import path from 'path';
import fs from 'fs';
import { defineConfig, loadEnv } from 'vite';
import react from '@vitejs/plugin-react';

export default defineConfig(({ mode }) => {
  const env = loadEnv(mode, '.', '');
  return {
    server: {
      port: 3000,
      host: '0.0.0.0',
      proxy: {
        '/api/fetch-data': {
          target: 'https://www.dropbox.com/scl/fi/b9zxn4z5i7sxwfakk5g5y/Amazon-Sell-Out-2023-2025.csv?rlkey=uoto6v0mm99py8nszy8ldtez8&st=pzn1zkrg&dl=1',
          changeOrigin: true,
          rewrite: () => '',  // Replace entire path with empty string (target has full URL)
          followRedirects: true
        },
        '/api/fetch-paneu-stock': {
          target: 'https://www.dropbox.com/scl/fi/xvsqi89mc8wk2i3jpndll/PANEU-Stock.xlsx?rlkey=djtbez2yi1sohjn203xnbjzl1&st=aogcoiw6&dl=1',
          changeOrigin: true,
          rewrite: () => '',
          followRedirects: true
        },
        '/api/fetch-uk-inventory': {
          target: 'https://www.dropbox.com/scl/fi/an1ldjmtej7tbt6fuh2ut/UK-Inventory.xlsx?rlkey=5h8e4st885bggibujk0b1lmm8&st=7vbagnwz&dl=1',
          changeOrigin: true,
          rewrite: () => '',
          followRedirects: true
        },
        '/api/fetch-buybox': {
          target: 'https://www.dropbox.com/scl/fi/dooz56abib51ifaf42cpx/Buy_Box_tracker.xlsx?rlkey=2sx85bne42fju3d8vekfygzau&dl=1',
          changeOrigin: true,
          rewrite: () => '',
          followRedirects: true
        },
        '/api/fetch-ads': {
          target: 'https://www.dropbox.com/scl/fi/wng8tep7awhvzd65amwad/Ads-Weekly.xlsx?rlkey=kcmoq8dxgibsb2eb8zz47xvyo&dl=1',
          changeOrigin: true,
          rewrite: () => '',
          followRedirects: true
        },
        '/api/fetch-stock': {
          target: 'https://www.dropbox.com/scl/fi/jaxc1y01ot7wj4ksswaoe/Item-Availability.xlsx?rlkey=v428jlri5jf1z5ggiebze7ovo&dl=1',
          changeOrigin: true,
          rewrite: () => '',
          followRedirects: true
        },
        '/api/fetch-bsr': {
          target: 'https://www.dropbox.com/scl/fi/r32r9x6r7bvgg6ckiaowk/BSR.xlsx?rlkey=vka50xyhc637riq901qo5bk16&st=y6ys2oz8&dl=1',
          changeOrigin: true,
          rewrite: () => '',
          followRedirects: true
        }
      }
    },
    // To support fetching local 'BSR.xlsx' in Vite dev mode, we configure a custom middleware 
    // since we use a local file instead of a dropbox link for BSR:
    plugins: [
      react(),
      {
        name: 'serve-local-bsr',
        configureServer(server) {
          server.middlewares.use('/api/fetch-bsr', (req, res, next) => {
            const filePath = path.join(process.cwd(), 'BSR.xlsx');

            try {
              if (fs.existsSync(filePath)) {
                res.setHeader('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
                res.setHeader('Content-Disposition', 'attachment; filename="BSR.xlsx"');
                res.setHeader('Cache-Control', 'public, max-age=3600');
                const fileStream = fs.createReadStream(filePath);
                fileStream.pipe(res);
              } else {
                res.statusCode = 404;
                res.end(JSON.stringify({ error: 'BSR data file not found' }));
              }
            } catch (err) {
              res.statusCode = 500;
              res.end(JSON.stringify({ error: 'Failed' }));
            }
          });
        }
      }
    ],
    define: {
      // loadEnv reads .env files; process.env has Vercel/system env vars at build time
      'process.env.API_KEY': JSON.stringify(
        env.GEMINI_API_KEY || env.API_KEY || process.env.GEMINI_API_KEY || process.env.API_KEY || ""
      ),
      'process.env.GEMINI_API_KEY': JSON.stringify(
        env.GEMINI_API_KEY || env.API_KEY || process.env.GEMINI_API_KEY || process.env.API_KEY || ""
      ),
      'process.env.SUPABASE_URL': JSON.stringify(
        env.SUPABASE_URL || process.env.SUPABASE_URL || ""
      ),
      'process.env.SUPABASE_ANON_KEY': JSON.stringify(
        env.SUPABASE_ANON_KEY || process.env.SUPABASE_ANON_KEY || ""
      ),
    },
    resolve: {
      alias: {
        '@': path.resolve(__dirname, '.'),
      }
    }
  };
});