (clientID → clientName) to avoid repeated lock
// acquisitions in loops.
func (p *GovernancePlugin) isMCPToolAllowedByVKWith(vk *configstoreTables.TableVirtualKey, toolPattern string, allowAllClients map[string]string) bool {
	// Check VK-specific MCP configs first — explicit config always overrides AllowOnAllVirtualKeys.
	for _, mcpConfig := range vk.MCPConfigs {
		clientName := mcpConfig.MCPClient.Name
		if toolPattern != clientName+"-*" && !strings.HasPrefix(toolPattern, clientName+"-") {
			continue
		}
		// Found an explicit config for this client — use it; do not fall back to AllowOnAllVirtualKeys.
		if toolPattern == clientName+"-*" {
			return !mcpConfig.ToolsToExecute.IsEmpty()
		}
		if mcpConfig.ToolsToExecute.IsUnrestricted() {
			return true
		}
		toolSuffix := strings.TrimPrefix(toolPattern, clientName+"-")
		return mcpConfig.ToolsToExecute.Contains(toolSuffix)
	}
	// No explicit VK config found — fall back to AllowOnAllVirtualKeys (allows all tools).
	for _, clientName := range allowAllClients {
		if strings.HasPrefix(toolPattern, clientName+"-") || toolPattern == clientName+"-*" {
			return true
		}
	}
	return false
}

// PreLLMHook intercepts requests before they are processed (governance decision point)
// Parameters:
//   - ctx: The Bifrost context
//   - req: The Bifrost request to be processed
//
// Returns:
//   - *schemas.BifrostRequest: The processed request
//   - *schemas.LLMPluginShortCircuit: The plugin short circuit if the request is not allowed
//   - error: Any error that occurred during processing
func (p *GovernancePlugin) PreLLMHook(ctx *schemas.BifrostContext, req *schemas.BifrostRequest) (*schemas.BifrostRequest, *schemas.LLMPluginShortCircuit, error) {
	// If its skip key selection - in that case we need to skip virtual key selection too
	if bifrost.GetBoolFromContext(ctx, schemas.BifrostContextKeySkipKeySelection) {
		return req, nil, nil
	}
	// Validate required headers are present
	if headerErr := p.validateRequiredHeaders(ctx); headerErr != nil {
		return req, &schemas.LLMPluginShortCircuit{Error: headerErr}, nil
	}
	// Extract governance headers and virtual key using utility functions
	virtualKeyValue := bifrost.GetStringFromContext(ctx, schemas.BifrostContextKeyVirtualKey)
	// Extract user ID for enterprise user-level governance
	userID := bifrost.GetStringFromContext(ctx, schemas.BifrostContextKeyUserID)
	// Getting provider and mode from the request
	provider, model, _ := req.GetRequestFields()
	// Create request context for evaluation
	evaluationRequest := &EvaluationRequest{
		VirtualKey: virtualKeyValue,
		Provider:   provider,
		Model:      model,
		UserID:     userID,
	}
	// Evaluate governance using common function
	_, bifrostError := p.EvaluateGovernanceRequest(ctx, evaluationRequest, req.RequestType)
	// Convert BifrostError to LLMPluginShortCircuit if needed
	if bifrostError != nil {
		return req, &schemas.LLMPluginShortCircuit{
			Error: bifrostError,
		}, nil
	}

	return req, nil, nil
}

// PostLLMHook processes the response and updates usage tracking (business logic execution)
// Parameters:
//   - ctx: The Bifrost context
//   - result: The Bifrost response to be processed
//   - err: The Bifrost error to be processed
//
// Returns:
//   - *schemas.BifrostResponse: The processed response
//   - *schemas.BifrostError: The processed error
//   - error: Any error that occurred during processing
func (p *GovernancePlugin) PostLLMHook(ctx *schemas.BifrostContext, result *schemas.BifrostResponse, err *schemas.BifrostError) (*schemas.BifrostResponse, *schemas.BifrostError, error) {
	if _, ok := ctx.Value(governanceRejectedContextKey).(bool); ok {
		return result, err, nil
	}

	// Extract request type, provider, and model
	requestType, provider, requestedModel, _ := bifrost.GetResponseFields(result, err)

	// Extract governance information
	virtualKey := bifrost.GetStringFromContext(ctx, schemas.BifrostContextKeyVirtualKey)
	requestID := bifrost.GetStringFromContext(ctx, schemas.BifrostContextKeyRequestID)
	// Extract user ID for enterprise user-level governance
	userID := bifrost.GetStringFromContext(ctx, schemas.BifrostContextKeyUserID)

	if requestType == schemas.ListModelsRequest && result != nil && result.ListModelsResponse != nil && virtualKey != "" {
		// filter models which are not supported on this virtual key
		result.ListModelsResponse.Data = p.filterModelsForVirtualKey(ctx, result.ListModelsResponse.Data, virtualKey)
	}

	isFinalChunk := bifrost.IsFinalChunk(ctx)

	// Build pricing scopes from context using the governance VK ID (not the raw VK token)
	pricingScopes := modelcatalog.PricingLookupScopesFromContext(ctx, string(provider))

	// Always process usage tracking (with or without virtual key)
	// When user auth is present, skip VK usage tracking to avoid double-counting
	effectiveVK := virtualKey
	if userID != "" {
		effectiveVK = ""
	}
	// If effectiveVK is empty, it will be passed as empty string to postHookWorker
	// The tracker will handle empty virtual keys gracefully by only updating provider-level and model-level usage
	if requestedModel != "" {
		p.wg.Add(1)
		go func() {
			defer p.wg.Done()
			// Use the requested model for usage tracking
			p.postHookWorker(result, provider, requestedModel, requestType, effectiveVK, requestID, userID, isFinalChunk, pricingScopes)
		}()
	}

	return result, err, nil
}

// PreMCPHook intercepts MCP tool execution requests before they are processed (governance decision point)
// Parameters:
//   - ctx: The Bifrost context
//   - req: The Bifrost MCP request to be processed
//
// Returns:
//   - *schemas.BifrostMCPRequest: The processed request
//   - *schemas.MCPPluginShortCircuit: The plugin short circuit if the request is not allowed
//   - error: Any error that occurred during processing
func (p *GovernancePlugin) PreMCPHook(ctx *schemas.BifrostContext, req *schemas.BifrostMCPRequest) (*schemas.BifrostMCPRequest, *schemas.MCPPluginShortCircuit, error) {
	toolName := req.GetToolName()

	// Skip governance for codemode tools
	if bifrost.IsCodemodeTool(toolName) {
		return req, nil, nil
	}

	// Validate required headers are present
	if headerErr := p.validateRequiredHeaders(ctx); headerErr != nil {
		return req, &schemas.MCPPluginShortCircuit{Error: headerErr}, nil
	}

	// Extract governance headers and virtual key using utility functions
	virtualKeyValue := bifrost.GetStringFromContext(ctx, schemas.BifrostContextKeyVirtualKey)
	// Extract user ID for enterprise user-level governance
	userID := bifrost.GetStringFromContext(ctx, schemas.BifrostContextKeyUserID)

	// Create request context for evaluation (MCP requests don't have provider/model)
	evaluationRequest := &EvaluationRequest{
		VirtualKey: virtualKeyValue,
		UserID:     userID,
	}

	// Evaluate governance using common function
	_, bifrostError := p.EvaluateGovernanceRequest(ctx, evaluationRequest, schemas.MCPToolExecutionRequest)

	// Convert BifrostError to MCPPluginShortCircuit if needed
	if bifrostError != nil {
		return req, &schemas.MCPPluginShortCircuit{
			Error: bifrostError,
		}, nil
	}

	// Blind single-tool check: validate the specific tool being executed against VK MCPConfigs.
	// This runs independently of EvaluateGovernanceRequest to enforce execution-time allow-list.
	if virtualKeyValue != "" {
		vk, ok := p.store.GetVirtualKey(ctx, virtualKeyValue)
		if !ok || vk == nil || !vk.IsActive {
			// VK became invalid after initial check - fail closed for security
			ctx.SetValue(governanceRejectedContextKey, true)
			return req, &schemas.MCPPluginShortCircuit{Error: &schemas.BifrostError{
				Type:       bifrost.Ptr(string(DecisionVirtualKeyNotFound)),
				StatusCode: bifrost.Ptr(403),
				Error: &schemas.ErrorField{
					Message: "Virtual key not found",
				},
			}}, nil
		}
		if !p.isMCPToolAllowedByVK(vk, toolName) {
			ctx.SetValue(governanceRejectedContextKey, true)
			return req, &schemas.MCPPluginShortCircuit{Error: &schemas.BifrostError{
				Type:       bifrost.Ptr(string(DecisionMCPToolBlocked)),
				StatusCode: bifrost.Ptr(403),
				Error: &schemas.ErrorField{
					Message: fmt.Sprintf("MCP tool '%s' is not allowed for virtual key '%s'", toolName, vk.Name),
				},
			}}, nil
		}
		return req, nil, nil
	}

	return req, nil, nil
}

// PostMCPHook processes the MCP response and updates usage tracking (business logic execution)
// Parameters:
//   - ctx: The Bifrost context
//   - resp: The Bifrost MCP response to be processed
//   - bifrostErr: The Bifrost error to be processed
//
// Returns:
//   - *schemas.BifrostMCPResponse: The processed response
//   - *schemas.BifrostError: The processed error
//   - error: Any error that occurred during processing
func (p *GovernancePlugin) PostMCPHook(ctx *schemas.BifrostContext, resp *schemas.BifrostMCPResponse, bifrostErr *schemas.BifrostError) (*schemas.BifrostMCPResponse, *schemas.BifrostError, error) {
	if _, ok := ctx.Value(governanceRejectedContextKey).(bool); ok {
		return resp, bifrostErr, nil
	}

	// Extract governance information
	virtualKey := bifrost.GetStringFromContext(ctx, schemas.BifrostContextKeyVirtualKey)
	requestID := bifrost.GetStringFromContext(ctx, schemas.BifrostContextKeyRequestID)
	userID := bifrost.GetStringFromContext(ctx, schemas.BifrostContextKeyUserID)

	// When user auth is present, skip VK usage tracking to avoid double-counting
	if userID != "" {
		virtualKey = ""
	}

	// Skip if no virtual key
	if virtualKey == "" {
		return resp, bifrostErr, nil
	}

	// Determine if request was successful
	success := (resp != nil && bifrostErr == nil)

	// Skip usage tracking for codemode tools
	if success && resp != nil && bifrost.IsCodemodeTool(resp.ExtraFields.ToolName) {
		return resp, bifrostErr, nil
	}

	// Calculate MCP tool cost from catalog if available
	var toolCost float64
	if success && resp != nil && p.mcpCatalog != nil && resp.ExtraFields.ClientName != "" && resp.ExtraFields.ToolName != "" {
		// Use separate client name and tool name fields
		if pricingEntry, ok := p.mcpCatalog.GetPricingData(resp.ExtraFields.ClientName, resp.ExtraFields.ToolName); ok {
			toolCost = pricingEntry.CostPerExecution
			p.logger.Debug("MCP tool cost for %s.%s: $%.6f", resp.ExtraFields.ClientName, resp.ExtraFields.ToolName, toolCost)
		}
	}

	// Create usage update for tracker (business logic) - MCP requests track request count and tool cost
	usageUpdate := &UsageUpdate{
		VirtualKey:   virtualKey,
		Success:      success,
		Cost:         toolCost,
		RequestID:    requestID,
		IsStreaming:  false,
		IsFinalChunk: true,
		HasUsageData: toolCost > 0, // Has usage data if we have a cost
	}

	// Queue usage update asynchronously using tracker
	p.wg.Add(1)
	go func() {
		defer p.wg.Done()
		p.tracker.UpdateUsage(p.ctx, usageUpdate)
	}()

	return resp, bifrostErr, nil
}

// Cleanup shuts down all components gracefully
func (p *GovernancePlugin) Cleanup() error {
	var cleanupErr error
	p.cleanupOnce.Do(func() {
		if p.cancelFunc != nil {
			p.cancelFunc()
		}
		p.wg.Wait() // Wait for all background workers to complete
		if err := p.tracker.Cleanup(); err != nil {
			cleanupErr = err
		}
	})
	return cleanupErr
}

// postHookWorker is a worker function that processes the response and updates usage tracking
// It is used to avoid blocking the main thread when updating usage tracking
// Handles both cases: with virtual key and without virtual key (empty string)
// When virtualKey is empty, the tracker will only update provider-level and model-level usage
// Parameters:
//   - result: The Bifrost response to be processed
//   - provider: The provider of the request
//   - model: The model of the request
//   - requestType: The type of the request
//   - virtualKey: The raw virtual key token of the request (empty string if not present)
//   - selectedKeyID: The selected provider key ID used for scoped pricing overrides
//   - requestID: The request ID
//   - userID: The user ID for enterprise user-level governance (empty string if not present)
//   - isCacheRead: Whether the request is a cache read
//   - isBatch: Whether the request is a batch request
//   - isFinalChunk: Whether the request is the final chunk
//   - pricingScopes: Prebuilt pricing lookup scopes using governance VK ID (nil if not applicable)
func (p *GovernancePlugin) postHookWorker(result *schemas.BifrostResponse, provider schemas.ModelProvider, model string, requestType schemas.RequestType, virtualKey, requestID, userID string, isFinalChunk bool, pricingScopes *modelcatalog.PricingLookupScopes) {
	// Determine if request was successful
	success := (result != nil)

	// Streaming detection
	isStreaming := bifrost.IsStreamRequestType(requestType)

	if !isStreaming || (isStreaming && isFinalChunk) {
		var cost float64
		if p.modelCatalog != nil && result != nil {
			cost = p.modelCatalog.CalculateCost(result, pricingScopes)
		}
		tokensUsed := 0
		if result != nil {
			switch {
			case result.TextCompletionResponse != nil && result.TextCompletionResponse.Usage != nil:
				tokensUsed = result.TextCompletionResponse.Usage.TotalTokens
			case result.ChatResponse != nil && result.ChatResponse.Usage != nil:
				tokensUsed = result.ChatResponse.Usage.TotalTokens
			case result.ResponsesResponse != nil && result.ResponsesResponse.Usage != nil:
				tokensUsed = result.ResponsesResponse.Usage.TotalTokens
			case result.ResponsesStreamResponse != nil && result.ResponsesStreamResponse.Response != nil && result.ResponsesStreamResponse.Response.Usage != nil:
				tokensUsed = result.ResponsesStreamResponse.Response.Usage.TotalTokens
			case result.EmbeddingResponse != nil && result.EmbeddingResponse.Usage != nil:
				tokensUsed = result.EmbeddingResponse.Usage.TotalTokens
			case result.SpeechResponse != nil && result.SpeechResponse.Usage != nil:
				tokensUsed = result.SpeechResponse.Usage.TotalTokens
			case result.SpeechStreamResponse != nil && result.SpeechStreamResponse.Usage != nil:
				tokensUsed = result.SpeechStreamResponse.Usage.TotalTokens
			case result.TranscriptionResponse != nil && result.TranscriptionResponse.Usage != nil && result.TranscriptionResponse.Usage.TotalTokens != nil:
				tokensUsed = *result.TranscriptionResponse.Usage.TotalTokens
			case result.TranscriptionStreamResponse != nil && result.TranscriptionStreamResponse.Usage != nil && result.TranscriptionStreamResponse.Usage.TotalTokens != nil:
				tokensUsed = *result.TranscriptionStreamResponse.Usage.TotalTokens
			}
		}
		// Create usage update for tracker (business logic)
		usageUpdate := &UsageUpdate{
			VirtualKey:   virtualKey,
			Provider:     provider,
			Model:        model,
			Success:      success,
			TokensUsed:   int64(tokensUsed),
			Cost:         cost,
			RequestID:    requestID,
			UserID:       userID,
			IsStreaming:  isStreaming,
			IsFinalChunk: isFinalChunk,
			HasUsageData: tokensUsed > 0,
		}

		// Queue usage update asynchronously using tracker
		// UpdateUsage handles empty virtual keys gracefully by only updating provider-level and model-level usage
		p.tracker.UpdateUsage(p.ctx, usageUpdate)
	}
}

// GetGovernanceStore returns the governance store
func (p *GovernancePlugin) GetGovernanceStore() GovernanceStore {
	return p.store
}

// GenerateVirtualKey is a helper function
func GenerateVirtualKey() string {
	return VirtualKeyPrefix + uuid.NewString()
}