<?php
// 가장 간단한 방법
$response = file_get_contents('https://api.example.com/data');
$data = json_decode($response, true);

// 옵션을 추가한 방법
$options = [
    'http' => [
        'method' => 'GET',
        'header' => [
            'Accept: application/json',
            'User-Agent: PHP Client/1.0'
        ],
        'timeout' => 10
    ]
];

$context = stream_context_create($options);
$response = file_get_contents('https://api.example.com/data', false, $context);
$data = json_decode($response, true);
?>

<?php
$postData = [
    'username' => 'testuser',
    'email' => 'test@example.com'
];

$options = [
    'http' => [
        'method' => 'POST',
        'header' => [
            'Content-Type: application/json',
            'Authorization: Bearer your_token'
        ],
        'content' => json_encode($postData),
        'timeout' => 10
    ]
];

$context = stream_context_create($options);
$response = file_get_contents('https://api.example.com/users', false, $context);

// HTTP 응답 코드 확인
$statusLine = $http_response_header[0];
preg_match('/\d{3}/', $statusLine, $matches);
$statusCode = $matches[0];

if ($statusCode == 200) {
    $data = json_decode($response, true);
    print_r($data);
} else {
    echo "에러: HTTP {$statusCode}\n";
}
?>

<?php
class WeatherAPI {
    private $apiKey;
    private $baseUrl = 'https://api.openweathermap.org/data/2.5';
    private $cacheDir = './cache';
    private $cacheTime = 1800; // 30분
    
    public function __construct($apiKey) {
        $this->apiKey = $apiKey;
        
        // 캐시 디렉토리 생성
        if (!is_dir($this->cacheDir)) {
            mkdir($this->cacheDir, 0755, true);
        }
    }
    
    /**
     * 현재 날씨 조회
     */
    public function getCurrentWeather($city, $units = 'metric') {
        // 캐시 확인
        $cacheKey = md5("current_{$city}_{$units}");
        $cachedData = $this->getCache($cacheKey);
        
        if ($cachedData !== null) {
            return $cachedData;
        }
        
        // API 호출
        $url = "{$this->baseUrl}/weather";
        $params = [
            'q' => $city,
            'appid' => $this->apiKey,
            'units' => $units,
            'lang' => 'kr'
        ];
        
        $data = $this->makeRequest($url, $params);
        
        // 데이터 가공
        $weather = [
            'city' => $data['name'],
            'country' => $data['sys']['country'],
            'temperature' => round($data['main']['temp'], 1),
            'feels_like' => round($data['main']['feels_like'], 1),
            'humidity' => $data['main']['humidity'],
            'pressure' => $data['main']['pressure'],
            'description' => $data['weather'][0]['description'],
            'icon' => $data['weather'][0]['icon'],
            'wind_speed' => $data['wind']['speed'],
            'timestamp' => $data['dt'],
            'sunrise' => $data['sys']['sunrise'],
            'sunset' => $data['sys']['sunset']
        ];
        
        // 캐시 저장
        $this->setCache($cacheKey, $weather);
        
        return $weather;
    }
    
    /**
     * 5일 예보 조회
     */
    public function getForecast($city, $units = 'metric') {
        $cacheKey = md5("forecast_{$city}_{$units}");
        $cachedData = $this->getCache($cacheKey);
        
        if ($cachedData !== null) {
            return $cachedData;
        }
        
        $url = "{$this->baseUrl}/forecast";
        $params = [
            'q' => $city,
            'appid' => $this->apiKey,
            'units' => $units,
            'lang' => 'kr'
        ];
        
        $data = $this->makeRequest($url, $params);
        
        // 일별로 그룹화
        $forecast = [];
        foreach ($data['list'] as $item) {
            $date = date('Y-m-d', $item['dt']);
            
            if (!isset($forecast[$date])) {
                $forecast[$date] = [
                    'date' => $date,
                    'temp_min' => $item['main']['temp_min'],
                    'temp_max' => $item['main']['temp_max'],
                    'description' => $item['weather'][0]['description'],
                    'icon' => $item['weather'][0]['icon'],
                    'items' => []
                ];
            }
            
            $forecast[$date]['temp_min'] = min(
                $forecast[$date]['temp_min'],
                $item['main']['temp_min']
            );
            
            $forecast[$date]['temp_max'] = max(
                $forecast[$date]['temp_max'],
                $item['main']['temp_max']
            );
            
            $forecast[$date]['items'][] = [
                'time' => date('H:i', $item['dt']),
                'temp' => round($item['main']['temp'], 1),
                'description' => $item['weather'][0]['description']
            ];
        }
        
        $this->setCache($cacheKey, $forecast);
        
        return $forecast;
    }
    
    /**
     * API 요청 실행
     */
    private function makeRequest($url, $params) {
        $fullUrl = $url . '?' . http_build_query($params);
        
        $ch = curl_init();
        
        curl_setopt_array($ch, [
            CURLOPT_URL => $fullUrl,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => 10,
            CURLOPT_SSL_VERIFYPEER => true,
            CURLOPT_HTTPHEADER => [
                'Accept: application/json'
            ]
        ]);
        
        $response = curl_exec($ch);
        
        if (curl_errno($ch)) {
            $error = curl_error($ch);
            curl_close($ch);
            throw new Exception("API 요청 실패: {$error}");
        }
        
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);
        
        if ($httpCode !== 200) {
            throw new Exception("API 에러: HTTP {$httpCode}");
        }
        
        $data = json_decode($response, true);
        
        if (json_last_error() !== JSON_ERROR_NONE) {
            throw new Exception("JSON 파싱 실패: " . json_last_error_msg());
        }
        
        return $data;
    }
    
    /**
     * 캐시 조회
     */
    private function getCache($key) {
        $cacheFile = "{$this->cacheDir}/{$key}.json";
        
        if (!file_exists($cacheFile)) {
            return null;
        }
        
        $cacheAge = time() - filemtime($cacheFile);
        
        if ($cacheAge > $this->cacheTime) {
            unlink($cacheFile);
            return null;
        }
        
        $content = file_get_contents($cacheFile);
        return json_decode($content, true);
    }
    
    /**
     * 캐시 저장
     */
    private function setCache($key, $data) {
        $cacheFile = "{$this->cacheDir}/{$key}.json";
        file_put_contents($cacheFile, json_encode($data));
    }
}

// 사용 예시
try {
    $weather = new WeatherAPI('your_api_key_here');
    
    // 현재 날씨
    $current = $weather->getCurrentWeather('Seoul');
    
    echo "=== {$current['city']} 현재 날씨 ===\n";
    echo "온도: {$current['temperature']}°C\n";
    echo "체감온도: {$current['feels_like']}°C\n";
    echo "날씨: {$current['description']}\n";
    echo "습도: {$current['humidity']}%\n";
    echo "풍속: {$current['wind_speed']}m/s\n\n";
    
    // 5일 예보
    $forecast = $weather->getForecast('Seoul');
    
    echo "=== 5일 예보 ===\n";
    foreach ($forecast as $day) {
        echo "{$day['date']}: ";
        echo "{$day['temp_min']}°C ~ {$day['temp_max']}°C ";
        echo "({$day['description']})\n";
    }
    
} catch (Exception $e) {
    echo "에러: " . $e->getMessage();
}
?>

<?php
function debugCurl($ch) {
    // 상세 정보 출력 활성화
    curl_setopt($ch, CURLOPT_VERBOSE, true);
    
    // 출력을 파일로 저장
    $verbose = fopen('php://temp', 'w+');
    curl_setopt($ch, CURLOPT_STDERR, $verbose);
    
    $response = curl_exec($ch);
    
    // 디버그 정보 읽기
    rewind($verbose);
    $verboseLog = stream_get_contents($verbose);
    
    echo "=== cURL 디버그 정보 ===\n";
    echo $verboseLog;
    
    // 요청 정보
    $info = curl_getinfo($ch);
    echo "\n=== 요청 정보 ===\n";
    echo "URL: {$info['url']}\n";
    echo "HTTP 코드: {$info['http_code']}\n";
    echo "총 시간: {$info['total_time']}초\n";
    echo "다운로드 크기: {$info['size_download']}바이트\n";
    
    fclose($verbose);
    
    return $response;
}
?>

<?php
class APILogger {
    private $logFile;
    
    public function __construct($logFile = './logs/api.log') {
        $this->logFile = $logFile;
        
        $dir = dirname($logFile);
        if (!is_dir($dir)) {
            mkdir($dir, 0755, true);
        }
    }
    
    public function log($level, $message, $context = []) {
        $timestamp = date('Y-m-d H:i:s');
        $contextStr = !empty($context) ? json_encode($context) : '';
        
        $logEntry = "[{$timestamp}] [{$level}] {$message}";
        if ($contextStr) {
            $logEntry .= " | Context: {$contextStr}";
        }
        $logEntry .= "\n";
        
        file_put_contents($this->logFile, $logEntry, FILE_APPEND);
    }
    
    public function logRequest($url, $method, $data = null) {
        $this->log('INFO', "API 요청", [
            'url' => $url,
            'method' => $method,
            'data' => $data
        ]);
    }
    
    public function logResponse($statusCode, $response, $duration) {
        $this->log('INFO', "API 응답", [
            'status' => $statusCode,
            'duration' => $duration . 'ms',
            'response_size' => strlen($response) . ' bytes'
        ]);
    }
    
    public function logError($error, $context = []) {
        $this->log('ERROR', $error, $context);
    }
}

// 사용 예시
$logger = new APILogger();

$startTime = microtime(true);
$logger->logRequest($url, 'GET', $params);

try {
    $response = curl_exec($ch);
    $duration = round((microtime(true) - $startTime) * 1000, 2);
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    
    $logger->logResponse($httpCode, $response, $duration);
    
} catch (Exception $e) {
    $logger->logError($e->getMessage(), [
        'url' => $url,
        'trace' => $e->getTraceAsString()
    ]);
}
?>

<?php
use PHPUnit\Framework\TestCase;

class WeatherAPITest extends TestCase {
    private $api;
    
    protected function setUp(): void {
        $this->api = new WeatherAPI('test_api_key');
    }
    
    public function testGetCurrentWeather() {
        $result = $this->api->getCurrentWeather('Seoul');
        
        // 필수 필드 확인
        $this->assertArrayHasKey('city', $result);
        $this->assertArrayHasKey('temperature', $result);
        $this->assertArrayHasKey('description', $result);
        
        // 데이터 타입 확인
        $this->assertIsString($result['city']);
        $this->assertIsFloat($result['temperature']);
        
        // 값 범위 확인
        $this->assertGreaterThanOrEqual(-50, $result['temperature']);
        $this->assertLessThanOrEqual(60, $result['temperature']);
    }
    
    public function testInvalidCity() {
        $this->expectException(Exception::class);
        $this->api->getCurrentWeather('InvalidCityName12345');
    }
    
    public function testCaching() {
        // 첫 번째 호출
        $start1 = microtime(true);
        $result1 = $this->api->getCurrentWeather('Seoul');
        $time1 = microtime(true) - $start1;
        
        // 두 번째 호출 (캐시에서)
        $start2 = microtime(true);
        $result2 = $this->api->getCurrentWeather('Seoul');
        $time2 = microtime(true) - $start2;
        
        // 캐시가 더 빨라야 함
        $this->assertLessThan($time1, $time2);
        
        // 결과는 동일해야 함
        $this->assertEquals($result1, $result2);
    }
}
?>

<?php
/**
 * 범용 API 클라이언트 라이브러리
 * 
 * 기능:
 * - GET, POST, PUT, DELETE 지원
 * - 자동 재시도
 * - 캐싱
 * - Rate limiting
 * - 로깅
 * - 에러 처리
 */
class APIClient {
    private $baseUrl;
    private $headers = [];
    private $timeout = 30;
    private $retryCount = 3;
    private $retryDelay = 1000; // 밀리초
    private $cache;
    private $logger;
    private $rateLimiter;
    
    public function __construct($baseUrl, $config = []) {
        $this->baseUrl = rtrim($baseUrl, '/');
        
        // 설정 적용
        if (isset($config['timeout'])) {
            $this->timeout = $config['timeout'];
        }
        
        if (isset($config['retry_count'])) {
            $this->retryCount = $config['retry_count'];
        }
        
        if (isset($config['retry_delay'])) {
            $this->retryDelay = $config['retry_delay'];
        }
        
        // 캐시 초기화
        $this->cache = new CacheManager();
        
        // 로거 초기화
        $this->logger = new APILogger();
        
        // Rate limiter 초기화
        if (isset($config['rate_limit'])) {
            $this->rateLimiter = new RateLimiter(
                $config['rate_limit']['max_requests'],
                $config['rate_limit']['time_window']
            );
        }
    }
    
    /**
     * 기본 헤더 설정
     */
    public function setHeaders($headers) {
        $this->headers = array_merge($this->headers, $headers);
        return $this;
    }
    
    /**
     * 인증 토큰 설정
     */
    public function setAuthToken($token, $type = 'Bearer') {
        $this->headers['Authorization'] = "{$type} {$token}";
        return $this;
    }
    
    /**
     * API Key 설정
     */
    public function setApiKey($key, $headerName = 'X-API-Key') {
        $this->headers[$headerName] = $key;
        return $this;
    }
    
    /**
     * GET 요청
     */
    public function get($endpoint, $params = [], $options = []) {
        if (!empty($params)) {
            $endpoint .= '?' . http_build_query($params);
        }
        
        return $this->request('GET', $endpoint, null, $options);
    }
    
    /**
     * POST 요청
     */
    public function post($endpoint, $data = [], $options = []) {
        return $this->request('POST', $endpoint, $data, $options);
    }
    
    /**
     * PUT 요청
     */
    public function put($endpoint, $data = [], $options = []) {
        return $this->request('PUT', $endpoint, $data, $options);
    }
    
    /**
     * DELETE 요청
     */
    public function delete($endpoint, $options = []) {
        return $this->request('DELETE', $endpoint, null, $options);
    }
    
    /**
     * 실제 HTTP 요청 실행
     */
    private function request($method, $endpoint, $data = null, $options = []) {
        $url = $this->baseUrl . '/' . ltrim($endpoint, '/');
        
        // Rate limiting 체크
        if ($this->rateLimiter) {
            try {
                $this->rateLimiter->checkLimit($this->baseUrl);
            } catch (Exception $e) {
                $this->logger->logError($e->getMessage());
                throw $e;
            }
        }
        
        // 캐시 확인 (GET 요청만)
        if ($method === 'GET' && !isset($options['no_cache'])) {
            $cacheKey = md5($url);
            $cached = $this->cache->get($cacheKey);
            
            if ($cached !== null) {
                $this->logger->log('INFO', "캐시 히트: {$url}");
                return $cached;
            }
        }
        
        // 재시도 로직
        $attempt = 0;
        $lastError = null;
        
        while ($attempt < $this->retryCount) {
            try {
                $attempt++;
                
                $this->logger->logRequest($url, $method, $data);
                $startTime = microtime(true);
                
                $response = $this->executeRequest($method, $url, $data, $options);
                
                $duration = round((microtime(true) - $startTime) * 1000, 2);
                $this->logger->logResponse(200, $response, $duration);
                
                // 캐시 저장 (GET 요청만)
                if ($method === 'GET' && !isset($options['no_cache'])) {
                    $cacheTTL = $options['cache_ttl'] ?? 3600;
                    $this->cache->set($cacheKey, $response, $cacheTTL);
                }
                
                return $response;
                
            } catch (Exception $e) {
                $lastError = $e;
                
                $this->logger->logError(
                    "요청 실패 (시도 {$attempt}/{$this->retryCount}): " . $e->getMessage(),
                    ['url' => $url, 'method' => $method]
                );
                
                // 마지막 시도가 아니면 대기 후 재시도
                if ($attempt < $this->retryCount) {
                    usleep($this->retryDelay * 1000);
                }
            }
        }
        
        // 모든 재시도 실패
        throw new Exception(
            "API 요청 실패 ({$this->retryCount}회 시도): " . $lastError->getMessage()
        );
    }
    
    /**
     * cURL로 실제 요청 실행
     */
    private function executeRequest($method, $url, $data, $options) {
        $ch = curl_init();
        
        // 기본 옵션
        $curlOptions = [
            CURLOPT_URL => $url,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => $this->timeout,
            CURLOPT_SSL_VERIFYPEER => true,
            CURLOPT_FOLLOWLOCATION => true
        ];
        
        // 헤더 설정
        $headers = [];
        foreach ($this->headers as $key => $value) {
            $headers[] = "{$key}: {$value}";
        }
        
        if (!empty($headers)) {
            $curlOptions[CURLOPT_HTTPHEADER] = $headers;
        }
        
        // 메서드별 설정
        switch ($method) {
            case 'POST':
                $curlOptions[CURLOPT_POST] = true;
                if ($data !== null) {
                    $curlOptions[CURLOPT_POSTFIELDS] = json_encode($data);
                    $headers[] = 'Content-Type: application/json';
                }
                break;
                
            case 'PUT':
                $curlOptions[CURLOPT_CUSTOMREQUEST] = 'PUT';
                if ($data !== null) {
                    $curlOptions[CURLOPT_POSTFIELDS] = json_encode($data);
                    $headers[] = 'Content-Type: application/json';
                }
                break;
                
            case 'DELETE':
                $curlOptions[CURLOPT_CUSTOMREQUEST] = 'DELETE';
                break;
        }
        
        curl_setopt_array($ch, $curlOptions);
        
        $response = curl_exec($ch);
        
        if (curl_errno($ch)) {
            $error = curl_error($ch);
            curl_close($ch);
            throw new Exception("cURL 에러: {$error}");
        }
        
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);
        
        // HTTP 상태 코드 체크
        if ($httpCode < 200 || $httpCode >= 300) {
            throw new Exception("HTTP 에러 {$httpCode}: {$response}");
        }
        
        // JSON 파싱
        $decoded = json_decode($response, true);
        
        if (json_last_error() !== JSON_ERROR_NONE) {
            throw new Exception("JSON 파싱 실패: " . json_last_error_msg());
        }
        
        return $decoded;
    }
    
    /**
     * 캐시 초기화
     */
    public function clearCache() {
        // 구현 필요
    }
}

// ============================================
// 사용 예시
// ============================================

// 1. 기본 사용
$client = new APIClient('https://api.example.com', [
    'timeout' => 30,
    'retry_count' => 3,
    'rate_limit' => [
        'max_requests' => 100,
        'time_window' => 3600
    ]
]);

// 인증 설정
$client->setAuthToken('your_token_here');

// GET 요청
try {
    $users = $client->get('/users', ['page' => 1, 'limit' => 10]);
    print_r($users);
} catch (Exception $e) {
    echo "에러: " . $e->getMessage();
}

// POST 요청
try {
    $newUser = $client->post('/users', [
        'name' => '홍길동',
        'email' => 'hong@example.com'
    ]);
    echo "사용자 생성 성공: {$newUser['id']}\n";
} catch (Exception $e) {
    echo "에러: " . $e->getMessage();
}

// PUT 요청
try {
    $updated = $client->put('/users/123', [
        'name' => '홍길동2'
    ]);
    echo "사용자 수정 성공\n";
} catch (Exception $e) {
    echo "에러: " . $e->getMessage();
}

// DELETE 요청
try {
    $client->delete('/users/123');
    echo "사용자 삭제 성공\n";
} catch (Exception $e) {
    echo "에러: " . $e->getMessage();
}

// 2. 여러 API 동시 호출
$weatherClient = new APIClient('https://api.weather.com');
$newsClient = new APIClient('https://api.news.com');

$weatherClient->setApiKey('weather_key');
$newsClient->setApiKey('news_key');

try {
    $weather = $weatherClient->get('/current', ['city' => 'Seoul']);
    $news = $newsClient->get('/latest', ['category' => 'tech']);
    
    echo "날씨: {$weather['temp']}°C\n";
    echo "뉴스: {$news['articles'][0]['title']}\n";
    
} catch (Exception $e) {
    echo "에러: " . $e->getMessage();
}
?>