'use strict';

function reqFromCwd(id) {
  // Resolve as if we required from the project root (where mocha is installed)
  return require(require.resolve(id, { paths: [process.cwd()] }));
}

const Mocha = reqFromCwd('mocha');
const bdd = reqFromCwd('mocha/lib/interfaces/bdd');

function escapeRegExp(s) {
  return s.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
}

function captureLocationForFile(file, stackStartFn) {
  const err = new Error();
  if (Error.captureStackTrace) Error.captureStackTrace(err, stackStartFn);

  const lines = String(err.stack || '').split('\n').slice(1);

  // Prefer exact match for current test file (absolute/normalized path as passed by mocha)
  const fileRe = new RegExp(`\\(?(${escapeRegExp(file)}):(\\d+):(\\d+)\\)?$`);
  for (const line of lines) {
    const m = line.match(fileRe);
    if (m) return { file: m[1], line: Number(m[2]), column: Number(m[3]) };
  }

  // Fallback: any frame containing this file path
  const anyRe = /\(?(.+?):(\d+):(\d+)\)?$/;
  for (const line of lines) {
    const m = line.match(anyRe);
    if (m && m[1] && m[1].includes(file)) {
      return { file: m[1], line: Number(m[2]), column: Number(m[3]) };
    }
  }

  return { file, line: null, column: null };
}

function markTest(test, loc, pendingType) {
  if (!test) return;
  test._akLocation = loc;
  if (pendingType) test._akPendingType = pendingType; // 'todo' | 'skip'
}

function markSuite(suite, loc, pendingType) {
  if (!suite) return;
  suite._akLocation = loc;
  if (pendingType) suite._akPendingType = pendingType; // 'skip'
}

// Register custom interface name
Mocha.interfaces['bdd-with-location'] = function (suite) {
  // First install standard BDD globals
  bdd(suite);

  // Then wrap globals on pre-require (Mocha passes "file" for each loaded test file)
  suite.on('pre-require', function (context, file) {
    if (!context || !file) return;

    function loc(stackStartFn) {
      return captureLocationForFile(file, stackStartFn);
    }

    // -------------------------
    // Wrap `it`
    // -------------------------
    const origIt = context.it;

    function itWrapped(title, fn) {
      const test = origIt.call(this, title, fn);

      // "todo" detection: it('x') without a function
      const pendingType = typeof fn !== 'function' ? 'todo' : null;

      markTest(test, loc(itWrapped), pendingType);
      return test;
    }

    // Copy properties like `.only`/`.skip` added by Mocha
    Object.assign(itWrapped, origIt);

    if (typeof origIt.only === 'function') {
      itWrapped.only = function (title, fn) {
        const test = origIt.only.call(this, title, fn);
        const pendingType = typeof fn !== 'function' ? 'todo' : null;
        markTest(test, loc(itWrapped.only), pendingType);
        return test;
      };
    }

    if (typeof origIt.skip === 'function') {
      itWrapped.skip = function (title, fn) {
        const test = origIt.skip.call(this, title, fn);
        // Explicit skip
        markTest(test, loc(itWrapped.skip), 'skip');
        return test;
      };
    }

    context.it = itWrapped;
    if (context.specify) context.specify = itWrapped;

    // -------------------------
    // Wrap `describe`
    // -------------------------
    const origDescribe = context.describe;

    function describeWrapped(title, fn) {
      const s = origDescribe.call(this, title, fn);
      markSuite(s, loc(describeWrapped), null);
      return s;
    }

    Object.assign(describeWrapped, origDescribe);

    if (typeof origDescribe.only === 'function') {
      describeWrapped.only = function (title, fn) {
        const s = origDescribe.only.call(this, title, fn);
        markSuite(s, loc(describeWrapped.only), null);
        return s;
      };
    }

    if (typeof origDescribe.skip === 'function') {
      describeWrapped.skip = function (title, fn) {
        const s = origDescribe.skip.call(this, title, fn);
        // Suite skip
        markSuite(s, loc(describeWrapped.skip), 'skip');
        return s;
      };
    }

    context.describe = describeWrapped;
    if (context.context) context.context = describeWrapped;
  });
};

module.exports = Mocha.interfaces['bdd-with-location'];