<?php

/**
 * Class DataConsistencyChecker
 *
 * The DataConsistencyChecker class is responsible for checking the consistency of data.
 */

class DataConsistencyChecker
{
    private $_cluster;
    private $session;
    private $cassandra;
    private $directory;
    private $structured_directory;
    private $retrived_csv;
    private static $clientId;
    private static $schemaVersion = 1;
    private static $bucketMagic = 4;

    private const DEFAULT_PAGE_SIZE = 30;
    private const CASSANDRA_RESULT_CSV = 'result_from_cassandra_entries.csv';
    private const CASSANDRA_HTML_REPORT = 'cassandra.html';
    private const PHYSICAL_RESULT_CSV = 'result_from_physical_files.csv';
    private const PHYSICAL_HTML_REPORT = 'physical.html';
    private const CSV_COLUMN_FILE_ATTACHMENT = 'File/Attachment';
    private const CSV_COLUMN_FILE_PATH = 'File path';
    private const CSV_COLUMN_FILE_NAME = 'File name';
    private const CSV_COLUMN_THUMB1 = 'Thumb 1';
    private const CSV_COLUMN_THUMB2 = 'Thumb 2';
    private const CSV_COLUMN_SIZE = 'Size';
    private const CSV_COLUMN_CREATION_TIME = 'Creation Time';
    private const CSV_COLUMN_CLIENT_ID = 'ClientId';
    private const CSV_COLUMN_BUCKET = 'Bucket';
    private const CSV_COLUMN_ID = 'Id';
    private const CSV_EXTENSION = '.csv';
    private const NUM_FIELDS = 3;
    private const DELIMITER = '-';

    public function __construct($directory = null)
    {
        if ($directory !== null) {
            $this->directory = $directory;
        }

        $this->runFromCommandLine($_SERVER['argv']);
    }

    /**
     * Initializes the Cassandra connection based on the configuration settings.
     *
     * @return void
     */
    
    public function init(): void
    {
        $config = parse_ini_file('config.ini', true);
        $cassandraConfig = $config['CASSANDRA'];
        $this->_cluster = Cassandra::cluster()
            ->withContactPoints($cassandraConfig['host'])
            ->withPort((int)$cassandraConfig['port'])
            ->withCredentials(
                $cassandraConfig['user'],
                $cassandraConfig['password']
            )
            ->build();
        if ($this->_cluster) {
            try {
                $this->cassandra = $this->_cluster->connect($cassandraConfig['keyspace']);
            } catch (Exception $e) {
                echo "An error occurred: " . $e->getMessage() . "\n";
            }
        }
    }

    /**
     * Runs the script from the command line with the provided arguments.
     *
     * @param array $arguments The command line arguments.
     * @return void
     */
    
     public function runFromCommandLine(array $arguments): void
     {
         $shortOptions = "hd:v:o:r:s:";
         $longOptions = ["help", "directory:", "version:", "v", "output:", "o", "remove:", "r", "source:", "s"];
     
         $options = getopt($shortOptions, $longOptions);
     
         if (count($options) === 0 || isset($options['h']) || isset($options['help'])) {
             $this->displayHelpMessage();
             exit;
         }
     
         $directory = $options['directory'] ?? $options['d'] ?? null;
         $schemaVersion = $options['version'] ?? $options['v'] ?? null;
         $source = $options['source'] ?? $options['s'] ?? null;
         $remove = $options['remove'] ?? $options['r'] ?? null;
         $structured_directory = $options['output'] ?? $options['o'] ?? null;
     
         if (!file_exists($structured_directory)) {

             if ($structured_directory === null && $source === null) {
                 echo "Output directory is required. Please specify the --output option.\n";
                 exit;
             }

	     if ($structured_directory !== null) {
             	mkdir($structured_directory, 0777, true);
	     }
         }
     
         $this->structured_directory = $structured_directory;
     
         if (($directory === null || $schemaVersion === null) && $remove === null && $source === null) {
             echo "Missing Attachment directory or schema version.\n";
             exit;
         }
     
         if ($schemaVersion && !in_array($schemaVersion, [1, 2])) {
             echo "Invalid schema version. Only versions 1 and 2 are supported.\n";
             exit;
         }

         if ($structured_directory === null && $source === null) {
            echo "Output directory is required. Please specify the --output option.\n";
            exit;
         }
     
         static::$schemaVersion = (int) $schemaVersion;
         $this->directory = $directory;
         $this->retrived_csv = './result_from_physical_files.csv';
     
         if ($remove && $source) {
             $this->processAttachmentDeletionCSV($remove, $source);
         } else {
             $this->checkConsistency('attachment_file_info');

             if (is_dir($this->structured_directory)) {
                 $this->removeDirectory($this->structured_directory);
             }
         }
         exit;
     }
     

    /**
     * Displays the help message with instructions on how to use the script.
     *
     * @return void
     */

    private function displayHelpMessage(): void
    {
        $helpMessage = <<<EOT
        Usage:
        php script.php [options]

        Options:
        -h, --help     Display this help screen.
        --version      Set the schema version (default: v1).
        --directory    Set the directory path for attachments.
        --output       Set the folder for temp files - note that this folder will be deleted after script completes
        --remove       We need to choose between file and cassandra what we want to remove

        Example:
        php script_name --version schema_version --directory=/path/to/directory --output ./out/
        For Delete:
        php script_name --remove result_from_cassandra_entries.csv --source file - to remove missing physical files
        php script_name --remove result_from_physical_files.csv --source cassandra --version 2 - to remove missing cassandra entries
        EOT;
        echo $helpMessage;
    }

    /**
     * Recursively removes a directory and its contents.
     *
     * @param string $directory The directory path to be removed.
     * @return void
     */
    
    private function removeDirectory(string $directory): void
    {
        if (!is_dir($directory)) {
            return;
        }

        $files = array_diff(
            scandir($directory),
            ['.', '..']
        );

        foreach ($files as $file) {
            $path = $directory . DIRECTORY_SEPARATOR . $file;

            if (is_dir($path)) {
                $this->removeDirectory($path);
            } else {
                unlink($path);
            }
        }
        rmdir($directory);
    }

    /**
     * Checks the consistency between database entries and file entries.
     *
     * @param string $tableName The name of the table in the database to check consistency for.
     * @return void
     */

    public function checkConsistency(string $tableName): void
    {
        $this->init();
        $dbEntries = $this->getDbEntries($tableName);
        $fileEntries = $this->getFileEntries($this->directory);
        $this->process_files_in_directory($this->structured_directory);
    }

    /**
     * Retrieves file entries from a directory and organizes them based on dynamic values.
     *
     * @param string $directory The directory path to retrieve file entries from.
     * @return array An array containing the file entries organized by dynamic values.
     */

    private function getFileEntries(string $directory): array
    {
        $files = glob($directory . '/*');
        $entries = [];

        foreach ($files as $file) {
            if (is_file($file)) {
                $fileName = basename($file);

                if (strpos($fileName, '-thumb1') !== false || strpos($fileName, '-thumb2') !== false) {
                    continue;
                }

                $dashParts = explode(self::DELIMITER, $fileName, 2);
                $dotParts = explode('.', $fileName);

                if (count($dashParts) === 2) {
                    $clientId = $dashParts[0];
                    $id = $dashParts[1];
                    $fileParts = $dashParts;
                    $delimiter = self::DELIMITER;
                } elseif (count($dotParts) >= 2) {
                    $clientId = $dotParts[0];
                    $id = implode('.', array_slice($dotParts, 1));
                    $fileParts = $dotParts;
                    $delimiter = '.';
                } else {
                    continue;
                }

                $filePath = $file;
                $size = filesize($filePath);
                $creationTime = date('Y-m-d H:i:s', filemtime($filePath));
                $dynamicValue = substr($id, 0, 2);
                $creationTime = str_replace('"', '', $creationTime);

                $entries[$dynamicValue][] = [
                    'client_id' => $clientId,
                    'file_path' => $filePath,
                    'file_name' => implode($delimiter, $fileParts),
                    'size' => $size,
                    'creation_time' => $creationTime,
                ];
            }
        }
        // create CSV file for each client ID's physical file entries
        foreach ($entries as $clientId => $clientEntries) {
            $this->createPhysicalFileCSV($clientId, $clientEntries);
        }
        return $entries;
    }


    /**
     * Creates a CSV file containing the physical file entries for a specific client ID.
     *
     * @param string $clientId The client ID.
     * @param array $entries An array containing the physical file entries for the client.
     * @return void
     */

      private function createPhysicalFileCSV(string $clientId, array $entries): void
     {
        $fileName = $this->structured_directory . 'physical_' . $clientId . self::CSV_EXTENSION;
        $csvFile = fopen($fileName, 'w');
        fputcsv($csvFile, ['id', 'size', 'creation_time', 'filename']);
        
        foreach ($entries as $entry) {
                $idx = strpos($entry['file_name'],'.');
                 $id = $idx === false ? $entry['file_name'] : substr($entry['file_name'],0,$idx);
                 fputcsv($csvFile, [
                    $id,
                    $entry['size'],
                    $entry['creation_time'],
                    $entry['file_name']
                  ]);
        }
        fclose($csvFile);
     }

    /**
     * Creates a CSV file containing the entries for a specific client ID.
     *
     * @param string $clientId The client ID.
     * @param array $entries An array containing the entries for the client.
     * @return void
     */

    private function createDBFileCSV(string $clientId, array $entries): void
    {
        $fileName = $this->structured_directory . 'cassandra_' . (string) $clientId . self::CSV_EXTENSION;
        $csvFile = fopen($fileName, 'w');

        $headers = ['id', 'size', 'creation_time', 'filename', 'bucket', 'client_id', 'attachment_id'];

        fputcsv($csvFile, $headers);
        foreach ($entries as $key => $entry) {
            $rowData = [
                $entry['id'],
                $entry['size'],
                $entry['creation_time'],
                $entry['filename'],
                $entry['bucket'],
                $entry['client_id'],
                $entry['attachment_id'],
            ];
            fputcsv($csvFile, $rowData);
        }
        fclose($csvFile);
    }

    /**
     * Retrieves entries from a database table.
     *
     * @param string $tableName The name of the database table.
     * @return array An array containing the retrieved entries.
     */

    private function getDbEntries(string $tableName): array
    {
        $query = sprintf(
            'SELECT client_id, id, size, filename, created_on%s FROM %s',
            $this->schema_version() === 1 ? '' : ', bucket',
            $tableName
        );
        $arguments = [];
        $result = $this->cassandra->execute(
            $query,
            [
                'arguments' => $arguments,
                'page_size' => static::DEFAULT_PAGE_SIZE
            ]
        );
        $entries = [];
        while ($result) {
            foreach ($result as $row) {

		        if ($row['bucket'] === 'x') {
                    continue; // Skip the current iteration if bucket is 'x'
                }

                if (preg_match('/^[0-9]+$/', $row['id'])) {
                    $dotParts = explode(".", $row['filename'], 2);
                    $dynamicValue = substr($dotParts[1], 0, 2);
                    $timestamp = (int) $row['created_on'];
                    $date = date('Y-m-d H:i:s', $timestamp);
                    $creationTime = str_replace('"', '', $date);
                    $entry = [
                        "id" => $row['id'],
                        "size" => (string) $row['size'],
                        "creation_time" => $creationTime,
                        'filename' => $row['filename'],
                        'bucket' => $row['bucket'] ? $row['bucket'] : '',
                        'client_id' => (string) $row['client_id'],
                        'attachment_id' => (string) $row['id'],
                    ];

                    if ($row['bucket'] !== 'x') {
                        $entries[$dynamicValue][$row['filename']] = $entry;
                    }
            
                } else {
                    $clientId = substr($row['id'], 0, 2);
                    $file = $row['client_id'] . self::DELIMITER . $row['id'];
                    $timestamp = (int) $row['created_on'];
                    $date = date('Y-m-d H:i:s', $timestamp);
                    $creationTime = str_replace('"', '', $date);
                    $entry = [
                        "id" => $file,
                        "size" => (string) $row['size'],
                        "creation_time" => $creationTime,
                        'filename' => $row['filename'],
                        'bucket' => $row['bucket'] ? $row['bucket'] : '',
                        'client_id' => (string) $row['client_id'],
                        'attachment_id' => (string) $row['id'],
                    ];
                    if (!isset($entries[$clientId])) {
                        $entries[$clientId] = [];
                    }
                    if ($row['bucket'] !== 'x') {
                        $entries[$clientId][$file] = $entry;
                    }
                }
            }
            $result = $result->nextPage();
        }
        // Merge all entries into a single array
        $allEntries = [];
        foreach ($entries as $clientEntries) {
            $allEntries = array_merge($allEntries, $clientEntries);
        }
        // Create CSV file for each client ID's physical file entries
        foreach ($entries as $clientId => $clientEntries) {
            $this->createDBFileCSV($clientId, $clientEntries);
        }

        return $entries;
    }


    /**
     * Compares a file entry with its corresponding entry in the Cassandra file association.
     *
     * @param string $id The ID of the file entry.
     * @param array $data An array containing data of the file entry.
     * @param array $cassandra_file_assoc The Cassandra file association.
     * @return array|null An array containing mismatched entries, or null if the entries match.
     */

    private function compareFileEntries(string $id, array $data, array $cassandra_file_assoc)
    {
        if (!isset($cassandra_file_assoc[$id])) {
            return [
                'id' => $id,
                'file1' => [$id, trim($data[0], '"'), trim($data[1], '"')],
            ];
        } else {
            $physical_value1 = trim($data[0], '"');
            $physical_value2 = trim($data[1], '"');
            $cassandra_value1 = trim($cassandra_file_assoc[$id][0], '"');
            $cassandra_value2 = trim($cassandra_file_assoc[$id][1], '"');

            if ($physical_value1 !== $cassandra_value1 || $physical_value2 !== $cassandra_value2) {
                return [
                    'id' => $id,
                    'file1' => [$id, $physical_value1, $physical_value2],
                    'file2' => [$id, $cassandra_value1, $cassandra_value2],
                ];
            }
        }
        return null;
    }

    /**
     * Retrieves the lines of a file and returns them as an array.
     *
     * @param string $file The path to the file.
     * @return array An array containing the lines of the file.
     */

    private function getFileLines(string $file): array
    {
        $file_contents = file_get_contents($file);
        return explode("\n", $file_contents);
    }

    /**
     * Filters out null entries and maps the remaining entries to their first element.
     *
     * @param array $entries An array containing entries to be filtered and mapped.
     * @return array An array of filtered and mapped entries.
     */

    private function filterAndMapEntries(array $entries): array
    {
        $filtered_entries = array_filter($entries);
        $mapped_entries = array_map(function ($entry) {
            return $entry[0];
        }, $filtered_entries);
        return array_values($mapped_entries);
    }

    /**
     * Processes files in a directory, performs comparisons, and generates CSV and HTML reports.
     *
     * @param string $dir The directory path containing the files to be processed.
     * @return void
     */

    private function process_files_in_directory(string $dir): void
    {
        $files = glob($dir . '/*.csv');
        $physical_files = array();
        $cassandra_files = array();
        foreach ($files as $file) {
            $filename = basename($file, static::CSV_EXTENSION);
            $csv_type = substr(
                $filename,
                0,
                strpos($filename, '_')
            );
            $file_num = substr(
                $filename,
                strpos($filename, '_') + 1
            );

            if ($csv_type === 'physical') {
                $physical_files[$file_num] = $file;
            } elseif ($csv_type === 'cassandra') {
                $cassandra_files[$file_num] = $file;
            }
        }

        ksort($physical_files);
        ksort($cassandra_files);

        $missing_physical_files = array();
        $missing_cassandra_entries = array();
        $cassandra_entries = [];
        $physical_entries = [];

        foreach ($physical_files as $file_num => $physical_file) {
            $cassandra_file = $dir . '/cassandra_' . $file_num . self::CSV_EXTENSION;

            if (file_exists($physical_file) && file_exists($cassandra_file)) {
                $compared_physical[] = $this->compare_csv_files($physical_file, $cassandra_file);
                $compared_cassandra[] = $this->compare_csv_files($cassandra_file, $physical_file);
                $physical_entries = $this->filterAndMapEntries($compared_cassandra);
                $cassandra_entries = $this->filterAndMapEntries($compared_physical);

            } else {
                if (!file_exists($physical_file)) {
                    $missing_physical_files[] = $physical_file;
                }
                if (!file_exists($cassandra_file)) {
                    $missing_cassandra_files[] = $cassandra_file;
                }
            }

            if (!file_exists($cassandra_file)) {
                $physical_file_lines = $this->getFileLines($physical_file);
                $file_assoc = array();

                foreach ($physical_file_lines as $line) {
                    if ($line === reset($physical_file_lines)) {
                        continue;
                    }
                    $values = explode(',', $line);
                    if (count($values) === self::NUM_FIELDS) {
                        $values[2] = str_replace('"', '', $values[2]);
                        $file_assoc[$values[0]] = [$values[1], $values[2]];
                    }
                }
                foreach ($file_assoc as $id => $data) {
                    if (!isset($cassandra_files_assoc[$id])) {
                        $missing_cassandra_entries[] = [
                            'id' => $id,
                            'file1' => [$id, $data[0], $data[1]],
                        ];
                    }
                }
            } else {

            }
        }

        foreach ($cassandra_files as $file_num => $cassandra_file) {
            $physical_file = $dir . '/physical_' . $file_num . self::CSV_EXTENSION;

            if (!file_exists($physical_file)) {
                $cassandra_file_lines = $this->getFileLines($cassandra_file);
                $file_assoc = $this->buildFileAssociation($cassandra_file_lines);

                foreach ($file_assoc as $id => $data) {
                    if (!isset($physical_files_assoc[$id])) {
                        $missing_physical_files[] = [
                            'id' => $id,
                            'file1' => [$id, $data[0], $data[1], $data[2], $data[3], $data[4], $data[5]],
                        ];
                    }
                }
            }
        }

        $result_from_cassandra_entries = array_unique(array_merge($cassandra_entries, $missing_cassandra_entries), SORT_REGULAR);
        $result_from_physical_files = array_unique(array_merge($physical_entries, $missing_physical_files), SORT_REGULAR);
        $this->generateCsvReportForDbEntries($result_from_cassandra_entries, self::CASSANDRA_RESULT_CSV);
        $this->generateHtmlReport($result_from_cassandra_entries, self::CASSANDRA_HTML_REPORT);
        $this->generateCsvReportForPhysicalFiles($result_from_physical_files, self::PHYSICAL_RESULT_CSV);
        $this->generateHtmlReport($result_from_physical_files, self::PHYSICAL_HTML_REPORT);
    }

    /**
     * Builds an associative array from file lines.
     *
     * @param array $file_lines An array containing lines of a file.
     * @return array An associative array representing the file association.
     */

    private function buildFileAssociation(array $file_lines): array
    {
        $file_assoc = [];
        foreach ($file_lines as $line) {
            if ($line === reset($file_lines)) {
                continue;
            }

            $values = explode(',', $line);
            if (count($values) === self::NUM_FIELDS) {
                $file_assoc[$values[0]] = [$values[1], $values[2]];
            }

            if (count($values) > 3) {
                $file_assoc[$values[0]] = [$values[1], $values[2], $values[3], $values[4], $values[5], $values[6]];
            }
        }
        return $file_assoc;
    }

    /**
     * Compares two CSV files and returns missing entries or entries with mismatched data.
     *
     * @param string $file1_path The file path of the first CSV file.
     * @param string $file2_path The file path of the second CSV file.
     * @return array An array containing missing entries or entries with mismatched data.
     */

    private function compare_csv_files(string $file1_path, string $file2_path): array
    {
        $file1_data = array_map('str_getcsv', file($file1_path));
        $file2_data = array_map('str_getcsv', file($file2_path));
        $file1_headers = array_shift($file1_data);
        $file2_headers = array_shift($file2_data);
        // find indexes of columns in each file
        $id_index_1 = array_search('id', $file1_headers);
        $id_index_2 = array_search('id', $file2_headers);
        $size_index_1 = array_search('size', $file1_headers);
        $size_index_2 = array_search('size', $file2_headers);
        $time_index_1 = array_search('creation_time', $file1_headers);
        $time_index_2 = array_search('creation_time', $file2_headers);
        $filename_index_1 = array_search('filename', $file1_headers);
        $filename_index_2 = array_search('filename', $file2_headers);
        $clientid_index_1 = array_search('client_id', $file1_headers);
        $bucket_index_1 = array_search('bucket', $file1_headers);
        $attachment_id_index_1 = array_search('attachment_id', $file1_headers);
        $file1_assoc = array_reduce(
            $file1_data, function ($result, $row) use (
                $id_index_1, 
                $size_index_1, 
                $time_index_1, 
                $filename_index_1, 
                $clientid_index_1, 
                $bucket_index_1, 
                $attachment_id_index_1
            ) {
            $result[$row[$id_index_1]] = [
                'id' => $row[$id_index_1],
                'file1' => [
                    $row[$id_index_1],
                    $row[$size_index_1],
                    $row[$time_index_1],
                    isset($row[$filename_index_1]) ? $row[$filename_index_1] : null,
                    isset($row[$clientid_index_1]) ? $row[$clientid_index_1] : null,
                    isset($row[$bucket_index_1]) ? $row[$bucket_index_1] : null,
                    isset($row[$attachment_id_index_1]) ? $row[$attachment_id_index_1] : null
                ],
            ];
            return $result;
        }, []);
        $file2_assoc = array_reduce(
            $file2_data, function ($result, $row) use (
                $id_index_2, 
                $size_index_2, 
                $time_index_2, 
                $filename_index_2
            ) {
            $result[$row[$id_index_2]] = [
                'id' => $row[$id_index_2],
                'file2' => [
                    $row[$id_index_2],
                    $row[$size_index_2],
                    $row[$time_index_2],
                    isset($row[$filename_index_2]) ? $row[$filename_index_2] : null
                ],
            ];
            return $result;
        }, []);
        $missing_entries = [];
        foreach ($file1_assoc as $id => $data) {
            if (!isset($file2_assoc[$id])) {
                $missing_entries[] = [
                    'id' => $id,
                    'file1' => $data['file1'],
                ];
            } else {
                $file2_data = $file2_assoc[$id]['file2'];
                if ($data['file1'][0] !== $file2_data[0] || $data['file1'][1] !== $file2_data[1]) {
                    $missing_entries[] = [
                        'id' => $id,
                        'file1' => $data['file1'],
                        'file2' => $file2_data,
                    ];
                }
            }
        }
        return $missing_entries;
    }

    /**
     * Generates a CSV report of inconsistent files.
     *
     * @param array $inconsistentFiles An array of inconsistent files.
     * @param string $filename The filename to use for the report.
     */

    private function generateCsvReportForPhysicalFiles(array $inconsistentFiles, string $name): void
    {
        $fp = fopen($name, 'w');
        fputcsv($fp, [
            self::CSV_COLUMN_FILE_ATTACHMENT, 
            self::CSV_COLUMN_FILE_PATH, 
            self::CSV_COLUMN_FILE_NAME, 
            self::CSV_COLUMN_THUMB1,  
            self::CSV_COLUMN_THUMB2, 
            self::CSV_COLUMN_SIZE, 
            self::CSV_COLUMN_CREATION_TIME, 
            self::CSV_COLUMN_CLIENT_ID, 
            self::CSV_COLUMN_BUCKET, 
            self::CSV_COLUMN_ID
        ]);

        foreach ($inconsistentFiles as $row) {
            $check_value = $row['id'];
            $filePath = $check_value ? $check_value : $row['file2'][0];
            if (is_numeric($row['id'])) {
                $filePath = $row['file1'][3];
                $check_value = $row['file1'][3];
            }

            $size = isset($row['file1'][1]) ? (string) $row['file1'][1] : filesize($filePath);
            $creationTime = isset($row['file1'][2]) ? (string) $row['file1'][2] : date('Y-m-d H:i:s', filectime($filePath));
            $thumb1 = isset($row['thumb1']) ? $row['thumb1'] : '';
            $thumb2 = isset($row['thumb2']) ? $row['thumb2'] : '';
            $bucket = isset($row['file1'][4]) ? $row['file1'][4] : '';
            $clientId = isset($row['file1'][5]) ? $row['file1'][5] : '';
            $attachmentId = isset($row['file1'][6]) ? $row['file1'][6] : '';

            fputcsv($fp, [
                'Attachment',
                $filePath,
                $check_value,
                $thumb1,
                $thumb2,
                $size,
                $creationTime,
                $clientId,
                $bucket,
                $attachmentId,
            ]);
        }
        fclose($fp);
        chmod($name, 0666);
    }

    /**
     * Generates a CSV report for inconsistent database entries.
     *
     * @param array $inconsistentFiles An array containing inconsistent file data.
     * @param string $name The name of the CSV report file to be generated.
     * @return void
     */

    private function generateCsvReportForDbEntries(array $inconsistentFiles, string $name): void
    {
        $fp = fopen($name, 'w');
        fputcsv($fp, [
            self::CSV_COLUMN_FILE_ATTACHMENT, 
            'Entry Path', 
            'Entry Name', 
            self::CSV_COLUMN_THUMB1, 
            self::CSV_COLUMN_THUMB2, 
            self::CSV_COLUMN_SIZE, 
            self::CSV_COLUMN_CREATION_TIME
        ]);

        foreach ($inconsistentFiles as $row) {
            $filePath = $this->directory . DIRECTORY_SEPARATOR . $row['file1'][3] ? $this->directory . DIRECTORY_SEPARATOR . $row['file1'][3] : $this->directory . DIRECTORY_SEPARATOR . $row['file2'][3];
            $size = isset($row['file1'][1]) ? (string) $row['file1'][1] : filesize($filePath);
            $creationTime = isset($row['file1'][2]) ? (string) $row['file1'][2] : date('Y-m-d H:i:s', filectime($filePath));
            $thumb1 = $row['file1'][3] . '-thumb1';
            $thumb2 = $row['file1'][3] . '-thumb2';
            if (is_string($row['id']) && strpos($row['id'], '.') !== false) {
                $old_attachment = explode('.', $row['id'])[0];
                $thumb1 = '';
                $thumb2 = '';
            }
            fputcsv($fp, [
                'File',
                $filePath,
                $row['file1'][0],
                $thumb1,
                $thumb2,
                $size,
                $creationTime
            ]);
        }
        fclose($fp);
        chmod($name, 0666);
    }


    /**
     * Generates an HTML report of inconsistent files.
     *
     * @param array $inconsistentFiles An array of inconsistent files.
     * @param string $filename The filename to use for the report.
     */

     private function generateHtmlReport(array $inconsistentFiles, string $name): void
     {   
         $templateFile = 'report_template.html';
         $templateContent = file_get_contents($templateFile);
 
         if ($templateContent === false) {
             throw new Exception('Failed to read the HTML template file.');
         }
 
         $tableRows = '';
         foreach ($inconsistentFiles as $row) {
             $filename = $row['file1'][0];
             $filePath = $this->directory . DIRECTORY_SEPARATOR . $filename;
             $size = isset($row['file1'][1]) ? (string) $row['file1'][1] : filesize($filePath);
             $creationTime = isset($row['file1'][2]) ? str_replace('"', '', $row['file1'][2]) : date('Y-m-d H:i:s', filectime($filePath));
             $thumb1 = $row['file1'][0] . '-thumb1';
             $thumb2 = $row['file1'][0] . '-thumb2';
             
             if (isset($row['file1'][3]) && preg_match('/^[0-9]+\./', $row['file1'][3])) {
                $filename = $row['file1'][3];
                $filePath = $this->directory . DIRECTORY_SEPARATOR . $filename;
                $thumb1 = '';
                $thumb2 = '';
            }
            
             if (is_string($row['id']) && strpos($row['id'], '.') !== false) {
                 $filename = $row['id'];
                 $filePath = $this->directory . DIRECTORY_SEPARATOR . $filename;
                 $thumb1 = '';
                 $thumb2 = '';
             }
            
             $tableRows .= '<tr><td>Attachment</td><td>' . htmlspecialchars($filePath) . '</td><td>' . htmlspecialchars($filename) . '</td><td>' . htmlspecialchars($thumb1) . '</td><td>' . htmlspecialchars($thumb2) . '</td><td>' . htmlspecialchars($size) . '</td><td>' . htmlspecialchars($creationTime) . '</td></tr>';  
         }  
         $html = str_replace('{{table_rows}}', $tableRows, $templateContent); 
         $file = fopen($name, 'w');
      
         if (!$file) {
             throw new Exception('Failed to open the file for writing.');
         }
 
         fwrite($file, $html);
         fclose($file);
     }

    /**
     * Returns cassandra schema version
     *
     *
     * @return int
     */
    
    private function schema_version(): int
    {
        return static::$schemaVersion;
    }
    
    /**
     * Returns info(id,size) for attachment file
     *
     * @param int $clientId
     * @param string|null $bucketId
     * @param string $id
     * @return object|null 
     */

    private function get_info(int $clientId, ?string $bucketId, string $id): ?object
    {
        $attachment = null;
        $args = [
            'client_id' => $clientId,
            'id' => $id
        ];

        if ($this->schema_version() == 1) {
            $query = $this->cassandra->prepare('SELECT * FROM attachment_file_info WHERE id = ? AND client_id = ?');
        } else {
            $q = 'SELECT * FROM attachment_file_info WHERE id = ? AND client_id = ? AND bucket = \'' . $bucketId . '\'';
            $query = $this->cassandra->prepare($q);
        }
        $res = $this->cassandra->execute(
            $query,
            [
                'arguments' => $args
            ]
        );
        if ($res && $res->valid()) {
            $tmp = $res->current();

            $attachment = (object) $tmp;
            $attachment->id = (string) $tmp['id'];
            if (array_key_exists('size', $tmp)) {
                $attachment->size = (int) $tmp['size'];
            }
        }
        return $attachment;
    }

    /**
     * prepares 'bucket' field for partitioning
     *
     * @param string $id
     * @return string
     */

    private function _set_bucket(string $id): string
    {
        return substr($id, 0, static::$bucketMagic);
    }

    /**
     * updates attachment count and size
     *
     * @param boolean $add
     * @param integer $size
     *
     * @return void
     */

    private function _update_attachment_stats(bool $add, int $size): void
    {
        $op = $add ? '+' : self::DELIMITER;
        $query = $this->cassandra->prepare('UPDATE attachment_stats SET count = count ' . $op . ' 1 where client_id = ?');
        $this->cassandra->execute($query, ['arguments' => ['client_id' => (int) static::$clientId]]);
        $query = $this->cassandra->prepare(
            'UPDATE attachment_stats SET size = size  ' . $op . ' ' . $size . ' where client_id = ?'
        );
        $this->cassandra->execute($query, ['arguments' => ['client_id' => static::$clientId]]);
    }

    /**
     * returns full attachment table key for given id
     *
     * @param string $id
     *
     * @return object|null
     */

    private function _get_attachment_key(string $id): ?object
    {
        $result = null;
        $query = $this->cassandra->prepare('SELECT * from attachment_ids where id = ? AND bucket = ? AND client_id = ?');
        $arguments = [
            'client_id' => static::$clientId,
            'bucket' => $this->_set_bucket($id),
            'id' => $id,
        ];
        $data = $this->cassandra->execute($query, ['arguments' => $arguments]);

        if ($data && $data->valid()) {
            $result = (object) $data->current();
        }
        return $result;
    }

    /**
     * returns single attachment data for provided ID
     *
     * @param string $attachmentId
     *
     * @return object|null
     */

    private function _get_attachment_by_id(string $attachmentId): ?object
    {
        $attachment = null;
        try {
            $properties = '*';
            $key = $this->_get_attachment_key($attachmentId);
            if ($key) {
                if ($this->schema_version() === 1) {
                    $query = $this->cassandra->prepare('SELECT ' . $properties . ' FROM attachments WHERE id = ? AND client_id = ? AND project_id = ? AND entity_type = ?');
                    $arguments = [
                        'client_id' => static::$clientId,
                        'id' => $key->id,
                        'project_id' => $key->project_id,
                        'entity_type' => $key->entity_type,
                    ];
                } else {
                    $query = $this->cassandra->prepare('SELECT ' . $properties . ' FROM attachments WHERE id = ? AND client_id = ? AND project_id = ? AND entity_type = ? AND entity_id = ?');
                    $arguments = [
                        'client_id' => static::$clientId,
                        'id' => $key->id,
                        'project_id' => $key->project_id,
                        'entity_id' => $key->entity_id,
                        'entity_type' => $key->entity_type,
                    ];
                }
                $attachment = $this->cassandra->execute($query, ['arguments' => $arguments]);
            }
        } catch (Cassandra\Exception\InvalidArgumentException $e) {
        }

        return $attachment != null && $attachment->valid() ? $this->_convert_to_object($attachment->current()) : null;
    }

    /**
     * deletes attachment_ids entry
     *
     * @param string $id
     */
    
    private function _delete_attachment_key(string $id): void
    {
        $this->cassandra->executeAsync(
            $this->cassandra->prepare('DELETE FROM attachment_ids WHERE id = ? AND bucket = ? AND client_id = ?'),
            [
                'arguments' => [
                    'client_id' => static::$clientId,
                    'bucket' => $this->_set_bucket($id),
                    'id' => $id
                ]
            ]
        );
    }

    /**
     * updates attachment data references
     *
     * @param string $data_id
     * @param bool $add
     * @param string $attachmentId
     *
     * @return void
     */

    private function _update_file_refs(string $data_id, bool $add, string $attachmentId = ''): void
    {
        $queryArguments = [
            'client_id' => static::$clientId,
            'bucket' => $this->_set_bucket($data_id),
            'id' => $data_id,
        ];
        $query = $this->cassandra->prepare('UPDATE attachment_file_refs SET ref_count = ref_count ' . ($add ? '+' : self::DELIMITER) . ' 1 WHERE bucket = ? AND id = ? AND client_id = ?');
        $this->cassandra->executeAsync($query, ['arguments' => $queryArguments]);

        if (!empty($attachmentId)) {
            $queryArguments['attachment_id'] = $attachmentId;
            if ($add) {
                $query = $this->cassandra->prepare('INSERT INTO attachment_file_ids (client_id,bucket,id,attachment_id) VALUES(?,?,?,?)');
            } else {
                $query = $this->cassandra->prepare('DELETE FROM attachment_file_ids WHERE client_id = ? AND bucket = ? AND attachment_id = ? AND id  = ?');
            }
            $this->cassandra->executeAsync($query, ['arguments' => $queryArguments]);

        }
    }


    /**
     * Deletes attachment from Cassandra
     *
     *
     * @param int $clientId
     * @param string|null $bucketId
     * @param string $id
     *
     * @return bool
     */

    public function deleteAttachment(int $clientId, ?string $bucketId, string $id): bool
    {
        static::$clientId = $clientId;
        $refData = [
            'client_id' => $clientId,
            'id' => $id,
        ];
        $fileInfo = $this->get_info($clientId, $bucketId, $id);
        if ($fileInfo) {
            $this->_update_attachment_stats(false, $fileInfo->size);
        } else {
            return false;
        }

        $q = 'DELETE FROM attachment_file_info WHERE id = ? AND client_id = ? ';
        if ($this->schema_version() === 2) {
            $q = $q . ' AND bucket = \'' . $bucketId . '\'';
        }
        $query = $this->cassandra->prepare($q);
        $this->cassandra->execute($query, ['arguments' => $refData]);
        $refData['bucket'] = $this->_set_bucket($id);
        $query = $this->cassandra->prepare(
            'DELETE FROM attachment_file_refs WHERE bucket = ? AND id = ? AND client_id = ?'
        );
        $result = $this->cassandra->execute($query, ['arguments' => $refData]);

        // get all attachments with deleted file and remove them
        $query = $this->cassandra->prepare(
            'SELECT attachment_id FROM attachment_file_ids WHERE bucket = ? AND id = ? AND client_id = ?'
        );
        $result = $this->cassandra->execute($query, ['arguments' => $refData]);

        if ($this->schema_version() === 1) {
            $delQuery = $this->cassandra->prepare(
                'DELETE FROM attachments WHERE id = ? AND client_id = ? AND project_id = ? AND entity_type = ?'
            );
        } else {
            $delQuery = $this->cassandra->prepare(
                'DELETE FROM attachments WHERE id = ? AND client_id = ? AND project_id = ? AND entity_type = ? AND entity_id = ?'
            );
        }
        while ($result && $result->valid()) {
            $attachmentId = $result->current()['attachment_id'];
            $key = $this->_get_attachment_key((string) $attachmentId);
            if ($key == null) {
                $result->next();
                continue;
            }
            if ($this->schema_version() === 1) {
                $selectQuery = $this->cassandra->prepare(
                    'SELECT entity_id FROM attachments WHERE id = ? AND client_id = ? AND project_id = ? AND entity_type = ?'
                );
                $attachment = $this->cassandra->execute($selectQuery, [
                    'arguments' => [
                        'client_id' => static::$clientId,
                        'project_id' => $key->project_id,
                        'entity_type' => $key->entity_type,
                        'id' => $attachmentId,
                    ]
                ]);
                $entity_id = $attachment->current()['entity_id'];
                $delArgs = [
                    'client_id' => static::$clientId,
                    'project_id' => $key->project_id,
                    'entity_type' => $key->entity_type,
                    'id' => $attachmentId,
                ];
            } else {
                $entity_id = $key->entity_id;
                $delArgs = [
                    'client_id' => static::$clientId,
                    'project_id' => $key->project_id,
                    'entity_type' => $key->entity_type,
                    'entity_id' => $entity_id,
                    'id' => $attachmentId,
                ];
            }
            $this->_delete_attachment_key((string) $attachmentId);
            $this->cassandra->execute($delQuery, ['arguments' => $delArgs]);
            $result->next();
        }
        $query = $this->cassandra->prepare(
            'DELETE FROM attachment_file_ids WHERE bucket = ? AND id = ? AND client_id = ?'
        );
        $this->cassandra->execute($query, ['arguments' => $refData]);
        $result = false;
        $attachment = $this->_get_attachment_by_id($id);
        if ($attachment) {
            if ($this->schema_version() === 1) {
                $query = $this->cassandra->prepare("DELETE FROM attachments WHERE id = ? AND project_id = ? AND entity_type = ? AND client_id = ?");
                $arguments = [
                    'arguments' => [
                        'client_id' => static::$clientId,
                        'id' => $id,
                        'project_id' => $attachment->project_id,
                        'entity_type' => $attachment->entity_type
                    ],
                ];
            } else {
                $query = $this->cassandra->prepare("DELETE FROM attachments WHERE id = ? AND project_id = ? AND entity_id = ? AND entity_type = ? AND client_id = ?");
                $arguments = [
                    'arguments' => [
                        'client_id' => static::$clientId,
                        'id' => $id,
                        'project_id' => $attachment->project_id,
                        'entity_type' => $attachment->entity_type,
                        'entity_id' => $attachment->entity_id
                    ],
                ];
            }
            $queryResult = $this->cassandra->execute($query, $arguments) != null;

            if ($queryResult) {
                $result = true;
                $this->_update_file_refs($attachment->data_id, false, $attachment->id);
                $this->_delete_attachment_key($id);
            }
        }

        return $result;
    }


    /**
     * Deletes attachments provided in file
     *
     *
     * @param string  $file
     * @param string $src ('cassandra'/'file')
     *
     * @return void
     *
     * example file:
     * 
     * cassandra,/test1/testx,testx,testx-thumb1,testx-thumb2,4343,20-02-22 13:30,1,a,abc-def
     * cassandra,/test1/testx1,testx1,testx1-thumb1,testx1-thumb2,4343,20-02-22 13:30,1,1,1abc-def
     * file,/tmp/testx3f,testx3f,testx3f-thumb1,testx3f-thumb2,4343,20-02-22 13:30,,,
     * cassandra,/test1/testx3,testx3,testx3-thumb1,testx3-thumb2,4343,20-02-22 13:30,1,3,3abc-def
     */

    public function processAttachmentDeletionCSV(string $file, string $src): void
    {

        echo "Before proceeding with the deletion, make sure you have a backup of your data." . PHP_EOL;
        echo "You can revert back to the backup in case of accidental data loss." . PHP_EOL;
        echo "Do you want to delete the physical files listed in the CSV report? (yes/no): ";
        $confirmation = trim(fgets(STDIN));

        if (strtolower($confirmation) !== 'yes') {
            return;
        }

	    $this->init();
        $file_contents = file_get_contents($file);
        $file_lines = explode("\n", $file_contents);
        $logFile = 'deleted_files.log';
        $logHandle = fopen($logFile, 'a');

        foreach ($file_lines as $line) {

            if ($line === reset($file_lines)) {
                continue;
            }
            $values = explode(',', $line);

            if ($values[0] === 'File/Attachment') {
                continue;
            }
            
            if (count($values) >= 7) {
                $data = (object) array();
                $data->source = $values[0];
                $data->path = $values[1];
                $data->name = $values[2];
                $data->thumb1 = $values[3];
                $data->thumb2 = $values[4];
                $data->size = $values[5];
                $data->created = $values[6];
                $path = dirname($data->path);

                if (count($values) >= 10) {
                    $data->clientId = (int) $values[7];
                    $data->bucket = $values[8];
                    $data->id = $values[9];
                }

                if ($data->source === 'Attachment' && $src === 'cassandra') {
                    echo "will delete " . $data->clientId . " : " . $data->bucket . " : " . $data->id . PHP_EOL;
                    $this->deleteAttachment($data->clientId, $data->bucket, $data->id);
                    fwrite($logHandle, "Deleted attachment: $data->id" . PHP_EOL);
                } else if ($data->source === 'File' && $src === 'file') {
                    $filePath = $values[1];
                    $thumb1Path = $path . DIRECTORY_SEPARATOR . $values[3];
                    $thumb2Path = $path . DIRECTORY_SEPARATOR . $values[4];
                    $filePath = str_replace('"', '', $filePath);
                    $thumb1Path = str_replace('"', '', $thumb1Path);
                    $thumb2Path = str_replace('"', '', $thumb2Path);

                    if (file_exists($thumb1Path) && file_exists($thumb2Path)) {
                        unlink($thumb1Path);
                        unlink($thumb2Path);
                        fwrite($logHandle, "Deleted thumbnail: " . $thumb1Path  . PHP_EOL);
                        fwrite($logHandle, "Deleted thumbnail: " . $thumb2Path  . PHP_EOL);
                    }

                    if (file_exists($filePath)) {
                        unlink($filePath);
                        unlink($thumb1Path);
                        unlink($thumb2Path);
                        echo "File deleted: $filePath" . PHP_EOL;
                        // Write the deleted file path to the log file
                        fwrite($logHandle, "Deleted file: $filePath" . PHP_EOL);
                    } else {
                        echo "File not found: $filePath" . PHP_EOL;
                    }
                }
            }
        }
        fclose($logHandle);
        echo "Deletion completed. The list of attachments is saved in '$logFile'." . PHP_EOL;
    }
}

$checker = new DataConsistencyChecker();
$checker->checkConsistency("attachment_file_info", true);