import { jest, describe, it, expect, beforeEach } from '@jest/globals';
import { Request, Response, NextFunction } from 'express';
import {
    validateRequest,
    sanitizeInput,
    errorHandler,
    rateLimiter,
    securityHeaders
} from '../../src/security/index.js';

type MockRequest = {
    headers: {
        'content-type'?: string;
        authorization?: string;
    };
    body?: any;
    is: jest.MockInstance<string | false | null, [type: string | string[]]>;
};

type MockResponse = {
    status: jest.MockInstance<MockResponse, [code: number]>;
    json: jest.MockInstance<MockResponse, [body: any]>;
    setHeader: jest.MockInstance<MockResponse, [name: string, value: string]>;
};

describe('Security Middleware', () => {
    let mockRequest: MockRequest;
    let mockResponse: MockResponse;
    let nextFunction: jest.Mock;

    beforeEach(() => {
        mockRequest = {
            headers: {},
            body: {},
            is: jest.fn<string | false | null, [string | string[]]>().mockReturnValue('json')
        };

        mockResponse = {
            status: jest.fn<MockResponse, [number]>().mockReturnThis(),
            json: jest.fn<MockResponse, [any]>().mockReturnThis(),
            setHeader: jest.fn<MockResponse, [string, string]>().mockReturnThis()
        };

        nextFunction = jest.fn();
    });

    describe('Request Validation', () => {
        it('should pass valid requests', () => {
            mockRequest.headers.authorization = 'Bearer valid-token';
            validateRequest(mockRequest as unknown as Request, mockResponse as unknown as Response, nextFunction);
            expect(nextFunction).toHaveBeenCalled();
        });

        it('should reject requests without authorization header', () => {
            validateRequest(mockRequest as unknown as Request, mockResponse as unknown as Response, nextFunction);
            expect(mockResponse.status).toHaveBeenCalledWith(401);
            expect(mockResponse.json).toHaveBeenCalledWith(expect.objectContaining({
                error: expect.stringContaining('authorization')
            }));
        });

        it('should reject requests with invalid authorization format', () => {
            mockRequest.headers.authorization = 'invalid-format';
            validateRequest(mockRequest as unknown as Request, mockResponse as unknown as Response, nextFunction);
            expect(mockResponse.status).toHaveBeenCalledWith(401);
            expect(mockResponse.json).toHaveBeenCalledWith(expect.objectContaining({
                error: expect.stringContaining('Bearer')
            }));
        });
    });

    describe('Input Sanitization', () => {
        it('should pass requests without body', () => {
            delete mockRequest.body;
            sanitizeInput(mockRequest as unknown as Request, mockResponse as unknown as Response, nextFunction);
            expect(nextFunction).toHaveBeenCalled();
        });

        it('should sanitize HTML in request body', () => {
            mockRequest.body = {
                text: '<script>alert("xss")</script>Hello',
                nested: {
                    html: '<img src="x" onerror="alert(1)">World'
                }
            };
            sanitizeInput(mockRequest as unknown as Request, mockResponse as unknown as Response, nextFunction);
            expect(mockRequest.body.text).toBe('Hello');
            expect(mockRequest.body.nested.html).toBe('World');
            expect(nextFunction).toHaveBeenCalled();
        });

        it('should handle non-object bodies', () => {
            mockRequest.body = '<p>text</p>';
            sanitizeInput(mockRequest as unknown as Request, mockResponse as unknown as Response, nextFunction);
            expect(mockRequest.body).toBe('text');
            expect(nextFunction).toHaveBeenCalled();
        });

        it('should preserve non-string values', () => {
            mockRequest.body = {
                number: 42,
                boolean: true,
                null: null,
                array: [1, 2, 3]
            };
            sanitizeInput(mockRequest as unknown as Request, mockResponse as unknown as Response, nextFunction);
            expect(mockRequest.body).toEqual({
                number: 42,
                boolean: true,
                null: null,
                array: [1, 2, 3]
            });
            expect(nextFunction).toHaveBeenCalled();
        });
    });

    describe('Error Handler', () => {
        const originalEnv = process.env.NODE_ENV;

        afterAll(() => {
            process.env.NODE_ENV = originalEnv;
        });

        it('should handle errors in production mode', () => {
            process.env.NODE_ENV = 'production';
            const error = new Error('Test error');
            errorHandler(error, mockRequest as Request, mockResponse as Response, nextFunction);
            expect(mockResponse.status).toHaveBeenCalledWith(500);
            expect(mockResponse.json).toHaveBeenCalledWith({
                error: 'Internal Server Error'
            });
        });

        it('should include error details in development mode', () => {
            process.env.NODE_ENV = 'development';
            const error = new Error('Test error');
            errorHandler(error, mockRequest as Request, mockResponse as Response, nextFunction);
            expect(mockResponse.status).toHaveBeenCalledWith(500);
            expect(mockResponse.json).toHaveBeenCalledWith({
                error: 'Test error',
                stack: expect.any(String)
            });
        });

        it('should handle non-Error objects', () => {
            const error = 'String error message';

            errorHandler(
                error as any,
                mockRequest as Request,
                mockResponse as Response,
                nextFunction
            );

            expect(mockResponse.status).toHaveBeenCalledWith(500);
        });
    });

    describe('Rate Limiter', () => {
        it('should be configured with correct options', () => {
            expect(rateLimiter).toBeDefined();
            const middleware = rateLimiter as any;
            expect(middleware.windowMs).toBeDefined();
            expect(middleware.max).toBeDefined();
        });
    });

    describe('Security Headers', () => {
        it('should set appropriate security headers', () => {
            securityHeaders(mockRequest as Request, mockResponse as Response, nextFunction);
            expect(mockResponse.setHeader).toHaveBeenCalledWith('X-Content-Type-Options', 'nosniff');
            expect(mockResponse.setHeader).toHaveBeenCalledWith('X-Frame-Options', 'DENY');
            expect(mockResponse.setHeader).toHaveBeenCalledWith('X-XSS-Protection', '1; mode=block');
            expect(nextFunction).toHaveBeenCalled();
        });
    });
});