import { defineConfig } from 'vite';
import vue from '@vitejs/plugin-vue';
import path from 'node:path';
import fs from 'node:fs/promises';

const RENDER_ROOT = path.resolve(__dirname, '..', '.output-render');
const CACHE_ROOT = path.resolve(__dirname, '..', '.cache');

// Tiny dev plugin that exposes the .output-render directory at /render and
// serves a /api/index endpoint enumerating maps and variants. Keeps the app
// dependency-free of any external server.
function renderRootPlugin() {
  return {
    name: 'psx-render-root',
    configureServer(server) {
      server.middlewares.use('/render', async (req, res, next) => {
        try {
          const url = decodeURIComponent(req.url.split('?')[0]);
          const filePath = path.join(RENDER_ROOT, url);
          if (!filePath.startsWith(RENDER_ROOT)) {
            res.statusCode = 403;
            res.end('Forbidden');
            return;
          }
          const stat = await fs.stat(filePath);
          if (stat.isDirectory()) {
            const entries = await fs.readdir(filePath, { withFileTypes: true });
            res.setHeader('Content-Type', 'application/json');
            res.end(JSON.stringify(entries.map((e) => ({ name: e.name, isDir: e.isDirectory() }))));
            return;
          }
          const ext = path.extname(filePath).toLowerCase();
          const mime = ext === '.png' ? 'image/png'
            : ext === '.json' ? 'application/json'
            : ext === '.log' ? 'text/plain'
            : 'application/octet-stream';
          res.setHeader('Content-Type', mime);
          res.setHeader('Cache-Control', 'no-cache');
          const data = await fs.readFile(filePath);
          res.end(data);
        } catch (error) {
          if (error.code === 'ENOENT') {
            res.statusCode = 404;
            res.end('Not found');
            return;
          }
          next(error);
        }
      });

      server.middlewares.use('/api/index', async (req, res) => {
        try {
          const indexPath = path.join(RENDER_ROOT, 'index.json');
          const data = await fs.readFile(indexPath, 'utf8');
          res.setHeader('Content-Type', 'application/json');
          res.setHeader('Cache-Control', 'no-cache');
          res.end(data);
        } catch (error) {
          res.statusCode = 500;
          res.end(JSON.stringify({ error: error.message }));
        }
      });

      // Serve per-map sprite cache: /sprites/<map>/bundle_<hex>/frame_NNN.png
      // The exporter writes individual decoded sprite PNGs into
      // <projectRoot>/.cache/<mapStem>/sprites/, sharing the cache between
      // both the auto and region01 variants of the same map (bundle decoding
      // is invariant to the record-set choice).
      server.middlewares.use('/sprites', async (req, res, next) => {
        try {
          const url = decodeURIComponent(req.url.split('?')[0]);
          // url like "/L2/bundle_00085c40/frame_000.png"
          // map to "<CACHE_ROOT>/L2/sprites/bundle_00085c40/frame_000.png"
          const segments = url.split('/').filter(Boolean);
          if (segments.length < 2) {
            res.statusCode = 404;
            res.end('Not found');
            return;
          }
          const [mapStem, ...rest] = segments;
          const filePath = path.join(CACHE_ROOT, mapStem, 'sprites', ...rest);
          if (!filePath.startsWith(CACHE_ROOT)) {
            res.statusCode = 403;
            res.end('Forbidden');
            return;
          }
          const data = await fs.readFile(filePath);
          res.setHeader('Content-Type', 'image/png');
          res.setHeader('Cache-Control', 'no-cache');
          res.end(data);
        } catch (error) {
          if (error.code === 'ENOENT') {
            res.statusCode = 404;
            res.end('Not found');
            return;
          }
          next(error);
        }
      });
    },
  };
}

export default defineConfig({
  plugins: [vue(), renderRootPlugin()],
  server: {
    port: 5180,
    strictPort: false,
  },
});