import { apiInitializer } from "discourse/lib/api";
import { ajax } from "discourse/lib/ajax";

const URL_REGEX = /^(https?:\/\/[^\s/$.?#][^\s]*)$/i;

const STRINGS = {
  bar_label: "URL detected — import as article?",
  fetch_button: "Import Article",
  onebox_button: "Use Onebox",
  dismiss: "Dismiss",
  fetching: "Fetching…",
  success: "Article imported!",
  error_generic: "Unknown error",
  error_prefix: "Error:",
  source_label: "Source",
  retry_button: "Retry",
};

export default apiInitializer("1.8.0", (api) => {
  if (!api.container.lookup("service:site-settings").bookmark_url_enabled) {
    return;
  }

  let titleInputEl = null;
  let titlePasteHandler = null;
  let pendingUrl = null;

  // ---- Bar UI -------------------------------------------------------

  function showArticleBar(url) {
    hideArticleBar();

    const bar = document.createElement("div");
    bar.className = "bookmark-url-bar";
    bar.innerHTML = `
      <span class="bookmark-url-icon">📄</span>
      <span class="bookmark-url-label">${STRINGS.bar_label}</span>
      <button class="btn btn-small btn-primary bookmark-url-btn">
        ${STRINGS.fetch_button}
      </button>
      <button class="btn btn-small btn-default bookmark-url-onebox-btn">
        ${STRINGS.onebox_button}
      </button>
      <button class="btn btn-small btn-flat bookmark-url-dismiss"
        aria-label="${STRINGS.dismiss}">✕</button>
    `;

    bar.querySelector(".bookmark-url-btn").addEventListener("click", () => {
      fetchAndPopulate(url);
    });

    bar.querySelector(".bookmark-url-onebox-btn").addEventListener("click", () => {
      hideArticleBar();
      commitUrlToModel();
    });

    bar.querySelector(".bookmark-url-dismiss").addEventListener("click", () => {
      hideArticleBar();
      pendingUrl = null;
    });

    const container = document.querySelector(".d-editor-container");
    if (container) {
      container.parentElement.insertBefore(bar, container);
    } else {
      document
        .querySelector(".composer-fields")
        ?.insertAdjacentElement("afterbegin", bar);
    }
  }

  function hideArticleBar() {
    document
      .querySelectorAll(".bookmark-url-bar")
      .forEach((el) => el.remove());
  }

  function setStatus(message, type = "info") {
    const bar = document.querySelector(".bookmark-url-bar");
    if (!bar) return;
    let status = bar.querySelector(".bookmark-url-status");
    if (!status) {
      status = document.createElement("span");
      status.className = "bookmark-url-status";
      bar.appendChild(status);
    }
    status.textContent = message;
    status.className = `bookmark-url-status bookmark-url-status--${type}`;
  }

  // Release the URL into Ember's data-binding so Discourse handles it normally
  function commitUrlToModel() {
    const input = titleInputEl;
    const url = pendingUrl;
    if (!input || !url) return;
    input.value = url;
    input.dispatchEvent(new Event("input", { bubbles: true }));
    pendingUrl = null;
  }

  // ---- Fetch & populate ---------------------------------------------

  async function fetchAndPopulate(url) {
    const bar = document.querySelector(".bookmark-url-bar");
    const btn = bar?.querySelector(".bookmark-url-btn");

    if (btn) {
      btn.disabled = true;
      btn.textContent = STRINGS.fetching;
    }
    setStatus(STRINGS.fetching, "info");

    try {
      const data = await ajax("/bookmark-url/extract", {
        type: "POST",
        data: { url },
      });

      if (data.error) throw new Error(data.error);

      populateComposer(data);
      setStatus(STRINGS.success, "success");
      setTimeout(() => hideArticleBar(), 3000);
    } catch (err) {
      const msg =
        err.jqXHR?.responseJSON?.error ||
        err.message ||
        STRINGS.error_generic;
      setStatus(`${STRINGS.error_prefix} ${msg}`, "error");
      if (btn) {
        btn.disabled = false;
        btn.textContent = STRINGS.retry_button;
      }
    }
  }

  function populateComposer(data) {
    const composerService = api.container.lookup("service:composer");
    const composerModel = composerService?.model;
    if (!composerModel) return;

    const lines = [];
    const siteName = data.site_name ? `**${data.site_name}**` : "";
    const byline = data.byline ? ` — *${data.byline}*` : "";
    if (siteName || byline) {
      lines.push(`> ${siteName}${byline}`);
      lines.push(`> ${STRINGS.source_label}: <${data.url}>`);
      lines.push("");
    } else {
      lines.push(`> ${STRINGS.source_label}: <${data.url}>`);
      lines.push("");
    }

    if (data.description) {
      lines.push(`*${data.description}*`);
      lines.push("");
      lines.push("---");
      lines.push("");
    }

    lines.push(data.markdown || "");

    composerModel.set("title", data.title || pendingUrl || "");
    composerModel.set("reply", lines.join("\n"));
    pendingUrl = null;

    if (titleInputEl) {
      titleInputEl.value = composerModel.get("title");
    }
  }

  // ---- Title paste interception -------------------------------------
  // capture:true so our handler runs before Discourse's, then
  // preventDefault + stopImmediatePropagation so Discourse never sees
  // the paste event — no title lookup, no onebox race.

  function attachTitlePasteListener(attempts = 0) {
    const input = document.querySelector("#reply-title");
    if (input) {
      titleInputEl = input;
      titlePasteHandler = (e) => {
        const text = (e.clipboardData || window.clipboardData)
          .getData("text/plain")
          .trim();
        if (!URL_REGEX.test(text)) return;

        e.preventDefault();
        e.stopImmediatePropagation();

        // Show URL in the field visually without going through Ember binding
        input.value = text;
        pendingUrl = text;
        showArticleBar(text);
      };
      input.addEventListener("paste", titlePasteHandler, true);
    } else if (attempts < 15) {
      setTimeout(() => attachTitlePasteListener(attempts + 1), 200);
    }
  }

  function detachTitlePasteListener() {
    if (titleInputEl && titlePasteHandler) {
      titleInputEl.removeEventListener("paste", titlePasteHandler, true);
    }
    titleInputEl = null;
    titlePasteHandler = null;
    pendingUrl = null;
    hideArticleBar();
  }

  // ---- Composer lifecycle -------------------------------------------

  api.onAppEvent("composer:opened", () => {
    attachTitlePasteListener();
  });

  api.onAppEvent("composer:closed", () => {
    detachTitlePasteListener();
  });
});