const ts = require('typescript');
const path = require('path');
const fs = require('fs');

function report(d) {
  const file = d.file ? path.relative(process.cwd(), d.file.fileName) : null;
  const msg = ts.flattenDiagnosticMessageText(d.messageText, '\n');
  const line = d.file && d.start !== undefined ? d.file.getLineAndCharacterOfPosition(d.start).line + 1 : null;
  const col = d.file && d.start !== undefined ? d.file.getLineAndCharacterOfPosition(d.start).character + 1 : null;
  console.log([file ? file : '', line ? ':' + line : '', col ? ':' + col : '', '-', msg].join(''));
}

async function run(tsconfigPath) {
  const abs = path.resolve(tsconfigPath);
  if (!fs.existsSync(abs)) {
    console.error('tsconfig not found:', abs);
    process.exit(2);
  }
  const configFile = ts.readConfigFile(abs, ts.sys.readFile);
  if (configFile.error) {
    report(configFile.error);
    process.exit(1);
  }
  const parseConfig = ts.parseJsonConfigFileContent(configFile.config, ts.sys, path.dirname(abs));
  if (parseConfig.errors && parseConfig.errors.length) {
    parseConfig.errors.forEach(report);
    process.exit(1);
  }
  const program = ts.createProgram(parseConfig.fileNames, parseConfig.options);
  const emitResult = program.emit();
  const allDiagnostics = ts.getPreEmitDiagnostics(program).concat(emitResult.diagnostics);
  if (allDiagnostics.length === 0) {
    console.log('TSC: no errors');
    process.exit(0);
  }
  allDiagnostics.forEach(report);
  console.log('TSC: errors=', allDiagnostics.length);
  process.exit(1);
}

const arg = process.argv[2] || 'packages/backend-api/tsconfig.json';
run(arg).catch(e => { console.error('runner failed', e); process.exit(3); });