import { Router } from "@oak/oak";
import { db } from "../config/database.ts";
import { authenticateToken, authorize, getCurrentUser } from "../middleware/auth.ts";
import type { Attendance, CheckInOutRequest, User } from "../types/index.ts";

const router = new Router();

// Get all attendance records
router.get("/", authenticateToken, async (ctx) => {
  try {
    const currentUser = getCurrentUser(ctx);
    const params = ctx.request.url.searchParams;
    const employeeId = params.get("employeeId");
    const startDate = params.get("startDate");
    const endDate = params.get("endDate");
    const status = params.get("status");
    
    let query = `
      SELECT a.*, 
             e.name as employee_name, e.username as employee_username,
             s.name as supervisor_name,
             d.name as department_name,
             c.name as contractor_name
      FROM attendance a
      JOIN users e ON a.employee_id = e.id
      JOIN users s ON a.supervisor_id = s.id
      LEFT JOIN departments d ON e.department_id = d.id
      LEFT JOIN users c ON e.contractor_id = c.id
      WHERE 1=1
    `;
    const queryParams: unknown[] = [];
    
    // Role-based filtering
    if (currentUser.role === "Supervisor") {
      query += " AND a.supervisor_id = ?";
      queryParams.push(currentUser.id);
    } else if (currentUser.role === "Employee") {
      query += " AND a.employee_id = ?";
      queryParams.push(currentUser.id);
    }
    
    if (employeeId) {
      query += " AND a.employee_id = ?";
      queryParams.push(employeeId);
    }
    
    if (startDate) {
      query += " AND a.work_date >= ?";
      queryParams.push(startDate);
    }
    
    if (endDate) {
      query += " AND a.work_date <= ?";
      queryParams.push(endDate);
    }
    
    if (status) {
      query += " AND a.status = ?";
      queryParams.push(status);
    }
    
    query += " ORDER BY a.work_date DESC, a.check_in_time DESC";
    
    const records = await db.query<Attendance[]>(query, queryParams);
    ctx.response.body = records;
  } catch (error) {
    console.error("Get attendance error:", error);
    ctx.response.status = 500;
    ctx.response.body = { error: "Internal server error" };
  }
});

// Get attendance by ID
router.get("/:id", authenticateToken, async (ctx) => {
  try {
    const attendanceId = ctx.params.id;
    
    const records = await db.query<Attendance[]>(
      `SELECT a.*, 
              e.name as employee_name, e.username as employee_username,
              s.name as supervisor_name,
              d.name as department_name,
              c.name as contractor_name
       FROM attendance a
       JOIN users e ON a.employee_id = e.id
       JOIN users s ON a.supervisor_id = s.id
       LEFT JOIN departments d ON e.department_id = d.id
       LEFT JOIN users c ON e.contractor_id = c.id
       WHERE a.id = ?`,
      [attendanceId]
    );
    
    if (records.length === 0) {
      ctx.response.status = 404;
      ctx.response.body = { error: "Attendance record not found" };
      return;
    }
    
    ctx.response.body = records[0];
  } catch (error) {
    console.error("Get attendance error:", error);
    ctx.response.status = 500;
    ctx.response.body = { error: "Internal server error" };
  }
});

// Check in employee (Supervisor or SuperAdmin)
router.post("/check-in", authenticateToken, authorize("Supervisor", "SuperAdmin"), async (ctx) => {
  try {
    const currentUser = getCurrentUser(ctx);
    const body = await ctx.request.body.json() as CheckInOutRequest;
    const { employeeId, workDate } = body;
    
    if (!employeeId || !workDate) {
      ctx.response.status = 400;
      ctx.response.body = { error: "Employee ID and work date required" };
      return;
    }
    
    // Verify employee exists
    let employeeQuery = "SELECT * FROM users WHERE id = ? AND role = ?";
    const employeeParams: unknown[] = [employeeId, "Employee"];
    
    if (currentUser.role === "Supervisor") {
      employeeQuery += " AND department_id = ?";
      employeeParams.push(currentUser.departmentId);
    }
    
    const employees = await db.query<User[]>(employeeQuery, employeeParams);
    
    if (employees.length === 0) {
      ctx.response.status = 403;
      ctx.response.body = { error: "Employee not found or not in your department" };
      return;
    }
    
    // Check if already checked in today
    const existing = await db.query<Attendance[]>(
      "SELECT * FROM attendance WHERE employee_id = ? AND work_date = ? AND status = ?",
      [employeeId, workDate, "CheckedIn"]
    );
    
    if (existing.length > 0) {
      ctx.response.status = 400;
      ctx.response.body = { error: "Employee already checked in today" };
      return;
    }
    
    const checkInTime = new Date().toISOString().slice(0, 19).replace("T", " ");
    
    const result = await db.execute(
      "INSERT INTO attendance (employee_id, supervisor_id, check_in_time, work_date, status) VALUES (?, ?, ?, ?, ?)",
      [employeeId, currentUser.id, checkInTime, workDate, "CheckedIn"]
    );
    
    const newRecord = await db.query<Attendance[]>(
      `SELECT a.*, 
              e.name as employee_name, e.username as employee_username,
              s.name as supervisor_name,
              d.name as department_name,
              c.name as contractor_name
       FROM attendance a
       JOIN users e ON a.employee_id = e.id
       JOIN users s ON a.supervisor_id = s.id
       LEFT JOIN departments d ON e.department_id = d.id
       LEFT JOIN users c ON e.contractor_id = c.id
       WHERE a.id = ?`,
      [result.insertId]
    );
    
    ctx.response.status = 201;
    ctx.response.body = newRecord[0];
  } catch (error) {
    console.error("Check in error:", error);
    ctx.response.status = 500;
    ctx.response.body = { error: "Internal server error" };
  }
});

// Check out employee (Supervisor or SuperAdmin)
router.post("/check-out", authenticateToken, authorize("Supervisor", "SuperAdmin"), async (ctx) => {
  try {
    const currentUser = getCurrentUser(ctx);
    const body = await ctx.request.body.json() as CheckInOutRequest;
    const { employeeId, workDate } = body;
    
    if (!employeeId || !workDate) {
      ctx.response.status = 400;
      ctx.response.body = { error: "Employee ID and work date required" };
      return;
    }
    
    // Find the check-in record
    let query = "SELECT * FROM attendance WHERE employee_id = ? AND work_date = ? AND status = ?";
    const params: unknown[] = [employeeId, workDate, "CheckedIn"];
    
    if (currentUser.role === "Supervisor") {
      query += " AND supervisor_id = ?";
      params.push(currentUser.id);
    }
    
    const records = await db.query<Attendance[]>(query, params);
    
    if (records.length === 0) {
      ctx.response.status = 404;
      ctx.response.body = { error: "No check-in record found for today" };
      return;
    }
    
    const checkOutTime = new Date().toISOString().slice(0, 19).replace("T", " ");
    
    await db.execute(
      "UPDATE attendance SET check_out_time = ?, status = ? WHERE id = ?",
      [checkOutTime, "CheckedOut", records[0].id]
    );
    
    const updatedRecord = await db.query<Attendance[]>(
      `SELECT a.*, 
              e.name as employee_name, e.username as employee_username,
              s.name as supervisor_name,
              d.name as department_name,
              c.name as contractor_name
       FROM attendance a
       JOIN users e ON a.employee_id = e.id
       JOIN users s ON a.supervisor_id = s.id
       LEFT JOIN departments d ON e.department_id = d.id
       LEFT JOIN users c ON e.contractor_id = c.id
       WHERE a.id = ?`,
      [records[0].id]
    );
    
    ctx.response.body = updatedRecord[0];
  } catch (error) {
    console.error("Check out error:", error);
    ctx.response.status = 500;
    ctx.response.body = { error: "Internal server error" };
  }
});

// Get attendance summary
router.get("/summary/stats", authenticateToken, async (ctx) => {
  try {
    const currentUser = getCurrentUser(ctx);
    const params = ctx.request.url.searchParams;
    const startDate = params.get("startDate");
    const endDate = params.get("endDate");
    const departmentId = params.get("departmentId");
    
    let query = `
      SELECT 
        COUNT(DISTINCT a.employee_id) as total_employees,
        COUNT(DISTINCT CASE WHEN a.status = 'CheckedIn' THEN a.employee_id END) as checked_in,
        COUNT(DISTINCT CASE WHEN a.status = 'CheckedOut' THEN a.employee_id END) as checked_out,
        d.name as department_name
      FROM attendance a
      JOIN users e ON a.employee_id = e.id
      LEFT JOIN departments d ON e.department_id = d.id
      WHERE 1=1
    `;
    const queryParams: unknown[] = [];
    
    if (currentUser.role === "Supervisor") {
      query += " AND a.supervisor_id = ?";
      queryParams.push(currentUser.id);
    }
    
    if (startDate) {
      query += " AND a.work_date >= ?";
      queryParams.push(startDate);
    }
    
    if (endDate) {
      query += " AND a.work_date <= ?";
      queryParams.push(endDate);
    }
    
    if (departmentId) {
      query += " AND e.department_id = ?";
      queryParams.push(departmentId);
    }
    
    query += " GROUP BY d.id, d.name";
    
    const summary = await db.query(query, queryParams);
    ctx.response.body = summary;
  } catch (error) {
    console.error("Get attendance summary error:", error);
    ctx.response.status = 500;
    ctx.response.body = { error: "Internal server error" };
  }
});

export default router;