first commit

cli/internal/config/config.go

@@ -0,0 +1,192 @@
+package config
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/bytedance/sonic"
+)
+
+const (
+	defaultDirName  = ".bifrost"
+	defaultFileName = "config.json"
+	stateFileName   = "state.json"
+)
+
+// FileConfig represents the on-disk bifrost configuration file (~/.bifrost/config.json).
+type FileConfig struct {
+	BaseURL            string `json:"base_url"`
+	VirtualKey         string `json:"virtual_key"`
+	DefaultHarness     string `json:"default_harness"`
+	DefaultModel       string `json:"default_model"`
+	AutoInstallHarness *bool  `json:"auto_install_harness"`
+	AutoAttachMCP      *bool  `json:"auto_attach_mcp"`
+}
+
+// Profile represents a named Bifrost connection profile with a base URL.
+type Profile struct {
+	ID      string `json:"id"`
+	Name    string `json:"name"`
+	BaseURL string `json:"base_url"`
+}
+
+// Selection stores the user's last chosen harness and model for a profile.
+type Selection struct {
+	Harness string `json:"harness"`
+	Model   string `json:"model"`
+}
+
+// State holds the persistent runtime state including profiles and per-profile selections.
+type State struct {
+	Profiles         []Profile            `json:"profiles"`
+	LastProfileID    string               `json:"last_profile_id"`
+	Selections       map[string]Selection `json:"selections"`
+	LastVersionCheck int64                `json:"last_version_check,omitempty"`
+	LastKnownVersion string               `json:"last_known_version,omitempty"`
+}
+
+// DefaultConfigPath returns the default path to the bifrost config file (~/.bifrost/config.json).
+func DefaultConfigPath() (string, error) {
+	h, err := os.UserHomeDir()
+	if err != nil {
+		return "", fmt.Errorf("resolve home dir: %w", err)
+	}
+	return filepath.Join(h, defaultDirName, defaultFileName), nil
+}
+
+// DefaultStatePath returns the default path to the bifrost state file (~/.bifrost/state.json).
+func DefaultStatePath() (string, error) {
+	h, err := os.UserHomeDir()
+	if err != nil {
+		return "", fmt.Errorf("resolve home dir: %w", err)
+	}
+	return filepath.Join(h, defaultDirName, stateFileName), nil
+}
+
+// LoadFile reads and parses a config file from disk.
+// Returns nil with no error if the file does not exist.
+func LoadFile(path string) (*FileConfig, string, error) {
+	b, err := os.ReadFile(path)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return nil, "", nil
+		}
+		return nil, "", fmt.Errorf("read config file: %w", err)
+	}
+
+	var c FileConfig
+	if err := sonic.Unmarshal(b, &c); err != nil {
+		return nil, "", fmt.Errorf("parse config file: %w", err)
+	}
+
+	abs := path
+	if a, err := filepath.Abs(path); err == nil {
+		abs = a
+	}
+	return &c, abs, nil
+}
+
+// LoadState reads and parses the state file from disk.
+// Returns a fresh State if the file does not exist.
+func LoadState(path string) (*State, error) {
+	b, err := os.ReadFile(path)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return &State{Selections: map[string]Selection{}}, nil
+		}
+		return nil, fmt.Errorf("read state: %w", err)
+	}
+
+	var s State
+	if err := sonic.Unmarshal(b, &s); err != nil {
+		return nil, fmt.Errorf("parse state: %w", err)
+	}
+	if s.Selections == nil {
+		s.Selections = map[string]Selection{}
+	}
+	return &s, nil
+}
+
+// WriteAtomic writes data to a temp file in the same directory and atomically
+// replaces the target path via rename, preventing partial/corrupt files on crash.
+func WriteAtomic(path string, data []byte, perm os.FileMode) error {
+	dir := filepath.Dir(path)
+	f, err := os.CreateTemp(dir, filepath.Base(path)+".tmp*")
+	if err != nil {
+		return err
+	}
+	tmpPath := f.Name()
+
+	if _, err := f.Write(data); err != nil {
+		f.Close()
+		os.Remove(tmpPath)
+		return err
+	}
+	if err := f.Sync(); err != nil {
+		f.Close()
+		os.Remove(tmpPath)
+		return err
+	}
+	if err := f.Close(); err != nil {
+		os.Remove(tmpPath)
+		return err
+	}
+	if err := os.Chmod(tmpPath, perm); err != nil {
+		os.Remove(tmpPath)
+		return err
+	}
+	if err := os.Rename(tmpPath, path); err != nil {
+		os.Remove(tmpPath)
+		return err
+	}
+	return nil
+}
+
+// SaveState writes the state to disk, creating parent directories as needed.
+func SaveState(path string, s *State) error {
+	d := filepath.Dir(path)
+	if err := os.MkdirAll(d, 0o755); err != nil {
+		return fmt.Errorf("create state dir: %w", err)
+	}
+
+	b, err := sonic.MarshalIndent(s, "", "  ")
+	if err != nil {
+		return fmt.Errorf("marshal state: %w", err)
+	}
+	if err := WriteAtomic(path, b, 0o600); err != nil {
+		return fmt.Errorf("write state: %w", err)
+	}
+	return nil
+}
+
+// SaveConfig writes the config to disk at the given path, creating parent
+// directories as needed. File permissions are set to 0o600.
+func SaveConfig(path string, c *FileConfig) error {
+	d := filepath.Dir(path)
+	if err := os.MkdirAll(d, 0o755); err != nil {
+		return fmt.Errorf("create config dir: %w", err)
+	}
+
+	persisted := *c
+	persisted.VirtualKey = ""
+	b, err := sonic.MarshalIndent(&persisted, "", "  ")
+	if err != nil {
+		return fmt.Errorf("marshal config: %w", err)
+	}
+	if err := WriteAtomic(path, b, 0o600); err != nil {
+		return fmt.Errorf("write config: %w", err)
+	}
+	return nil
+}
+
+// ProfileByID returns a pointer to the profile with the given ID, or nil if not found.
+func (s *State) ProfileByID(id string) *Profile {
+	for i := range s.Profiles {
+		if s.Profiles[i].ID == id {
+			return &s.Profiles[i]
+		}
+	}
+	return nil
+}