initial: bootstrap from BukidBountyApp base

resources/js/composables/useQrph.js

@@ -0,0 +1,102 @@
+/**
+ * Client-side QRPH / EMV QRCPS utilities.
+ *
+ * All operations run in the browser — no external API calls.
+ *
+ * Exports:
+ *   parseTlv(str)                      → { tag: value, … }
+ *   buildTlv(fields)                   → EMV TLV string (sorted, CRC appended)
+ *   injectAmount(qrphStr, amount)      → new QRPH string with amount + fresh CRC
+ *   generateQrDataUrl(text, opts)      → Promise<dataURL> via qrcode library
+ */
+
+// ── CRC-16 / CCITT-FALSE (polynomial 0x1021, seed 0xFFFF) ──────────────────
+function crc16(data) {
+    let crc = 0xFFFF;
+    for (let i = 0; i < data.length; i++) {
+        crc ^= data.charCodeAt(i) << 8;
+        for (let j = 0; j < 8; j++) {
+            crc = (crc & 0x8000) ? ((crc << 1) ^ 0x1021) & 0xFFFF : (crc << 1) & 0xFFFF;
+        }
+    }
+    return crc.toString(16).toUpperCase().padStart(4, '0');
+}
+
+// ── TLV parser ──────────────────────────────────────────────────────────────
+export function parseTlv(data) {
+    const fields = {};
+    let pos = 0;
+    while (pos + 4 <= data.length) {
+        const tag = data.substring(pos, pos + 2);
+        const len = parseInt(data.substring(pos + 2, pos + 4), 10);
+        const val = data.substring(pos + 4, pos + 4 + len);
+        fields[tag] = val;
+        pos += 4 + len;
+        if (tag === '63') break;
+    }
+    return fields;
+}
+
+// ── TLV builder ─────────────────────────────────────────────────────────────
+// Reassembles fields in ascending tag order, appends a fresh CRC-16.
+function buildTlv(fields) {
+    // Sort numerically, excluding CRC (will be appended fresh)
+    const sorted = Object.keys(fields)
+        .filter(t => t !== '63')
+        .sort((a, b) => parseInt(a, 10) - parseInt(b, 10));
+
+    let body = '';
+    for (const tag of sorted) {
+        const val  = fields[tag];
+        const lpad = String(val.length).padStart(2, '0');
+        body += tag + lpad + val;
+    }
+
+    // Append CRC header then compute over the full string including header
+    const withHeader = body + '6304';
+    return withHeader + crc16(withHeader);
+}
+
+// ── Amount injector ─────────────────────────────────────────────────────────
+/**
+ * Returns a new QRPH string with field 54 (Transaction Amount) set to
+ * the given amount and a freshly computed CRC.
+ *
+ * @param {string} qrphStr  Base QRPH string (stored static QR)
+ * @param {number} amount   PHP amount, e.g. 500
+ * @returns {string}        Modified QRPH string
+ */
+export function injectAmount(qrphStr, amount) {
+    const fields = parseTlv(qrphStr);
+
+    if (!amount || amount <= 0) {
+        // Remove amount field and rebuild
+        delete fields['54'];
+    } else {
+        // EMV spec: amount as decimal string, e.g. "500.00"
+        fields['54'] = parseFloat(amount).toFixed(2);
+    }
+
+    return buildTlv(fields);
+}
+
+// ── QR image renderer ───────────────────────────────────────────────────────
+/**
+ * Renders a string as a QR code and returns a data URL (PNG).
+ *
+ * @param {string} text
+ * @param {object} opts  qrcode options (width, margin, color…)
+ * @returns {Promise<string>} data URL
+ */
+export async function generateQrDataUrl(text, opts = {}) {
+    const QRCode = (await import('qrcode')).default;
+    return QRCode.toDataURL(text, {
+        width:            opts.width   ?? 260,
+        margin:           opts.margin  ?? 2,
+        errorCorrectionLevel: opts.ecl ?? 'M',
+        color: {
+            dark:  opts.dark  ?? '#000000',
+            light: opts.light ?? '#FFFFFF',
+        },
+    });
+}