Pink-Crab/WPDB_Migrations

<?php

declare(strict_types=1);

/**
 * Holds a log of the last table constructed
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Glynn Quelch <glynn.quelch@gmail.com>
 * @license http://www.opensource.org/licenses/mit-license.html  MIT License
 * @package PinkCrab\DB_Migration
 */

namespace PinkCrab\DB_Migration\Log;

use InvalidArgumentException;
use PinkCrab\Table_Builder\Schema;
use PinkCrab\DB_Migration\Log\Migration_Log;

class Migration_Log_Manager {

    /**
     * The key used to hold all migration dates
     * Can be shared between multiple plugins.
     *
     * @var string
     */
    protected $option_key;

    /**
     * Current migration details
     *
     * @var array<Migration_Log>
     */
    protected $migration_details = array();

    public function __construct( string $option_key = null ) {
        $this->option_key = $option_key ?? 'pinkcrab_migration_log';
        $this->set_migration_details();
    }

    /**
     * Sets the migration details held in optiosn
     *
     * @return void
     * @throws InvalidArgumentException If can not unserialize
     */
    protected function set_migration_details(): void {
        $migrations = get_option( $this->option_key, null );

        if ( $migrations === null ) {
            return;
        }

        // Handle errors as exceptions.
        set_error_handler( // phpcs:ignore
            function ( int $errno, string $errstr ) { // phpcs:ignore
                throw new InvalidArgumentException( 'Migration details as unserialize from options, failed to be decoded.' );
            }
        );
        $migrations = \unserialize( $migrations ); // phpcs:ignore
        restore_error_handler();

        $this->migration_details = $migrations;
    }

    /**
     * Checks if a table has been migrated
     *
     * @param \PinkCrab\Table_Builder\Schema $schema
     * @return boolean
     */
    public function has_migration( Schema $schema ): bool {
        return array_key_exists( $schema->get_table_name(), $this->migration_details );
    }

    /**
     * Gets a migration log based on its name
     *
     * @return \PinkCrab\DB_Migration\Log\Migration_Log|null
     */
    public function get_migration( Schema $schema ): ?Migration_Log {
        return $this->has_migration( $schema )
            ? $this->migration_details[ $schema->get_table_name() ]
            : null;
    }

    /**
     * Check if a table can be migrated.
     *
     * @param \PinkCrab\Table_Builder\Schema $schema
     * @return bool
     */
    public function can_migrate( Schema $schema ): bool {
        return ! $this->check_hash( $schema );
    }

    /**
     * Checks if the define table has been seeded.
     *
     * @param \PinkCrab\Table_Builder\Schema $schema
     * @return bool
     */
    public function is_seeded( Schema $schema ): bool {
        return $this->has_migration( $schema )
        && $this->migration_details[ $schema->get_table_name() ]->is_seeded();
    }

    /**
     * Checks if the passed schema's hash matches the existing schema hash.
     *
     * @param \PinkCrab\Table_Builder\Schema $schema
     * @return bool
     */
    private function check_hash( Schema $schema ): bool {
        // If table doesnt exist, return false;
        if ( ! $this->has_migration( $schema ) ) {
            return false;
        }

        $schema_hash = Migration_Log::compose_column_hash( $schema );
        $migration   = $this->migration_details[ $schema->get_table_name() ];
        return strcmp( $schema_hash, $migration->schema_hash() ) === 0;
    }

    /**
     * Upserts a migration based on its schema.
     *
     * - Upates if Migration exists, but schema is different.
     * - Creates if Migration doesnt exist.
     *
     * Only updates the schema is actually upserted.
     *
     * @param \PinkCrab\Table_Builder\Schema $schema
     * @return self
     */
    public function upsert_migration( Schema $schema ): self {
        // Update if table exists and we have a new schema defined.
        if ( $this->has_migration( $schema )
        && ! $this->check_hash( $schema ) ) {
            $this->migration_details[ $schema->get_table_name() ] =
                $this->migration_details[ $schema->get_table_name() ]->as_updated( $schema );

            $this->save();
        }

        // If a new hash.
        if ( $this->has_migration( $schema ) === false ) {
            $this->migration_details[ $schema->get_table_name() ] =
                Migration_Log::new_from_schema( $schema );

            $this->save();
        }

        return $this;
    }

    /**
     * Removes a migration from the log based on its schema.
     *
     * @param \PinkCrab\Table_Builder\Schema $schema
     * @return self
     */
    public function remove_migration( Schema $schema ): self {
        if ( $this->has_migration( $schema ) ) {
            unset( $this->migration_details[ $schema->get_table_name() ] );

            $this->save();
        }
        return $this;
    }

    /**
     * If the table has not already been seeded, update the to denote it has.
     *
     * @param \PinkCrab\Table_Builder\Schema $schema
     * @return self
     */
    public function mark_table_seeded( Schema $schema ): self {
        if ( ! $this->is_seeded( $schema ) ) {
            $this->migration_details[ $schema->get_table_name() ] =
                $this->migration_details[ $schema->get_table_name() ]->as_seeded();

            $this->save();
        }

        return $this;
    }

    /**
     * Saves the current migration details
     *
     * @return void
     */
    protected function save(): void {
        \update_option( $this->option_key, serialize( $this->migration_details ), false ); // phpcs:ignore
    }

    /**
     * Returns the migration log key
     *
     * @return string
     */
    public function get_log_key(): string {
        return $this->option_key;
    }

    /**
     * Clears the log from options table
     *
     * @return void
     */
    public function clear_log(): void {
        \delete_option( $this->option_key );
    }
}