module Ethereum
  class Client

    DEFAULT_GAS_LIMIT = 4_000_000

    DEFAULT_GAS_PRICE = 22_000_000_000

    # https://github.com/ethereum/wiki/wiki/JSON-RPC
    RPC_COMMANDS = %w(web3_clientVersion web3_sha3 net_version net_peerCount net_listening eth_protocolVersion eth_syncing eth_coinbase eth_mining eth_hashrate eth_gasPrice eth_accounts eth_blockNumber eth_getBalance eth_getStorageAt eth_getTransactionCount eth_getBlockTransactionCountByHash eth_getBlockTransactionCountByNumber eth_getUncleCountByBlockHash eth_getUncleCountByBlockNumber eth_getCode eth_sign eth_sendTransaction eth_sendRawTransaction eth_call eth_estimateGas eth_getBlockByHash eth_getBlockByNumber eth_getTransactionByHash eth_getTransactionByBlockHashAndIndex eth_getTransactionByBlockNumberAndIndex eth_getTransactionReceipt eth_getUncleByBlockHashAndIndex eth_getUncleByBlockNumberAndIndex eth_getCompilers eth_compileLLL eth_compileSolidity eth_compileSerpent eth_newFilter eth_newBlockFilter eth_newPendingTransactionFilter eth_uninstallFilter eth_getFilterChanges eth_getFilterLogs eth_getLogs eth_getWork eth_submitWork eth_submitHashrate db_putString db_getString db_putHex db_getHex shh_post shh_version shh_newIdentity shh_hasIdentity shh_newGroup shh_addToGroup shh_newFilter shh_uninstallFilter shh_getFilterChanges shh_getMessages)

    # https://github.com/ethereum/go-ethereum/wiki/Management-APIs
    RPC_MANAGEMENT_COMMANDS = %w(admin_addPeer admin_datadir admin_nodeInfo admin_peers admin_setSolc admin_startRPC admin_startWS admin_stopRPC admin_stopWS debug_backtraceAt debug_blockProfile debug_cpuProfile debug_dumpBlock debug_gcStats debug_getBlockRlp debug_goTrace debug_memStats debug_seedHash debug_setHead debug_setBlockProfileRate debug_stacks debug_startCPUProfile debug_startGoTrace debug_stopCPUProfile debug_stopGoTrace debug_traceBlock debug_traceBlockByNumber debug_traceBlockByHash debug_traceBlockFromFile debug_traceTransaction debug_verbosity debug_vmodule debug_writeBlockProfile debug_writeMemProfile miner_hashrate miner_makeDAG miner_setExtra miner_setGasPrice miner_start miner_startAutoDAG miner_stop miner_stopAutoDAG personal_importRawKey personal_listAccounts personal_lockAccount personal_newAccount personal_unlockAccount personal_sendTransaction txpool_content txpool_inspect txpool_status)

    attr_accessor :command, :id, :log, :logger, :default_account, :gas_price, :gas_limit

    def initialize(log = false)
      @id = 0
      @log = log
      @batch = nil
      @formatter = Ethereum::Formatter.new
      @gas_price = DEFAULT_GAS_PRICE
      @gas_limit = DEFAULT_GAS_LIMIT
      if @log == true
        @logger = Logger.new("/tmp/ethereum_ruby_http.log")
      end
    end

    def self.create(host_or_ipcpath, log = false)
      return IpcClient.new(host_or_ipcpath, log) if host_or_ipcpath.end_with? '.ipc'
      return HttpClient.new(host_or_ipcpath, log) if host_or_ipcpath.start_with? 'http'
      raise ArgumentError.new('Unable to detect client type')
    end

    def batch
      @batch = []

      yield
      result = send_batch(@batch)

      @batch = nil
      reset_id

      return result
    end

    def get_id
      @id += 1
      return @id
    end

    def reset_id
      @id = 0
    end

    def default_account
      @default_account ||= eth_accounts["result"][0]
    end

    def int_to_hex(p)
      p.is_a?(Integer) ? "0x#{p.to_s(16)}" : p 
    end

    def encode_params(params)
      params.map(&method(:int_to_hex))
    end

    def get_balance(address)
      eth_get_balance(address)["result"].to_i(16)
    end

    def get_chain
      @net_version ||= net_version["result"].to_i
    end

    def get_nonce(address)
      eth_get_transaction_count(address, "pending")["result"].to_i(16)
    end
    

    def transfer_to(address, amount)
      eth_send_transaction({to: address, value: int_to_hex(amount)})
    end

    def transfer_to_and_wait(address, amount)
      wait_for(transfer_to(address, amount)["result"])
    end


    def transfer(key, address, amount)
      Eth.configure { |c| c.chain_id = net_version["result"].to_i }
      args = { 
        from: key.address,
        to: address,
        value: amount,
        data: "",
        nonce: get_nonce(key.address),
        gas_limit: gas_limit,
        gas_price: gas_price
      }
      tx = Eth::Tx.new(args)
      tx.sign key
      eth_send_raw_transaction(tx.hex)["result"]
    end
    
    def transfer_and_wait(key, address, amount)
      return wait_for(transfer(key, address, amount))
    end
    
    def wait_for(tx)
      transaction = Ethereum::Transaction.new(tx, self, "", [])
      transaction.wait_for_miner
      return transaction
    end

    def send_command(command,args)
      if ["eth_getBalance", "eth_call"].include?(command)
        args << "latest"
      end

      payload = {jsonrpc: "2.0", method: command, params: encode_params(args), id: get_id}
      @logger.info("Sending #{payload.to_json}") if @log
      if @batch
        @batch << payload
        return true
      else
        output = JSON.parse(send_single(payload.to_json))
        @logger.info("Received #{output.to_json}") if @log
        reset_id
        raise IOError, output["error"]["message"] if output["error"]
        return output
      end
    end

    (RPC_COMMANDS + RPC_MANAGEMENT_COMMANDS).each do |rpc_command|
      method_name = rpc_command.underscore
      define_method method_name do |*args|
        send_command(rpc_command, args)
      end
    end

  end

end

