module Scide

  # Scide configuration for one project.
  class Project

    # The project key in the projects configuration hash.
    attr_reader :key

    # The path where the project is located. See {#initialize}.
    attr_reader :path

    # Project-specific options. Can be used by commands. See {#initialize}.
    attr_reader :options

    # The GNU Screen windows of this project.
    attr_reader :windows

    # The name or index of the window that should be displayed by default for
    # this project (defaults to the last window).
    attr_reader :default_window

    # Returns a project configuration.
    #
    # If not given in the project hash, {#path} is built by joining
    # the global path and <tt>key</tt>.
    #
    # == Arguments
    # * <tt>global</tt> - The global configuration.
    # * <tt>key</tt> - The key identifying the project. This is the
    #   key in the projects hash.
    # * <tt>contents</tt> - The project hash.
    #
    # == Project Options
    #
    # {#options} is built by merging the options given in the project
    # hash with the global options.
    #
    # The following default options are added if not given:
    # * <tt>name</tt> - Defaults to the project key.
    # * <tt>path</tt> - The path where the project is located.
    def initialize global, key, contents
      raise ArgumentError, "project '#{key}' must be a hash" unless contents.kind_of? Hash
      raise ArgumentError, "windows of project '#{key}' must be an array" unless contents[:windows].kind_of?(Array)
      raise ArgumentError, "options of project '#{key}' must be a hash" unless contents[:options].nil? or contents[:options].kind_of?(Hash)

      @key = key

      # path defaults to project key
      @path = contents[:path].try(:to_s) || key.to_s
      unless path.match /^\//
        # if not absolute
        if global.path
          # expand from global directory
          @path = File.join global.path, @path
        else
          # or from home directory
          @path = File.join File.expand_path('~'), @path
        end
      end

      @options = global.options.dup
      @options[:name] = key
      @options[:path] = @path
      @options.merge!(contents[:options] || {})

      @windows = contents[:windows].collect{ |w| Scide::Window.new self, w }

      # find default window if specified
      @default_window = if contents[:default_window].kind_of? Fixnum
        @windows[contents[:default_window]]
      elsif contents[:default_window].kind_of?(String) or contents[:default_window].kind_of?(Symbol)
        @windows.find{ |w| w.name == contents[:default_window].to_s }
      elsif !contents[:default_window].nil?
        raise ArgumentError, "default window of project '#{key}' should be an integer, string or symbol"
      end
      raise ArgumentError, "default window of project '#{key}' must be the name or index of one of its windows" if !contents[:default_window].nil? and @default_window.nil?
    end

    # Returns a representation of this project as a GNU Screen
    # configuration fragment. Returns nil if this project has
    # no configured windows.
    def to_screen
      return nil if @windows.blank?
      String.new.tap do |s|
        @windows.each_with_index do |w,i|
          s << w.to_screen(i)
          s << "\n" if i != (@windows.length - 1)
        end
        s << "\nselect #{@default_window.name}" if @default_window
      end
    end
  end
end