#!/usr/bin/env node

var path = require('path')
var fs = require('fs')
var resolve = require('resolve')
var info = require('../lib/log')

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)

// TODO(vojta): remove once we don't care about Karma 0.10
var karmaCliRun = function (karmaCli, karmaPath) {
  var config = karmaCli.process()

  switch (config.cmd) {
    case 'start':
      require(path.join(karmaPath, 'lib', 'server')).start(config)
      break
    case 'run':
      require(path.join(karmaPath, 'lib', 'runner')).run(config)
      break
    case 'init':
      require(path.join(karmaPath, 'lib', 'init')).init(config)
      break
    case 'completion':
      require(path.join(karmaPath, 'lib', 'completion')).completion(config)
      break
  }
}

var requireCliAndRun = function (karmaPath) {
  if (process.argv.indexOf('--which') !== -1) {
    info.log(karmaPath)
  } else {
    var karmaCli = require(path.join(karmaPath, 'lib', 'cli'))

    if (karmaCli.run) {
      karmaCli.run()
    } else {
      karmaCliRun(karmaCli, karmaPath)
    }
  }
}

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(path.join(__dirname, '..', '..', 'karma'))
    if (fs.existsSync(siblinkKarma)) {
      return requireCliAndRun(siblinkKarma)
    }

    info.fatal('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', 1)
    return
  }

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

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

  info.fatal('Cannot find local Karma!\n' +
    '  Please install karma by `npm install karma --save-dev`.\n', 1)
})