#!/usr/bin/env node
// BOM generator — walks asset directories, lists files, prompts for descriptions, outputs BOM.yaml
//
// Usage:
//   npx tsx scripts/bom-gen.ts [asset-root]
//
// Expected directory structure:
//   audio/          — audio files
//   images/         — image files
//   fonts/          — font files
//   videos/         — material video clips
//
// Output: BOM.yaml (YAML frontmatter-style)

import { readdirSync, statSync, writeFileSync } from "node:fs";
import { resolve, relative, join } from "node:path";
import { createInterface } from "node:readline";

type Asset = { path: string; size: number; description: string };

const ASSET_DIRS = ["audio", "images", "fonts", "videos"];

function walk(dir: string): Asset[] {
  const assets: Asset[] = [];
  for (const entry of readdirSync(dir, { withFileTypes: true })) {
    const full = resolve(dir, entry.name);
    if (entry.isDirectory()) {
      assets.push(...walk(full));
    } else {
      assets.push({
        path: relative(".", full),
        size: statSync(full).size,
        description: "",
      });
    }
  }
  return assets;
}

function humanSize(bytes: number): string {
  const units = ["B", "KB", "MB", "GB"];
  let i = 0;
  while (bytes >= 1024 && i < units.length - 1) {
    bytes /= 1024;
    i++;
  }
  return `${bytes.toFixed(1)} ${units[i]}`;
}

async function main() {
  const root = process.argv[2] || ".";
  const rl = createInterface({ input: process.stdin, output: process.stdout });

  console.log("BOM Generator");
  console.log("=============\n");

  let all: Asset[] = [];

  for (const dir of ASSET_DIRS) {
    const full = resolve(root, dir);
    try {
      const assets = walk(full);
      all.push(...assets);
      console.log(`  ${dir}/ — ${assets.length} file(s)`);
    } catch {
      console.log(`  ${dir}/ — not found (skipped)`);
    }
  }

  if (all.length === 0) {
    console.log("\nNo assets found. Nothing to do.\n");
    rl.close();
    return;
  }

  const totalSize = all.reduce((s, a) => s + a.size, 0);
  console.log(`\nTotal: ${all.length} file(s), ${humanSize(totalSize)}\n`);

  for (let i = 0; i < all.length; i++) {
    const a = all[i];
    console.log(`[${i + 1}/${all.length}] ${a.path} (${humanSize(a.size)})`);
    a.description = (await new Promise<string>((r) =>
      rl.question("  Description: ", r)
    )).trim();
  }

  // Build YAML manually (no dependency)
  let yaml = "---\nbom:\n";
  for (const a of all) {
    const desc = a.description.replace(/"/g, '\\"');
    yaml += `  ${a.path}:\n    description: "${desc}"\n`;
  }
  yaml += `total_files: ${all.length}\ntotal_size: ${totalSize}\n...`;

  const bomPath = resolve(root, "BOM.yaml");
  writeFileSync(bomPath, yaml);
  console.log(`\n✓ Written to ${relative(root, bomPath)}\n`);

  rl.close();
}

main().catch(console.error);