require 'hashie'
require 'faraday/error'
require 'rash'
require 'mtgox/connection'
require 'mtgox/request'

module MtGox
  class Client
    include MtGox::Connection
    include MtGox::Request

    ORDER_TYPES = {:sell => 1, :buy => 2}

    # Fetch the latest ticker data
    #
    # @authenticated false
    # @return [Hashie::Rash] with keys `buy` - current highest bid price, `sell` - current lowest ask price, `high` - highest price trade for the day, `low` - lowest price trade for the day, `last` - price of most recent trade, and `vol`
    # @example
    #   MtGox.ticker #=> <#Hashie::Rash buy=19.29 high=19.96 last=19.36 low=19.01 sell=19.375 vol=29470>
    def ticker
      get('/code/data/ticker.php')['ticker']
    end

    # Fetch both bids and asks in one call, for network efficiency
    #
    # @authenticated false
    # @return [Hashie::Rash] a hash with keys :asks and :bids, which contain arrays as described in #asks and #bids.
    # @example
    #   offers = MtGox.offers
    #   offers.asks[0, 3] #=> [[19.3898, 3.9], [19.4, 48.264], [19.409, 1]]
    #   offers.bids[0, 3] #=> [[19.3898, 77.42], [19.3, 3.02], [19.29, 82.378]]
    def offers
      get('/code/data/getDepth.php')
    end

    # Fetch open asks
    #
    # @authenticated false
    # @return [Array<Array<Numeric>>] in the form `[price, quantity]`, sorted in price ascending order
    # @example
    #   MtGox.asks[0, 3] #=> [[19.3898, 3.9], [19.4, 48.264], [19.409, 1]]
    def asks
      offers['asks']
    end

    # Fetch open bids
    #
    # @authenticated false
    # @return [Array<Array<Numeric>>] in the form `[price, quantity]`, sorted in price descending order
    # @example
    #   MtGox.bids[0, 3] #=> [[19.3898, 77.42], [19.3, 3.02], [19.29, 82.378]]
    def bids
      offers['bids']
    end

    # Fetch recent trades
    #
    # @authenticated false
    # @return [Array<Hashie::Rash>] an array of trades, sorted in chronological order. Each trade is a `Hashie::Rash` with keys `amount` - number of bitcoins traded, `price` - price they were traded at in US dollars, `date` - time and date of the trade (a `Time` object), and `tid` - the trade ID.
    # @example
    #   MtGox.trades[0, 3] #=> [<#Hashie::Rash amount=41 date=2011-06-14 11:26:32 -0700 price=18.5 tid="183747">, <#Hashie::Rash amount=5 date=2011-06-14 11:26:44 -0700 price=18.5 tid="183748">, <#Hashie::Rash amount=5 date=2011-06-14 11:27:00 -0700 price=18.42 tid="183749">]
    def trades
      get('/code/data/getTrades.php').each do |t|
        t['date'] = Time.at(t['date'])
      end
    end

    # Fetch your balance
    #
    # @authenticated true
    # @return [Hashie::Rash] with keys `btcs` - amount of bitcoins in your account and `usds` - amount of US dollars in your account
    # @example
    #   MtGox.balance #=> <#Hashie::Rash btcs=3.7 usds=12>
    def balance
      post('/code/getFunds.php', pass_params)
    end

    # Fetch your open orders, both buys and sells, for network efficiency
    #
    # @authenticated true
    # @return [<Hashie::Rash>] with keys `buy` and `sell`, which contain arrays as described in {MtGox::Client#buys} and {MtGox::Client#sells}
    # @example
    #   MtGox.orders[0, 3]  #=> [<#Hashie::Rash amount=0.73 dark="0" date="1307949196" oid="929284" price=2 status=:active type=2>, <#Hashie::Rash amount=0.36 dark="0" date="1307949201" oid="929288" price=4 status=:active type=2>, <#Hashie::Rash amount=0.24 dark="0" date="1307949212" oid="929292" price=6 status=:active type=2>]
    def orders
      post('/code/getOrders.php', pass_params)['orders']
    end

    # Fetch your open buys
    #
    # @authenticated true
    # @return [Array<Hashie::Rash>] an array of your open bids, sorted in price ascending order with the keys `amount`, `dark`, `date`, `oid`, `price`, `status`, and `type`
    # @example
    #   MtGox.buys[0, 3] #=> [<#Hashie::Rash amount=0.73 dark="0" date="1307949196" oid="929284" price=2 status=:active type=2>, <#Hashie::Rash amount=0.36 dark="0" date="1307949201" oid="929288" price=4 status=:active type=2>, <#Hashie::Rash amount=0.24 dark="0" date="1307949212" oid="929292" price=6 status=:active type=2>]
    def buys
      orders.select do |o|
        o['type'] == ORDER_TYPES[:buy]
      end
    end

    # Fetch your open sells
    #
    # @authenticated true
    # @return [Array<Hashie::Rash>] an array of your open asks, sorted in price ascending order with the keys `amount`, `dark`, `date`, `oid`, `price`, `status`, and `type`
    # @example
    #   MtGox.sells[0, 3] #=> [<#Hashie::Rash amount=0.1 dark="0" date="1307949384" oid="663465" price=24.92 status=nil type=1>, <#Hashie::Rash amount=0.12 dark="0" date="1307949391" oid="663468" price=25.65 status=nil type=1>, <#Hashie::Rash amount=0.15 dark="0" date="1307949396" oid="663470" price=26.38 status=nil type=1>]
    def sells
      orders.select do |o|
        o['type'] == ORDER_TYPES[:sell]
      end
    end

    # Place a limit order to buy BTC
    #
    # @authenticated true
    # @param amount [Numeric] the number of bitcoins to purchase
    # @param price [Numeric] the bid price in US dollars
    # @return [Array<Hashie::Rash>]
    # @example
    #   # Buy one bitcoin for $0.011
    #   MtGox.buy! 1.0, 0.011
    def buy!(amount, price)
      post('/code/buyBTC.php', pass_params.merge({:amount => amount, :price => price}))
    end

    # Place a limit order to sell BTC
    #
    # @authenticated true
    # @param amount [Numeric] the number of bitcoins to sell
    # @param price [Numeric] the ask price in US dollars
    # @return [Array<Hashie::Rash>]
    # @example
    #   # Sell one bitcoin for $100
    #   MtGox.sell! 1.0, 100.0
    def sell!(amount, price)
      post('/code/sellBTC.php', pass_params.merge({:amount => amount, :price => price}))
    end

    # Cancel an open order
    #
    # @authenticated true
    # @overload cancel(oid)
    #   @param oid [String] an order ID
    #   @return Array<Hashie::Rash>
    #   @example
    #     my_order = MtGox.orders.first
    #     MtGox.cancel my_order.oid
    #     MtGox.cancel 1234567890
    # @overload cancel(order)
    #   @param order [Hash] a hash-like object, with keys `oid` - the order ID of the transaction to cancel and `type` - the type of order to cancel (`1` for sell or `2` for buy)
    #   @return Array<Hashie::Rash>
    #   @example
    #     my_order = MtGox.orders.first
    #     MtGox.cancel my_order
    #     MtGox.cancel {"oid" => "1234567890", "type" => 2}
    def cancel(args)
      if args.is_a?(Hash)
        order = args.delete_if{|k, v| !['oid', 'type'].include?(k.to_s)}
        post('/code/cancelOrder.php', pass_params.merge(order))
      else
        order = orders.select{|o| o['oid'] == args.to_s}.first
        if order
          order = order.delete_if{|k, v| !['oid', 'type'].include?(k.to_s)}
          post('/code/cancelOrder.php', pass_params.merge(order))
        else
          raise Faraday::Error::ResourceNotFound, {:status => 404, :headers => {}, :body => "Order not found."}
        end
      end
    end

    # Transfer bitcoins from your Mt. Gox account into another account
    #
    # @authenticated true
    # @param amount [Numeric] the number of bitcoins to withdraw
    # @param btca [String] the bitcoin address to send to
    # @return [Array<Hashie::Rash>]
    # @example
    #   # Withdraw 1 BTC from your account
    #   MtGox.withdraw! 1.0, "1KxSo9bGBfPVFEtWNLpnUK1bfLNNT4q31L"
    def withdraw!(amount, btca)
      post('/code/withdraw.php', pass_params.merge({:group1 => "BTC", :amount => amount, :btca => btca}))
    end

    private

    def pass_params
      {:name => MtGox.name, :pass => MtGox.pass}
    end
  end
end