first commit

cli/internal/runtime/runtime.go

@@ -0,0 +1,163 @@
+package runtime
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/maximhq/bifrost/cli/internal/apis"
+	"github.com/maximhq/bifrost/cli/internal/harness"
+)
+
+// LaunchSpec holds the parameters needed to launch a harness subprocess.
+type LaunchSpec struct {
+	Harness    harness.Harness
+	BaseURL    string
+	VirtualKey string
+	Model      string
+	Worktree   string // empty = no worktree, non-empty = worktree name (or " " for unnamed)
+}
+
+// BuildEnv constructs the environment variables for the harness process,
+// including the provider endpoint, API key, and model overrides.
+func BuildEnv(spec LaunchSpec) ([]string, error) {
+	endpoint, err := apis.BuildEndpoint(spec.BaseURL, spec.Harness.BasePath)
+	if err != nil {
+		return nil, err
+	}
+	env := os.Environ()
+	env = append(env, spec.Harness.BaseURLEnv+"="+endpoint)
+
+	vk := strings.TrimSpace(spec.VirtualKey)
+	if vk != "" {
+		env = append(env, spec.Harness.APIKeyEnv+"="+vk)
+		if spec.Harness.AuthTokenEnv != "" {
+			env = append(env, spec.Harness.AuthTokenEnv+"="+vk)
+		}
+	}
+	model := strings.TrimSpace(spec.Model)
+	if model != "" {
+		env = append(env, "BIFROST_MODEL="+model)
+		if spec.Harness.ModelEnv != "" {
+			env = append(env, spec.Harness.ModelEnv+"="+model)
+		}
+	}
+
+	// Mark session as running inside bifrost
+	env = append(env, "BIFROST_SESSION=1")
+	env = append(env, "BIFROST_BASE_URL="+spec.BaseURL)
+	return env, nil
+}
+
+// PreparedCmd holds a command ready to execute along with any cleanup
+// function that should be called after the process exits.
+type PreparedCmd struct {
+	Cmd     *exec.Cmd
+	Cleanup func()
+}
+
+// PrepareCommand builds the exec.Cmd for a harness launch, including
+// environment variables, pre-launch hooks, and CLI arguments.
+func PrepareCommand(ctx context.Context, spec LaunchSpec) (*PreparedCmd, error) {
+	env, err := BuildEnv(spec)
+	if err != nil {
+		return nil, err
+	}
+
+	var cleanup func()
+	if spec.Harness.PreLaunch != nil {
+		endpoint, err := apis.BuildEndpoint(spec.BaseURL, spec.Harness.BasePath)
+		if err != nil {
+			return nil, fmt.Errorf("build endpoint for pre-launch: %w", err)
+		}
+		vk := strings.TrimSpace(spec.VirtualKey)
+		if vk == "" {
+			vk = "dummy-key"
+		}
+		extraEnv, c, err := spec.Harness.PreLaunch(endpoint, vk, spec.Model)
+		if err != nil {
+			return nil, fmt.Errorf("pre-launch %s: %w", spec.Harness.Label, err)
+		}
+		cleanup = c
+		env = append(env, extraEnv...)
+	}
+
+	args := []string{}
+	if spec.Harness.RunArgsForMod != nil {
+		args = append(args, spec.Harness.RunArgsForMod(spec.Model)...)
+	}
+	if spec.Worktree != "" && spec.Harness.WorktreeArgs != nil {
+		args = append(args, spec.Harness.WorktreeArgs(spec.Worktree)...)
+	}
+
+	cmd := exec.CommandContext(ctx, spec.Harness.Binary, args...)
+	cmd.Env = env
+
+	return &PreparedCmd{Cmd: cmd, Cleanup: cleanup}, nil
+}
+
+// RunInteractive launches the harness as an interactive subprocess with full
+// TTY access. It prints a bifrost banner before launch and a summary after exit.
+func RunInteractive(ctx context.Context, stdout, stderr io.Writer, spec LaunchSpec) error {
+	p, err := PrepareCommand(ctx, spec)
+	if err != nil {
+		return err
+	}
+	if p.Cleanup != nil {
+		defer p.Cleanup()
+	}
+
+	fmt.Fprint(stdout, renderBanner(spec))
+
+	if err := runWithPTY(ctx, stdout, p.Cmd); err != nil {
+		fmt.Fprintf(stdout, "\n\033[36mbifrost>\033[0m session ended with error: %v\n", err)
+		return fmt.Errorf("run harness: %w", err)
+	}
+	fmt.Fprintf(stdout, "\n\033[36mbifrost>\033[0m session ended\n")
+	return nil
+}
+
+// renderBanner builds the pre-launch info box showing harness, model,
+// endpoint, and the equivalent command.
+func renderBanner(spec LaunchSpec) string {
+	endpoint, err := apis.BuildEndpoint(spec.BaseURL, spec.Harness.BasePath)
+	if err != nil {
+		endpoint = spec.BaseURL + " (invalid)"
+	}
+
+	vkStatus := "no"
+	if strings.TrimSpace(spec.VirtualKey) != "" {
+		vkStatus = "yes"
+	}
+
+	cmdLine := spec.Harness.Binary
+	if spec.Harness.RunArgsForMod != nil {
+		if a := spec.Harness.RunArgsForMod(spec.Model); len(a) > 0 {
+			cmdLine += " " + strings.Join(a, " ")
+		}
+	}
+	if spec.Worktree != "" && spec.Harness.WorktreeArgs != nil {
+		if a := spec.Harness.WorktreeArgs(spec.Worktree); len(a) > 0 {
+			cmdLine += " " + strings.Join(a, " ")
+		}
+	}
+
+	cyan := "\033[36m"
+	dim := "\033[2m"
+	bold := "\033[1m"
+	reset := "\033[0m"
+
+	var b strings.Builder
+	b.WriteString("\n")
+	b.WriteString(dim + "───────────────────────────────────────────────────" + reset + "\n")
+	b.WriteString(cyan + "bifrost>" + reset + " " + bold + spec.Harness.Label + reset + "  " + dim + spec.Model + reset + "\n")
+	b.WriteString(dim + "  endpoint : " + reset + endpoint + "\n")
+	b.WriteString(dim + "  vk       : " + reset + vkStatus + "\n")
+	b.WriteString(dim + "  command  : " + reset + cmdLine + "\n")
+	b.WriteString(dim + "───────────────────────────────────────────────────" + reset + "\n")
+	b.WriteString("\n")
+	return b.String()
+}