module Teamocil
  # This class act as a wrapper around a tmux YAML layout file.
  class Layout

    # Initialize a new layout from a file
    #
    # @param file [String] the complete layout file path
    # @param options [Hash]
    def initialize(file, options) # {{{
      @layout = YAML.load_file(file)
      @options = options
    end # }}}

    # Generate commands and sends them to tmux
    def to_tmux # {{{
      commands = generate_commands
      execute_commands(commands)
    end # }}}

    # Generate tmux commands based on the data found in the layout file
    def generate_commands # {{{
      output = []

      if @layout["session"].nil?
        windows = @layout["windows"]
      else
        output << "tmux rename-session #{@layout["session"]["name"]}" if @layout["session"]["name"]
        windows = @layout["session"]["windows"]
      end

      windows.each_with_index do |window, window_index|

        # Create a new window unless we used the `--here` option
        if @options.include?(:here) and window_index == 0
          output << "tmux rename-window \"#{window["name"]}\""
        else
          output << "tmux new-window -n \"#{window["name"]}\""
        end

        # Make sure our filters return arrays
        window["filters"] ||= {}
        window["filters"]["before"] ||= []
        window["filters"]["after"] ||= []
        window["filters"]["before"] = [window["filters"]["before"]] unless window["filters"]["before"].is_a? Array
        window["filters"]["after"] = [window["filters"]["after"]] unless window["filters"]["after"].is_a? Array

        # Create splits
        window["splits"].each_with_index do |split, index|
          unless index == 0
            if split.include?("width")
              cmd = "tmux split-window -h -p #{split["width"]}"
            elsif split.include?("height")
              cmd = "tmux split-window -p #{split["height"]}"
            else
              cmd = "tmux split-window"
            end
            cmd << " -t #{split["target"]}" if split.include?("target")
            output << cmd
          end

          # Support single command splits, but treat it as an array nevertheless
          split["cmd"] = [split["cmd"]] unless split["cmd"].is_a? Array

          # Wrap all commands around filters
          split["cmd"] = window["filters"]["before"] + split["cmd"] + window["filters"]["after"]

          # If a `root` key exist, start each split in this directory
          split["cmd"] = ["cd \"#{window["root"]}\""] + split["cmd"] if window.include?("root")

          # Execute each split command
          split["cmd"].compact.each do |command|
            output << "tmux send-keys -t #{index} \"#{command}\""
            output << "tmux send-keys -t #{index} Enter"
          end
        end

      end

      output << "tmux select-pane -t 0"
    end # }}}

    # Execute each command in the shell
    #
    # @param commands [Array] an array of complete commands to send to the shell
    def execute_commands(commands) # {{{
      `#{commands.join("; ")}`
    end # }}}

  end
end