#!/usr/bin/env node
/**
 * Sync ftp-images -> public/images and report changes.
 * Usage: node scripts/sync-ftp-images.mjs [--dry-run]
 *
 * Mapping:
 *   ftp-images/bilder-bp/ -> public/images/dishes/  (menu uses /images/dishes/...)
 *   ftp-images/<other>/   -> public/images/<other>/
 */
import fs from "node:fs";
import path from "node:path";
import crypto from "node:crypto";
import { fileURLToPath } from "node:url";

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const ROOT = path.resolve(__dirname, "..");
const DRY_RUN = process.argv.includes("--dry-run");
const FTP_ROOT = path.join(ROOT, "ftp-images");
const PUBLIC_IMAGES = path.join(ROOT, "public", "images");
const LOG_FILE = path.join(ROOT, "sync-images-log.txt");
const RESULT_FILE = path.join(ROOT, "sync-result.json");

/** FTP subfolder name -> public/images subfolder name */
const DEST_ALIASES = {
  "bilder-bp": "dishes",
};

const IMAGE_EXT = new Set([".jpg", ".jpeg", ".png", ".webp", ".gif", ".svg", ".avif"]);

const logLines = [];
const log = (...args) => {
  const line = args.map(String).join(" ");
  logLines.push(line);
  console.log(...args);
};

function hashFile(filePath) {
  const data = fs.readFileSync(filePath);
  return crypto.createHash("md5").update(data).digest("hex");
}

function walk(dir) {
  const out = [];
  if (!fs.existsSync(dir)) return out;
  for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
    const full = path.join(dir, entry.name);
    if (entry.isDirectory()) out.push(...walk(full));
    else if (entry.isFile()) out.push(full);
  }
  return out;
}

function rel(from, to) {
  return path.relative(from, to).split(path.sep).join("/");
}

function discoverSources() {
  if (!fs.existsSync(FTP_ROOT)) return [];
  const pairs = [];
  for (const entry of fs.readdirSync(FTP_ROOT, { withFileTypes: true })) {
    if (!entry.isDirectory()) continue;
    const destName = DEST_ALIASES[entry.name] ?? entry.name;
    pairs.push({
      src: path.join(FTP_ROOT, entry.name),
      dest: path.join(PUBLIC_IMAGES, destName),
      srcLabel: `ftp-images/${entry.name}`,
      destLabel: `public/images/${destName}`,
    });
  }
  return pairs;
}

function syncPair({ src, dest, srcLabel, destLabel }) {
  fs.mkdirSync(dest, { recursive: true });

  const srcFiles = walk(src).filter((f) => IMAGE_EXT.has(path.extname(f).toLowerCase()));
  const destFiles = walk(dest).filter((f) => IMAGE_EXT.has(path.extname(f).toLowerCase()));
  const srcSet = new Set(srcFiles.map((f) => rel(src, f)));

  const copied = [];
  const updated = [];
  const unchanged = [];
  const removed = [];

  for (const file of srcFiles) {
    const relPath = rel(src, file);
    const target = path.join(dest, relPath);
    fs.mkdirSync(path.dirname(target), { recursive: true });

    if (!fs.existsSync(target)) {
      if (!DRY_RUN) fs.copyFileSync(file, target);
      copied.push(relPath);
      continue;
    }

    if (hashFile(file) !== hashFile(target)) {
      if (!DRY_RUN) fs.copyFileSync(file, target);
      updated.push(relPath);
    } else {
      unchanged.push(relPath);
    }
  }

  for (const file of destFiles) {
    const relPath = rel(dest, file);
    if (!srcSet.has(relPath)) {
      if (!DRY_RUN) fs.unlinkSync(file);
      removed.push(relPath);
    }
  }

  log(`\n=== ${srcLabel} -> ${destLabel} ===`);
  log(`  new: ${copied.length}  updated: ${updated.length}  unchanged: ${unchanged.length}  removed: ${removed.length}`);
  for (const f of copied) log(`    + ${f}`);
  for (const f of updated) log(`    ~ ${f}`);
  for (const f of removed) log(`    - ${f}`);

  return { copied, updated, unchanged, removed, src: srcLabel, dest: destLabel };
}

function checkMenuReferences() {
  const menuFile = path.join(ROOT, "infrastructure", "menu", "static-menu-data.ts");
  if (!fs.existsSync(menuFile)) {
    log("\nMenu file not found; skipping reference check.");
    return { unique: [], missing: [] };
  }

  const text = fs.readFileSync(menuFile, "utf8");
  const refs = [...text.matchAll(/["'`](\/images\/[^"'`]+)["'`]/g)].map((m) => m[1]);
  const unique = [...new Set(refs)];
  const missing = unique.filter((ref) => !fs.existsSync(path.join(ROOT, "public", ref.replace(/^\//, ""))));

  log(`\n=== Menu references: ${unique.length} unique, ${missing.length} missing ===`);
  for (const m of missing) log(`    ! ${m}`);
  return { unique, missing };
}

function writeOutputs(result) {
  if (!DRY_RUN) {
    fs.writeFileSync(LOG_FILE, logLines.join("\n") + "\n");
    fs.writeFileSync(RESULT_FILE, JSON.stringify(result, null, 2) + "\n");
    log(`\nWrote ${path.relative(ROOT, LOG_FILE)}`);
    log(`Wrote ${path.relative(ROOT, RESULT_FILE)}`);
  }
}

if (!fs.existsSync(FTP_ROOT)) {
  console.error(`ftp-images not found at ${FTP_ROOT}`);
  process.exit(1);
}

log(DRY_RUN ? "DRY RUN\n" : "Syncing...\n");

const pairs = discoverSources();
if (pairs.length === 0) {
  log("No subfolders found in ftp-images/");
  writeOutputs({ totals: { copied: 0, updated: 0, unchanged: 0, removed: 0 }, pairs: [], menu: { unique: [], missing: [] } });
  process.exit(0);
}

const pairResults = [];
const totals = { copied: 0, updated: 0, unchanged: 0, removed: 0 };

for (const pair of pairs) {
  const result = syncPair(pair);
  pairResults.push(result);
  totals.copied += result.copied.length;
  totals.updated += result.updated.length;
  totals.unchanged += result.unchanged.length;
  totals.removed += result.removed.length;
}

log(`\n=== TOTALS: ${totals.copied} new, ${totals.updated} updated, ${totals.unchanged} unchanged, ${totals.removed} removed ===`);

const menu = checkMenuReferences();
writeOutputs({ dryRun: DRY_RUN, totals, pairs: pairResults, menu });

if (menu.missing.length) process.exitCode = 1;