import { HexMix } from "/utils";

/**
 * Initializes the send page functionality.
 * This function sets up event listeners and handles the form submission process.
 */
export function initializeSendPage() {
  const copyButton = document.getElementById("copyButton");
  const fileInput = document.getElementById("file");
  const form = document.getElementById("secretForm");
  const resultInput = document.getElementById("result");
  const encryptedDataTextarea = document.getElementById("encryptedData");

  /**
   * Copies the result URL to the clipboard.
   */
  copyButton.addEventListener("click", async () => {
    resultInput.select();
    await navigator.clipboard.writeText(resultInput.value);
    alert("URL copied to clipboard!");
  });

  /**
   * Toggles the text input based on file selection.
   * @param {Event} e - The change event.
   */
  fileInput.addEventListener("change", (e) => {
    const file = e.target.files[0];
    document.getElementById("text").disabled = !!file;
  });

  /**
   * Handles the form submission.
   * @param {Event} e - The submit event.
   */
  form.addEventListener("submit", async (e) => {
    e.preventDefault();

    const formData = new FormData(form);
    const text = formData.get("text");
    const file = formData.get("file");
    const serviceIdentifier = formData.get("serviceIdentifier");
    const service = formData.get("service");

    let plaintext = text;
    let filetype = "text/plain";
    let filename = "secret.txt";

    if (file.size > 0) {
      if (file.size > 2097152) {
        alert("Error: Max file size is 2mb.");
        return;
      }
      plaintext = await file.arrayBuffer();
      filetype = file.type;
      filename = file.name;
    }

    /**
     * Generates a new AES-GCM key.
     * @type {CryptoKey}
     */
    const key = await window.crypto.subtle.generateKey({ name: "AES-GCM", length: 256 }, true, ["encrypt", "decrypt"]);

    const iv = window.crypto.getRandomValues(new Uint8Array(16));
    const exported = await window.crypto.subtle.exportKey("raw", key);

    /**
     * Encrypts the plaintext.
     * @type {ArrayBuffer}
     */
    const encrypted = await window.crypto.subtle.encrypt(
      { name: "AES-GCM", iv },
      key,
      typeof plaintext === "string" ? HexMix.stringToArrayBuffer(plaintext) : plaintext
    );

    // Convert the encrypted ArrayBuffer to a Base64 string
    const encryptedBase64 = HexMix.arrayBufferToBase64(encrypted);
    encryptedDataTextarea.value = encryptedBase64;

    const keyHex = HexMix.uint8ToHex(new Uint8Array(exported));
    const ivHex = HexMix.uint8ToHex(iv);
    const keyParams = { key: keyHex, iv: ivHex };

    const params = JSON.stringify({
      service: service,
      serviceIdentifier: serviceIdentifier,
      text: encryptedBase64,
      iv: ivHex,
      filetype: filetype,
      filename: filename
    });

    try {
      const response = await fetch("/rest/links", {
        method: "POST",
        headers: {
          "Content-Type": "application/json"
        },
        body: params
      });
      const data = await response.json();
      const url = `http://${window.location.host}/rest/links/${data.id}#${btoa(JSON.stringify(keyParams))}`;
      resultInput.value = url;
    } catch (err) {
      alert(`Error: ${err.message}`);
    }
  });
}