# frozen_string_literal: true

module Peatio
  module Ndc
    # TODO: Processing of unconfirmed transactions from mempool isn't supported now.
    class Blockchain < Peatio::Blockchain::Abstract
      DEFAULT_FEATURES = {case_sensitive: true, cash_addr_format: false}.freeze

      def initialize(custom_features={})
        @features = DEFAULT_FEATURES.merge(custom_features).slice(*SUPPORTED_FEATURES)
        @settings = {}
      end

      def configure(settings={})
        # Clean client state during configure.
        @client = nil
        @settings.merge!(settings.slice(*SUPPORTED_SETTINGS))
      end

      def fetch_block!(block_number)
        block_hash = client.json_rpc(:getblockhash, [block_number])

        block_txs = client.json_rpc(:getblock, [block_hash, 2])
                          .fetch("tx").each_with_object([]) do |tx, txs_array|
          txs = build_transaction(tx).map do |ntx|
            Peatio::Transaction.new(ntx.merge(block_number: block_number))
          end
          txs_array.append(*txs)
        end

        Peatio::Block.new(block_number, block_txs)
      rescue Client::Error => e
        raise Peatio::Blockchain::ClientError, e
      end

      def latest_block_number
        client.json_rpc(:getblockcount)
      rescue Client::Error => e
        raise Peatio::Blockchain::ClientError, e
      end

      def load_balance_of_address!(address, _currency_id)
        address_with_balance = client.json_rpc(:listaddressgroupings)
                                     .flatten(1)
                                     .find {|addr| addr[0] == address }

        raise Peatio::Blockchain::UnavailableAddressBalanceError, address if address_with_balance.blank?

        address_with_balance[1].to_d
      rescue Client::Error => e
        raise Peatio::Blockchain::ClientError, e
      end

      private

      def filter_vout(tx_hash)
        tx_hash.fetch("vout").select do |entry|
          entry.fetch("value").to_d.positive? && entry["scriptPubKey"].has_key?("addresses")
        end
      end

      def build_transaction(tx_hash)
        filter_vout(tx_hash).each_with_object([]) do |entry, formatted_txs|
          no_currency_tx = {hash: tx_hash["txid"], txout: entry["n"],
                            to_address: entry["scriptPubKey"]["addresses"][0],
                            amount: entry.fetch("value").to_d,
                            status: "success"}

          # Build transaction for each currency belonging to blockchain.
          settings_fetch(:currencies).pluck(:id).each do |currency_id|
            formatted_txs << no_currency_tx.merge(currency_id: currency_id)
          end
        end
      end

      def client
        @client ||= Client.new(settings_fetch(:server))
      end

      def settings_fetch(key)
        @settings.fetch(key) { raise Peatio::Blockchain::MissingSettingError, key.to_s }
      end
    end
  end
end