Use a table field as array - php + wordpress

TableDateFieldAsArray.php

<?php

class TableDateFieldAsArray {
    private $postId;      // The post ID for context
    private $primaryKey;  // Primary key for rows
    private $tableName;   // Custom table name
    private $fieldName;   // Field in the table to store serialized data
    private $data = [];   // The actual data
    private $nextIndex = 1;
    private $usedKeys = []; // Track all used keys
    private $wpdb;        // WordPress database object

    public function __construct( $postId, $tableName, $fieldName, $primaryKey = 'id' ) {
        global $wpdb;

        $this->postId     = $postId;
        $this->primaryKey = $primaryKey;
        $this->tableName  = $tableName; // Custom table name
        $this->fieldName  = $fieldName; // Field name to store serialized data
        $this->wpdb       = $wpdb;     // Access the global $wpdb object

        $this->loadData();
    }

    // Load data from the custom table
    private function loadData() {
        $query = $this->wpdb->prepare(
            "SELECT {$this->fieldName} FROM {$this->tableName} WHERE post_id = %d",
            $this->postId
        );
        $result = $this->wpdb->get_var( $query );

        if ( $result ) {
            $decodedData = maybe_unserialize( $result );
            if ( is_array( $decodedData ) ) {
                $this->data      = $decodedData['data'] ?? [];
                $this->nextIndex = $decodedData['nextIndex'] ?? 1;
                $this->usedKeys  = $decodedData['usedKeys'] ?? [];
            }
        }
    }

    // Save data to the custom table
    private function saveData() {
        $serializedData = maybe_serialize( [
            'data'      => $this->data,
            'nextIndex' => $this->nextIndex,
            'usedKeys'  => $this->usedKeys,
        ] );

        $this->wpdb->replace(
            $this->tableName,
            [
                'post_id'   => $this->postId,
                $this->fieldName => $serializedData,
            ],
            [
                '%d',
                '%s',
            ]
        );
    }

    // Insert a new row
    public function insert( $row ) {
        $primaryKey = $this->primaryKey;

        if ( ! isset( $row[ $primaryKey ] ) ) {
            $row[ $primaryKey ] = $this->nextIndex;
            $this->nextIndex++;
        } else {
            foreach ( $this->data as $dataRow ) {
                if ( $dataRow[ $primaryKey ] === $row[ $primaryKey ] ) {
                    throw new InvalidArgumentException( "Primary key {$row[$primaryKey]} already exists." );
                }
            }
            $this->nextIndex = max( $this->nextIndex, $row[ $primaryKey ] + 1 );
        }

        $this->data[] = $row;
        $this->saveData();
    }

    // Get a row by primary key
    public function get( $key ) {
        $primaryKey = $this->primaryKey;

        foreach ( $this->data as $dataRow ) {
            if ( $dataRow[ $primaryKey ] === $key ) {
                return $dataRow;
            }
        }

        return null;
    }

    // Update a row by primary key
    public function update( $key, $row ) {
        $primaryKey = $this->primaryKey;

        foreach ( $this->data as &$dataRow ) {
            if ( $dataRow[ $primaryKey ] === $key ) {
                $dataRow = array_merge( $dataRow, $row );
                $this->saveData();
                return;
            }
        }

        throw new OutOfBoundsException( "Row with primary key $key does not exist." );
    }

    // Delete a row by primary key
    public function delete( $key ) {
        $primaryKey = $this->primaryKey;

        foreach ( $this->data as $index => $dataRow ) {
            if ( $dataRow[ $primaryKey ] === $key ) {
                unset( $this->data[ $index ] );
                $this->saveData();
                return;
            }
        }

        throw new OutOfBoundsException( "Row with primary key $key does not exist." );
    }

    // Get all rows with optional sorting
    public function getAll( $orderBy = null, $order = 'asc' ) {
        $data = $this->data;

        if ( $orderBy !== null ) {
            usort( $data, function ( $a, $b ) use ( $orderBy, $order ) {
                if ( ! isset( $a[ $orderBy ] ) || ! isset( $b[ $orderBy ] ) ) {
                    return 0;
                }
                $comparison = $a[ $orderBy ] <=> $b[ $orderBy ];

                return $order === 'desc' ? - $comparison : $comparison;
            } );
        }

        return $data;
    }

    // Get the total number of rows
    public function getTotalRows() {
        return count( $this->data );
    }
}