require "option_parser"

module Guff
  class Config
    DEFAULTS = {
      "host":         "localhost",
      "port":         "8989",
      "data":         "./data",
      "public":       "./public",
      "environment":  "development",
    }

    DIRS = %w{
      data
      public
    }

    def initialize(app, args)
      @data = defaults
      parse_args(app, args)
    end

    def [](key : String) : String
      @data[key]
    end

    def []=(key : String, val : String | Nil) : String
      @data[key] = val
    end

    private def defaults : Hash(String, String)
      DEFAULTS.merge(DEFAULTS.keys.reduce({} of String => String) do |r, key|
        env_key = "GUFF_" + key.upcase
        r[key] = ENV[env_key] if ENV.has_key?(env_key)
        r
      end)
    end

    private def parse_args(app, args)
      OptionParser.parse(args) do |p|
        p.on(
          "-h HOST",
          "--host HOST",
          "Host (defaults to \"localhost\")."
        ) do |host|
          self["host"] = host
        end

        p.on(
          "-p PORT",
          "--port PORT",
          "Port (defaults to 8989)."
        ) do |port|
          self["port"] = port
        end

        p.on(
          "-d PATH",
          "--data-dir PATH",
          "Path to data directory (defaults to \"./data\")."
        ) do |path|
          self["data"] = path
        end
        
        p.on(
          "-u PATH",
          "--public-dir PATH",
          "Path to public directory (defaults to \"./public\")."
        ) do |path|
          self["public"] = path
        end

        p.on(
          "-e ENV",
          "--environment ENV",
          "Environment (defaults to \"development\")."
        ) do |path|
          self["public"] = path
        end


        p.on(
          "--help",
          "Print usage"
        ) do 
          puts p.to_s
          exit 0
        end
      end

      # expand output directory paths and create them
      %w{data public}.each do |key|
        self[key] = File.expand_path(File.join(File.dirname(app), self[key]))
        # puts "DEBUG: %s: %s" % [key, self[key]]
        Dir.mkdir(self[key], 0o770) unless File.directory?(self[key])
      end
    end
  end
end