#!/usr/bin/env node

var path = require('path');
var fs = require('fs');
var resolve = require('resolve');

var NODE_PATH = process.env.NODE_PATH;

// This wrapper only resolves which instance of Karma should be run.
// All the logic is in the main Karma module.
// The resolving algorithm checks (in this order):
//   - a local module (using `require`, so it will traverse up, looking for `node_modules/karma`),
//   - a siblink module to karma-cli (that loads the global karma, when using NVM),
//   - a global module (NODE_PATH)


var requireCliAndRun = function(karmaPath) {
  if (process.argv.indexOf('--which') !== -1) {
    console.log(karmaPath);
  } else {
    require(karmaPath + '/lib/cli').run();
  }
};

resolve('karma', {basedir: process.cwd()}, function(err, pathToKarma) {
  // There is a local version, let's use it.
  if (!err) {
    return requireCliAndRun(pathToKarma.replace(/\/lib\/index\.js/, ''));
  }

  // We can't load a global one, since NODE_PATH is not defined.
  if (!NODE_PATH) {
    // Let's try a siblink to karma-cli, that is a global module with NVM.
    var siblinkKarma = path.normalize(__dirname + '/../../karma');
    if (fs.existsSync(siblinkKarma)) {
      return requireCliAndRun(siblinkKarma);
    }

    console.error('Cannot find local Karma!\n' +
                  '  Please install Karma by `npm install karma --save-dev`.\n' +
                  '  If you wanna use a global instance, please set NODE_PATH env variable.\n');
    return;
  }

  // Let's try global paths.
  var globalPaths = NODE_PATH.split(path.delimiter);
  var globalKarma;

  while (globalPaths.length) {
    globalKarma = path.normalize(globalPaths.shift() + '/karma');
    if (fs.existsSync(globalKarma)) {
      return requireCliAndRun(globalKarma);
    }
  }

  console.error('Cannot find local Karma!\n' +
                '  Please install karma by `npm install karma --save-dev`.\n');
});