package birdfmt

import (
	"embed"
	"io/fs"
	"path"
	"sort"
)

//go:embed testdata/scenarios
var scenariosFS embed.FS

// BirdScenarioPaths returns POSIX-style directory paths (under testdata/scenarios)
// that contain a bird.conf file, sorted for stable iteration.
func BirdScenarioPaths() ([]string, error) {
	var dirs []string
	err := fs.WalkDir(scenariosFS, "testdata/scenarios", func(p string, d fs.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if d.IsDir() || d.Name() != "bird.conf" {
			return nil
		}
		dir := path.Dir(p)
		if dir == "testdata/scenarios" {
			return nil
		}
		dirs = append(dirs, dir)
		return nil
	})
	if err != nil {
		return nil, err
	}
	sort.Strings(dirs)
	return dirs, nil
}

// ScenarioBirdConfRel returns the path relative to module root internal/birdfmt/ for bird.conf.
func ScenarioBirdConfRel(scenarioDir string) string {
	return path.Join(scenarioDir, "bird.conf")
}

// ReadScenarioBirdConf returns the contents of bird.conf for a scenario directory from embed.
func ReadScenarioBirdConf(scenarioDir string) ([]byte, error) {
	return scenariosFS.ReadFile(path.Join(scenarioDir, "bird.conf"))
}

// RepoRelativeBirdConf is the path from the repository root (for CI / docker bind mounts).
func RepoRelativeBirdConf(scenarioDir string) string {
	return path.Join("internal/birdfmt", scenarioDir, "bird.conf")
}

// AllScenarioNames returns leaf scenario names (last path segment) for tables / docs.
func AllScenarioNames() ([]string, error) {
	paths, err := BirdScenarioPaths()
	if err != nil {
		return nil, err
	}
	names := make([]string, len(paths))
	for i, p := range paths {
		names[i] = path.Base(p)
	}
	return names, nil
}