require 'middleman-core'
require 'middleman-webp/logger'
require 'middleman-webp/converter'

require 'shell'

module Middleman
  class WebPExtension < Extension
    option(:conversion_options, {},
           'Custom conversion options for cwebp/gif2webp')
    option(:append_extension, false,
           'keep the original filename and extension and append .webp (image.png => image.png.webp)')
    option(:ignore, [], 'Ignores files with matching paths')
    option(:verbose, false, 'Display all external command which are executed '\
           'to help debugging.')
    option(:allow_skip, true, 'Skip saving .webp files which are larger than their source')
    option(:run_before_build, false, 'Run before build and save .webp files in source dir')

    def initialize(app, options_hash = {}, &block)
      super
      @app = app
    end

    def before_build(builder)
      return unless options[:run_before_build]

      initialize_logger builder
      return unless dependencies_installed?
      Middleman::WebP::Converter.new(@app, options, builder, @logger).convert
    end

    def after_build(builder)
      return if options[:run_before_build]

      initialize_logger builder
      return unless dependencies_installed?
      Middleman::WebP::Converter.new(@app, options, builder, @logger).convert
    end

    # Internal: Check that cwebp and gif2webp commandline tools are available.
    #
    # Returns true if all is OK.
    def dependencies_installed?
      warn_if_gif2webp_missing
      cwebp_installed?
    end

    def initialize_logger(builder)
      @logger = Middleman::WebP::Logger.new(builder, verbose: @options.verbose)
    end

    private

    def warn_if_gif2webp_missing
      Shell.new.find_system_command('gif2webp')
    rescue Shell::Error::CommandNotFound => e
      @logger.error "#{e.message} Please install latest version of webp library and tools to get gif2webp and be able to convert gif files also."
    end

    def cwebp_installed?
      true if Shell.new.find_system_command('cwebp')
    rescue Shell::Error::CommandNotFound => e
      @logger.error "ERROR: #{e.message} Please install cwebp and gif2webp commandline tools first."
      false
    end
  end
end