lib.rb

# frozen_string_literal: true

class BitfexApi
  class AuthError < StandardError; end

  # @param server_url [String] URL of the main server
  def initialize(server_url: "https://bitfex.trade")
    @_server_url = server_url
  end

  # @return [String] URL of the server
  def server_url
    @_server_url
  end

  # @param url [String] set URL of the server
  def server_url=(url)
    @_server_url = url
  end

  # Get token for API operations
  # @param email [String] email
  # @param password [String] password
  def auth(email, password)
    body = request_post("/auth", auth: { email: email, password: password })
    return @token = body["jwt"] if body["jwt"]
    raise AuthError.new
  end

  # Return account balances
  # @return [Hash<String, Fixnum>] balances
  def balances
    response = request_get("/api/v1/user")
    raise StandardError.new(response["errors"].to_json) unless response["success"]
    response["balances"]
  end

  # Return list of orders for all pairs
  # @return [Array<Hash>] list of orders (id, pair, amount, price, operation, completed, updated)
  def orders_list
    response = request_get("/api/v1/orders")
    raise StandardError.new(response["errors"].to_json) unless response["success"]
    response["orders"]
  end

  # Return list of my orders
  # @return [Array<Hash>] list of my orders (id, pair, amount, price, operation, completed, updated)
  def my_orders
    response = request_get("/api/v1/orders/my")
    raise StandardError.new(response["errors"].to_json) unless response["success"]
    response["orders"]
  end

  # Delete order by id
  # @param id [Fixnum] order ID
  # @return TrueClass
  # @raise StandardError(error json) if response not success
  def delete_order(id)
    response = request_delete("/api/v1/orders/#{id}")
    raise StandardError.new(response["errors"].to_json) unless response["success"]
    true
  end

  # Create new order
  # @param operation [String] operation - one of (buy/sell)
  # @param pair [String] pair (like BTC_RUR)
  # @param amount [Decimal] amount in normal units (roubles or bitcoins)
  # @param price [Decimal] price in normal units (roubles or bitcoins)
  def create_order(operation, pair, amount, price)
    response = request_post(
      "/api/v1/orders",
      order: {
        pair: pair,
        operation: operation,
        amount: amount,
        price: price
      }
    )
    raise StandardError.new(response["error"].to_json) unless response["success"]

    true
  end

  attr_reader :btc_rate, :token, :my_orders_list, :balance

  private

  def request_post(endpoint, body)
    request(endpoint, Net::HTTP::Post, body)
  end

  def request_delete(endpoint, body = nil)
    request(endpoint, Net::HTTP::Delete, body)
  end

  def request_get(endpoint)
    request(endpoint, Net::HTTP::Get)
  end

  def request(endpoint, klass, body = nil)
    url = @_server_url + endpoint
    uri = URI.parse(url)
    http = Net::HTTP.new(uri.host, uri.port)
    http.use_ssl = uri.port == 443

    request = klass.new(uri.request_uri, "Content-Type" => "application/json")

    request.add_field("Authorization", "Bearer #{token}") if token
    request.body = JSON.dump(body) if body
    response = http.request(request)
    JSON.parse(response.body || "{}")
  end
end