package storage

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

// Store manages AsciiDoc files on disk.
type Store struct {
	root string
}

func New(root string) (*Store, error) {
	if err := os.MkdirAll(root, 0755); err != nil {
		return nil, err
	}
	return &Store{root: root}, nil
}

// Read returns the content of a document by its slug path (e.g. "guides/install").
func (s *Store) Read(slug string) (string, error) {
	data, err := os.ReadFile(s.filePath(slug))
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			return "", ErrNotFound
		}
		return "", err
	}
	return string(data), nil
}

// Write persists content to disk, creating parent directories as needed.
func (s *Store) Write(slug, content string) error {
	path := s.filePath(slug)
	if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
		return err
	}
	return os.WriteFile(path, []byte(content), 0644)
}

// Delete removes a document from disk.
func (s *Store) Delete(slug string) error {
	return os.Remove(s.filePath(slug))
}

// List returns all document slugs under an optional prefix.
func (s *Store) List(prefix string) ([]string, error) {
	base := filepath.Join(s.root, filepath.FromSlash(prefix))
	var slugs []string
	err := filepath.WalkDir(base, func(path string, d os.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if !d.IsDir() && strings.HasSuffix(path, ".adoc") {
			rel, _ := filepath.Rel(s.root, path)
			slug := strings.TrimSuffix(filepath.ToSlash(rel), ".adoc")
			slugs = append(slugs, slug)
		}
		return nil
	})
	return slugs, err
}

func (s *Store) filePath(slug string) string {
	return filepath.Join(s.root, filepath.FromSlash(slug)+".adoc")
}

var ErrNotFound = errors.New("document not found")