require 'active_support/core_ext/string/inflections'
require 'active_support/core_ext/hash/slice'

module HerokuSan
  class Project
    attr_reader :config_file
  
    include Git
    
    def initialize(config_file, options = {})
      @apps = []
      @config_file = config_file
      @app_settings = {}
      config = parse(@config_file)
      config.each do |stage, settings|
        # TODO: Push this eval later (j.i.t.)
        @app_settings[stage] = HerokuSan::Stage.new(stage, settings.merge(options.slice(:deploy)))
      end
    end

    def create_config
      # TODO: Convert true/false returns to success/exception
      template = File.expand_path(File.join(File.dirname(__FILE__), '../templates', 'heroku.example.yml'))
      if File.exists?(@config_file)
        false
      else
        FileUtils.cp(template, @config_file)
        true
      end
    end
  
    def all
      @app_settings.keys
    end
  
    def [](stage)
      @app_settings[stage]
    end
  
    def <<(*app)
      app.flatten.each do |a|
        @apps << a if all.include?(a)
      end
      self
    end
  
    def apps
      if @apps.present?
        @apps
      else
        @apps = if all.size == 1
          $stdout.puts "Defaulting to #{all.first.inspect} since only one app is defined"
          all
        else
          active_branch = self.git_active_branch
          all.select do |app| 
            app == active_branch and ($stdout.puts("Defaulting to '#{app}' as it matches the current branch") || true)
          end
        end
      end
    end
  
    def each_app
      raise NoApps if apps.empty?
      apps.each do |stage|
        yield(self[stage])
      end
    end
    
  private
    
    def parse_yaml(config_file)
      if File.exists?(config_file)
        if defined?(ERB)
          YAML.load(ERB.new(File.read(config_file)).result)
        else
          YAML.load_file(config_file)
        end
      else
        {}
      end
    end
  
    def parse(config_file)
      app_settings = parse_yaml(config_file)
    
      # support heroku_san format
      if app_settings.has_key? 'apps'
        app_settings = app_settings['apps']
        app_settings.each_pair do |stage, app_name|
          app_settings[stage] = {'app' => app_name}
        end
      end
    
      # load external config
      if (config_repo = app_settings.delete('config_repo'))
        require 'tmpdir'
        tmp_config_dir = Dir.mktmpdir
        tmp_config_file = File.join tmp_config_dir, 'config.yml'
        git_clone(config_repo, tmp_config_dir)
        extra_config = parse_yaml(tmp_config_file)
      else
        extra_config = {}
      end
    
      # make sure each app has a 'config' section & merge w/extra
      app_settings.keys.each do |name|
        app_settings[name] ||= {}
        app_settings[name]['config'] ||= {}
        app_settings[name]['config'].merge!(extra_config[name]) if extra_config[name]
      end  
    
      app_settings  
    end
  end
end