import {createHash} from 'node:crypto';
import {createWriteStream} from 'node:fs';
import {cp, mkdir, readFile, readdir, rm, stat, rename, unlink, writeFile} from 'node:fs/promises';
import {join} from 'node:path';
import {Readable, Transform} from 'node:stream';
import {pipeline} from 'node:stream/promises';
import {assetPrefix, requiredOnnxFiles, voiceFiles, voiceRepository, voiceRevision} from './assets.mjs';

const root = process.cwd();
const output = join(root, 'public', 'static', assetPrefix);
const onnxSource = join(root, 'node_modules', 'onnxruntime-web', 'dist');
const piperSource = join(root, 'node_modules', '@diffusionstudio', 'piper-wasm', 'build');
const localAiPrefix = 'wllama-gemma3-v2';
const wllamaUrl = 'https://registry.npmjs.org/@wllama/wllama/-/wllama-3.8.1.tgz';
const wllamaSha512 = 'Pl7BEJhPU8OHnV/yhn3DFZYhLLOdSHh+4TND79WCftHnlUAdQPAsyc/CfIOY+4mVxvf5VW3Xw3Uf7BBfotS1gw==';
const gemmaUrl = 'https://huggingface.co/ggml-org/gemma-3-1b-it-GGUF/resolve/f9c28bcd85737ffc5aef028638d3341d49869c27/gemma-3-1b-it-Q4_K_M.gguf';
const gemmaSize = 806058240;
const gemmaSha256 = '8ccc5cd1f1b3602548715ae25a66ed73fd5dc68a210412eea643eb20eb75a135';

async function downloadVoiceFile(file) {
  const destination = join(output, 'voices', file.path);
  const temporary = `${destination}.part`;
  await mkdir(join(destination, '..'), {recursive: true});
  const response = await fetch(`${voiceRepository}/${voiceRevision}/${file.path}`);
  if (!response.ok || !response.body) throw new Error(`Unable to download ${file.path}: HTTP ${response.status}`);
  const sha256 = createHash('sha256');
  const sha1 = createHash('sha1').update(Buffer.from(`blob ${file.size}\0`));
  let size = 0;
  const verify = new Transform({
    transform(chunk, _encoding, callback) {
      size += chunk.length;
      sha256.update(chunk);
      sha1.update(chunk);
      callback(null, chunk);
    },
  });
  try {
    await pipeline(Readable.fromWeb(response.body), verify, createWriteStream(temporary));
    if (size !== file.size || (file.sha256 && sha256.digest('hex') !== file.sha256) ||
        (file.gitBlobSha1 && sha1.digest('hex') !== file.gitBlobSha1)) {
      throw new Error(`Integrity check failed for ${file.path} (${size} bytes)`);
    }
    await rename(temporary, destination);
  } catch (error) {
    await unlink(temporary).catch(() => {});
    throw error;
  }
}

await rm(join(root, 'public', 'static'), {recursive: true, force: true});
const localAiRoot = join(root, 'public', 'static', localAiPrefix);
const wllamaRoot = join(localAiRoot, 'wllama');
const modelRoot = join(localAiRoot, 'models');
const licenseRoot = join(localAiRoot, 'licenses');
await mkdir(wllamaRoot, {recursive: true});
await mkdir(modelRoot, {recursive: true});
await mkdir(licenseRoot, {recursive: true});

// Build-time downloads are pinned and integrity checked. Browser clients use only our /static URLs.
const wllamaResponse = await fetch(wllamaUrl);
if (!wllamaResponse.ok || !wllamaResponse.body) throw new Error(`Unable to download Wllama: HTTP ${wllamaResponse.status}`);
const tgzPath = join(root, '.wllama-3.8.1.tgz');
const wllamaHash = createHash('sha512');
await pipeline(Readable.fromWeb(wllamaResponse.body), new Transform({transform(chunk, _encoding, callback) { wllamaHash.update(chunk); callback(null, chunk); }}), createWriteStream(tgzPath));
if (wllamaHash.digest('base64') !== wllamaSha512) throw new Error('Wllama package integrity check failed');
const {execFile} = await import('node:child_process');
const {promisify} = await import('node:util');
await promisify(execFile)('tar', ['-xzf', tgzPath, '-C', wllamaRoot, '--strip-components=1']);
await unlink(tgzPath);
for (const relative of ['esm/index.js', 'esm/wasm/wllama.wasm']) {
  if (!(await stat(join(wllamaRoot, relative))).isFile()) throw new Error(`Missing Wllama runtime asset: ${relative}`);
}
for (const file of ['GEMMA_USER_TERMS.html', 'GEMMA_TERMS.html', 'GEMMA_PROHIBITED_USE_POLICY.html', 'GEMMA_NOTICE.txt', 'GEMMA_SOURCE.txt', 'WLLAMA_LICENSE.txt', 'LLAMA_CPP_LICENSE.txt']) {
  const source = join(root, 'licenses', file);
  if (!(await stat(source).catch(() => null))?.isFile()) throw new Error(`Missing Gemma legal asset: ${file}`);
  await cp(source, join(licenseRoot, file));
}
await downloadVerified(gemmaUrl, join(modelRoot, 'gemma-3-1b-it-Q4_K_M.gguf'), gemmaSize, gemmaSha256);
await cp(join(root, 'prompts', 'browser-assistance.yaml'), join(localAiRoot, 'browser-assistance.yaml'));
await cp(join(root, 'client', 'local-ai.js'), join(localAiRoot, 'local-ai.js'));
const termsSha256 = createHash('sha256').update(await readFile(join(licenseRoot, 'GEMMA_TERMS.html'))).digest('hex');
const policySha256 = createHash('sha256').update(await readFile(join(licenseRoot, 'GEMMA_PROHIBITED_USE_POLICY.html'))).digest('hex');
const userTermsSha256 = createHash('sha256').update(await readFile(join(licenseRoot, 'GEMMA_USER_TERMS.html'))).digest('hex');
const acceptanceId = createHash('sha256').update(`${termsSha256}:${policySha256}:${userTermsSha256}`).digest('hex');
await writeFile(join(localAiRoot, 'manifest.json'), JSON.stringify({
  asset_version: '1', model: {id: 'google/gemma-3-1b-it', quantization: 'Q4_K_M', bytes: gemmaSize, sha256: gemmaSha256, url: `/static/${localAiPrefix}/models/gemma-3-1b-it-Q4_K_M.gguf`},
  runtime: {name: 'wllama', version: '3.8.1', module: `/static/${localAiPrefix}/wllama/esm/index.js`, wasm: `/static/${localAiPrefix}/wllama/esm/wasm/wllama.wasm`},
  prompt: {id: 'browser-assistance', version: 1, url: `/static/${localAiPrefix}/browser-assistance.yaml`},
  license: {
    acceptance_id: acceptanceId,
    user_terms_sha256: userTermsSha256,
    terms_sha256: termsSha256,
    policy_sha256: policySha256,
    terms: `/static/${localAiPrefix}/licenses/GEMMA_TERMS.html`,
    user_terms: `/static/${localAiPrefix}/licenses/GEMMA_USER_TERMS.html`,
    prohibited_use_policy: `/static/${localAiPrefix}/licenses/GEMMA_PROHIBITED_USE_POLICY.html`,
    notice: `/static/${localAiPrefix}/licenses/GEMMA_NOTICE.txt`,
    source: `/static/${localAiPrefix}/licenses/GEMMA_SOURCE.txt`,
    runtime: `/static/${localAiPrefix}/licenses/WLLAMA_LICENSE.txt`,
    llama_cpp_runtime: `/static/${localAiPrefix}/licenses/LLAMA_CPP_LICENSE.txt`,
  },
}, null, 2));
await mkdir(join(output, 'onnx'), {recursive: true});
await mkdir(join(output, 'piper'), {recursive: true});
for (const file of voiceFiles) await downloadVoiceFile(file);
await cp(join(root, 'PIPER_VOICE_NOTICES.txt'), join(output, 'voices', 'ATTRIBUTION.txt'));

const onnxFiles = (await readdir(onnxSource)).filter(name => name.endsWith('.wasm') || name.endsWith('.mjs'));
for (const file of requiredOnnxFiles) {
  if (!onnxFiles.includes(file)) throw new Error(`Missing ONNX Runtime asset: ${file}`);
}
for (const file of onnxFiles) await cp(join(onnxSource, file), join(output, 'onnx', file));

for (const file of ['piper_phonemize.wasm', 'piper_phonemize.data']) {
  const source = join(piperSource, file);
  const fileStat = await stat(source).catch(() => null);
  if (!fileStat?.isFile() || fileStat.size === 0) throw new Error(`Missing Piper runtime file: ${file}`);
  await cp(source, join(output, 'piper', file));
}

for (const file of voiceFiles) {
  const downloaded = join(output, 'voices', file.path);
  if ((await stat(downloaded)).size !== file.size) throw new Error(`Missing verified voice file: ${file.path}`);
}
console.log(`Static voice and local AI assets prepared at ${output}`);

async function downloadVerified(url, destination, expectedSize, expectedSha256) {
  await mkdir(join(destination, '..'), {recursive: true});
  const response = await fetch(url);
  if (!response.ok || !response.body) throw new Error(`Unable to download ${destination}: HTTP ${response.status}`);
  const hash = createHash('sha256'); let size = 0;
  const verify = new Transform({transform(chunk, _encoding, callback) { size += chunk.length; hash.update(chunk); callback(null, chunk); }});
  await pipeline(Readable.fromWeb(response.body), verify, createWriteStream(destination));
  if (size !== expectedSize || hash.digest('hex') !== expectedSha256) throw new Error(`Integrity check failed for ${destination} (${size} bytes)`);
}