Feat: Migrate dash logic to TypeScript

Co-authored-by: gemini-3.7-flash <noreply@google.com>

dash.ts

@@ -0,0 +1,57 @@
+import zwus from 'zwus';
+import * as speck48_96ctr from './speck48_96ctr.js';
+import * as speck32_64ecb from './speck32_64ecb.js';
+
+type Cipher = 'PLAIN' | 'SPECK48_96CTR' | 'SPECK32_64ECB (insecure)';
+type Op = 'NO' | 'YES';
+type Transform = (ptStr: string, base: string, kStr: string) => string;
+
+const textarea = document.getElementById('textarea') as HTMLTextAreaElement;
+const encoderDropdown = document.getElementById('encoder') as HTMLSelectElement;
+const cipherDropdown = document.getElementById('cipher') as HTMLSelectElement;
+document.getElementById('encodeButton')?.addEventListener('click', ACT);
+document.getElementById('decodeButton')?.addEventListener('click', ACT);
+
+const DESCRY: Record<Op, Record<Cipher, Transform>> = {
+    NO: {
+        PLAIN: (ptStr, base) => zwus.encodeString(ptStr, base),
+        SPECK48_96CTR: (ptStr, base, kStr) =>
+            zwus.encodeNumberArray(speck48_96ctr.encrypt(ptStr, speck48_96ctr.getKey(kStr)), base),
+        'SPECK32_64ECB (insecure)': (ptStr, base, kStr) =>
+            zwus.encodeNumberArray(speck32_64ecb.encrypt(ptStr, speck32_64ecb.getKey(kStr)), base),
+    },
+    YES: {
+        PLAIN: (ptStr, base) => zwus.decodeToString(ptStr, base),
+        SPECK48_96CTR: (ptStr, base, kStr) =>
+            speck48_96ctr.decrypt(zwus.decodeToNumberArray(ptStr, base), speck48_96ctr.getKey(kStr)),
+        'SPECK32_64ECB (insecure)': (ptStr, base, kStr) =>
+            speck32_64ecb.decrypt(zwus.decodeToNumberArray(ptStr, base), speck32_64ecb.getKey(kStr)),
+    }
+};
+
+function ACT(event: MouseEvent): void {
+    if (!textarea.value) {
+        textarea.value = 'The text box is empty.';
+        return;
+    }
+
+    const op: Op = (event.target as HTMLElement).id === 'encodeButton' ? 'NO' : 'YES';
+    const cipher = cipherDropdown.value as Cipher;
+    const base = encoderDropdown.value.split('-')[1];
+    const needsKey = cipher !== 'PLAIN';
+    const kStr = needsKey ? prompt('enter password.') : '';
+
+    if (needsKey && !kStr) return;
+
+    try {
+        textarea.value = DESCRY[op][cipher](textarea.value, base, kStr || '');
+    } catch (e) {
+        console.error(e);
+    }
+
+    if (op === 'NO') {
+        textarea.select();
+        document.execCommand('copy');
+        textarea.value = `Copied to your clipboard.\n A copy has been placed between these brackets [${textarea.value}]`;
+    }
+}