#!/usr/bin/env node

/**
 * Generate output HTML from template + data for collecting-asteroids documents.
 *
 * Usage: node generate.mjs <docId>
 * Example: node generate.mjs collecting-asteroids-3
 *
 * Reads:  docs/<docId>.template.html
 * Reads:  docs/<docId>.data.json (optional)
 * Writes: docs/<docId>.output.html
 *
 * data.json format:
 * {
 *   pages: [{
 *     page: 1,
 *     asteroids: [{ index, left, top, rotate, scale, value, asteroid }],
 *     ships: [{ index, left, top, value }],
 *     baseScales: { "asteroid5": 0.35 }
 *   }]
 * }
 */

import { readFileSync, writeFileSync, existsSync } from 'fs';
import { join, dirname } from 'path';
import { fileURLToPath } from 'url';
import { postGenerate } from '../../../src/scripts/post-generate.mjs';

const __dirname = dirname(fileURLToPath(import.meta.url));
const docsDir = join(__dirname, '..', 'docs');

const docId = process.argv[2];
if (!docId) {
  console.error('Usage: node generate.mjs <docId>');
  process.exit(1);
}

const templatePath = join(docsDir, `${docId}.template.html`);
const dataPath = join(docsDir, `${docId}.data.json`);
const outputPath = join(docsDir, `${docId}.output.html`);

if (!existsSync(templatePath)) {
  console.error(`Template not found: ${templatePath}`);
  process.exit(1);
}

let html = readFileSync(templatePath, 'utf-8');

if (existsSync(dataPath)) {
  const data = JSON.parse(readFileSync(dataPath, 'utf-8'));
  html = applyData(html, data);
  console.log(`Applied data from ${data.pages?.length || 0} pages`);
}

writeFileSync(outputPath, html);
console.log(`Generated: ${outputPath}`);
await postGenerate(outputPath);

function applyData(html, data) {
  if (!data.pages) return html;

  // Split HTML into pages by PAGE comment markers or by w-[210mm] divs
  const pageMarker = /<!-- PAGE (\d+)/g;
  const hasPageComments = pageMarker.test(html);

  if (hasPageComments) {
    // Split by page comments
    return applyByPageComments(html, data.pages);
  } else {
    // Split by page divs
    return applyByPageDivs(html, data.pages);
  }
}

function applyByPageDivs(html, pages) {
  // Find page boundaries: <div class="w-[210mm] h-[297mm]"
  const pageRegex = /<div class="w-\[210mm\] h-\[297mm\]"/g;
  const starts = [];
  let match;
  while ((match = pageRegex.exec(html)) !== null) {
    starts.push(match.index);
  }

  if (starts.length === 0) return html;

  // Process pages in reverse order to preserve indices
  for (let i = pages.length - 1; i >= 0; i--) {
    const pageData = pages[i];
    const pageNum = pageData.page || (i + 1);
    const pageIdx = pageNum - 1;

    if (pageIdx >= starts.length) continue;

    const pageStart = starts[pageIdx];
    const pageEnd = pageIdx + 1 < starts.length ? starts[pageIdx + 1] : html.length;
    let pageHtml = html.slice(pageStart, pageEnd);

    // Apply asteroid positions
    if (pageData.asteroids) {
      pageHtml = applyAsteroids(pageHtml, pageData.asteroids);
    }

    // Apply ship positions
    if (pageData.ships) {
      pageHtml = applyShips(pageHtml, pageData.ships);
    }

    html = html.slice(0, pageStart) + pageHtml + html.slice(pageEnd);
  }

  return html;
}

function applyByPageComments(html, pages) {
  // Same logic but split by <!-- PAGE N -->
  const parts = html.split(/(<!-- PAGE \d+)/);
  const pageChunks = [];
  let prelude = parts[0];

  for (let i = 1; i < parts.length; i += 2) {
    pageChunks.push(parts[i] + (parts[i + 1] || ''));
  }

  for (const pageData of pages) {
    const pageIdx = (pageData.page || 1) - 1;
    if (pageIdx >= pageChunks.length) continue;

    if (pageData.asteroids) {
      pageChunks[pageIdx] = applyAsteroids(pageChunks[pageIdx], pageData.asteroids);
    }
    if (pageData.ships) {
      pageChunks[pageIdx] = applyShips(pageChunks[pageIdx], pageData.ships);
    }
  }

  return prelude + pageChunks.join('');
}

function applyAsteroids(pageHtml, asteroids) {
  // Match asteroid containers: <div class="absolute" style="left: Xmm; top: Ymm;">
  // followed by pack3-asteroids image
  const asteroidRegex = /(<div class="absolute" style="left: )-?\d+mm; top: -?\d+mm(;"><div class="relative w-\[88px\] h-\[88px\]"><img src="[^"]*pack3-asteroids\/[^"]*" class="w-full h-full object-contain" style="transform: rotate\()-?\d+deg(\) scale\()[\d.]+(\);" alt=""><div class="absolute inset-0 flex items-center justify-center"><span class="text-white font-extrabold text-2xl" style="text-shadow[^"]*">)\d+(<\/span>)/g;

  let idx = 0;
  return pageHtml.replace(asteroidRegex, (match, prefix, rotPrefix, scalePrefix, scaleSuffix, valueSuffix) => {
    const ast = asteroids[idx++];
    if (!ast) return match;

    const left = ast.left.replace('mm', '');
    const top = ast.top.replace('mm', '');
    const rotate = ast.rotate.replace('deg', '');
    const scale = ast.scale.toFixed(2);
    const value = ast.value;

    return `${prefix}${left}mm; top: ${top}mm${rotPrefix}${rotate}deg${scalePrefix}${scale}${scaleSuffix}${value}${valueSuffix}`;
  });
}

function applyShips(pageHtml, ships) {
  // Match ship capacity circles
  const shipRegex = /(<div class="absolute w-12 h-12 rounded-full bg-indigo-600[^"]*" style="left: )[\d.]+%(; top: )[\d.]+(%[^>]*><span class="text-white font-extrabold text-xl">)\d+(<\/span>)/g;

  let idx = 0;
  return pageHtml.replace(shipRegex, (match, prefix, topPrefix, valueSuffix, spanClose) => {
    const ship = ships[idx++];
    if (!ship) return match;

    const left = ship.left.replace('%', '');
    const top = ship.top.replace('%', '');

    return `${prefix}${left}%${topPrefix}${top}${valueSuffix}${ship.value}${spanClose}`;
  });
}