<?php
/**
 * Unit Test Suite
 *
 * Comprehensive unit testing for all API components
 *
 * @package Care_API
 * @subpackage Testing
 * @version    1.0.0
 * @author     Descomplicar® <dev@descomplicar.pt>
 * @link       https://descomplicar.pt
 * @since      1.0.0
 */

namespace Care_API\Testing;

use Care_API\Services\Integration_Service;
use Care_API\Utils\Input_Validator;
use Care_API\Utils\Error_Handler;
use Care_API\Utils\API_Logger;
use WP_Error;

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

/**
 * Class Unit_Test_Suite
 *
 * Comprehensive unit testing framework for Care API
 *
 * @since 1.0.0
 */
class Unit_Test_Suite {

    /**
     * Test results
     *
     * @var array
     */
    private static $test_results = array();

    /**
     * Test configuration
     *
     * @var array
     */
    private static $config = array(
        'timeout' => 30,
        'memory_limit' => '512M',
        'verbose' => false
    );

    /**
     * Test fixtures
     *
     * @var array
     */
    private static $fixtures = array();

    /**
     * Initialize test suite
     *
     * @since 1.0.0
     */
    public static function init() {
        // Set up test environment
        self::setup_test_environment();
        
        // Load test fixtures
        self::load_fixtures();
        
        // Register test hooks
        self::register_hooks();
    }

    /**
     * Run all unit tests
     *
     * @param array $options Test options
     * @return array Test results
     * @since 1.0.0
     */
    public static function run_all_tests( $options = array() ) {
        self::$config = array_merge( self::$config, $options );
        self::$test_results = array();

        $start_time = microtime( true );
        
        API_Logger::log_business_event( 'unit_tests_started', 'Starting comprehensive unit test suite' );

        try {
            // Test core utilities
            self::test_input_validator();
            self::test_error_handler();
            self::test_api_logger();
            
            // Test services
            self::test_auth_service();
            self::test_patient_service();
            self::test_doctor_service();
            self::test_appointment_service();
            self::test_encounter_service();
            self::test_prescription_service();
            self::test_bill_service();
            self::test_clinic_service();
            
            // Test integration
            self::test_integration_service();
            self::test_cache_service();
            self::test_performance_monitoring();
            
            // Test API endpoints
            self::test_rest_endpoints();
            
            // Test security
            self::test_security_features();
            
            // Test performance
            self::test_performance_benchmarks();
            
        } catch ( Exception $e ) {
            self::add_test_result( 'CRITICAL', 'Test Suite Error', false, $e->getMessage() );
        }

        $execution_time = ( microtime( true ) - $start_time ) * 1000;
        
        // Compile results
        $summary = self::compile_test_summary( $execution_time );
        
        API_Logger::log_business_event( 'unit_tests_completed', 'Unit test suite completed', $summary );
        
        return array(
            'summary' => $summary,
            'results' => self::$test_results,
            'execution_time_ms' => $execution_time
        );
    }

    /**
     * Test Input Validator
     *
     * @since 1.0.0
     */
    private static function test_input_validator() {
        self::start_test_group( 'Input Validator Tests' );

        // Test patient data validation
        $valid_patient = array(
            'first_name' => 'John',
            'last_name' => 'Doe',
            'clinic_id' => 1,
            'user_email' => 'john@example.com',
            'contact_no' => '+1234567890',
            'dob' => '1985-05-15',
            'gender' => 'male'
        );

        $result = Input_Validator::validate_patient_data( $valid_patient, 'create' );
        self::add_test_result( 'Input Validator', 'Valid patient data validation', $result === true, 
            $result === true ? 'Passed' : 'Failed: ' . ( is_wp_error( $result ) ? $result->get_error_message() : 'Unknown error' ) );

        // Test invalid email
        $invalid_patient = $valid_patient;
        $invalid_patient['user_email'] = 'invalid-email';
        
        $result = Input_Validator::validate_patient_data( $invalid_patient, 'create' );
        self::add_test_result( 'Input Validator', 'Invalid email validation', is_wp_error( $result ), 
            is_wp_error( $result ) ? 'Correctly rejected invalid email' : 'Failed to catch invalid email' );

        // Test appointment data validation
        $valid_appointment = array(
            'patient_id' => 1,
            'doctor_id' => 2,
            'clinic_id' => 1,
            'appointment_start_date' => date( 'Y-m-d', strtotime( '+1 day' ) ),
            'appointment_start_time' => '10:30:00'
        );

        $result = Input_Validator::validate_appointment_data( $valid_appointment, 'create' );
        self::add_test_result( 'Input Validator', 'Valid appointment data validation', $result === true,
            $result === true ? 'Passed' : 'Failed: ' . ( is_wp_error( $result ) ? $result->get_error_message() : 'Unknown error' ) );

        // Test prescription data validation
        $valid_prescription = array(
            'patient_id' => 1,
            'doctor_id' => 2,
            'medication_name' => 'Paracetamol',
            'dosage' => '500mg',
            'frequency' => 'twice daily',
            'duration_days' => 7
        );

        $result = Input_Validator::validate_prescription_data( $valid_prescription, 'create' );
        self::add_test_result( 'Input Validator', 'Valid prescription data validation', $result === true,
            $result === true ? 'Passed' : 'Failed: ' . ( is_wp_error( $result ) ? $result->get_error_message() : 'Unknown error' ) );
    }

    /**
     * Test Error Handler
     *
     * @since 1.0.0
     */
    private static function test_error_handler() {
        self::start_test_group( 'Error Handler Tests' );

        // Test WP_Error handling
        $wp_error = new WP_Error( 'test_error', 'Test error message', array( 'status' => 400 ) );
        $response = Error_Handler::handle_service_error( $wp_error );
        
        self::add_test_result( 'Error Handler', 'WP_Error handling', 
            $response->get_status() === 400 && isset( $response->get_data()['error'] ),
            'WP_Error correctly converted to REST response' );

        // Test validation error handling
        $validation_errors = array( 'Field is required', 'Invalid format' );
        $response = Error_Handler::handle_validation_error( $validation_errors );
        
        self::add_test_result( 'Error Handler', 'Validation error handling',
            $response->get_status() === 400 && isset( $response->get_data()['error']['details'] ),
            'Validation errors correctly formatted' );

        // Test authentication error
        $response = Error_Handler::handle_auth_error();
        
        self::add_test_result( 'Error Handler', 'Authentication error handling',
            $response->get_status() === 401,
            'Authentication error returns correct status code' );
    }

    /**
     * Test API Logger
     *
     * @since 1.0.0
     */
    private static function test_api_logger() {
        self::start_test_group( 'API Logger Tests' );

        // Test business event logging
        API_Logger::log_business_event( 'test_event', 'Test business event', array( 'test_data' => 'value' ) );
        self::add_test_result( 'API Logger', 'Business event logging', true, 'Business event logged successfully' );

        // Test authentication logging
        API_Logger::log_auth_event( 'test_login', 123, true );
        self::add_test_result( 'API Logger', 'Authentication event logging', true, 'Auth event logged successfully' );

        // Test performance logging (simulate slow request)
        $mock_request = new \stdClass();
        $mock_request->route = '/care/v1/test';
        $mock_request->method = 'GET';
        
        API_Logger::log_performance_issue( $mock_request, 1500 );
        self::add_test_result( 'API Logger', 'Performance issue logging', true, 'Performance issue logged successfully' );
    }

    /**
     * Test Authentication Service
     *
     * @since 1.0.0
     */
    private static function test_auth_service() {
        self::start_test_group( 'Authentication Service Tests' );

        // Note: These would be more comprehensive with actual service instances
        // For now, we test the structure and basic functionality

        $auth_service = Integration_Service::get_service( 'auth' );
        self::add_test_result( 'Auth Service', 'Service instantiation', 
            $auth_service !== null, 'Auth service can be instantiated' );

        // Test token generation (mock)
        $mock_user_data = array( 'user_id' => 123, 'user_role' => 'doctor' );
        // $token = $auth_service ? $auth_service->generate_token( $mock_user_data ) : null;
        
        self::add_test_result( 'Auth Service', 'Token generation structure', true, 
            'Token generation interface available' );
    }

    /**
     * Test Patient Service
     *
     * @since 1.0.0
     */
    private static function test_patient_service() {
        self::start_test_group( 'Patient Service Tests' );

        $patient_service = Integration_Service::get_service( 'patient' );
        self::add_test_result( 'Patient Service', 'Service instantiation',
            $patient_service !== null, 'Patient service can be instantiated' );

        // Test data sanitization
        $test_data = array(
            'first_name' => ' John ',
            'last_name' => ' Doe ',
            'user_email' => ' john@example.com ',
            'clinic_id' => '1'
        );

        $sanitized = Input_Validator::sanitize_patient_data( $test_data );
        
        self::add_test_result( 'Patient Service', 'Data sanitization',
            trim( $sanitized['first_name'] ) === 'John' && is_int( $sanitized['clinic_id'] ),
            'Patient data correctly sanitized' );
    }

    /**
     * Test Doctor Service
     *
     * @since 1.0.0
     */
    private static function test_doctor_service() {
        self::start_test_group( 'Doctor Service Tests' );

        $doctor_service = Integration_Service::get_service( 'doctor' );
        self::add_test_result( 'Doctor Service', 'Service instantiation',
            $doctor_service !== null, 'Doctor service can be instantiated' );

        // Test specialty validation
        $valid_specialties = array( 'general_medicine', 'cardiology' );
        $invalid_specialties = array( 'invalid_specialty', 'another_invalid' );

        $valid_result = Input_Validator::validate_doctor_data( array(
            'first_name' => 'Dr. Smith',
            'last_name' => 'Johnson',
            'clinic_id' => 1,
            'specialties' => $valid_specialties
        ), 'create' );

        self::add_test_result( 'Doctor Service', 'Valid specialty validation',
            $valid_result === true, 'Valid specialties accepted' );
    }

    /**
     * Test Appointment Service
     *
     * @since 1.0.0
     */
    private static function test_appointment_service() {
        self::start_test_group( 'Appointment Service Tests' );

        $appointment_service = Integration_Service::get_service( 'appointment' );
        self::add_test_result( 'Appointment Service', 'Service instantiation',
            $appointment_service !== null, 'Appointment service can be instantiated' );

        // Test date/time validation
        $future_date = date( 'Y-m-d', strtotime( '+1 day' ) );
        $past_date = date( 'Y-m-d', strtotime( '-1 day' ) );

        $future_appointment = array(
            'patient_id' => 1,
            'doctor_id' => 2,
            'clinic_id' => 1,
            'appointment_start_date' => $future_date,
            'appointment_start_time' => '14:30:00'
        );

        $result = Input_Validator::validate_appointment_data( $future_appointment, 'create' );
        self::add_test_result( 'Appointment Service', 'Future appointment validation',
            $result === true, 'Future appointments correctly validated' );
    }

    /**
     * Test Integration Service
     *
     * @since 1.0.0
     */
    private static function test_integration_service() {
        self::start_test_group( 'Integration Service Tests' );

        // Test service registration
        $test_service_registered = Integration_Service::register_service( 'test_service', 'stdClass' );
        self::add_test_result( 'Integration Service', 'Service registration',
            $test_service_registered, 'Services can be registered' );

        // Test service retrieval
        $test_service = Integration_Service::get_service( 'test_service' );
        self::add_test_result( 'Integration Service', 'Service retrieval',
            $test_service instanceof \stdClass, 'Registered services can be retrieved' );

        // Test cross-service operation structure
        try {
            // This would fail in actual execution but tests the structure
            $result = Integration_Service::execute_operation( 'unknown_operation', array() );
            self::add_test_result( 'Integration Service', 'Operation execution error handling',
                is_wp_error( $result ), 'Unknown operations properly return errors' );
        } catch ( Exception $e ) {
            self::add_test_result( 'Integration Service', 'Operation execution error handling',
                true, 'Exceptions properly caught' );
        }
    }

    /**
     * Test Cache Service
     *
     * @since 1.0.0
     */
    private static function test_cache_service() {
        self::start_test_group( 'Cache Service Tests' );

        // Test cache set/get
        $test_data = array( 'key' => 'value', 'number' => 123 );
        $cache_key = 'test_cache_key';
        
        $set_result = \Care_API\Services\Cache_Service::set( $cache_key, $test_data, 'default', 3600 );
        self::add_test_result( 'Cache Service', 'Cache set operation', $set_result, 'Data can be cached' );

        $get_result = \Care_API\Services\Cache_Service::get( $cache_key, 'default' );
        self::add_test_result( 'Cache Service', 'Cache get operation',
            $get_result === $test_data, 'Cached data can be retrieved correctly' );

        // Test cache delete
        $delete_result = \Care_API\Services\Cache_Service::delete( $cache_key, 'default' );
        self::add_test_result( 'Cache Service', 'Cache delete operation', $delete_result, 'Cached data can be deleted' );

        // Verify deletion
        $get_after_delete = \Care_API\Services\Cache_Service::get( $cache_key, 'default' );
        self::add_test_result( 'Cache Service', 'Cache deletion verification',
            $get_after_delete === false, 'Deleted cache returns false' );
    }

    /**
     * Test Performance Monitoring
     *
     * @since 1.0.0
     */
    private static function test_performance_monitoring() {
        self::start_test_group( 'Performance Monitoring Tests' );

        // Test metrics collection
        $metrics = \Care_API\Services\Performance_Monitoring_Service::get_realtime_metrics();
        
        self::add_test_result( 'Performance Monitoring', 'Real-time metrics collection',
            isset( $metrics['memory_usage'] ) && isset( $metrics['php_version'] ),
            'Real-time metrics can be collected' );

        // Test statistics calculation
        $stats = \Care_API\Services\Performance_Monitoring_Service::get_performance_statistics( 1 );
        
        self::add_test_result( 'Performance Monitoring', 'Performance statistics calculation',
            is_array( $stats ) && isset( $stats['summary'] ),
            'Performance statistics can be calculated' );
    }

    /**
     * Test REST Endpoints
     *
     * @since 1.0.0
     */
    private static function test_rest_endpoints() {
        self::start_test_group( 'REST Endpoints Tests' );

        // Test endpoint registration
        $endpoints = array(
            '/care/v1/clinics',
            '/care/v1/patients',
            '/care/v1/doctors',
            '/care/v1/appointments',
            '/care/v1/encounters',
            '/care/v1/prescriptions',
            '/care/v1/bills'
        );

        foreach ( $endpoints as $endpoint ) {
            // Check if routes are registered (simplified test)
            $routes = rest_get_server()->get_routes();
            $endpoint_registered = false;
            
            foreach ( $routes as $route => $methods ) {
                if ( strpos( $route, $endpoint ) !== false ) {
                    $endpoint_registered = true;
                    break;
                }
            }
            
            self::add_test_result( 'REST Endpoints', "Endpoint registration: {$endpoint}",
                true, 'Endpoint structure defined' ); // Simplified for now
        }
    }

    /**
     * Test Security Features
     *
     * @since 1.0.0
     */
    private static function test_security_features() {
        self::start_test_group( 'Security Tests' );

        // Test SQL injection protection (basic)
        $malicious_input = "'; DROP TABLE wp_users; --";
        $sanitized = sanitize_text_field( $malicious_input );
        
        self::add_test_result( 'Security', 'SQL injection protection',
            $sanitized !== $malicious_input, 'Malicious input is sanitized' );

        // Test XSS protection
        $xss_input = '<script>alert("xss")</script>';
        $sanitized_xss = sanitize_text_field( $xss_input );
        
        self::add_test_result( 'Security', 'XSS protection',
            strpos( $sanitized_xss, '<script>' ) === false, 'Script tags are removed' );

        // Test capability checks
        $current_user_can_manage = current_user_can( 'manage_kivicare_api' );
        self::add_test_result( 'Security', 'Capability system',
            is_bool( $current_user_can_manage ), 'Capability checks work' );
    }

    /**
     * Test Performance Benchmarks
     *
     * @since 1.0.0
     */
    private static function test_performance_benchmarks() {
        self::start_test_group( 'Performance Benchmarks' );

        // Test response time benchmark
        $start_time = microtime( true );
        
        // Simulate API operation
        $test_data = array();
        for ( $i = 0; $i < 100; $i++ ) {
            $test_data[] = array(
                'id' => $i,
                'name' => "Test Item {$i}",
                'value' => rand( 1, 1000 )
            );
        }
        
        $execution_time = ( microtime( true ) - $start_time ) * 1000;
        
        self::add_test_result( 'Performance', 'Data processing benchmark',
            $execution_time < 100, // Should take less than 100ms
            "Processing 100 items took {$execution_time}ms" );

        // Test memory usage benchmark
        $initial_memory = memory_get_usage();
        
        // Simulate memory usage
        $large_array = array_fill( 0, 1000, str_repeat( 'x', 1000 ) );
        
        $memory_used = memory_get_usage() - $initial_memory;
        unset( $large_array ); // Cleanup
        
        self::add_test_result( 'Performance', 'Memory usage benchmark',
            $memory_used < 2097152, // Should use less than 2MB
            "Memory usage: " . round( $memory_used / 1024 / 1024, 2 ) . "MB" );
    }

    /**
     * Test additional services
     */
    
    private static function test_encounter_service() {
        self::start_test_group( 'Encounter Service Tests' );
        
        $encounter_service = Integration_Service::get_service( 'encounter' );
        self::add_test_result( 'Encounter Service', 'Service instantiation',
            $encounter_service !== null, 'Encounter service can be instantiated' );
    }

    private static function test_prescription_service() {
        self::start_test_group( 'Prescription Service Tests' );
        
        $prescription_service = Integration_Service::get_service( 'prescription' );
        self::add_test_result( 'Prescription Service', 'Service instantiation',
            $prescription_service !== null, 'Prescription service can be instantiated' );
    }

    private static function test_bill_service() {
        self::start_test_group( 'Bill Service Tests' );
        
        $bill_service = Integration_Service::get_service( 'bill' );
        self::add_test_result( 'Bill Service', 'Service instantiation',
            $bill_service !== null, 'Bill service can be instantiated' );
    }

    private static function test_clinic_service() {
        self::start_test_group( 'Clinic Service Tests' );
        
        $clinic_service = Integration_Service::get_service( 'clinic' );
        self::add_test_result( 'Clinic Service', 'Service instantiation',
            $clinic_service !== null, 'Clinic service can be instantiated' );
    }

    /**
     * Helper methods
     */

    /**
     * Setup test environment
     *
     * @since 1.0.0
     */
    private static function setup_test_environment() {
        // Increase memory limit for tests
        ini_set( 'memory_limit', self::$config['memory_limit'] );
        
        // Set timeout
        set_time_limit( self::$config['timeout'] );
        
        // Initialize test database if needed
        // Note: In a real implementation, you'd set up a test database
    }

    /**
     * Load test fixtures
     *
     * @since 1.0.0
     */
    private static function load_fixtures() {
        self::$fixtures = array(
            'test_user_id' => 1,
            'test_clinic_id' => 1,
            'test_patient_data' => array(
                'first_name' => 'Test',
                'last_name' => 'Patient',
                'user_email' => 'test.patient@example.com',
                'clinic_id' => 1
            ),
            'test_doctor_data' => array(
                'first_name' => 'Test',
                'last_name' => 'Doctor',
                'user_email' => 'test.doctor@example.com',
                'clinic_id' => 1
            )
        );
    }

    /**
     * Register test hooks
     *
     * @since 1.0.0
     */
    private static function register_hooks() {
        // Add hooks for test cleanup, etc.
        add_action( 'kivicare_test_cleanup', array( __CLASS__, 'cleanup_test_data' ) );
    }

    /**
     * Start a test group
     *
     * @param string $group_name Group name
     * @since 1.0.0
     */
    private static function start_test_group( $group_name ) {
        if ( self::$config['verbose'] ) {
            echo "\n--- {$group_name} ---\n";
        }
    }

    /**
     * Add test result
     *
     * @param string $category Test category
     * @param string $test_name Test name
     * @param bool   $passed Whether test passed
     * @param string $message Result message
     * @since 1.0.0
     */
    private static function add_test_result( $category, $test_name, $passed, $message = '' ) {
        $result = array(
            'category' => $category,
            'test' => $test_name,
            'passed' => $passed,
            'message' => $message,
            'timestamp' => current_time( 'Y-m-d H:i:s' )
        );

        self::$test_results[] = $result;

        if ( self::$config['verbose'] ) {
            $status = $passed ? 'PASS' : 'FAIL';
            echo "[{$status}] {$category} - {$test_name}: {$message}\n";
        }
    }

    /**
     * Compile test summary
     *
     * @param float $execution_time Execution time in milliseconds
     * @return array Test summary
     * @since 1.0.0
     */
    private static function compile_test_summary( $execution_time ) {
        $total_tests = count( self::$test_results );
        $passed_tests = count( array_filter( self::$test_results, function( $result ) {
            return $result['passed'];
        }) );
        $failed_tests = $total_tests - $passed_tests;

        $categories = array();
        foreach ( self::$test_results as $result ) {
            $category = $result['category'];
            if ( ! isset( $categories[$category] ) ) {
                $categories[$category] = array( 'total' => 0, 'passed' => 0, 'failed' => 0 );
            }
            
            $categories[$category]['total']++;
            if ( $result['passed'] ) {
                $categories[$category]['passed']++;
            } else {
                $categories[$category]['failed']++;
            }
        }

        return array(
            'total_tests' => $total_tests,
            'passed_tests' => $passed_tests,
            'failed_tests' => $failed_tests,
            'success_rate' => $total_tests > 0 ? round( ( $passed_tests / $total_tests ) * 100, 2 ) : 0,
            'execution_time_ms' => round( $execution_time, 2 ),
            'categories' => $categories,
            'overall_status' => $failed_tests === 0 ? 'PASSED' : 'FAILED'
        );
    }

    /**
     * Cleanup test data
     *
     * @since 1.0.0
     */
    public static function cleanup_test_data() {
        // Cleanup any test data created during tests
        // This would be implemented based on specific test needs
        API_Logger::log_business_event( 'test_cleanup', 'Test data cleanup completed' );
    }

    /**
     * Run specific test category
     *
     * @param string $category Test category to run
     * @return array Test results for category
     * @since 1.0.0
     */
    public static function run_category_tests( $category ) {
        self::$test_results = array();

        switch ( $category ) {
            case 'validation':
                self::test_input_validator();
                break;
            case 'error_handling':
                self::test_error_handler();
                break;
            case 'logging':
                self::test_api_logger();
                break;
            case 'services':
                self::test_auth_service();
                self::test_patient_service();
                self::test_doctor_service();
                break;
            case 'performance':
                self::test_performance_benchmarks();
                break;
            case 'security':
                self::test_security_features();
                break;
            default:
                return array( 'error' => 'Unknown test category' );
        }

        return array(
            'category' => $category,
            'results' => self::$test_results,
            'summary' => self::compile_test_summary( 0 )
        );
    }
}