import { Router } from 'express';
import { z } from 'zod';
import { grok } from '../services/llm/GrokHeadlessClient.js';
import { createLogger } from '../lib/logger.js';
import crypto from 'crypto';

const log = createLogger('chat-api');
const router = Router();

const ChatRequestSchema = z.object({
  message: z.string().min(1).max(2000),
  vehicle: z.object({ name: z.string(), rangeKm: z.number() }),
  itinerary: z.any().optional(),
  history: z.array(z.object({ role: z.enum(['user', 'assistant']), content: z.string() })).optional(),
  selectedVariant: z.enum(['fast', 'scenic', 'cheap']).optional(),
});

router.post('/chat', async (req, res) => {
  const requestId = crypto.randomUUID().slice(0, 8);
  const start = Date.now();

  log.info({ requestId, body: req.body }, '=== INCOMING /api/chat REQUEST ===');

  try {
    const parsed = ChatRequestSchema.safeParse(req.body);
    if (!parsed.success) {
      log.error({ requestId, errors: parsed.error.format() }, 'Invalid request body');
      return res.status(400).json({ error: 'Invalid request' });
    }

    const { message, vehicle, itinerary, history = [], selectedVariant = 'fast' } = parsed.data;

    log.info({
      requestId,
      userMessage: message,
      vehicle: vehicle.name,
      historyLength: history.length,
      currentItineraryDays: itinerary?.days?.length || 0,
      selectedVariant,
    }, 'Parsed chat request');

    // Call Grok (this will produce very detailed logs inside GrokHeadlessClient)
    const result = await grok.chat(
      [...history, { role: 'user' as const, content: message }],
      itinerary,
      vehicle,
      selectedVariant,
    );

    const duration = Date.now() - start;

    const payload: any = { reply: result.text };
    if (result.updatedItinerary) {
      payload.itinerary = result.updatedItinerary;
    }
    if (result.variants && Array.isArray(result.variants)) {
      payload.variants = result.variants;
    }
    if (result.selectedVariant) {
      payload.selectedVariant = result.selectedVariant;
    }

    log.info({
      requestId,
      durationMs: duration,
      replyLength: result.text.length,
      itineraryUpdated: !!result.updatedItinerary,
      newDays: result.updatedItinerary?.days?.length || 0,
    }, '=== SENDING RESPONSE TO FRONTEND ===');

    if (result.updatedItinerary) {
      log.debug({ requestId, fullItinerary: result.updatedItinerary }, 'Full updated itinerary being sent');
    }

    res.json(payload);
  } catch (err) {
    log.error({ requestId, err }, 'Chat route crashed');
    res.status(500).json({ reply: "Something went wrong on the server." });
  }
});


router.get('/grok/status', async (_req, res) => {
  try {
    const status = await grok.getStatus();
    res.json(status);
  } catch (err) {
    res.json({
      provider: 'fallback',
      label: 'Fallback',
      detail: 'Basic mode',
      isLocal: false,
      model: 'unknown',
    });
  }
});

export default router;