docs: add complex multi-keychain example

Author: thunderbiscuit

examples/multi_keychain_wallet.rs

@@ -0,0 +1,128 @@
+use bitcoin::Network;
+use miniscript::descriptor::DescriptorType;
+use bdk_wallet::keyring::KeyRing;
+use bdk_wallet::Wallet;
+// The KeyRing holds a map of keychain identifiers (`K`) to public descriptors. These keychain
+// identifiers can be simple (something like the `DescriptorId` or the `KeychainKind` types work
+// well, e.g. see the `simple_keyring.rs` example), but they can also be more complex if required by
+// the application. This example shows how the keychain identifier can be used to carry metadata
+// about the descriptors, which could be used to select which keychain to use in different scenarios
+// when calling methods like `Wallet::reveal_next_address`.
+
+// In this example, Johnny has a lot of keychains he keeps track of in his wallet. The map of
+// KeychainIdentifier -> Descriptor uses keys that are custom-made at the application layer, and
+// useful for its business logic (for example, choose a weekend keychain when Johnny is out partying
+// on the weekend).
+
+// The application creates a helper structure that returns the keychain identifier Johnny wants
+// to use in certain situations (party keychain on the weekend, donation keychain when people donate
+// to his open source project, default keychain otherwise).
+
+const DESC_1: &str = "tr([5bc5d243/86'/1'/0']tpubDC72NVP1RK5qwy2QdEfWphDsUBAfBu7oiV6jEFooHP8tGQGFVUeFxhgZxuk1j6EQRJ1YsS3th2RyDgReRqCL4zqp4jtuV2z7gbiqDH2iyUS/0/*)#xh44xwsp";
+const DESC_2: &str = "wpkh([5bc5d243/84'/1'/0']tpubDCA4DcMLVSDifbfUxyJaVVAx57ztsVjke6DRYF95jFFgJqvzA9oENovVd7n34NNURmZxFNRB1VLGyDEqxvaZNXie3ZroEGFbeTS2xLYuaN1/0/*)#q8afsa3z";
+const DESC_3: &str = "pkh([5bc5d243/44'/1'/0']tpubDDNQtvd8Sg1mXtSGtxRWEcgg7PbPwUSAyAmBonDSL3HLuutthe54Yih4XDYcywVdcduwqaQonpbTAGjjSh5kcLeCj5MTjYooa9ve2Npx6ho/1/*)#g73kgtdn";
+const DESC_4: &str = "tr([5bc5d243/86'/1'/0']tpubDC72NVP1RK5qwy2QdEfWphDsUBAfBu7oiV6jEFooHP8tGQGFVUeFxhgZxuk1j6EQRJ1YsS3th2RyDgReRqCL4zqp4jtuV2z7gbiqDH2iyUS/42/42)";
+const DESC_5: &str = "sh(wpkh([5bc5d243/49'/1'/0']tpubDDd6eupua2nhRp2egUAgYGjkxHeh5jPrBDaKLExeySwRvUb1hU7s8osoeACRhXs2w1UGZSMmEpZ1FkjYJ2Pxvfsy7w6XRqYYW7Vw89Unrzr/0/*))#svvvc6el";
+
+fn main() {
+    let keychain_1 = KeychainId {
+        number: 1,
+        nickname: "Johnny's favorite keychain",
+        script_type: DescriptorType::Tr,
+        color: Color::Blue,
+        time_of_week_keychain: DayType::WeekDay,
+    };
+    let keychain_2 = KeychainId {
+        number: 2,
+        nickname: "Johnny's party keychain",
+        script_type: DescriptorType::Wpkh,
+        color: Color::Green,
+        time_of_week_keychain: DayType::WeekEnd,
+    };
+    let keychain_3 = KeychainId {
+        number: 3,
+        nickname: "Johnny's old P2PKH keychain",
+        script_type: DescriptorType::Pkh,
+        color: Color::Blue,
+        time_of_week_keychain: DayType::AnyDay,
+    };
+    let keychain_4 = KeychainId {
+        number: 4,
+        nickname: "Johnny's project donations keychain",
+        script_type: DescriptorType::Tr,
+        color: Color::Yellow,
+        time_of_week_keychain: DayType::AnyDay,
+    };
+    let keychain_5 = KeychainId {
+        number: 5,
+        nickname: "The secret keychain",
+        script_type: DescriptorType::ShWpkh,
+        color: Color::Blue,
+        time_of_week_keychain: DayType::AnyDay,
+    };
+
+    let mut keyring: KeyRing<KeychainId> = KeyRing::new(Network::Signet, keychain_1, DESC_1);
+    keyring.add_descriptor(keychain_2, DESC_2, false);
+    keyring.add_descriptor(keychain_3, DESC_3, false);
+    keyring.add_descriptor(keychain_4, DESC_4, false);
+    keyring.add_descriptor(keychain_5, DESC_5, false);
+
+    // DESC_1 is the default keychain (the first one added to the keyring is automatically the
+    // default keychain), but this can also be changed later on with the KeyRing::set_default_keychain
+    // API. This default keychain is useful because you can use APIs like
+    // `Wallet::reveal_next_default_address()` which will always work with your default keychain.
+
+    let mut wallet = Wallet::new(keyring);
+
+    let address1 = wallet.reveal_next_default_address();
+    println!("Default keychain address: {}", address1.address);
+
+    let party_address = wallet.reveal_next_address(keychain_2).unwrap();
+    println!("Party address:            {}", party_address.address);
+
+    let donation_address = wallet.reveal_next_address(keychain_4).unwrap();
+    println!("Donation address:         {}", donation_address.address);
+}
+
+#[derive(Debug, Clone, Copy)]
+struct KeychainId {
+    number: u32,
+    nickname: &'static str,
+    script_type: DescriptorType,
+    color: Color,
+    time_of_week_keychain: DayType,
+}
+
+impl PartialEq for KeychainId {
+    fn eq(&self, other: &Self) -> bool {
+        self.number == other.number
+    }
+}
+
+impl Eq for KeychainId {}
+
+impl PartialOrd for KeychainId {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for KeychainId {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        self.number.cmp(&other.number)
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+enum Color {
+    Blue,
+    Green,
+    Yellow,
+}
+
+#[derive(Debug, Clone, Copy)]
+enum DayType {
+    AnyDay,
+    WeekDay,
+    WeekEnd,
+}