/* eslint-disable @typescript-eslint/no-var-requires */
const util = require('util');
const https = require('https');
const exec = util.promisify(require('child_process').exec);
const { promises: fs, mkdirSync } = require('fs');
const { join, sep, dirname } = require('path');
const { platform } = require('os');
const appPath = join(__dirname, '..');

/**
 * Specify the pattern under which the project's version can be found in the
 * root directory's go.mod file.
 */
const LND_VERSION_PATTERN = /^\tgithub\.com\/lightningnetwork\/lnd (v[\d.]+-beta(?:\.rc\d)?)/ms;
const LOOP_VERSION_PATTERN = /^\tgithub\.com\/lightninglabs\/loop (v[\d.]+-beta)/ms;
const POOL_VERSION_PATTERN = /^\tgithub\.com\/lightninglabs\/pool (v[\d.]+-beta)/ms;

/** mapping of proto files to the github url to download each from */
const protoSources = async () => {
  console.log('Parsing go.mod for versions...');
  const goModPath = join(appPath, '..', 'go.mod');
  const goModSource = (await fs.readFile(goModPath)).toString();

  const lndVersion = goModSource.match(LND_VERSION_PATTERN);
  if (!lndVersion || lndVersion.length !== 2) {
    throw new Error(`go.mod did not match pattern ${LND_VERSION_PATTERN}`);
  }

  const loopVersion = goModSource.match(LOOP_VERSION_PATTERN);
  if (!loopVersion || loopVersion.length !== 2) {
    throw new Error(`go.mod did not match pattern ${LOOP_VERSION_PATTERN}`);
  }

  const poolVersion = goModSource.match(POOL_VERSION_PATTERN);
  if (!poolVersion || poolVersion.length !== 2) {
    throw new Error(`go.mod did not match pattern ${POOL_VERSION_PATTERN}`);
  }

  console.log(
    `Found:\n LND ${lndVersion[1]}\n Loop ${loopVersion[1]}\n Pool ${poolVersion[1]}`,
  );
  return {
    lnd: `lightningnetwork/lnd/${lndVersion[1]}/lnrpc/lightning.proto`,
    loop: `lightninglabs/loop/${loopVersion[1]}/looprpc/client.proto`,
    'swapserverrpc/server': `lightninglabs/loop/${loopVersion[1]}/swapserverrpc/server.proto`,
    'swapserverrpc/common': `lightninglabs/loop/${loopVersion[1]}/swapserverrpc/common.proto`,
    'swapserverrpc/reservation': `lightninglabs/loop/${loopVersion[1]}/swapserverrpc/reservation.proto`,
    trader: `lightninglabs/pool/${poolVersion[1]}/poolrpc/trader.proto`,
    'auctioneerrpc/auctioneer': `lightninglabs/pool/${poolVersion[1]}/auctioneerrpc/auctioneer.proto`,
  };
};

/** list of proto files and patches to apply */
const filePatches = {
  lnd: 'lnrpc: {}',
  loop: 'looprpc: {}',
  'swapserverrpc/common': 'looprpc: {}',
  'swapserverrpc/reservation': 'looprpc: {}',
  'swapserverrpc/server': 'looprpc: {}',
  trader: 'poolrpc: {}',
  'auctioneerrpc/auctioneer': 'poolrpc: {}',
  'lit-sessions': 'litrpc: {}',
  'lit-accounts': 'litrpc: {}',
  'lit-autopilot': 'litrpc: {}',
  'firewall': 'litrpc: {}',
  'proxy': 'litrpc: {}',
  'lit-status': 'litrpc: {}',
};

/**
 * Downloads the *.proto files into the `../proto` dir
 */
const download = async () => {
  console.log('\nDownloading proto files...');
  for ([name, urlPath] of Object.entries(await protoSources())) {
    const url = `https://raw.githubusercontent.com/${urlPath}`;
    const filePath = join(appPath, '..', 'proto', `${name}.proto`);
    mkdirSync(dirname(filePath), { recursive: true });
    console.log(`${url}`);
    console.log(` -> ${filePath}`);
    const content = await new Promise((resolve, reject) => {
      https.get(url, res => {
        let data = '';
        res.on('data', chunk => (data += chunk));
        res.on('error', err => reject(err));
        res.on('end', () => resolve(data));
      });
    });
    await fs.writeFile(filePath, content);
  }
  // copy the lit proto files from litrpc to the proto dir so that the original
  // files are not modified by `sanitize`
  const litProtoFiles = ['lit-sessions', 'lit-accounts', 'lit-autopilot', 'proxy', 'firewall', 'lit-status'];
  for (name of litProtoFiles) {
    const src = join(appPath, '..', 'litrpc', `${name}.proto`);
    const dest = join(appPath, '..', 'proto', `${name}.proto`);
    await fs.copyFile(src, dest);
  }
};

/**
 * Adds "[jstype = JS_STRING]" to uint64 fields to indicate that they should be
 * represented as strings to avoid Number overflow issues
 */
const sanitize = async () => {
  const filePaths = Object.keys(filePatches).map(name =>
    join(appPath, '..', 'proto', `${name}.proto`),
  );
  for (path of filePaths) {
    let content = (await fs.readFile(path)).toString();
    content = content.replace(
      /^(\s*)(repeated )?(u?int64) (\S+) = (\d+);$/gm,
      '$1$2$3 $4 = $5 [jstype = JS_STRING];',
    );
    content = content.replace(
      /^(\s*)(repeated )?(u?int64) (\S+) = (\d+) \[((?!jstype).*)];$/gm,
      '$1$2$3 $4 = $5 [$6, jstype = JS_STRING];',
    );
    content = content.replace(
      'import "common.proto"',
      'import "swapserverrpc/common.proto"',
    );
    content = content.replace(
        'import "reservation.proto"',
        'import "swapserverrpc/reservation.proto"',
    );
    content = content.replace(
      'import "lnrpc/lightning.proto"',
      'import "lnd.proto"',
    );
    content = content.replace(
        'import "proto/lnd.proto";',
        'import "lnd.proto";',
    );
    await fs.writeFile(path, content);
  }
};

/**
 * Executes the `protoc` compiler to convert *.proto files into TS & JS code
 */
const generate = async () => {
  console.log('\nCompiling protobuf definitions...');
  await fs.mkdir('./src/types/generated', { recursive: true });

  const protocGen = join(
    appPath,
    'node_modules',
    '.bin',
    platform() === 'win32' ? 'protoc-gen-ts.cmd' : 'protoc-gen-ts',
  );
  const files = Object.keys(filePatches).map(name => `../proto/${name}.proto`);
  const protocCmd = [
    'protoc',
    `-I../proto`,
    `-I../litrpc`,
    `--plugin=protoc-gen-ts=${protocGen}`,
    '--proto_path=../proto',
    '--js_out=import_style=commonjs,binary:./src/types/generated',
    '--ts_out=service=grpc-web:./src/types/generated',
    ...files,
  ].join(' ');

  console.log(protocCmd);
  const { stderr } = await exec(protocCmd, { cwd: appPath });
  if (stderr) {
    throw new Error(`exec stderr:\n${stderr}`);
  }
};

/**
 * Patches the generated JS files as they contain a type error that prevents webpack from bundling properly.
 * The code below will prepend the necessary code to resolve the error.
 * Example: prepends `var proto = { lnrpc: {} };` to lnd_pb.js
 */
const patch = async () => {
  console.log('\nPatching generated JS files');

  for (const filename of Object.keys(filePatches)) {
    const path = join(
      appPath,
      'src',
      'types',
      'generated',
      `${filename.replace(/\//, sep)}_pb.js`,
    );

    console.log(` - ${path}`);
    let content = await fs.readFile(path);

    // apply the webpack patch
    const patch = [
      '/* eslint-disable */',
      `var proto = { ${filePatches[filename]} };`,
      '',
    ].join('\n');
    content = `${patch}\n${content}`;

    await fs.writeFile(path, content);
  }
};

/**
 * *Temporary* patch to workaround a grpc-web issue with deserializing the GetInfoResponse.market_info field.
 * This patch will just comment it out in the proto file, which will omit the field in the JS/TS serialization
 * code that is generated by the protoc-gen-ts plugin.
 * See: https://github.com/lightninglabs/lightning-terminal/pull/337
 */
const patchPool = async () => {
  console.log('\nPatching Pool proto file');
  const path = join(appPath, '..', 'proto', 'trader.proto');

  console.log(` - ${path}`);
  let content = await fs.readFile(path);

  // comment out the `market_info` field
  const line = 'map<uint32, MarketInfo> market_info = 15;';
  const patch = '// [workaround, see patchPool() in build-protos.js] ';
  content = content.toString().replace(line, patch + line);

  await fs.writeFile(path, content);
};

/**
 * An async wrapper with error handling around the two funcs above
 */
const main = async () => {
  try {
    await download();
    await sanitize();
    await patchPool();
    await generate();
    await patch();
  } catch (error) {
    console.error(error);
    process.exit(1);
  }
};

/**
 * execute the main function
 */
main();