import { Router } from "@oak/oak";
import { db } from "../config/database.ts";
import { authenticateToken, authorize, getCurrentUser } from "../middleware/auth.ts";
import { sanitizeInput } from "../middleware/security.ts";
import type { Department, SubDepartment } from "../types/index.ts";

const router = new Router();

// Get all departments
router.get("/", authenticateToken, async (ctx) => {
  try {
    const departments = await db.query<Department[]>(
      "SELECT * FROM departments ORDER BY name"
    );
    ctx.response.body = departments;
  } catch (error) {
    console.error("Get departments error:", error);
    ctx.response.status = 500;
    ctx.response.body = { error: "Internal server error" };
  }
});

// Get department by ID
router.get("/:id", authenticateToken, async (ctx) => {
  try {
    const deptId = ctx.params.id;
    
    const departments = await db.query<Department[]>(
      "SELECT * FROM departments WHERE id = ?",
      [deptId]
    );
    
    if (departments.length === 0) {
      ctx.response.status = 404;
      ctx.response.body = { error: "Department not found" };
      return;
    }
    
    ctx.response.body = departments[0];
  } catch (error) {
    console.error("Get department error:", error);
    ctx.response.status = 500;
    ctx.response.body = { error: "Internal server error" };
  }
});

// Get sub-departments by department ID
router.get("/:id/sub-departments", authenticateToken, async (ctx) => {
  try {
    const deptId = ctx.params.id;
    
    const subDepartments = await db.query<SubDepartment[]>(
      "SELECT * FROM sub_departments WHERE department_id = ? ORDER BY name",
      [deptId]
    );
    
    ctx.response.body = subDepartments;
  } catch (error) {
    console.error("Get sub-departments error:", error);
    ctx.response.status = 500;
    ctx.response.body = { error: "Internal server error" };
  }
});

// Create department (SuperAdmin only)
router.post("/", authenticateToken, authorize("SuperAdmin"), async (ctx) => {
  try {
    const body = await ctx.request.body.json() as { name: string };
    const { name } = body;
    
    if (!name) {
      ctx.response.status = 400;
      ctx.response.body = { error: "Department name required" };
      return;
    }
    
    const sanitizedName = sanitizeInput(name);
    
    const result = await db.execute(
      "INSERT INTO departments (name) VALUES (?)",
      [sanitizedName]
    );
    
    const newDepartment = await db.query<Department[]>(
      "SELECT * FROM departments WHERE id = ?",
      [result.insertId]
    );
    
    ctx.response.status = 201;
    ctx.response.body = newDepartment[0];
  } catch (error) {
    const err = error as { code?: string };
    if (err.code === "ER_DUP_ENTRY") {
      ctx.response.status = 400;
      ctx.response.body = { error: "Department already exists" };
      return;
    }
    console.error("Create department error:", error);
    ctx.response.status = 500;
    ctx.response.body = { error: "Internal server error" };
  }
});

// Create sub-department (SuperAdmin or Supervisor for their own department)
router.post("/sub-departments", authenticateToken, async (ctx) => {
  try {
    const user = getCurrentUser(ctx);
    const body = await ctx.request.body.json() as { department_id: number; name: string };
    const { department_id, name } = body;
    
    if (!name || !department_id) {
      ctx.response.status = 400;
      ctx.response.body = { error: "Department ID and name are required" };
      return;
    }

    // Check authorization
    if (user.role === 'Supervisor' && user.departmentId !== department_id) {
      ctx.response.status = 403;
      ctx.response.body = { error: "You can only create sub-departments for your own department" };
      return;
    }
    
    if (user.role !== 'SuperAdmin' && user.role !== 'Supervisor') {
      ctx.response.status = 403;
      ctx.response.body = { error: "Unauthorized" };
      return;
    }
    
    const sanitizedName = sanitizeInput(name);
    
    const result = await db.execute(
      "INSERT INTO sub_departments (department_id, name) VALUES (?, ?)",
      [department_id, sanitizedName]
    );
    
    const newSubDepartment = await db.query<SubDepartment[]>(
      "SELECT * FROM sub_departments WHERE id = ?",
      [result.lastInsertId]
    );
    
    ctx.response.status = 201;
    ctx.response.body = newSubDepartment[0];
  } catch (error) {
    const err = error as { code?: string };
    if (err.code === "ER_DUP_ENTRY") {
      ctx.response.status = 400;
      ctx.response.body = { error: "Sub-department already exists in this department" };
      return;
    }
    console.error("Create sub-department error:", error);
    ctx.response.status = 500;
    ctx.response.body = { error: "Internal server error" };
  }
});

// Delete sub-department (SuperAdmin or Supervisor for their own department)
router.delete("/sub-departments/:id", authenticateToken, async (ctx) => {
  try {
    const user = getCurrentUser(ctx);
    const subDeptId = ctx.params.id;
    
    // Get the sub-department to check department ownership
    const subDepts = await db.query<SubDepartment[]>(
      "SELECT * FROM sub_departments WHERE id = ?",
      [subDeptId]
    );
    
    if (subDepts.length === 0) {
      ctx.response.status = 404;
      ctx.response.body = { error: "Sub-department not found" };
      return;
    }
    
    const subDept = subDepts[0];
    
    // Check authorization
    if (user.role === 'Supervisor' && user.departmentId !== subDept.department_id) {
      ctx.response.status = 403;
      ctx.response.body = { error: "You can only delete sub-departments from your own department" };
      return;
    }
    
    if (user.role !== 'SuperAdmin' && user.role !== 'Supervisor') {
      ctx.response.status = 403;
      ctx.response.body = { error: "Unauthorized" };
      return;
    }
    
    // Delete associated activities first (cascade should handle this, but being explicit)
    await db.execute("DELETE FROM activities WHERE sub_department_id = ?", [subDeptId]);
    
    // Delete the sub-department
    await db.execute("DELETE FROM sub_departments WHERE id = ?", [subDeptId]);
    
    ctx.response.body = { message: "Sub-department deleted successfully" };
  } catch (error) {
    console.error("Delete sub-department error:", error);
    ctx.response.status = 500;
    ctx.response.body = { error: "Internal server error" };
  }
});

// Legacy route for creating sub-department under specific department (SuperAdmin only)
router.post("/:id/sub-departments", authenticateToken, authorize("SuperAdmin"), async (ctx) => {
  try {
    const deptId = ctx.params.id;
    const body = await ctx.request.body.json() as { name: string };
    const { name } = body;
    
    if (!name) {
      ctx.response.status = 400;
      ctx.response.body = { error: "Name is required" };
      return;
    }
    
    const sanitizedName = sanitizeInput(name);
    
    const result = await db.execute(
      "INSERT INTO sub_departments (department_id, name) VALUES (?, ?)",
      [deptId, sanitizedName]
    );
    
    const newSubDepartment = await db.query<SubDepartment[]>(
      "SELECT * FROM sub_departments WHERE id = ?",
      [result.lastInsertId]
    );
    
    ctx.response.status = 201;
    ctx.response.body = newSubDepartment[0];
  } catch (error) {
    const err = error as { code?: string };
    if (err.code === "ER_DUP_ENTRY") {
      ctx.response.status = 400;
      ctx.response.body = { error: "Sub-department already exists in this department" };
      return;
    }
    console.error("Create sub-department error:", error);
    ctx.response.status = 500;
    ctx.response.body = { error: "Internal server error" };
  }
});

export default router;