NIP-19 work in progress

src/Examples/bech32-encoded-entities.php

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+<?php
+
+declare(strict_types=1);
+
+require __DIR__ . '/../../vendor/autoload.php';
+
+use swentel\nostr\Key\Key;
+use swentel\nostr\Nip19\Nip19Helper;
+
+try {
+    $nip19 = new Nip19Helper(); // Helper.
+    $id = '43fb0422457c1fadec68c5ad18378abb2c626d6b787790973e888d0998f6ced4'; // This is an event hex id.
+    //$id = 'fb0422457c1fadec68c5ad18378abb2c626d6b787790973e888d0998f6ce'; // Invalid ID.
+
+    // Encode it to a bech32 encoded note ID.
+    $note = $nip19->encodeNote($id);
+    // Expected result:
+    // note1g0asggj90s06mmrgckk3sdu2hvkxymtt0pmep9e73zxsnx8kem2qulye77
+    print $note . PHP_EOL;
+
+    // Encode a profile pubkey or npub, this already works.
+    $key = new Key();
+    $pubkey = '06639a386c9c1014217622ccbcf40908c4f1a0c33e23f8d6d68f4abf655f8f71';
+    // Alternative: $npub = $key->convertPublicKeyToBech32($pubkey);
+    $npub = $nip19->encodeNpub($pubkey);
+    // Expected result:
+    // npub1qe3e5wrvnsgpggtkytxteaqfprz0rgxr8c3l34kk3a9t7e2l3acslezefe
+    print $npub . PHP_EOL;
+
+    // Using the more generic encode method
+    $note1 = $nip19->encode($id, 'note');
+    print $note1 . PHP_EOL;
+
+    // TODO:
+    // Encode to nevent with TLV data
+
+    // Encode it bech32 encoded nevent ID,
+    // $nevent = $nip19->encodeEvent($id);
+    // Expected result:
+    // nevent1qqsy87cyyfzhc8ada35vttgcx79tktrzd44hsausjulg3rgfnrmva4qey0p0j
+    // print $nevent . PHP_EOL;
+
+    // Encode to nprofile with TLV data
+
+    // Encode to naddr with TLV data
+
+    // Decode a bech32 encoded entity to an event ID.
+    $nevent = '';
+
+} catch (Exception $e) {
+    print $e->getMessage() . PHP_EOL;
+}

src/Nip19/Nip19Helper.php

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+<?php
+
+declare(strict_types=1);
+
+namespace swentel\nostr\Nip19;
+
+use BitWasp\Bech32\Exception\Bech32Exception;
+use swentel\nostr\Key\Key;
+
+use function BitWasp\Bech32\convertBits;
+use function BitWasp\Bech32\encode;
+
+/**
+ * NIP-19 bech32-encoded entities
+ *
+ * Example reference: https://github.com/nbd-wtf/go-nostr/blob/master/nip19/nip19.go
+ *
+ * https://github.com/Bit-Wasp/bech32/blob/master/src/bech32.php
+ */
+class Nip19Helper
+{
+    /**
+     * @var string $prefix
+     */
+    protected $prefix;
+
+    public function __construct() {}
+
+    public function decode(string $bech32string)
+    {
+        $length = strlen($bech32string);
+        if ($length > 90) {
+            throw new \Exception('Bech32 string cannot exceed 90 characters in length');
+        }
+        if ($length < 8) {
+            throw new \Exception('Bech32 string is too short');
+        }
+
+        //        switch ($prefix) {
+        //            case 'npub':
+        //                break;
+        //            case 'nsec':
+        //                break;
+        //            case 'note':
+        //                break;
+        //            default:
+        //                throw new \Exception('Unexpected value');
+        //        }
+    }
+
+    public function encode(string $value, string $prefix): string
+    {
+        return $this->convertToBech32($value, $prefix);
+    }
+
+    public function encodeNote(string $event_hex): string
+    {
+        return $this->convertToBech32($event_hex, 'note');
+    }
+
+    public function encodeEvent(string $event_hex): string
+    {
+        $hexInBin = hex2bin($event_hex); // Convert hex formatted string to binary string.
+        if (strlen($hexInBin) !== 32) {
+            throw new \Exception(sprintf('This is an invalid ID: %s', $event_hex));
+        }
+        // todo process TLV
+        return $this->convertToBech32($event_hex, 'nevent');
+    }
+
+    public function encodeProfile(string $profile_hex): string
+    {
+        // todo
+        return '';
+    }
+
+    public function encodeAddr(string $event_hex): string
+    {
+        // todo
+        return '';
+    }
+
+    /**
+     * @param string $pubkey
+     * @return string
+     */
+    public function encodeNpub(string $pubkey): string
+    {
+        $key = new Key();
+        return $key->convertPublicKeyToBech32($pubkey);
+    }
+
+    /**
+     * @param string $seckey
+     * @return string
+     */
+    public function encodeNsec(string $seckey): string
+    {
+        $key = new Key();
+        return $key->convertPrivateKeyToBech32($seckey);
+    }
+
+    private function convertToBech32(string $key, string $prefix): string
+    {
+        $str = '';
+
+        $dec = [];
+        $split = str_split($key, 2);
+        foreach ($split as $item) {
+            $dec[] = hexdec($item);
+        }
+        $bytes = convertBits($dec, count($dec), 8, 5);
+        $str = encode($prefix, $bytes);
+
+        return $str;
+    }
+
+    private function readTLVEntry($value) {}
+
+    private function writeTLVEntry($value, string $type) {}
+}

src/Nip19/TLVEnum.php

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+<?php
+
+declare(strict_types=1);
+
+namespace swentel\nostr\Nip19;
+
+/**
+ * Enum with TLV types.
+ */
+enum TLVEnum: int
+{
+    case TLVDefault = 0;
+    case TLVRelay   = 1;
+    case TLVAuthor  = 2;
+    case TLVKind    = 3;
+}