require 'picsolve_docker_builder/base'
require 'picsolve_docker_builder/helpers/config/variable_object'
require 'picsolve_docker_builder/composer/container'

module PicsolveDockerBuilder
  module Helpers
    # Parses the config file
    class ConfigManager
      include PicsolveDockerBuilder::Base
      def initialize(paths, stage)
        if paths.is_a?(Array)
          @paths = paths
        else
          @paths = [paths]
        end

        # TODO: Do this properly, this is a very very dirty hack
        stage = (
          !ENV['STAGE'].nil? &&
          ENV['STAGE'].downcase
        ) || 'ci' if stage.nil?
        @stage = stage
      end

      def default
        {}
      end

      def config
        return @config unless @config.nil?
        read
        parse_variables
      end

      def eval_container_config(config)
        # eval environment if key exits
        config['environment'] = eval_container_env(config['environment']) \
          if config.key? 'environment'
        config
      end

      def eval_container_env_split(env)
        output = {}
        env.each do |key, lst|
          output[key] = {}
          lst.each do |elem|
            ikey, val = elem.split('=', 2)
            output[key][ikey] = val
          end
        end
        output
      end

      def eval_container_env(env)
        env = eval_container_env_split(env)
        output = {}
        output = output.update(env['default']) if env.key?('default')
        output = output.update(env[@stage]) if env.key?(@stage)
        output
      end

      def containers(composer)
        config['compose']['containers'].map do |name, raw_config|
          PicsolveDockerBuilder::Composer::Container.new(
            name,
            eval_container_config(raw_config),
            composer
          )
        end
      end

      def parse_variables
        parse_variables_real(@config)
      end

      def parse_variables_real(obj)
        if obj.is_a?(Hash)
          obj.each do |k, v|
            obj[k] = parse_variables_real(v)
          end
        elsif obj.is_a?(Array)
          obj.map do |v|
            parse_variables_real(v)
          end
        elsif obj.is_a?(String)
          Config::VariableObject.replace_string(obj)
        else
          obj
        end
      end

      def read
        @config = default
        @paths.each do |file|
          begin
            yaml = Psych.load_file file
            @config = @config.deep_merge(yaml)
          rescue Errno::ENOENT
            raise "cannot find config at '#{file}'"
          end
        end
      end
    end
  end
end