<?php

/**
 * BoxClient - Handles Box.com API integration for Ferrero workflow
 * Uploads assets with metadata and unique ID tracking
 */
class BoxClient
{
    private $accessToken;
    private $rootFolderId;
    private $baseUrl = 'https://api.box.com/2.0';
    private $clientId;
    private $clientSecret;

    public function __construct($clientIdOrToken, $clientSecret = null, $rootFolderId = '348304357505')
    {
        $this->rootFolderId = $rootFolderId;

        // If clientSecret is null, treat first param as a developer token
        if ($clientSecret === null) {
            $this->accessToken = $clientIdOrToken;
            error_log("Box: Using provided developer token");
        } else {
            // Use OAuth client credentials
            $this->clientId = $clientIdOrToken;
            $this->clientSecret = $clientSecret;
            $this->accessToken = $this->getOAuthToken();
        }
    }

    /**
     * Get OAuth 2.0 access token using JWT authentication
     * Box uses JWT with RSA private key signing
     */
    private function getOAuthToken()
    {
        // Load Box config for JWT details
        $configPath = __DIR__ . '/../Box-config.json';
        if (!file_exists($configPath)) {
            error_log("Box JWT: Config file not found at " . $configPath);
            return null;
        }

        $config = json_decode(file_get_contents($configPath), true);
        $privateKey = $config['boxAppSettings']['appAuth']['privateKey'] ?? null;
        $passphrase = $config['boxAppSettings']['appAuth']['passphrase'] ?? null;
        $publicKeyID = $config['boxAppSettings']['appAuth']['publicKeyID'] ?? null;
        $enterpriseID = $config['enterpriseID'] ?? null;

        if (!$privateKey || !$publicKeyID || !$enterpriseID) {
            error_log("Box JWT: Missing required JWT configuration");
            return null;
        }

        // Create JWT assertion
        $header = [
            'alg' => 'RS256',
            'typ' => 'JWT',
            'kid' => $publicKeyID
        ];

        $claims = [
            'iss' => $this->clientId,
            'sub' => $enterpriseID,
            'box_sub_type' => 'enterprise',
            'aud' => 'https://api.box.com/oauth2/token',
            'jti' => bin2hex(random_bytes(16)),
            'exp' => time() + 60 // Valid for 60 seconds
        ];

        // Encode JWT
        $headerEncoded = $this->base64UrlEncode(json_encode($header));
        $claimsEncoded = $this->base64UrlEncode(json_encode($claims));
        $signatureInput = $headerEncoded . '.' . $claimsEncoded;

        // Sign with private key
        $privateKeyResource = openssl_pkey_get_private($privateKey, $passphrase);
        if (!$privateKeyResource) {
            error_log("Box JWT: Failed to load private key");
            return null;
        }

        openssl_sign($signatureInput, $signature, $privateKeyResource, OPENSSL_ALGO_SHA256);
        $signatureEncoded = $this->base64UrlEncode($signature);

        $jwt = $signatureInput . '.' . $signatureEncoded;

        // Request token with JWT assertion
        $tokenUrl = 'https://api.box.com/oauth2/token';

        $ch = curl_init();
        curl_setopt_array($ch, [
            CURLOPT_URL => $tokenUrl,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_POST => true,
            CURLOPT_POSTFIELDS => http_build_query([
                'grant_type' => 'urn:ietf:params:oauth:grant-type:jwt-bearer',
                'assertion' => $jwt,
                'client_id' => $this->clientId,
                'client_secret' => $this->clientSecret
            ]),
            CURLOPT_SSL_VERIFYPEER => false
        ]);

        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        error_log("Box JWT Token Request: HTTP " . $httpCode);

        if ($httpCode == 200) {
            $data = json_decode($response, true);
            $token = $data['access_token'] ?? null;
            if ($token) {
                error_log("Box JWT: Token received successfully");
                return $token;
            }
        }

        error_log("Box JWT Failed: " . $response);
        return null;
    }

    /**
     * Base64 URL encode (for JWT)
     */
    private function base64UrlEncode($data)
    {
        return rtrim(strtr(base64_encode($data), '+/', '-_'), '=');
    }

    /**
     * Create a subfolder for a campaign
     */
    public function createCampaignFolder($campaignId, $campaignName)
    {
        $folderName = $campaignId . '_' . preg_replace('/[^a-zA-Z0-9_-]/', '_', $campaignName);

        $data = [
            'name' => $folderName,
            'parent' => ['id' => $this->rootFolderId]
        ];

        $response = $this->apiRequest('POST', '/folders', $data);

        if ($response['success']) {
            return [
                'success' => true,
                'folder_id' => $response['data']['id'] ?? null,
                'folder_name' => $folderName
            ];
        }

        // Check if folder already exists
        if (isset($response['data']['status']) && $response['data']['status'] == 409) {
            // Folder exists - find it
            $existingFolder = $this->findFolderByName($folderName);
            if ($existingFolder) {
                return [
                    'success' => true,
                    'folder_id' => $existingFolder['id'],
                    'folder_name' => $folderName,
                    'existed' => true
                ];
            }
        }

        return [
            'success' => false,
            'error' => $response['error'] ?? 'Failed to create folder'
        ];
    }

    /**
     * Upload file to Box with unique ID and metadata
     */
    public function uploadFile($localPath, $originalFilename, $uniqueId, $targetFolderId, $metadata = [])
    {
        if (!file_exists($localPath)) {
            return [
                'success' => false,
                'error' => 'File not found: ' . $localPath
            ];
        }

        // Build new filename with unique ID
        $pathInfo = pathinfo($originalFilename);
        $newFilename = $pathInfo['filename'] . '_' . $uniqueId . '.' . $pathInfo['extension'];

        // Upload file
        $uploadUrl = 'https://upload.box.com/api/2.0/files/content';

        $ch = curl_init();

        $postFields = [
            'attributes' => json_encode([
                'name' => $newFilename,
                'parent' => ['id' => $targetFolderId]
            ]),
            'file' => new \CURLFile($localPath, mime_content_type($localPath), $newFilename)
        ];

        curl_setopt_array($ch, [
            CURLOPT_URL => $uploadUrl,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_POST => true,
            CURLOPT_POSTFIELDS => $postFields,
            CURLOPT_HTTPHEADER => [
                'Authorization: Bearer ' . $this->accessToken
            ],
            CURLOPT_SSL_VERIFYPEER => false
        ]);

        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($httpCode == 201) {
            $data = json_decode($response, true);
            $fileId = $data['entries'][0]['id'] ?? null;

            // If metadata provided, set custom metadata
            if ($fileId && !empty($metadata)) {
                $this->setCustomMetadata($fileId, $metadata);
            }

            return [
                'success' => true,
                'file_id' => $fileId,
                'filename' => $newFilename,
                'unique_id' => $uniqueId,
                'box_url' => 'https://app.box.com/file/' . $fileId
            ];
        }

        return [
            'success' => false,
            'error' => 'Upload failed',
            'http_code' => $httpCode,
            'response' => $response
        ];
    }

    /**
     * Set custom metadata on Box file using metadata template
     * Stores full DAM metadata JSON in "Ferrero-DAM-Metadata" field
     */
    public function setCustomMetadata($fileId, $metadata)
    {
        // TEST: Send minimal string value to verify template works
        $testValue = "Test metadata - Asset ID: " . ($metadata['asset_id'] ?? 'Unknown');

        // Apply metadata template to file
        // Template: https://oliver-na.app.box.com/master/metadata/templates/ferrerodammetadata
        $templateScope = 'enterprise';
        $templateKey = 'ferrerodammetadata';

        // Try with simple string value first
        $metadataValues = [
            'damMetadata' => $testValue  // Start with camelCase (Box standard)
        ];

        $endpoint = "/files/{$fileId}/metadata/{$templateScope}/{$templateKey}";

        error_log("Box Metadata: Attempting POST to " . $endpoint);
        error_log("Box Metadata: Values: " . json_encode($metadataValues));

        $response = $this->apiRequest('POST', $endpoint, $metadataValues);

        if ($response['success']) {
            error_log("Box Metadata: SUCCESS! Template applied");
            return true;
        }

        error_log("Box Metadata: POST failed with: " . ($response['raw'] ?? 'Unknown'));

        // Try different field name variations if first attempt failed
        $fieldVariations = ['DAMMetadata', 'DAM-Metadata', 'dam_metadata', 'metadata'];

        foreach ($fieldVariations as $fieldName) {
            $metadataValues = [$fieldName => $testValue];
            $response = $this->apiRequest('POST', $endpoint, $metadataValues);

            if ($response['success']) {
                error_log("Box Metadata: Success with field name: " . $fieldName);
                return true;
            }
        }

        // All attempts failed
        error_log("Box Metadata: All template attempts failed");

        // POST to create metadata instance on file
        $endpoint = "/files/{$fileId}/metadata/{$templateScope}/{$templateKey}";

        $response = $this->apiRequest('POST', $endpoint, $metadataValues);

        // If template doesn't exist or metadata already applied, try PUT to update
        if (!$response['success'] && $response['http_code'] == 409) {
            error_log("Box Metadata: Template instance exists, updating instead");
            $response = $this->apiRequest('PUT', $endpoint, [
                [
                    'op' => 'replace',
                    'path' => '/Ferrero-DAM-Metadata',
                    'value' => $metadataJson
                ]
            ]);
        }

        if (!$response['success']) {
            error_log("Box Metadata Error: " . ($response['raw'] ?? 'Unknown'));
            error_log("Box Metadata: Falling back to file description");

            // Fallback: Use file description
            $data = [
                'description' => 'DAM Asset - ID: ' . ($metadata['asset_id'] ?? 'Unknown')
            ];
            $this->apiRequest('PUT', "/files/{$fileId}", $data);
        }

        return $response['success'];
    }

    /**
     * Find folder by name in root
     */
    private function findFolderByName($folderName)
    {
        $response = $this->apiRequest('GET', "/folders/{$this->rootFolderId}/items");

        if ($response['success'] && isset($response['data']['entries'])) {
            foreach ($response['data']['entries'] as $item) {
                if ($item['type'] === 'folder' && $item['name'] === $folderName) {
                    return $item;
                }
            }
        }

        return null;
    }

    /**
     * Generic Box API request
     */
    private function apiRequest($method, $endpoint, $data = null)
    {
        $url = $this->baseUrl . $endpoint;

        $ch = curl_init();
        $options = [
            CURLOPT_URL => $url,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_CUSTOMREQUEST => $method,
            CURLOPT_HTTPHEADER => [
                'Authorization: Bearer ' . $this->accessToken,
                'Content-Type: application/json'
            ],
            CURLOPT_SSL_VERIFYPEER => false
        ];

        if ($data !== null && in_array($method, ['POST', 'PUT', 'PATCH'])) {
            $options[CURLOPT_POSTFIELDS] = json_encode($data);
        }

        curl_setopt_array($ch, $options);

        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        return [
            'success' => $httpCode >= 200 && $httpCode < 300,
            'http_code' => $httpCode,
            'data' => json_decode($response, true),
            'raw' => $response
        ];
    }

    /**
     * Test Box connection
     */
    public function testConnection()
    {
        $response = $this->apiRequest('GET', '/folders/' . $this->rootFolderId);

        // Log detailed response for debugging
        error_log("Box API Response: HTTP " . $response['http_code']);
        if (!$response['success']) {
            error_log("Box API Error: " . ($response['raw'] ?? 'No response'));
        }

        return [
            'success' => $response['success'],
            'folder_name' => $response['data']['name'] ?? 'Unknown',
            'http_code' => $response['http_code'],
            'error' => $response['raw'] ?? null
        ];
    }
}