Updated PaymentURLDecoder to support metamask like addresses <#22>

Gem/Core/Decoder/PaymentURLDecoder.swift

@@ -2,49 +2,95 @@
 
 import Foundation
 import Primitives
+import BigInt
 
 struct Payment: Equatable {
     let address: String
     let amount: String?
     let memo: String?
+    var network: String?
 }
 
 struct PaymentURLDecoder {
+    private let chainSchemes = Chain.allCases.map({ $0.rawValue })
+
     func decode(_ string: String) throws -> Payment {
+        guard !string.isEmpty else {
+            throw AnyError("Input string is empty")
+        }
+
         let chunks = string.split(separator: ":")
-
-        // has more than an address
-        if chunks.count == 2 {
-            //TODO: Check prefix for bitcoin and other chains
-            //let _prefix = chunks[0]
-            let path = chunks[1]
-            let pathChunks = path.split(separator: "?")
-
-            if pathChunks.count == 1 {
-                return Payment(address: String(path), amount: .none, memo: .none)
-            } else if pathChunks.count == 2 {
-                // BIP21 parsing
-                let address = String(pathChunks[0])
-                let query = String(pathChunks[1])
-                let params = decodeQueryString(query)
-                let amount = params["amount"]
-                let memo = params["memo"]
-
-                return Payment(address: address, amount: amount, memo: memo)
-            } else {
-                throw AnyError("BIP21 format is incorrect")
-            }
+        guard chunks.count >= 2 else {
+            return try parseAddressAndNetwork(path: string)
+        }
+
+        let scheme = String(chunks[0])
+        guard chainSchemes.contains(scheme) else {
+            throw AnyError("Unsupported scheme: \(scheme)")
+        }
+
+        let path = String(chunks[1])
+        let pathChunks = path.split(separator: "?")
+
+        if pathChunks.count == 1 {
+            return try parseAddressAndNetwork(path: String(pathChunks[0]))
+        } else if pathChunks.count == 2 {
+            return try parseBIP21(path: String(pathChunks[0]), query: String(pathChunks[1]))
         }
-        return Payment(address: string, amount: .none, memo: .none)
+
+        throw AnyError("Invalid URL format")
     }
-
-    func decodeQueryString(_ queryString: String) -> [String: String] {
+}
+
+// MARK: - Private
+
+extension PaymentURLDecoder {
+    private func parseAddressAndNetwork(path: String) throws -> Payment {
+        let addressAndNetwork = path.split(separator: "@")
+
+        if addressAndNetwork.count == 2 {
+            let address = String(addressAndNetwork[0])
+            let networkHex = String(addressAndNetwork[1])
+            let network = BigInt(hex: networkHex)?.description
+            return Payment(address: address, amount: .none, memo: .none, network: network)
+        } else if addressAndNetwork.count == 1 {
+            return Payment(address: String(path), amount: .none, memo: .none, network: .none)
+        }
+
+        throw AnyError("Invalid address or network format")
+    }
+
+    private func parseBIP21(path: String, query: String) throws -> Payment {
+        let addressAndNetwork = path.split(separator: "@")
+        let address: String
+        let network: String?
+
+        if addressAndNetwork.count == 2 {
+            address = String(addressAndNetwork[0])
+            let networkHex = String(addressAndNetwork[1])
+            network = BigInt(hex: networkHex)?.description
+        } else {
+            address = String(addressAndNetwork[0])
+            network = .none
+        }
+
+        let params = decodeQueryString(query)
+        let amount = params["amount"]
+        let memo = params["memo"]
+
+        return Payment(address: address, amount: amount, memo: memo, network: network)
+    }
+
+    private func decodeQueryString(_ queryString: String) -> [String: String] {
         return Dictionary(
             uniqueKeysWithValues: queryString
                 .split(separator: "&")
                 .compactMap { pair in
                     let components = pair.split(separator: "=")
-                    return components.count == 2 ? (String(components[0]), String(components[1])) : nil
+                    guard components.count == 2 else { return nil }
+                    let key = String(components[0]).removingPercentEncoding ?? String(components[0])
+                    let value = String(components[1]).removingPercentEncoding ?? String(components[1])
+                    return (key, value)
                 }
         )
     }

GemTests/Core/Decoder/PaymentURLDecoderTests.swift

@@ -9,43 +9,48 @@ final class PaymentURLDecoderTests: XCTestCase {
         // Put setup code here. This method is called before the invocation of each test method in the class.
     }
 
-    func testAddress() {
-        XCTAssertEqual(
-            try! PaymentURLDecoder().decode(""),
-            Payment(address: "", amount: .none, memo: .none)
-        )
+        func testAddress() {
+            XCTAssertThrowsError(try PaymentURLDecoder().decode(""))
+            XCTAssertEqual(
+                try! PaymentURLDecoder().decode("0x1f9090aaE28b8a3dCeaDf281B0F12828e676c326"),
+                Payment(address: "0x1f9090aaE28b8a3dCeaDf281B0F12828e676c326", amount: .none, memo: .none, network: .none)
+            )
+        }
+
+    func testAddressWithNetwork() {
         XCTAssertEqual(
-            try! PaymentURLDecoder().decode("0x1f9090aaE28b8a3dCeaDf281B0F12828e676c326"),
-            Payment(address: "0x1f9090aaE28b8a3dCeaDf281B0F12828e676c326", amount: .none, memo: .none)
+            try! PaymentURLDecoder().decode("0xcB3028d6120802148f03d6c884D6AD6A210Df62A@0x38"),
+            Payment(address: "0xcB3028d6120802148f03d6c884D6AD6A210Df62A", amount: .none, memo: .none, network: "56")
         )
     }
-    
+
     func testSolana() {
         XCTAssertEqual(
             try! PaymentURLDecoder().decode("HA4hQMs22nCuRN7iLDBsBkboz2SnLM1WkNtzLo6xEDY5"),
-            Payment(address: "HA4hQMs22nCuRN7iLDBsBkboz2SnLM1WkNtzLo6xEDY5", amount: .none, memo: .none)
+            Payment(address: "HA4hQMs22nCuRN7iLDBsBkboz2SnLM1WkNtzLo6xEDY5", amount: .none, memo: .none, network: .none)
         )
         XCTAssertEqual(
             try! PaymentURLDecoder().decode("solana:HA4hQMs22nCuRN7iLDBsBkboz2SnLM1WkNtzLo6xEDY5?amount=0.266232"),
-            Payment(address: "HA4hQMs22nCuRN7iLDBsBkboz2SnLM1WkNtzLo6xEDY5", amount: "0.266232", memo: .none)
+            Payment(address: "HA4hQMs22nCuRN7iLDBsBkboz2SnLM1WkNtzLo6xEDY5", amount: "0.266232", memo: .none, network: .none)
         )
     }
 
     func testBIP21() {
         XCTAssertEqual(
             try! PaymentURLDecoder().decode("bitcoin:bc1pn6pua8a566z7t822kphpd2el45ntm23354c3krfmpe3nnn33lkcskuxrdl?amount=0.00001"),
-            Payment(address: "bc1pn6pua8a566z7t822kphpd2el45ntm23354c3krfmpe3nnn33lkcskuxrdl", amount: "0.00001", memo: .none)
+            Payment(address: "bc1pn6pua8a566z7t822kphpd2el45ntm23354c3krfmpe3nnn33lkcskuxrdl", amount: "0.00001", memo: .none, network: .none)
         )
 
         XCTAssertEqual(
             try! PaymentURLDecoder().decode("ethereum:0xA20d8935d61812b7b052E08f0768cFD6D81cB088?amount=0.01233&memo=test"),
-            Payment(address: "0xA20d8935d61812b7b052E08f0768cFD6D81cB088", amount: "0.01233", memo: "test")
+            Payment(address: "0xA20d8935d61812b7b052E08f0768cFD6D81cB088", amount: "0.01233", memo: "test", network: .none)
         )
 
         XCTAssertEqual(
             try! PaymentURLDecoder().decode("solana:3u3ta6yXYgpheLGc2GVF3QkLHAUwBrvX71Eg8XXjJHGw?amount=0.42301"),
-            Payment(address: "3u3ta6yXYgpheLGc2GVF3QkLHAUwBrvX71Eg8XXjJHGw", amount: "0.42301", memo: .none)
+            Payment(address: "3u3ta6yXYgpheLGc2GVF3QkLHAUwBrvX71Eg8XXjJHGw", amount: "0.42301", memo: .none, network: .none)
         )
+
         XCTAssertEqual(
             try! PaymentURLDecoder().decode("ton:EQAzoUpalAaXnVm5MoiYWRZguLFzY0KxFjLv3MkRq5BXzyiQ?amount=0.00001"),
             Payment(address: "EQAzoUpalAaXnVm5MoiYWRZguLFzY0KxFjLv3MkRq5BXzyiQ", amount: "0.00001", memo: .none)