import { createSpace, el } from "./shared/ui.js";
import { callRest } from "./shared/api-client.js";
import { ENDPOINTS, siteUrl } from "./shared/config.js";

const TOOL_KEY = "screenshot";
const API_PATH = ENDPOINTS[TOOL_KEY].apiPath; // "/api/v1/screenshot"
const FULL_TOOL_URL = siteUrl(ENDPOINTS[TOOL_KEY].fullToolPath); // mesmer.tools/api-tools/screenshot

// Allowed dimension ranges (validated client-side before the API call).
const WIDTH = { min: 320, max: 1920, default: 1280 };
const HEIGHT = { min: 240, max: 1080, default: 720 };

const space = createSpace({
  toolKey: TOOL_KEY,
  emoji: "📸",
  title: "Free Website Screenshot API",
  subtitle: "Capture a screenshot of any website URL as an image. Paste a link, pick a size, get a JPG — free, no signup.",
  intro: "Turn any URL into an image right from your browser. Great for previews, thumbnails, and link cards.",
});

/* --- Form ----------------------------------------------------------------- */

const urlInput = el("input", {
  className: "ms-input",
  type: "url",
  id: "url",
  name: "url",
  required: "",
  placeholder: "https://example.com",
  autocomplete: "off",
  autocapitalize: "off",
  spellcheck: "false",
});

const widthInput = el("input", {
  className: "ms-input",
  type: "number",
  id: "width",
  name: "width",
  inputmode: "numeric",
  min: String(WIDTH.min),
  max: String(WIDTH.max),
  step: "1",
  placeholder: String(WIDTH.default),
});

const heightInput = el("input", {
  className: "ms-input",
  type: "number",
  id: "height",
  name: "height",
  inputmode: "numeric",
  min: String(HEIGHT.min),
  max: String(HEIGHT.max),
  step: "1",
  placeholder: String(HEIGHT.default),
});

const widthHint = el("span", { className: "ms-hint", text: `Optional · ${WIDTH.min}–${WIDTH.max}, default ${WIDTH.default}` });
const heightHint = el("span", { className: "ms-hint", text: `Optional · ${HEIGHT.min}–${HEIGHT.max}, default ${HEIGHT.default}` });

function preset(label, w, h) {
  return el("button", {
    className: "ms-btn-ghost",
    type: "button",
    onClick: () => {
      widthInput.value = String(w);
      heightInput.value = String(h);
      validate(widthInput, widthHint, WIDTH);
      validate(heightInput, heightHint, HEIGHT);
    },
  }, label);
}

const submitBtn = el("button", { className: "ms-btn", type: "submit" }, "Capture screenshot");

space.form.append(
  el("div", { className: "ms-field" },
    el("label", { for: "url", text: "Website URL" }),
    urlInput,
    el("span", { className: "ms-hint", text: "Any public page, e.g. https://github.com" }),
  ),
  el("div", { className: "ms-row" },
    el("div", { className: "ms-field" },
      el("label", { for: "width", text: "Width (px)" }),
      widthInput,
      widthHint,
    ),
    el("div", { className: "ms-field" },
      el("label", { for: "height", text: "Height (px)" }),
      heightInput,
      heightHint,
    ),
  ),
  el("div", { className: "ms-field" },
    el("label", { text: "Size presets" }),
    el("div", { className: "ms-presets" },
      preset("Desktop 1280×720", 1280, 720),
      preset("Wide 1920×1080", 1920, 1080),
      preset("Mobile 390×844", 390, 844),
    ),
  ),
  submitBtn,
  el("p", { className: "ms-api-note" },
    "Free demo: ",
    String(ENDPOINTS[TOOL_KEY].freeLimitPerHour),
    " screenshots/hour per visitor. Need more? ",
    el("a", { href: FULL_TOOL_URL, target: "_blank", rel: "noopener", text: "Higher limits on mesmer.tools →" }),
  ),
);

// Live-validate dimension fields as the user edits them.
widthInput.addEventListener("input", () => validate(widthInput, widthHint, WIDTH));
heightInput.addEventListener("input", () => validate(heightInput, heightHint, HEIGHT));

/* --- Validation ----------------------------------------------------------- */

/**
 * Validates a dimension input. Empty means "use the default".
 * Returns { value, ok }; on failure marks the hint red and value is null.
 */
function validate(input, hint, range) {
  const raw = input.value.trim();
  if (raw === "") {
    resetHint(hint, range, "ok");
    return { value: range.default, ok: true };
  }
  const n = Number(raw);
  if (!Number.isInteger(n)) {
    setHint(hint, "Enter a whole number of pixels.", true);
    return { value: null, ok: false };
  }
  if (n < range.min || n > range.max) {
    setHint(hint, `Must be between ${range.min} and ${range.max}px.`, true);
    return { value: null, ok: false };
  }
  resetHint(hint, range, "ok");
  return { value: n, ok: true };
}

function resetHint(hint, range, _state) {
  const min = range === WIDTH ? WIDTH.min : HEIGHT.min;
  const max = range === WIDTH ? WIDTH.max : HEIGHT.max;
  setHint(hint, `Optional · ${min}–${max}, default ${range.default}`, false);
}

function setHint(hint, text, isError) {
  hint.textContent = text;
  hint.style.color = isError ? "#fca5a5" : "";
}

/* --- Submit --------------------------------------------------------------- */

space.form.addEventListener("submit", async (e) => {
  e.preventDefault();

  const url = urlInput.value.trim();
  if (!url) {
    urlInput.focus();
    return;
  }

  const w = validate(widthInput, widthHint, WIDTH);
  const h = validate(heightInput, heightHint, HEIGHT);
  if (!w.ok || !h.ok) {
    (!w.ok ? widthInput : heightInput).focus();
    return;
  }

  space.clearOutput();
  space.setLoading(true, "Capturing screenshot…");
  submitBtn.disabled = true;

  try {
    const data = await callRest(API_PATH, {
      params: { url, width: w.value, height: h.value },
    });
    space.clearStatus();
    renderResult(data);
  } catch (err) {
    space.clearOutput();
    space.showError(err);
  } finally {
    submitBtn.disabled = false;
  }
});

/* --- Result --------------------------------------------------------------- */

function renderResult(data) {
  // Success shape: { url, width, height, cached }
  const imgUrl = data.url;
  const width = data.width;
  const height = data.height;

  const filename = `screenshot-${width}x${height}.jpg`;

  space.output.append(
    el("div", { className: "ms-result-frame" },
      el("img", {
        src: imgUrl,
        alt: `Screenshot of ${urlInput.value.trim()} at ${width}×${height}`,
        loading: "lazy",
      }),
    ),
    el("div", { className: "ms-result-actions" },
      el("a", { className: "ms-btn-ghost", href: imgUrl, target: "_blank", rel: "noopener", text: "Open full size ↗" }),
      el("a", { className: "ms-btn-ghost", href: imgUrl, download: filename, text: "Download" }),
    ),
    el("p", { className: "ms-meta",
      text: `${width}×${height} · ${data.cached ? "served from cache" : "freshly captured"}` }),
  );
}