import { type Context, Router, type RouterContext } 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: Context) => {
  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: RouterContext<"/:id">) => {
  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 all sub-departments (for reporting/filtering)
router.get(
  "/sub-departments/all",
  authenticateToken,
  async (ctx: Context) => {
    try {
      const subDepartments = await db.query<SubDepartment[]>(
        "SELECT sd.*, d.name as department_name FROM sub_departments sd LEFT JOIN departments d ON sd.department_id = d.id ORDER BY d.name, sd.name",
      );

      ctx.response.body = subDepartments;
    } catch (error) {
      console.error("Get all sub-departments 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: RouterContext<"/:id/sub-departments">) => {
    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: Context) => {
    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: Context) => {
  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.insertId],
    );

    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: RouterContext<"/sub-departments/:id">) => {
    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: RouterContext<"/:id/sub-departments">) => {
    try {
      const deptId: string | number = 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.insertId],
      );

      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;