/**
 * Generates optimized, responsive images from assets/source into public/images.
 * Runs automatically before `next build`. Safe to re-run; skips up-to-date files.
 *
 *   npm run images
 */
import sharp from "sharp";
import { promises as fs } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

const ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
const SRC = path.join(ROOT, "assets/source");
const OUT = path.join(ROOT, "public/images");

/** name → { file, widths, quality } */
const PHOTOS = {
  "hero-worship": { file: "photos/hero-north-attleboro-worship.jpg", widths: [640, 1024, 1600, 2000], quality: 72 },
  "campus-north-attleboro": { file: "photos/campus-north-attleboro.jpg", widths: [480, 960], quality: 74 },
  "campus-norwood": { file: "photos/campus-norwood.jpg", widths: [480, 960], quality: 74 },
  "campus-woonsocket": { file: "photos/campus-woonsocket.jpg", widths: [480, 960], quality: 74 },
  "campus-southcoast": { file: "photos/campus-southcoast.jpg", widths: [480, 960], quality: 74 },
  "campus-apollo-beach": { file: "photos/campus-apollo-beach.jpg", widths: [480, 960], quality: 74 },
  "campus-orlando": { file: "photos/campus-orlando.jpg", widths: [480, 960], quality: 74 },
  "worship-southcoast": { file: "photos/worship-southcoast.jpg", widths: [640, 1200], quality: 72 },
  "community-1": { file: "photos/community-1.jpg", widths: [640, 1200], quality: 74 },
  "save-a-seat": { file: "photos/save-a-seat.jpg", widths: [640, 1200], quality: 74 },
};

const LOGOS = {
  "waters-mark-teal": { file: "logos/waters-mark-teal.png", widths: [96, 192, 512] },
};

const SVGS = ["logos/waters-mark-white.svg", "logos/waters-church-wordmark-white.svg"];

async function newer(src, out) {
  try {
    const [a, b] = await Promise.all([fs.stat(src), fs.stat(out)]);
    return a.mtimeMs > b.mtimeMs;
  } catch {
    return true;
  }
}

async function main() {
  await fs.mkdir(OUT, { recursive: true });
  const manifest = {};

  for (const [name, spec] of Object.entries(PHOTOS)) {
    const src = path.join(SRC, spec.file);
    const meta = await sharp(src).metadata();
    manifest[name] = { width: meta.width, height: meta.height, widths: [], formats: ["avif", "webp", "jpg"] };
    for (const w of spec.widths) {
      if (w > meta.width) continue;
      manifest[name].widths.push(w);
      const base = path.join(OUT, `${name}-${w}`);
      const resized = () => sharp(src).resize({ width: w, withoutEnlargement: true });
      if (await newer(src, `${base}.webp`)) await resized().webp({ quality: spec.quality }).toFile(`${base}.webp`);
      if (await newer(src, `${base}.avif`)) await resized().avif({ quality: Math.max(40, spec.quality - 20) }).toFile(`${base}.avif`);
      if (await newer(src, `${base}.jpg`)) await resized().jpeg({ quality: spec.quality + 4, mozjpeg: true }).toFile(`${base}.jpg`);
    }
    // tiny blurred placeholder to avoid layout flash
    const { data } = await sharp(src).resize(24).webp({ quality: 30 }).toBuffer({ resolveWithObject: true });
    manifest[name].blur = `data:image/webp;base64,${data.toString("base64")}`;
  }

  for (const [name, spec] of Object.entries(LOGOS)) {
    const src = path.join(SRC, spec.file);
    for (const w of spec.widths) {
      const out = path.join(OUT, `${name}-${w}.png`);
      if (await newer(src, out)) await sharp(src).resize({ width: w }).png({ compressionLevel: 9 }).toFile(out);
    }
  }

  for (const rel of SVGS) {
    const out = path.join(OUT, path.basename(rel));
    if (await newer(path.join(SRC, rel), out)) await fs.copyFile(path.join(SRC, rel), out);
  }

  // Favicons / social image
  const mark = path.join(SRC, LOGOS["waters-mark-teal"].file);
  await sharp(mark).resize(32).png().toFile(path.join(OUT, "favicon-32.png"));
  await sharp(mark).resize(180).png().toFile(path.join(OUT, "apple-touch-icon.png"));
  await sharp(mark).resize(512).png().toFile(path.join(OUT, "icon-512.png"));
  const og = path.join(OUT, "og-image.jpg");
  if (await newer(path.join(SRC, PHOTOS["hero-worship"].file), og)) {
    await sharp(path.join(SRC, PHOTOS["hero-worship"].file))
      .resize(1200, 630, { fit: "cover", position: "centre" })
      .jpeg({ quality: 78, mozjpeg: true })
      .toFile(og);
  }

  await fs.writeFile(path.join(ROOT, "src/config/images.manifest.json"), JSON.stringify(manifest, null, 2));
  const files = await fs.readdir(OUT);
  let total = 0;
  for (const f of files) total += (await fs.stat(path.join(OUT, f))).size;
  console.log(`images: ${files.length} files, ${(total / 1024).toFixed(0)} KB total in public/images`);
}

main().catch((e) => {
  console.error(e);
  process.exit(1);
});