module TxCatcher

  VERSION = File.read(File.expand_path('../../', File.dirname(__FILE__)) + '/VERSION')

  class << self
    attr_accessor :db_connection, :rpc_node, :current_block_height, :config_dir
  end

  module Initializer

    GEM_ROOT = File.expand_path('../..', File.dirname(__FILE__))
    MIGRATIONS_ROOT = GEM_ROOT + '/db/migrations/'

    module ConfigFile

      class << self

        # Determine config dir or set default. Useful when we want to
        # have different settings for production or staging or development environments.
        def set!(path=nil)
          @@config_file = path and return if path
          @@config_file = ENV['HOME'] + '/.txcatcher/config.yml'
          ARGV.each_with_index do |a,i|
            if a =~ /\A--config-file=.+/
              @@config_file = File.expand_path(a.sub('--config-file=', ''))
              ARGV.delete_at(i)
              break
            elsif a =~ /\A-c\Z/
              @@config_file = File.expand_path(ARGV[1])
              ARGV.delete_at(i) and ARGV.delete_at(i+1)
              break
            end
          end
          TxCatcher::Config.config_dir = File.dirname(@@config_file)
          puts "Using config file: #{@@config_file}"
        end

        def path
          @@config_file
        end

      end

    end

    def prepare
      ConfigFile.set!
      create_config_files
      read_config_file
      connect_to_db
      connect_to_rpc_node
      run_migrations if migrations_pending?
      set_server_port
    end

    def add_route(path, &block)
      @routes[path] = block
    end

    def create_config_files
      FileUtils.mkdir_p(ConfigFile.path) unless File.exist?(ConfigFile.path)

      unless File.exist?(ConfigFile.path)
        puts "\e[1;33mWARNING!\e[0m \e[33mNo file #{ConfigFile.path} was found. Created a sample one for you.\e[0m"
        puts "You should edit it and try starting the server again.\n"

        FileUtils.cp(GEM_ROOT + '/templates/config.yml', ConfigFile.path)
        config_contents = File.read(ConfigFile.path)
        config_contents.sub!("$home", File.expand_path('~'))
        File.open(ConfigFile.path, "w") { |f| f.write(config_contents) }
        puts "Shutting down now.\n\n"
        exit
      end

    end

    def read_config_file
      YAML.load_file(ConfigFile.path).each do |k,v|
        TxCatcher::Config.send(k + '=', v)
      end
    end

    def set_server_port
      # Setting default port to 9498
      unless ARGV.include?("-p")
        ARGV.push "-p"
        if Config.server_port
          ARGV.push Config.server_port.to_s
        else
          ARGV.push "9498"
        end
      end
    end

    def connect_to_db

      # symbolize keys for convenience
      db_config = TxCatcher::Config.db.keys_to_sym

      db_name = if db_config[:adapter] == 'sqlite'
        if db_config[:db_path].start_with?("/")
          db_config[:db_path]
        else
          "#{File.dirname(ConfigFile.path)}/#{db_config[:db_path]}"
        end
      else
        db_config[:db_name]
      end

      TxCatcher.db_connection = Sequel.connect(
        "#{db_config[:adapter]}://"                                                   +
        "#{db_config[:user]}#{(":" if db_config[:user])}"                             +
        "#{db_config[:password]}#{("@" if db_config[:user] || db_config[:password])}" +
        "#{db_config[:host]}#{(":" if db_config[:port])}"                             +
        "#{db_config[:port]}#{("/" if db_config[:host] || db_config[:port])}"         +
        "#{db_name}"
      )
    end

    # Connects to all bitcoin daemons listed in config
    def connect_to_rpc_node
      n = TxCatcher::Config.rpcnode
      print "Checking #{n["name"]} RPC connection... "
      TxCatcher.rpc_node = BitcoinRPC.new("http://#{n["user"]}:#{n["password"]}@#{n["host"]}:#{n["port"]}")
      
      i = 0 # try to connect to RPC 100 times before exiting with error
      until TxCatcher.current_block_height
        begin
          TxCatcher.current_block_height = TxCatcher.rpc_node.getblockcount
        rescue Errno::ECONNREFUSED, BitcoinRPC::JSONRPCError => e
          if i > 100
            print "ERROR, cannot connect using connection data #{n["name"]}\n"
            exit
          else
            print "Bitcoin RPC connection error: #{e.to_s}; will try again in 1 sec...\n"
            i += 1
            sleep 1
          end
        end
      end
      print "current block height: #{TxCatcher.current_block_height}\n"
    end

    def run_migrations
      Sequel.extension :migration
      print "\nPending migrations for the database detected. Migrating..."
      Sequel::Migrator.run(TxCatcher.db_connection, MIGRATIONS_ROOT)
      print "done\n\n"
    end

    def migrations_pending?
      !Sequel::Migrator.is_current?(TxCatcher.db_connection, MIGRATIONS_ROOT)
    end

  end

end