1# frozen_string_literal: true
 2
 3require "bigdecimal"
 4require "json"
 5require "net/http"
 6require "securerandom"
 7
 8class Electrum
 9	def initialize(rpc_uri:, rpc_username:, rpc_password:)
10		@rpc_uri = URI(rpc_uri)
11		@rpc_username = rpc_username
12		@rpc_password = rpc_password
13	end
14
15	def getaddresshistory(address)
16		rpc_call(:getaddresshistory, address: address)["result"]
17	end
18
19	def gettransaction(tx_hash)
20		Transaction.new(self, tx_hash, rpc_call(
21			:deserialize,
22			[rpc_call(:gettransaction, txid: tx_hash)["result"]]
23		)["result"])
24	end
25
26	def get_tx_status(tx_hash)
27		rpc_call(:get_tx_status, txid: tx_hash)["result"]
28	end
29
30	class Transaction
31		def initialize(electrum, tx_hash, tx)
32			@electrum = electrum
33			@tx_hash = tx_hash
34			@tx = tx
35		end
36
37		def confirmations
38			@electrum.get_tx_status(@tx_hash)["confirmations"]
39		end
40
41		def amount_for(*addresses)
42			BigDecimal.new(
43				@tx["outputs"]
44					.select { |o| addresses.include?(o["address"]) }
45					.map { |o| o["value_sats"] }
46					.sum
47			) * 0.00000001
48		end
49	end
50
51protected
52
53	def rpc_call(method, params)
54		JSON.parse(post_json(
55			jsonrpc: "2.0",
56			id: SecureRandom.hex,
57			method: method.to_s,
58			params: params
59		).body)
60	end
61
62	def post_json(data)
63		req = Net::HTTP::Post.new(@rpc_uri, "Content-Type" => "application/json")
64		req.basic_auth(@rpc_username, @rpc_password)
65		req.body = data.to_json
66		Net::HTTP.start(
67			@rpc_uri.hostname,
68			@rpc_uri.port,
69			use_ssl: @rpc_uri.scheme == "https"
70		) do |http|
71			http.request(req)
72		end
73	end
74end