fs             = require "fs"
gulp           = require "gulp"
gulpCoffee     = require "gulp-coffee"
gulpSourcemaps = require "gulp-sourcemaps"
path           = require "path"

log         = require "../../lib/log"
diskWatcher = require "../../lib/disk-watcher"

module.exports = (coffeeProjectOptions) ->
	options             = coffeeProjectOptions.coffee
	enabled             = options.enabled
	sourceDirectoryPath = path.resolve options.sourceDirectoryPath
	targetDirectoryPath = path.resolve options.targetDirectoryPath
	watchEnabled        = coffeeProjectOptions.watch.enabled
	isProduction        = process.env.NODE_ENV is "production"
	noSourcemaps        = if isProduction then true else (not not options.noSourcemaps)

	gulp.task "coffee:watch", (cb) ->
		unless enabled and watchEnabled
			log.info "Skipping browserify:watch: Disabled."
			return cb()

		log.debug "[coffee:watch] Source directory path: `#{sourceDirectoryPath}`."
		log.debug "[coffee:watch] Target directory path: `#{targetDirectoryPath}`."

		compilePath = (sourcePath) ->
			coffeeCompiler = gulpCoffee bare: true

			coffeeCompiler.on "error", log.error.bind log

			sourceDirectory = path.dirname sourcePath
			targetDirectory = sourceDirectory.replace sourceDirectoryPath, targetDirectoryPath

			s = gulp.src sourcePath
			s = s.pipe gulpSourcemaps.init() unless noSourcemaps
			s = s.pipe coffeeCompiler
			s = s.pipe gulpSourcemaps.write() unless noSourcemaps

			s.pipe gulp.dest targetDirectory

		removePath = (sourcePath) ->
			targetPath = sourcePath
				.replace sourceDirectoryPath, targetDirectoryPath
				.replace ".coffee", ".js"

			fs.unlink targetPath, (error) ->
				log.error error if error

		watcher = diskWatcher(coffeeProjectOptions).src()

		watcher.on "change", (filePath) ->
			return unless filePath.match /\.coffee$/
			return unless filePath.match new RegExp sourceDirectoryPath
			log.info "[coffee:watch] Compiling `#{filePath}`."
			compilePath filePath

		watcher.on "add", (filePath) ->
			return unless filePath.match /\.coffee$/
			return unless filePath.match new RegExp sourceDirectoryPath
			log.info "[coffee:watch] Compiling `#{filePath}`."
			compilePath filePath

		watcher.on "unlink", (filePath) ->
			return unless filePath.match /\.coffee$/
			return unless filePath.match new RegExp sourceDirectoryPath
			log.info "[coffee:watch] Removing `#{filePath}`."
			removePath filePath

		return