module.exports = exports = build

/**
 * Module dependencies.
 */

var fs = require('graceful-fs')
  , path = require('path')
  , glob = require('glob')
  , which = require('which')
  , mkdirp = require('./util/mkdirp')
  , win = process.platform == 'win32'
  , openbsd = process.platform == 'openbsd'

exports.usage = 'Invokes `' + (win ? 'msbuild' : 'make') + '` and builds the module'

function build (gyp, argv, callback) {

  gyp.verbose('build args', argv)
  var makeCommand = openbsd ? 'gmake' : 'make'
  var command = win ? 'msbuild' : makeCommand
    , buildDir = path.resolve('build')
    , configPath = path.resolve(buildDir, 'config.gypi')
    , buildType
    , config
    , arch
    , nodeDir
    , copyDevLib

  loadConfigGypi()

  /**
   * Load the "config.gypi" file that was generated during "configure".
   */

  function loadConfigGypi () {
    fs.readFile(configPath, 'utf8', function (err, data) {
      if (err) {
        if (err.code == 'ENOENT') {
          callback(new Error('You must run `node-gyp configure` first!'))
        } else {
          callback(err)
        }
        return
      }
      config = JSON.parse(data.replace(/\#.+\n/, ''))

      // get the 'arch', 'buildType', and 'nodeDir' vars from the config
      buildType = config.target_defaults.default_configuration
      arch = config.variables.target_arch
      nodeDir = config.variables.nodedir
      copyDevLib = config.variables.copy_dev_lib == 'true'

      if ('debug' in gyp.opts) {
        buildType = gyp.opts.debug ? 'Debug' : 'Release'
      }
      if (!buildType) {
        buildType = 'Release'
      }

      gyp.verbose('build type:', buildType)
      gyp.verbose('architecture:', arch)
      gyp.verbose('node dev dir:', nodeDir)

      if (win) {
        findSolutionFile()
      } else {
        doWhich()
      }
    })
  }

  /**
   * On Windows, find the first build/*.sln file.
   */

  function findSolutionFile () {
    glob('build/*.sln', function (err, files) {
      if (err) return callback(err)
      if (files.length === 0) {
        return callback(new Error('Could not find *.sln file. Did you run "configure"?'))
      }
      guessedSolution = files[0]
      gyp.verbose('found first Solution file', guessedSolution)
      doWhich()
    })
  }

  /**
   * Uses node-which to locate the msbuild / make executable.
   */

  function doWhich () {
    // First make sure we have the build command in the PATH
    which(command, function (err, execPath) {
      if (err) {
        if (win && /not found/.test(err.message)) {
          // On windows and no 'msbuild' found. Let's guess where it is
          guessMsbuild()
        } else {
          // Some other error or 'make' not found on Unix, report that to the user
          callback(err)
        }
        return
      }
      gyp.verbose('`which` succeeded for `' + command + '`', execPath)
      copyNodeLib()
    })
  }

  /**
   * Guess the location of the "msbuild.exe" file on Windows.
   */

  function guessMsbuild () {
    gyp.verbose('could not find "msbuild.exe". guessing location')
    // This is basically just hard-coded. If this causes problems
    // then we'll think of something more clever.
    var windir = process.env.WINDIR || process.env.SYSTEMROOT || 'C:\\WINDOWS'
      , frameworkDir = path.resolve(windir, 'Microsoft.NET', 'Framework')
      , versionDir = path.resolve(frameworkDir, 'v4.0.30319') // This is probably the most brittle part...
      , msbuild = path.resolve(versionDir, 'msbuild.exe')
    fs.stat(msbuild, function (err, stat) {
      if (err) {
        if (err.code == 'ENOENT') {
          callback(new Error('Can\'t find "msbuild.exe". Do you have Microsoft Visual Studio C++ 2010 installed?'))
        } else {
          callback(err)
        }
        return
      }
      command = msbuild
      copyNodeLib()
    })
  }

  /**
   * Copies the node.lib file for the current target architecture into the
   * current proper dev dir location.
   */

  function copyNodeLib () {
    if (!win || !copyDevLib) return doBuild()

    var buildDir = path.resolve(nodeDir, buildType)
      , archNodeLibPath = path.resolve(nodeDir, arch, 'node.lib')
      , buildNodeLibPath = path.resolve(buildDir, 'node.lib')

    mkdirp(buildDir, function (err, isNew) {
      if (err) return callback(err)
      gyp.verbose('"' + buildType + '" dir needed to be created?', isNew)
      var rs = fs.createReadStream(archNodeLibPath)
        , ws = fs.createWriteStream(buildNodeLibPath)
      rs.pipe(ws)
      rs.on('error', callback)
      ws.on('error', callback)
      rs.on('end', doBuild)
    })
  }

  /**
   * Actually spawn the process and compile the module.
   */

  function doBuild () {

    // Enable Verbose build
    if (!win && gyp.opts.verbose) {
      argv.push('V=1')
    }
    if (win && !gyp.opts.verbose) {
      argv.push('/clp:Verbosity=minimal')
    }

    // Turn off the Microsoft logo on Windows
    if (win) {
      argv.push('/nologo')
    }

    // Specify the build type, Release by default
    if (win) {
      var p = arch === 'x64' ? 'x64' : 'Win32'
      argv.push('/p:Configuration=' + buildType + ';Platform=' + p)
    } else {
      argv.push('BUILDTYPE=' + buildType)
      // Invoke the Makefile in the 'build' dir.
      argv.push('-C')
      argv.push('build')
    }

    if (win) {
      // did the user specify their own .sln file?
      var hasSln = argv.some(function (arg) {
        return path.extname(arg) == '.sln'
      })
      if (!hasSln) {
        argv.unshift(gyp.opts.solution || guessedSolution)
      }
    }

    var proc = gyp.spawn(command, argv)
    proc.on('exit', onExit)
  }

  /**
   * Invoked after the make/msbuild command exits.
   */

  function onExit (code, signal) {
    if (code !== 0) {
      return callback(new Error('`' + command + '` failed with exit code: ' + code))
    }
    if (signal) {
      return callback(new Error('`' + command + '` got signal: ' + signal))
    }
    callback()
  }

}