// session_mutate.go — codex session file path resolution. The actual
// JSONL rewrite is deferred (see main.go MutateSession comment): codex
// keys tool calls by `call_<id>`, not the `toolu_<id>` Plexum uses,
// so a v1 mirror would never match anything. We expose the path
// finder here so the host-side wiring telemetry stays useful and the
// v2 rewriter has its entry point.
//
// Codex layout (observed):
//
//	~/.codex/sessions/<YYYY>/<MM>/<DD>/rollout-<ISO>-<thread_id>.jsonl
//
// Older layout (pre-0.5x) wrote into the top-level sessions dir with
// the same filename convention. We probe both.

package runner

import (
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

// FindCodexSessionFile resolves the rollout JSONL for the thread_id
// captured into workspace/.plexum-codex-session. Returns ("", error)
// when no session id is recorded yet OR no matching file is on disk.
func FindCodexSessionFile(workspace string) (string, error) {
	threadID := loadSessionID(workspace)
	if threadID == "" {
		return "", errors.New("no thread_id captured yet")
	}
	home, err := os.UserHomeDir()
	if err != nil {
		return "", err
	}
	root := filepath.Join(home, ".codex", "sessions")
	var found string
	err = filepath.WalkDir(root, func(p string, d os.DirEntry, err error) error {
		if err != nil {
			return nil // tolerate per-entry errors; keep walking
		}
		if d.IsDir() {
			return nil
		}
		name := d.Name()
		if !strings.HasSuffix(name, ".jsonl") && !strings.HasSuffix(name, ".json") {
			return nil
		}
		if strings.Contains(name, threadID) {
			found = p
			return filepath.SkipAll
		}
		return nil
	})
	if err != nil {
		return "", err
	}
	if found == "" {
		return "", fmt.Errorf("no rollout file for thread_id=%s under %s", threadID, root)
	}
	return found, nil
}