/**
 * Form-Widget bootstrap loader (Phase 05 Task #58).
 *
 * Tenants embed this on their site with:
 *
 *   <script src="https://<host>/embed/widget.js" data-form-key="abc123"
 *           data-host="https://forms.example.com"
 *           async></script>
 *
 * The loader:
 *  1. Reads `data-form-key` and optional `data-host` from its own <script> tag.
 *  2. Inserts a sandboxed <iframe> pointing at `<host>/embed/forms/<formKey>`.
 *  3. Listens for postMessage events from the iframe:
 *     - `tcform:resize` -> updates iframe height for dynamic content
 *     - `tcform:submitted` / `tcform:error` -> re-emits as
 *       CustomEvents on document for parent-site code to listen on.
 *
 * Build-target: hand-crafted minified ES5-compatible JS in
 * `apps/web/public/embed/widget.js`. This file is the readable source
 * kept for documentation + tests. Keep both in sync.
 */

(function () {
  if (typeof window === "undefined" || typeof document === "undefined") return;
  const script = (document.currentScript as HTMLScriptElement | null) ?? findSelf();
  if (!script) return;

  const formKey = script.getAttribute("data-form-key");
  if (!formKey) return;

  const explicitHost = script.getAttribute("data-host");
  const defaultHost = new URL(script.src).origin;
  const host = explicitHost ?? defaultHost;

  const iframe = document.createElement("iframe");
  iframe.src = host + "/embed/forms/" + encodeURIComponent(formKey) + "?origin=" + encodeURIComponent(location.origin);
  iframe.setAttribute("title", "Form");
  iframe.setAttribute("loading", "lazy");
  iframe.setAttribute("sandbox", "allow-scripts allow-forms allow-same-origin");
  iframe.style.cssText = "border:0;width:100%;min-height:200px;max-width:100%;display:block";

  const parent = script.parentNode;
  if (!parent) return;
  parent.insertBefore(iframe, script.nextSibling);

  window.addEventListener("message", (event) => {
    if (event.source !== iframe.contentWindow) return;
    const data = event.data;
    if (!data || typeof data !== "object" || typeof data.type !== "string") return;
    if (data.type === "tcform:resize" && typeof data.height === "number") {
      iframe.style.height = Math.max(100, Math.min(8000, data.height)) + "px";
      return;
    }
    if (data.type === "tcform:submitted" || data.type === "tcform:error") {
      document.dispatchEvent(new CustomEvent(data.type, { detail: data }));
    }
  });

  function findSelf(): HTMLScriptElement | null {
    const scripts = document.getElementsByTagName("script");
    for (let i = scripts.length - 1; i >= 0; i--) {
      const s = scripts[i];
      if (s.src && s.src.indexOf("/embed/widget.js") !== -1) return s;
    }
    return null;
  }
})();