import { createRequire } from 'node:module';

import { dirname, join } from 'node:path';

import { mkdirSync, writeFileSync } from 'node:fs';

import type { PublicAgentCard } from '../../../packages/protocol/src/index.js';

let sharpModule: Promise<typeof import('sharp')> | undefined;

function loadSharp() {

  if (sharpModule) return sharpModule;

  const require = createRequire(import.meta.url);

  const fontDirectory = join(dirname(require.resolve('geist/font/sans')), 'fonts/geist-sans');

  const configDirectory = '/tmp/openclasp-fontconfig';

  const cacheDirectory = join(configDirectory, 'cache');

  const configFile = join(configDirectory, 'fonts.conf');

  mkdirSync(cacheDirectory, { recursive: true });

  writeFileSync(

    configFile,

    `<?xml version="1.0"?><!DOCTYPE fontconfig SYSTEM "urn:fontconfig:fonts.dtd"><fontconfig><dir>${fontDirectory}</dir><cachedir>${cacheDirectory}</cachedir></fontconfig>`,

  );

  process.env.FONTCONFIG_FILE = configFile;

  process.env.FONTCONFIG_PATH = configDirectory;

  sharpModule = import('sharp');

  return sharpModule;

}

const shorten = (value: string, length: number) =>

  value.length > length ? `${value.slice(0, length - 1).trimEnd()}…` : value;

const escapeXml = (value: string) =>

  value.replace(/[&<>"']/g, (character) => {

    const entities: Record<string, string> = {

      '&': '&',

      '<': '&lt;',

      '>': '>',

      '"': '"',

      "'": ''',

    };

    return entities[character]!;

  });

function capabilityChips(capabilities: string[]) {

  let x = 64;

  return capabilities

    .slice(0, 4)

    .map((capability) => {

      const label = shorten(capability, 25);

      const width = Math.min(250, Math.max(96, label.length * 10 + 32));

      const chip = `<g transform="translate(${x} 430)">

        <rect width="${width}" height="42" rx="8" fill="#ffffff0b" stroke="#ffffff28"/>

        <text x="16" y="27" fill="#ddd4d0" font-size="17">${escapeXml(label)}</text>

      </g>`;

      x += width + 12;

      return chip;

    })

    .join('');

}

function descriptionLines(value: string) {

  const words = value.trim().split(/\s+/);

  const lines: string[] = [];

  for (const word of words) {

    const current = lines.at(-1);

    if (!current || (current.length + word.length + 1 > 66 && lines.length < 2)) lines.push(word);

    else lines[lines.length - 1] = `${current} ${word}`;

  }

  if (lines.length > 2) lines.length = 2;

  if (lines[1] && lines[1].length > 66) lines[1] = shorten(lines[1], 66);

  return lines

    .map((line, index) => `<tspan x="220" dy="${index === 0 ? 0 : 34}">${escapeXml(line)}</tspan>`)

    .join('');

}

export async function renderAgentCardImage(card: PublicAgentCard) {

  const initials = card.name

    .split(/\s+/)

    .filter(Boolean)

    .slice(0, 2)

    .map((part) => part[0]?.toUpperCase())

    .join('');

  const publicReference = shorten(card.profileUrl ?? card.cardUrl, 88);

  const name = shorten(card.name, 42);

  const nameSize = name.length > 30 ? 50 : 62;

  const description = card.description || 'Public agent identity on OpenClasp';

  const svg = `<svg width="1200" height="630" viewBox="0 0 1200 630" xmlns="http://www.w3.org/2000/svg">

    <defs>

      <linearGradient id="background" x1="0" y1="0" x2="1" y2="1">

        <stop offset="0" stop-color="#0c0a0a"/>

        <stop offset="0.62" stop-color="#17100e"/>

        <stop offset="1" stop-color="#2a120d"/>

      </linearGradient>

      <radialGradient id="glow" cx="0" cy="0" r="1" gradientTransform="translate(1030 120) rotate(140) scale(430 340)">

        <stop stop-color="#f04b2d" stop-opacity="0.2"/>

        <stop offset="1" stop-color="#f04b2d" stop-opacity="0"/>

      </radialGradient>

    </defs>

    <rect width="1200" height="630" fill="url(#background)"/>

    <rect width="1200" height="630" fill="url(#glow)"/>

    <path d="M64 66h18l10 10-10 10H64l-10-10 10-10Z" fill="none" stroke="#f04b2d" stroke-width="4"/>

    <text x="108" y="84" fill="#f04b2d" font-family="Geist" font-size="27" font-weight="700" letter-spacing="-1">OpenClasp</text>

    <g transform="translate(936 58)">

      <rect width="200" height="42" rx="21" fill="#44d37e0d" stroke="#44d37e88"/>

      <path d="M18 21l5 5 9-11" fill="none" stroke="#44d37e" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"/>

      <text x="42" y="27" fill="#44d37e" font-family="Geist" font-size="16">Publisher verified</text>

    </g>

    <g transform="translate(64 165)">

      <rect width="122" height="122" rx="28" fill="#f04b2d1a" stroke="#f04b2d80"/>

      <text x="61" y="78" text-anchor="middle" fill="#ff8068" font-family="Geist" font-size="42" font-weight="700">${escapeXml(initials || 'AI')}</text>

    </g>

    <text x="220" y="176" fill="#a99e99" font-family="Geist" font-size="18" letter-spacing="2">${escapeXml(shorten(card.framework, 44).toUpperCase())} · AGENT CARD</text>

    <text x="220" y="246" fill="#f7f2ef" font-family="Geist" font-size="${nameSize}" font-weight="700" letter-spacing="-2">${escapeXml(name)}</text>

    <text x="220" y="308" fill="#c7bdb8" font-family="Geist" font-size="24">${descriptionLines(description)}</text>

    <g font-family="Geist">${capabilityChips(card.capabilities)}</g>

    <line x1="64" y1="540" x2="1136" y2="540" stroke="#ffffff21"/>

    <text x="64" y="582" fill="#8f8580" font-family="Geist" font-size="16">${escapeXml(publicReference)}</text>

    <text x="1136" y="582" text-anchor="end" fill="#8f8580" font-family="Geist" font-size="16">Capabilities are self-declared</text>

  </svg>`;

  const { default: sharp } = await loadSharp();

  return sharp(Buffer.from(svg)).png().toBuffer();

}