import * as fs from 'fs';
import * as path from 'path';

const IMAGE_EXTS = new Set(['.jpg', '.jpeg', '.png', '.webp', '.gif', '.heic', '.heif']);

/**
 * Lists image files from the configured photos directory.
 * Recurses one level deep so users can organise photos into subfolders.
 */
export class PhotoManager {
  constructor(private photosDir: string) {}

  setDir(dir: string): void {
    this.photosDir = dir;
  }

  getDir(): string {
    return this.photosDir;
  }

  list(): string[] {
    if (!this.photosDir || !fs.existsSync(this.photosDir)) return [];
    const files: string[] = [];
    try {
      this.walk(this.photosDir, files, 0);
    } catch (err) {
      console.error('PhotoManager: failed to list photos', err);
    }
    // Return paths relative to photosDir so the renderer can build photo:// URLs
    return files.map((f) => path.relative(this.photosDir, f));
  }

  private walk(dir: string, out: string[], depth: number): void {
    if (depth > 2) return;
    for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
      if (entry.name.startsWith('.')) continue;
      const full = path.join(dir, entry.name);
      if (entry.isDirectory()) {
        this.walk(full, out, depth + 1);
      } else if (entry.isFile() && IMAGE_EXTS.has(path.extname(entry.name).toLowerCase())) {
        out.push(full);
      }
    }
  }

  resolve(relative: string): string | null {
    if (!this.photosDir) return null;
    const safe = path.normalize(relative).replace(/^(\.\.[\/\\])+/, '');
    const full = path.join(this.photosDir, safe);
    if (!full.startsWith(this.photosDir)) return null;
    return full;
  }
}