import { Hono } from 'hono';
import { eq, and, desc, sql, gt, sum, count } from 'drizzle-orm';
import { z } from 'zod';
import { zValidator } from '@hono/zod-validator';
import { db } from './db';
import { topics, users, subscriptions, alertTasks, topicGroupChats, knownGroupChats } from './db/schema';
import { requireAuth, requireAdmin, AuthSession } from './middleware';

const api = new Hono<{ Variables: { session: AuthSession } }>();

const topicSchema = z.object({
  name: z.string().min(1),
  slug: z.string().min(1),
  description: z.string().optional(),
});

const groupBindingSchema = z.object({
  chatId: z.string().min(1),
  name: z.string().min(1),
});

const userSchema = z.object({
  name: z.string().min(1),
  feishuUserId: z.string().min(1),
  email: z.string().email().optional().or(z.literal('')),
});

// --- Topics ---

// --- Topics ---

api.get('/topics', requireAuth, async (c) => {
  const session = c.get('session');
  const isAdmin = session.isAdmin;
  const currentUserId = session.id;

  const allTopics = await db.query.topics.findMany({
    where: eq(topics.status, 'approved'),
    with: {
      creator: true,
      approver: true,
      subscriptions: {
        where: (subscriptions, { eq }) =>
          isAdmin ? undefined : (currentUserId ? eq(subscriptions.userId, currentUserId) : undefined),
        with: {
          user: true
        }
      }
    }
  });

  return c.json(allTopics);
});

api.get('/topics/requests', requireAdmin, async (c) => {
  const requests = await db.query.topics.findMany({
    where: eq(topics.status, 'pending'),
    with: {
      creator: true
    }
  });
  return c.json(requests);
});

api.get('/topics/all', requireAdmin, async (c) => {
  const allTopics = await db.query.topics.findMany({
    with: {
      creator: true,
      approver: true,
      subscriptions: true
    },
    orderBy: [desc(topics.createdAt)]
  });
  return c.json(allTopics);
});

api.get('/topics/my-requests', requireAuth, async (c) => {
  const session = c.get('session');
  const requests = await db.query.topics.findMany({
    where: eq(topics.createdBy, session.id),
    orderBy: [desc(topics.createdAt)],
    with: {
      approver: true,
    }
  });
  return c.json(requests);
});

api.post('/topics/:id/approve', requireAdmin, async (c) => {
  const id = c.req.param('id');
  const session = c.get('session');
  const result = await db.update(topics)
    .set({ status: 'approved', approvedBy: session.id })
    .where(eq(topics.id, id))
    .returning();
  return c.json(result[0]);
});

api.post('/topics/:id/reject', requireAdmin, async (c) => {
  const id = c.req.param('id');
  const result = await db.update(topics)
    .set({ status: 'rejected' })
    .where(eq(topics.id, id))
    .returning();
  return c.json(result[0]);
});

// Only admins can create topics
// Authenticated users can create topics (requests)
api.post('/topics', requireAuth, zValidator('json', topicSchema), async (c) => {
  const body = c.req.valid('json');
  const session = c.get('session');

  const status = session.isAdmin ? 'approved' : 'pending';

  const result = await db.insert(topics).values({
    ...body,
    status,
    createdBy: session.id,
    approvedBy: session.isAdmin ? session.id : null,
  }).returning();
  return c.json(result[0]);
});

// Only admins can update topics
api.put('/topics/:id', requireAdmin, zValidator('json', topicSchema.partial()), async (c) => {
  const id = c.req.param('id');
  const body = c.req.valid('json');
  const result = await db.update(topics).set(body).where(eq(topics.id, id)).returning();
  return c.json(result[0]);
});

// Only admins can delete topics
api.delete('/topics/:id', requireAdmin, async (c) => {
  const id = c.req.param('id');
  await db.delete(topics).where(eq(topics.id, id));
  return c.json({ success: true });
});

// --- Users ---

api.get('/users', requireAdmin, async (c) => {
  const allUsers = await db.query.users.findMany({
    with: {
      subscriptions: {
        with: {
          topic: true
        }
      }
    }
  });
  return c.json(allUsers);
});

api.post('/users', requireAdmin, zValidator('json', userSchema), async (c) => {
  const body = c.req.valid('json');
  const result = await db.insert(users).values(body).returning();
  return c.json(result[0]);
});

api.put('/users/:id', requireAdmin, zValidator('json', userSchema.partial()), async (c) => {
  const id = c.req.param('id');
  const body = c.req.valid('json');
  const result = await db.update(users).set(body).where(eq(users.id, id)).returning();
  return c.json(result[0]);
});

api.delete('/users/:id', requireAdmin, async (c) => {
  const id = c.req.param('id');
  await db.delete(users).where(eq(users.id, id));
  return c.json({ success: true });
});

// --- Subscriptions ---

// --- Subscriptions ---

// Users can subscribe themselves or admins can subscribe anyone
api.post('/topics/:topicId/subscribe/:userId', requireAuth, async (c) => {
  const { topicId, userId } = c.req.param();
  const session = c.get('session');

  // Check if user is subscribing themselves or is an admin
  if (session.id !== userId && !session.isAdmin) {
    return c.json({ error: 'You can only subscribe yourself' }, 403);
  }

  const result = await db.insert(subscriptions).values({ topicId, userId }).returning();
  return c.json(result[0]);
});

// Users can unsubscribe themselves or admins can unsubscribe anyone
api.delete('/topics/:topicId/subscribe/:userId', requireAuth, async (c) => {
  const { topicId, userId } = c.req.param();
  const session = c.get('session');

  // Check if user is unsubscribing themselves or is an admin
  if (session.id !== userId && !session.isAdmin) {
    return c.json({ error: 'You can only unsubscribe yourself' }, 403);
  }

  await db.delete(subscriptions)
    .where(and(
      eq(subscriptions.topicId, topicId),
      eq(subscriptions.userId, userId)
    ));
  return c.json({ success: true });
});

// --- Group Bindings (App Bot) ---

// Get list of known groups (for selection)
api.get('/groups', requireAuth, async (c) => {
  // Return recent active groups
  const groups = await db.select().from(knownGroupChats)
    .orderBy(desc(knownGroupChats.lastActiveAt))
    .limit(50);
  return c.json(groups);
});

// Get bindings for a topic
api.get('/topics/:id/groups', requireAuth, async (c) => {
  const topicId = c.req.param('id');
  const groups = await db.select().from(topicGroupChats)
    .where(eq(topicGroupChats.topicId, topicId))
    .orderBy(desc(topicGroupChats.createdAt));
  return c.json(groups);
});

// Bind a group to a topic
api.post('/topics/:id/groups', requireAuth, zValidator('json', groupBindingSchema), async (c) => {
  const topicId = c.req.param('id');
  const body = c.req.valid('json');
  const session = c.get('session');

  const result = await db.insert(topicGroupChats).values({
    topicId,
    chatId: body.chatId,
    name: body.name,
    createdBy: session.id,
  }).returning();

  return c.json(result[0]);
});

// Unbind a group
api.delete('/topics/:id/groups/:bindingId', requireAuth, async (c) => {
  const { id: topicId, bindingId } = c.req.param();

  await db.delete(topicGroupChats)
    .where(and(
      eq(topicGroupChats.id, bindingId),
      eq(topicGroupChats.topicId, topicId)
    ));

  return c.json({ success: true });
});

// --- Alert Tasks ---

api.get('/alerts/tasks', requireAdmin, async (c) => {
  const limit = Math.min(Number(c.req.query('limit') || 50), 100);
  const tasks = await db.query.alertTasks.findMany({
    orderBy: [desc(alertTasks.createdAt)],
    limit,
    with: {
      sender: true,
      logs: {
        limit: 10,  // Only show first 10 logs inline
      }
    }
  });
  return c.json(tasks);
});

api.get('/alerts/tasks/:id', requireAuth, async (c) => {
  const id = c.req.param('id');
  const task = await db.query.alertTasks.findFirst({
    where: eq(alertTasks.id, id),
    with: {
      sender: true,
      logs: true // Show all logs for detail view
    }
  });

  if (!task) {
    return c.json({ error: 'Task not found' }, 404);
  }

  return c.json(task);
});

// --- Stats ---

api.get('/stats', requireAdmin, async (c) => {
  // 1. Message count per topic
  const topicStats = await db.select({
    topicSlug: alertTasks.topicSlug,
    totalTasks: count(),
    totalRecipients: sql<number>`cast(${sum(alertTasks.recipientCount)} as int)`,
    totalSuccess: sql<number>`cast(${sum(alertTasks.successCount)} as int)`,
  })
    .from(alertTasks)
    .groupBy(alertTasks.topicSlug);

  // 2. Recent metrics (last 24h)
  const last24h = new Date(Date.now() - 24 * 60 * 60 * 1000);
  const recentStats = await db.select({
    totalRecipients: sql<number>`cast(${sum(alertTasks.recipientCount)} as int)`,
    totalSuccess: sql<number>`cast(${sum(alertTasks.successCount)} as int)`,
    taskCount: count(),
  })
    .from(alertTasks)
    .where(gt(alertTasks.createdAt, last24h));

  const recent = recentStats[0] || { totalRecipients: 0, totalSuccess: 0, taskCount: 0 };
  const totalRecipients = Number(recent.totalRecipients || 0);
  const totalSuccess = Number(recent.totalSuccess || 0);
  const failedCount = totalRecipients - totalSuccess;
  const successRate = totalRecipients > 0 ? (totalSuccess / totalRecipients) * 100 : 100;

  return c.json({
    topics: topicStats,
    recent: {
      alertsReceived: Number(recent.taskCount || 0),
      plannedMessages: totalRecipients,
      successCount: totalSuccess,
      failedCount: failedCount,
      successRate: successRate,
    }
  });
});

export default api;