import fs from "fs";
import path from "path";
import {
  RECYCLE_DIR,
  RECYCLE_POSTS_DIR,
  RECYCLE_META_DIR,
  RECYCLE_DAYS,
} from "./config";

export interface RecycleItem {
  slug: string;
  title: string;
  deletedAt: string; // ISO date
  originalPath: string;
  expiresAt: string; // ISO date
  daysRemaining: number;
}

export function initRecycleBin(): void {
  if (!fs.existsSync(RECYCLE_DIR)) {
    fs.mkdirSync(RECYCLE_DIR, { recursive: true });
  }
  if (!fs.existsSync(RECYCLE_POSTS_DIR)) {
    fs.mkdirSync(RECYCLE_POSTS_DIR, { recursive: true });
  }
  if (!fs.existsSync(RECYCLE_META_DIR)) {
    fs.mkdirSync(RECYCLE_META_DIR, { recursive: true });
  }
}

export function moveToRecycle(
  slug: string,
  sourceDir: string,
  title: string
): void {
  initRecycleBin();

  const now = new Date();
  const expires = new Date(now);
  expires.setDate(expires.getDate() + RECYCLE_DAYS);

  const meta: Omit<RecycleItem, "daysRemaining"> = {
    slug,
    title,
    deletedAt: now.toISOString(),
    originalPath: sourceDir,
    expiresAt: expires.toISOString(),
  };

  // Move post directory to recycle
  const targetDir = path.join(RECYCLE_POSTS_DIR, slug);
  if (fs.existsSync(targetDir)) {
    fs.rmSync(targetDir, { recursive: true, force: true });
  }
  fs.renameSync(sourceDir, targetDir);

  // Save metadata
  const metaPath = path.join(RECYCLE_META_DIR, `${slug}.json`);
  fs.writeFileSync(metaPath, JSON.stringify(meta, null, 2), "utf-8");
}

export function listRecycle(): RecycleItem[] {
  initRecycleBin();

  if (!fs.existsSync(RECYCLE_META_DIR)) return [];

  const items: RecycleItem[] = [];
  const files = fs.readdirSync(RECYCLE_META_DIR).filter((f) => f.endsWith(".json"));

  for (const file of files) {
    const metaPath = path.join(RECYCLE_META_DIR, file);
    const raw = fs.readFileSync(metaPath, "utf-8");
    const meta = JSON.parse(raw);
    const now = new Date();
    const expires = new Date(meta.expiresAt);
    const daysRemaining = Math.max(
      0,
      Math.ceil((expires.getTime() - now.getTime()) / (1000 * 60 * 60 * 24))
    );

    items.push({ ...meta, daysRemaining });
  }

  items.sort(
    (a, b) =>
      new Date(b.deletedAt).getTime() - new Date(a.deletedAt).getTime()
  );

  return items;
}

export function restoreFromRecycle(slug: string): boolean {
  const metaPath = path.join(RECYCLE_META_DIR, `${slug}.json`);
  if (!fs.existsSync(metaPath)) return false;

  const raw = fs.readFileSync(metaPath, "utf-8");
  const meta = JSON.parse(raw);
  const recyclePostPath = path.join(RECYCLE_POSTS_DIR, slug);

  if (!fs.existsSync(recyclePostPath)) return false;

  // Ensure target directory exists
  const targetDir = path.dirname(meta.originalPath);
  if (!fs.existsSync(targetDir)) {
    fs.mkdirSync(targetDir, { recursive: true });
  }

  // If target already exists, remove it first
  if (fs.existsSync(meta.originalPath)) {
    fs.rmSync(meta.originalPath, { recursive: true, force: true });
  }

  fs.renameSync(recyclePostPath, meta.originalPath);
  fs.unlinkSync(metaPath);

  return true;
}

export function permanentDelete(slug: string): boolean {
  const metaPath = path.join(RECYCLE_META_DIR, `${slug}.json`);
  const recyclePostPath = path.join(RECYCLE_POSTS_DIR, slug);

  let deleted = false;
  if (fs.existsSync(recyclePostPath)) {
    fs.rmSync(recyclePostPath, { recursive: true, force: true });
    deleted = true;
  }
  if (fs.existsSync(metaPath)) {
    fs.unlinkSync(metaPath);
    deleted = true;
  }

  return deleted;
}

export function cleanExpired(): number {
  const items = listRecycle();
  let count = 0;
  for (const item of items) {
    if (item.daysRemaining <= 0) {
      permanentDelete(item.slug);
      count++;
    }
  }
  return count;
}