const fsp = require('fs').promises;
const { validateConfig } = require('../../config-schema');
const { exists } = require('../../fs-helpers');

module.exports = function(ctx) {
  const express = require('express');
  const router = express.Router();

  // ===== DASHCADDY CONFIG ENDPOINTS =====
  // Server-side config storage for setup wizard (shared across all browsers/machines)

  router.get('/config', ctx.asyncHandler(async (req, res) => {
    if (!await exists(ctx.CONFIG_FILE)) {
      return res.json({ setupComplete: false });
    }
    const data = await fsp.readFile(ctx.CONFIG_FILE, 'utf8');
    const config = JSON.parse(data);
    res.json(config);
  }, 'config-get'));

  router.post('/config', ctx.asyncHandler(async (req, res) => {
    const incoming = req.body;

    if (!incoming || typeof incoming !== 'object') {
      return ctx.errorResponse(res, 400, 'Invalid config object');
    }

    // Merge with existing config so partial saves don't wipe fields
    let existing = {};
    if (await exists(ctx.CONFIG_FILE)) {
      try {
        existing = JSON.parse(await fsp.readFile(ctx.CONFIG_FILE, 'utf8'));
      } catch (_) { /* start fresh if file is corrupt */ }
    }
    const config = { ...existing, ...incoming };

    // Merge nested dns object so partial dns updates don't wipe dns fields
    if (existing.dns && incoming.dns) {
      config.dns = { ...existing.dns, ...incoming.dns };
    }
    // Merge nested dnsServers object
    if (existing.dnsServers && incoming.dnsServers) {
      config.dnsServers = { ...existing.dnsServers, ...incoming.dnsServers };
    }

    // Validate merged config against schema
    const { valid, errors, warnings } = validateConfig(config);
    if (!valid) {
      return ctx.errorResponse(res, 400, 'Config validation failed', { errors });
    }

    // Add timestamp
    config.updatedAt = new Date().toISOString();

    await fsp.writeFile(ctx.CONFIG_FILE, JSON.stringify(config, null, 2), 'utf8');
    ctx.loadSiteConfig(); // Refresh in-memory config
    ctx.log.info('config', 'Config saved', { path: ctx.CONFIG_FILE });

    res.json({ success: true, message: 'Configuration saved', config, warnings });
  }, 'config-save'));

  router.delete('/config', ctx.asyncHandler(async (req, res) => {
    if (await exists(ctx.CONFIG_FILE)) {
      await fsp.unlink(ctx.CONFIG_FILE);
    }
    res.json({ success: true, message: 'Configuration reset' });
  }, 'config-delete'));

  return router;
};