import samples from "./gallery-samples.json";
import { resolveControlTemplate } from "@wrnexus/core";

const illustration = `data:image/svg+xml,${encodeURIComponent('<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 640 360"><rect width="640" height="360" fill="#dbeafe"/><path d="M0 260L190 100l130 140 120-100 200 160v60H0Z" fill="#2563eb"/><circle cx="470" cy="80" r="36" fill="#f59e0b"/></svg>')}`;
const map = `data:image/svg+xml,${encodeURIComponent('<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 640 360"><rect width="640" height="360" fill="#e2e8d5"/><path d="M0 140h640M200 0v360M440 0v360" stroke="#fff" stroke-width="32"/><path d="M0 140h640M200 0v360M440 0v360" stroke="#b7c2ca" stroke-width="2"/><rect x="260" y="210" width="120" height="100" rx="20" fill="#a4c7a1"/></svg>')}`;

function localAssets(value: unknown, key = ""): unknown {
  if (typeof value === "string")
    return /^(?:https?:\/\/|\/showcase-images\/)/.test(value) &&
      /src|image|avatar|poster|logo/i.test(key)
      ? illustration
      : /^https?:\/\//.test(value) && /href|action/i.test(key)
        ? "#sample"
        : value;
  if (Array.isArray(value)) return value.map((entry) => localAssets(entry, key));
  if (value && typeof value === "object")
    return Object.fromEntries(Object.entries(value).map(([k, v]) => [k, localAssets(v, k)]));
  return value;
}
/** Fixed, populated sample content; never contains draft-supplied executable markup. */
export function gallerySample(name: string) {
  const source = (samples as Record<string, { props: Record<string, unknown>; content: string }>)[
    name
  ];
  if (!source) throw Error(`Missing gallery sample: ${name}`);
  const props = localAssets(structuredClone(source.props)) as Record<string, unknown>;
  const field = [
    "Input",
    "Textarea",
    "Select",
    "Checkbox",
    "Radio",
    "Switch",
    "AdvancedSelect",
    "ComboBox",
    "DatePicker",
    "TimePicker",
    "RangeSlider",
    "InputNumber",
    "PinInput",
    "FileInput",
    "StrongPassword",
    "TogglePassword",
  ].includes(name);
  if (Object.hasOwn(props, "id") || field) props.id = `sample-${name.toLowerCase()}`;
  if (field && !props.name) props.name = `sample-${name.toLowerCase()}`;
  props.class = "";
  let content = source.content;
  let hint = "Sample data. Interact with the controls to try this component.";
  if (name === "Map") {
    Object.assign(props, {
      title: "Sample location map",
      description: "Schematic sample: select a marker or use the zoom controls.",
      imageSrc: map,
      imageAlt: "Schematic sample map",
      items: [
        { label: "Office", x: 32, y: 42 },
        { label: "Park", x: 68, y: 70 },
      ],
    });
    hint = "Local schematic sample; no map service or API key is needed.";
  }
  if (name === "DrawflowCanvas" || name === "FlowCanvas")
    Object.assign(props, {
      nodes: [
        {
          id: "start",
          label: "Start",
          x: 30,
          y: 50,
          input: false,
          ports: [{ key: "next", label: "Next", target: "review" }],
        },
        {
          id: "review",
          label: "Review",
          x: 260,
          y: 100,
          ports: [],
        },
      ],
      palette: [{ kind: "task", label: "Add task" }],
    });
  if (name === "Toaster")
    content = '<button type="button" data-preview-toast>Show sample notification</button>';
  if (name === "BackToTop") {
    props.threshold = 0;
    props.alwaysVisible = true;
    props.showLabel = true;
    hint = "Scroll this preview, then use the back-to-top control.";
  }
  if (name === "DeviceFrame") {
    props.items = [];
    content =
      "<article><h2>Sample mobile page</h2><p>This local content sits inside the device frame.</p><h3>Account preferences</h3><p>Rotate the preview to compare portrait and landscape layouts.</p></article>";
  }
  if (name === "VisuallyHidden")
    hint = "This accessibility component intentionally hides its content visually.";
  if (name === "CustomScrollbar")
    content = Array.from(
      { length: 12 },
      (_, i) => `<p>Sample row ${i + 1} — scroll to see more content.</p>`,
    ).join("");
  if (["AdvancedSelect", "Checkbox", "Select"].includes(name)) delete props.values;
  if (["AuthForm", "AuthSplitLayout", "FileInput"].includes(name))
    hint = "Preview only. Submissions and file uploads are not sent anywhere.";
  return { props, content, hint };
}

export function previewSlots(html: string, content: string) {
  const named = new Map<string, string>();
  // Author-controlled sample slots are the only HTML accepted here.
  let defaultContent = "";
  let cursor = 0;
  const slots = /<div data-slot="([\w-]+)">/g;
  for (let match = slots.exec(content); match; match = slots.exec(content)) {
    defaultContent += content.slice(cursor, match.index);
    const tags = /<\/?div\b[^>]*>/g;
    tags.lastIndex = slots.lastIndex;
    let depth = 1;
    let end = tags.lastIndex;
    for (let tag = tags.exec(content); tag; tag = tags.exec(content)) {
      depth += tag[0].startsWith("</") ? -1 : 1;
      if (depth === 0) {
        named.set(match[1]!, content.slice(slots.lastIndex, tag.index));
        end = tags.lastIndex;
        break;
      }
    }
    if (depth !== 0) throw Error("Unbalanced sample slot markup.");
    cursor = end;
    slots.lastIndex = end;
  }
  defaultContent += content.slice(cursor);
  return html.replace(/<slot\b([^>]*)>([\s\S]*?)<\/slot>/g, (all, attributes) => {
    const name = /\bname=["']([^"']+)["']/.exec(attributes)?.[1];
    const replacement = name ? named.get(name) : defaultContent;
    return replacement ? `<slot${attributes}>${replacement}</slot>` : all;
  });
}

/** Conditional/loop bodies are request-owned templates, and need the same slots as SSR. */
export function previewSampleMarkup(html: string, content: string) {
  const seen = new Set<string>();
  const visit = (markup: string): string => {
    for (const match of markup.matchAll(/data-wrn-(?:if|each)="(@[^"]+)"/g)) {
      if (seen.has(match[1]!)) continue;
      seen.add(match[1]!);
      const definition = resolveControlTemplate(match[1]!);
      for (const entry of Array.isArray(definition) ? definition : [definition]) {
        if (!entry || typeof entry !== "object") continue;
        for (const key of ["body", "empty"]) {
          if (typeof entry[key] === "string") entry[key] = visit(entry[key]);
        }
      }
    }
    return previewSlots(markup, content);
  };
  return visit(html);
}