import { escapeHtml } from "../inline/render.js";
import type { BlockHandler, IdentifyResult } from "./handler.type.js";

/**
 * Match a standalone image line: `![alt](url)` or `![alt](url "title")`.
 * The entire trimmed line must be the image — no surrounding text.
 */
const IMAGE_RE = /^!\[([^\]]*)\]\((\S+?)(?:\s+"([^"]*)")?\)$/;

export const imageHandler = {
  identify(lines: string[], index: number): IdentifyResult | null {
    const trimmed = lines[index].trim();
    const match = trimmed.match(IMAGE_RE);
    if (!match) return null;

    const [, alt, src, title] = match;
    const attrs: Record<string, string> = { src };
    if (title !== undefined) attrs.title = title;

    return { raw: alt, attrs, nextIndex: index + 1 };
  },

  render(raw: string, attrs?: Record<string, string>): string {
    const src = escapeHtml(attrs?.src ?? "");
    const alt = escapeHtml(raw);
    const title = attrs?.title;

    let img = `<img src="${src}" alt="${alt}"`;
    if (title !== undefined) {
      img += ` title="${escapeHtml(title)}"`;
    }
    img += ">";

    return `<figure>${img}</figure>`;
  },

  serialize(raw: string, attrs?: Record<string, string>): string {
    const src = attrs?.src ?? "";
    const title = attrs?.title;
    if (title !== undefined) {
      return `![${raw}](${src} "${title}")`;
    }
    return `![${raw}](${src})`;
  },
} satisfies BlockHandler;