# dependencies
fs = require 'fs'
path = require 'path'
nib = require 'nib'
stylus = require 'stylus'
Asset = require('../asset').Asset
CleanCSS = require 'clean-css'

# asset
class exports.StylusAsset extends Asset
  ext: 'css'
  name: 'stylus'
  type: 'text/css'
  compile: ->

    # defaults
    @config.paths ?= []
    @config.compress = @config.compress or @config.minify

    # read source
    @read (err, source) =>
      return @emit 'error', err if err

      try

        # pre-process
        if @config.preprocess
          source = @config.preprocess source

        # compile, minify
        s = stylus(source, {
          filename: @src
          paths: @config.paths.concat [path.dirname @src]
        }).use(nib())
          .define('url', stylus.url())
          .set('compress', @config.compress)
          .set('include css', true)
        @parseVariables s, @config.vars, @config.vars_prefix

      catch err
        return @emit 'error', err if err

      s.render (err, result) =>
        return @emit 'error', err if err

        try

          # post-process
          if @config.postprocess
            result = @config.postprocess result

          # cleancss
          if @config.cleancss
            result = new CleanCSS({}).minify result

        catch err
          return @emit 'err', err if err

        # complete
        @data = result
        @emit 'compiled'

  # parse variables to enforce using proper stylus nodes
  # otherwise all variables end up as strings in the styl file
  parseVariables: (s, vars, vars_prefix="") ->
    parseColors = (colors) ->
      parse = (hex) ->
        hex = "#{hex}#{hex}" if hex.length == 1
        parseInt hex, 16

      rgba = [0, 0, 0, 255]
      rgba[index] = parse color for index, color of colors
      new stylus.nodes.RGBA rgba[0], rgba[1], rgba[2], rgba[3]/255

    for k, v of vars
      if vars_prefix
       k = "#{vars_prefix}#{k}"

      # boolean
      if v in ['true', 'false']
        s.define k, new stylus.nodes.Boolean v is 'true'

      # shorthand rgb
      else if /^#(?:([0-9a-fA-F]){3})$/.test v
        rgb = v.match /^#([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])$/
        s.define k, parseColors rgb[1..3]

      # shorthand rgba
      else if /^#(?:([0-9a-fA-F]){4})$/.test v
        rgba = v.match /^#([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])$/
        s.define k, parseColors rgb[1..4]

      # rgb
      else if /^#(?:([0-9a-fA-F]){6})$/.test v
        rgb = v.match /^#([0-9a-fA-F]{2})([0-9a-fA-F]{2})([0-9a-fA-F]{2})$/
        s.define k, parseColors rgb[1..3]

      # rgba
      else if /^#(?:([0-9a-fA-F]){8})$/.test v
        rgba = v.match /^#([0-9a-fA-F]{2})([0-9a-fA-F]{2})([0-9a-fA-F]{2})([0-9a-fA-F]{2})$/
        s.define k, parseColors rgba[1..4]

      # integer
      else if /^[0-9]+$/.test v
        s.define k, new stylus.nodes.Unit parseInt v, 10

      # literal
      else
        s.define k, new stylus.nodes.Literal v