switch to bech32 everywhere

You can now use @npub, @note or @nsec to reference notes and pubkeys

Changelog-Changed: use bech32 ids everywhere
Signed-off-by: William Casarin <jb55@jb55.com>

damus/Models/Post.swift

@@ -32,15 +32,76 @@ func parse_post_reference(_ p: Parser) -> ReferencedId? {
         return parse_nostr_ref_uri(p)
     }
     
-    guard let id = parse_hexstr(p, len: 64) else {
+    if let ref = parse_post_mention(p, mention_type: typ) {
+        return ref
+    }
+    
+    p.pos = start
+    
+    return nil
+}
+
+func is_bech32_char(_ c: Character) -> Bool {
+    let contains = "qpzry9x8gf2tvdw0s3jn54khce6mua7l".contains(c)
+    return contains
+}
+
+func parse_post_mention(_ p: Parser, mention_type: MentionType) -> ReferencedId? {
+    if let id = parse_hexstr(p, len: 64) {
+        return ReferencedId(ref_id: id, relay_id: nil, key: mention_type.ref)
+    } else if let bech32_ref = parse_post_bech32_mention(p) {
+        return bech32_ref
+    } else {
+        return nil
+    }
+}
+
+func parse_post_bech32_mention(_ p: Parser) -> ReferencedId? {
+    let start = p.pos
+    if parse_str(p, "note") {
+    } else if parse_str(p, "npub") {
+    } else if parse_str(p, "nsec") {
+    } else {
+        return nil
+    }
+    
+    if !parse_char(p, "1") {
         p.pos = start
         return nil
     }
     
-    return ReferencedId(ref_id: id, relay_id: nil, key: typ.ref)
+    var end = p.pos
+    if consume_until(p, match: { c in !is_bech32_char(c) }) {
+        end = p.pos
+    } else {
+        p.pos = start
+        return nil
+    }
+    
+    let sliced = String(substring(p.str, start: start, end: end))
+    guard let decoded = try? bech32_decode(sliced) else {
+        p.pos = start
+        return nil
+    }
+    
+    let hex = hex_encode(decoded.data)
+    switch decoded.hrp {
+    case "note":
+        return ReferencedId(ref_id: hex, relay_id: nil, key: "e")
+    case "npub":
+        return ReferencedId(ref_id: hex, relay_id: nil, key: "p")
+    case "nsec":
+        guard let pubkey = privkey_to_pubkey(privkey: hex) else {
+            p.pos = start
+            return nil
+        }
+        return ReferencedId(ref_id: pubkey, relay_id: nil, key: "p")
+    default:
+        p.pos = start
+        return nil
+    }
 }
 
-
 /// Return a list of tags
 func parse_post_blocks(content: String) -> [PostBlock] {
     let p = Parser(pos: 0, str: content)