From c1152ce43054d59e0aed8487c043d1c4bc369bf1 Mon Sep 17 00:00:00 2001
From: w3irdrobot <dro@w3ird.tech>
Date: Wed, 21 Dec 2022 14:44:50 -0500
Subject: [PATCH] improvement(NIP-19): identify and parse NIP-19 addresses

---
 Cargo.lock      |  7 +++++++
 Cargo.toml      |  1 +
 src/hexrange.rs | 11 +++++------
 src/utils.rs    | 29 +++++++++++++++++++++++++++++
 4 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 3a21c24..356a5c7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -280,6 +280,12 @@ version = "0.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a4a4ddaa51a5bc52a6948f74c06d20aaaddb71924eab79b8c97a8c556e942d6a"
 
+[[package]]
+name = "bech32"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d86b93f97252c47b41663388e6d155714a9d0c398b99f1005cbc5f978b29f445"
+
 [[package]]
 name = "bitcoin_hashes"
 version = "0.10.0"
@@ -1531,6 +1537,7 @@ dependencies = [
  "anyhow",
  "async-std",
  "async-trait",
+ "bech32",
  "bitcoin_hashes",
  "chrono",
  "clap",
diff --git a/Cargo.toml b/Cargo.toml
index b67aa2e..35ef257 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -48,6 +48,7 @@ sqlx = { version ="0.6.2", features=["runtime-tokio-rustls", "postgres", "chrono
 chrono = "0.4.23"
 prometheus = "0.13.3"
 indicatif = "0.17.3"
+bech32 = "0.9.1"
 
 [dev-dependencies]
 anyhow = "1"
diff --git a/src/hexrange.rs b/src/hexrange.rs
index b0566ff..3020faa 100644
--- a/src/hexrange.rs
+++ b/src/hexrange.rs
@@ -1,5 +1,5 @@
 //! Utilities for searching hexadecimal
-use crate::utils::is_hex;
+use crate::utils::{is_hex};
 use hex;
 
 /// Types of hexadecimal queries.
@@ -20,15 +20,14 @@ fn is_all_fs(s: &str) -> bool {
 
 /// Find the next hex sequence greater than the argument.
 #[must_use] pub fn hex_range(s: &str) -> Option<HexSearch> {
-    // handle special cases
-    if !is_hex(s) || s.len() > 64 {
+    let mut hash_base = s.to_owned();
+    if !is_hex(&hash_base) || hash_base.len() > 64 {
         return None;
     }
-    if s.len() == 64 {
-        return Some(HexSearch::Exact(hex::decode(s).ok()?));
+    if hash_base.len() == 64 {
+        return Some(HexSearch::Exact(hex::decode(&hash_base).ok()?));
     }
     // if s is odd, add a zero
-    let mut hash_base = s.to_owned();
     let mut odd = hash_base.len() % 2 != 0;
     if odd {
         // extend the string to make it even
diff --git a/src/utils.rs b/src/utils.rs
index 6eff34d..92ca8d0 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -1,4 +1,5 @@
 //! Common utility functions
+use bech32::FromBase32;
 use std::time::SystemTime;
 
 /// Seconds since 1970.
@@ -14,6 +15,17 @@ use std::time::SystemTime;
     s.chars().all(|x| char::is_ascii_hexdigit(&x))
 }
 
+/// Check if string is a nip19 string
+pub fn is_nip19(s: &str) -> bool {
+    s.starts_with("npub") || s.starts_with("note")
+}
+
+pub fn nip19_to_hex(s: &str) -> Result<String, bech32::Error> {
+    let (_hrp, data, _checksum) = bech32::decode(s)?;
+    let data = Vec::<u8>::from_base32(&data)?;
+    Ok(hex::encode(data))
+}
+
 /// Check if a string contains only lower-case hex chars.
 #[must_use] pub fn is_lower_hex(s: &str) -> bool {
     s.chars().all(|x| {
@@ -30,4 +42,21 @@ mod tests {
         let hexstr = "abcd0123";
         assert_eq!(is_lower_hex(hexstr), true);
     }
+
+    #[test]
+    fn nip19() {
+        let hexkey = "3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d";
+        let nip19key = "npub180cvv07tjdrrgpa0j7j7tmnyl2yr6yr7l8j4s3evf6u64th6gkwsyjh6w6";
+        assert_eq!(is_nip19(hexkey), false);
+        assert_eq!(is_nip19(nip19key), true);
+    }
+
+    #[test]
+    fn nip19_hex() {
+        let nip19key = "npub180cvv07tjdrrgpa0j7j7tmnyl2yr6yr7l8j4s3evf6u64th6gkwsyjh6w6";
+        let expected = "3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d";
+        let got = nip19_to_hex(nip19key).unwrap();
+
+        assert_eq!(expected, got);
+    }
 }