/**
 * render.mjs - Renders a video from a VideoScript JSON file.
 *
 * Usage: node render.mjs <script.json> [output.mp4]
 */
import { bundle } from "@remotion/bundler";
import { renderMedia, selectComposition } from "@remotion/renderer";
import path from "path";
import fs from "fs";
import { fileURLToPath } from "url";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

async function main() {
  const args = process.argv.slice(2);

  if (args.length < 1) {
    console.error("Usage: node render.mjs <script.json> [output.mp4]");
    process.exit(1);
  }

  const scriptPath = path.resolve(args[0]);
  const outputPath = args[1]
    ? path.resolve(args[1])
    : path.join(__dirname, "out", "video.mp4");

  // Ensure output directory exists
  const outputDir = path.dirname(outputPath);
  if (!fs.existsSync(outputDir)) {
    fs.mkdirSync(outputDir, { recursive: true });
  }

  console.log("Loading script:", scriptPath);
  const script = JSON.parse(fs.readFileSync(scriptPath, "utf-8"));

  console.log(`Video: "${script.title}"`);
  console.log(`  Scenes: ${script.scenes.length}`);
  console.log(`  Duration: ${script.totalDurationInSeconds}s`);
  console.log(`  Resolution: ${script.width}x${script.height}`);
  console.log(`  FPS: ${script.fps}`);

  const totalFrames = script.totalDurationInSeconds * script.fps;

  console.log("\nBundling Remotion project...");
  const bundleLocation = await bundle({
    entryPoint: path.resolve(__dirname, "src/index.ts"),
    webpackOverride: (config) => config,
  });

  console.log("Selecting composition...");
  const composition = await selectComposition({
    serveUrl: bundleLocation,
    id: "PromptVideo",
    inputProps: { script },
  });

  // Override composition metadata with our script values
  composition.durationInFrames = totalFrames;
  composition.fps = script.fps;
  composition.width = script.width;
  composition.height = script.height;

  console.log(`Rendering ${totalFrames} frames to ${outputPath} ...`);

  let lastProgress = 0;
  await renderMedia({
    composition,
    serveUrl: bundleLocation,
    codec: "h264",
    outputLocation: outputPath,
    inputProps: { script },
    onProgress: ({ progress }) => {
      const pct = Math.floor(progress * 100);
      if (pct >= lastProgress + 10) {
        lastProgress = pct;
        process.stdout.write(`  ${pct}%\r`);
      }
    },
  });

  const stats = fs.statSync(outputPath);
  console.log(`\nDone! ${outputPath} (${(stats.size / 1024 / 1024).toFixed(2)} MB)`);
}

main().catch((err) => {
  console.error("Render failed:", err.message || err);
  process.exit(1);
});