<?php

class ApiClient
{
    private $baseUrl;
    private $headers;
    private $timeout;

    public function __construct($baseUrl = '', $timeout = 30)
    {
        $this->baseUrl = $baseUrl;
        $this->headers = [];
        $this->timeout = $timeout;
    }

    public function setBaseUrl($url)
    {
        $this->baseUrl = rtrim($url, '/');
    }

    public function setHeader($key, $value)
    {
        $this->headers[$key] = $value;
    }

    public function setHeaders($headers)
    {
        $this->headers = array_merge($this->headers, $headers);
    }

    public function executeRequest($request)
    {
        $url = $this->buildUrl($request);
        $method = strtoupper($request['method'] ?? 'GET');
        
        $ch = curl_init();
        
        curl_setopt_array($ch, [
            CURLOPT_URL => $url,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => $this->timeout,
            CURLOPT_CONNECTTIMEOUT => 30,
            CURLOPT_CUSTOMREQUEST => $method,
            CURLOPT_HTTPHEADER => $this->buildHeaders($request),
            CURLOPT_SSL_VERIFYPEER => false,
            CURLOPT_HEADER => true,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_BUFFERSIZE => 4096,  // Smaller buffer for better streaming
            CURLOPT_NOPROGRESS => false, // Enable progress monitoring
        ]);

        if (in_array($method, ['POST', 'PUT', 'PATCH']) && isset($request['body'])) {
            $body = $this->buildRequestBody($request['body']);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $body);
        }

        $startTime = microtime(true);
        $response = curl_exec($ch);
        $endTime = microtime(true);
        
        $responseTime = ($endTime - $startTime) * 1000;
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $headerSize = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
        
        if (curl_error($ch)) {
            $error = curl_error($ch);
            curl_close($ch);
            
            return [
                'success' => false,
                'error' => $error,
                'response_time' => $responseTime,
                'http_code' => 0,
                'headers' => [],
                'body' => ''
            ];
        }
        
        curl_close($ch);
        
        $headers = substr($response, 0, $headerSize);
        $body = substr($response, $headerSize);
        
        return [
            'success' => true,
            'http_code' => $httpCode,
            'response_time' => round($responseTime, 2),
            'headers' => $this->parseHeaders($headers),
            'body' => $body,
            'url' => $url,
            'method' => $method
        ];
    }

    private function buildUrl($request)
    {
        $url = '';
        
        if (isset($request['url'])) {
            if (is_array($request['url'])) {
                $url = $request['url']['raw'] ?? '';
            } else {
                $url = $request['url'];
            }
        }
        
        if (strpos($url, 'http') !== 0 && $this->baseUrl) {
            $url = $this->baseUrl . '/' . ltrim($url, '/');
        }
        
        return $url;
    }

    private function buildHeaders($request)
    {
        $headers = $this->headers;
        
        if (isset($request['header'])) {
            foreach ($request['header'] as $header) {
                if (isset($header['key']) && isset($header['value']) && !($header['disabled'] ?? false)) {
                    $headers[$header['key']] = $header['value'];
                }
            }
        }
        
        $formattedHeaders = [];
        foreach ($headers as $key => $value) {
            $formattedHeaders[] = $key . ': ' . $value;
        }
        
        return $formattedHeaders;
    }

    private function buildRequestBody($body)
    {
        if (isset($body['raw'])) {
            return $body['raw'];
        }
        
        if (isset($body['formdata'])) {
            $data = [];
            foreach ($body['formdata'] as $item) {
                if (!($item['disabled'] ?? false)) {
                    $data[$item['key']] = $item['value'];
                }
            }
            return http_build_query($data);
        }
        
        if (isset($body['urlencoded'])) {
            $data = [];
            foreach ($body['urlencoded'] as $item) {
                if (!($item['disabled'] ?? false)) {
                    $data[$item['key']] = $item['value'];
                }
            }
            return http_build_query($data);
        }
        
        return '';
    }

    private function parseHeaders($headerString)
    {
        $headers = [];
        $lines = explode("\n", $headerString);
        
        foreach ($lines as $line) {
            $line = trim($line);
            if (strpos($line, ':') !== false) {
                list($key, $value) = explode(':', $line, 2);
                $headers[trim($key)] = trim($value);
            }
        }
        
        return $headers;
    }

    public function testConnection($url = null)
    {
        $testUrl = $url ?? $this->baseUrl;
        
        $ch = curl_init();
        curl_setopt_array($ch, [
            CURLOPT_URL => $testUrl,
            CURLOPT_NOBODY => true,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => 10,
            CURLOPT_SSL_VERIFYPEER => false
        ]);
        
        $result = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $error = curl_error($ch);
        curl_close($ch);
        
        return [
            'success' => !$error && $httpCode < 400,
            'http_code' => $httpCode,
            'error' => $error
        ];
    }
}