import { Router } from 'express';
import { z } from 'zod';
import * as repo from '../../db/repos/messages.js';
import * as conversations from '../../db/repos/conversations.js';
import { validate } from '../validate.js';
import { NotFoundError, ValidationError, asyncWrap } from '../errors.js';

const appendSchema = z.object({
  role: z.string().min(1).max(64),
  body: z.string().min(1),
  agent_id: z.string().uuid().nullable().optional(),
  metadata: z.record(z.string(), z.any()).optional()
});

const convParams = z.object({ conversation_id: z.string().uuid() });

export const conversationsScopedRouter = Router({ mergeParams: true });

conversationsScopedRouter.get('/',
  validate({ params: convParams,
    query: z.object({ limit: z.string().optional() }) }),
  asyncWrap(async (req, res) => {
    const existing = await conversations.getById(req.params.conversation_id);
    if (!existing) throw new NotFoundError('conversation not found');
    const limit = req.validatedQuery.limit ? Number(req.validatedQuery.limit) : 1000;
    if (!Number.isFinite(limit) || limit < 1 || limit > 5000) {
      throw new ValidationError('limit must be 1..5000');
    }
    res.json(await repo.listByConversation(req.params.conversation_id, { limit }));
  })
);

conversationsScopedRouter.post('/',
  validate({ params: convParams, body: appendSchema }),
  asyncWrap(async (req, res) => {
    const existing = await conversations.getById(req.params.conversation_id);
    if (!existing) throw new NotFoundError('conversation not found');
    const row = await repo.append(req.params.conversation_id, req.body);
    res.status(201).json(row);
  })
);