# frozen_string_literal: true

require "braintree"
require "delegate"
require "dhall"
require "pg"
require "redis"
require "roda"

require_relative "lib/electrum"

REDIS = Redis.new
BRAINTREE_CONFIG = Dhall.load("env:BRAINTREE_CONFIG").sync
ELECTRUM = Electrum.new(
	**Dhall::Coder.load("env:ELECTRUM_CONFIG", transform_keys: :to_sym)
)

DB = PG.connect(dbname: "jmp")
DB.type_map_for_results = PG::BasicTypeMapForResults.new(DB)
DB.type_map_for_queries = PG::BasicTypeMapForQueries.new(DB)

class CreditCardGateway
	def initialize(jid, customer_id=nil)
		@jid = jid
		@customer_id = customer_id

		@gateway = Braintree::Gateway.new(
			environment: BRAINTREE_CONFIG[:environment].to_s,
			merchant_id: BRAINTREE_CONFIG[:merchant_id].to_s,
			public_key: BRAINTREE_CONFIG[:public_key].to_s,
			private_key: BRAINTREE_CONFIG[:private_key].to_s
		)
	end

	def check_customer_id(cid)
		return cid unless ENV["RACK_ENV"] == "production"

		raise "customer_id does not match" unless @customer_id == cid

		cid
	end

	def customer_id
		customer_id = REDIS.get(redis_key_jid)
		return customer_id if check_customer_id(customer_id)

		result = @gateway.customer.create
		raise "Braintree customer create failed" unless result.success?
		@customer_id = result.customer.id
		save_customer_id!
	end

	def save_customer_id!
		unless REDIS.set(redis_key_jid, @customer_id) == "OK"
			raise "Saving new jid,customer to redis failed"
		end

		unless REDIS.set(redis_key_customer_id, @jid) == "OK"
			raise "Saving new customer,jid to redis failed"
		end

		@customer_id
	end

	def client_token
		@gateway.client_token.generate(customer_id: customer_id)
	end

	def default_payment_method=(nonce)
		@gateway.payment_method.create(
			customer_id: customer_id,
			payment_method_nonce: nonce,
			options: {
				make_default: true
			}
		)
	end

protected

	def redis_key_jid
		"jmp_customer_id-#{@jid}"
	end

	def redis_key_customer_id
		"jmp_customer_jid-#{@customer_id}"
	end
end

class UnknownTransactions
	def self.from(customer_id, address, tx_hashes)
		values = tx_hashes.map do |tx_hash|
			"('#{DB.escape_string(tx_hash)}/#{DB.escape_string(address)}')"
		end
		rows = DB.exec_params(<<-SQL)
			SELECT transaction_id FROM
				(VALUES #{values.join(',')}) AS t(transaction_id)
				LEFT JOIN transactions USING (transaction_id)
			WHERE transactions.transaction_id IS NULL
		SQL
		new(customer_id, rows.map { |row| row["transaction_id"] })
	end

	def initialize(customer_id, transaction_ids)
		@customer_id = customer_id
		@transaction_ids = transaction_ids
	end

	def enqueue!
		REDIS.hset(
			"pending_btc_transactions",
			*@transaction_ids.flat_map { |txid| [txid, @customer_id] }
		)
	end
end

class JmpPay < Roda
	plugin :render, engine: "slim"
	plugin :common_logger, $stdout

	def redis_key_btc_addresses
		"jmp_customer_btc_addresses-#{request.params['customer_id']}"
	end

	def verify_address_customer_id(r)
		return if REDIS.sismember(redis_key_btc_addresses, request.params["address"])

		warn "Address and customer_id do not match"
		r.halt(
			403,
			{"Content-Type" => "text/plain"},
			"Address and customer_id do not match"
		)
	end

	route do |r|
		r.on "electrum_notify" do
			verify_address_customer_id(r)

			UnknownTransactions.from(
				request.params["customer_id"],
				request.params["address"],
				ELECTRUM
					.getaddresshistory(request.params["address"])
					.map { |item| item["tx_hash"] }
			).enqueue!

			"OK"
		end

		r.on :jid do |jid|
			r.on "credit_cards" do
				gateway = CreditCardGateway.new(
					jid,
					request.params["customer_id"]
				)

				r.get do
					view(
						"credit_cards",
						locals: {
							token: gateway.client_token,
							customer_id: gateway.customer_id
						}
					)
				end

				r.post do
					gateway.default_payment_method = request.params["braintree_nonce"]
					"OK"
				end
			end
		end
	end
end

run JmpPay.freeze.app