SchemaMaintenance.php

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<?php
 
use MediaWiki\DB\AbstractSchemaValidationError;
use MediaWiki\DB\AbstractSchemaValidator;
 
require_once __DIR__ . '/../Maintenance.php';
 
abstract class SchemaMaintenance extends Maintenance {
    public const SUPPORTED_PLATFORMS = [
        'mysql',
        'sqlite',
        'postgres'
    ];
 
    protected $scriptName;
 
    public function __construct() {
        parent::__construct();
 
        $types = implode( ', ', array_map( static function ( string $type ): string {
            return "'$type'";
        }, self::SUPPORTED_PLATFORMS ) );
 
        $this->addOption(
            'json',
            'Path to the json file. Default: tables.json',
            false,
            true
        );
        $this->addOption(
            'sql',
            'Path to output. If --type=all is given, ' .
            'the output will be placed in a directory named after the dbms. ' .
            'For mysql, a directory will only be used if it already exists. Default: tables-generated.sql',
            false,
            true
        );
        $this->addOption(
            'type',
            "Can be either $types, or 'all'. Default: mysql",
            false,
            true
        );
        $this->addOption(
            'validate',
            'Validate the schema instead of generating sql files.'
        );
    }
 
    public function execute() {
        global $IP;
 
        $platform = $this->getOption( 'type', 'mysql' );
        $jsonPath = $this->getOption( 'json', dirname( __DIR__ ) );
 
        $installPath = $IP;
 
        // For windows
        if ( DIRECTORY_SEPARATOR === '\\' ) {
            $installPath = strtr( $installPath, '\\', '/' );
            $jsonPath = strtr( $jsonPath, '\\', '/' );
        }
 
        if ( $this->hasOption( 'validate' ) ) {
            $this->getSchema( $jsonPath );
 
            return;
        }
 
        // Allow to specify a folder and use a default name
        if ( is_dir( $jsonPath ) ) {
            $jsonPath .= '/tables.json';
        }
 
        $relativeJsonPath = str_replace(
            [ "$installPath/extensions/", "$installPath/" ],
            '',
            $jsonPath
        );
 
        if ( in_array( $platform, self::SUPPORTED_PLATFORMS, true ) ) {
            $platforms = [ $platform ];
        } elseif ( $platform === 'all' ) {
            $platforms = self::SUPPORTED_PLATFORMS;
        } else {
            $platforms = [];
            $this->fatalError( "'$platform' is not a supported platform!" );
        }
 
        foreach ( $platforms as $platform ) {
            $sqlPath = $this->getOption( 'sql', dirname( $jsonPath ) );
 
            // MediaWiki, and some extensions place mysql .sql files in the directory root, instead of a dedicated
            // sub directory. If mysql/ doesn't exist, assume that the .sql files should be in the directory root.
            if ( $platform === 'mysql' && !is_dir( $sqlPath . '/mysql' ) ) {
                // Allow to specify a folder and build the name from the json filename
                if ( is_dir( $sqlPath ) ) {
                    $sqlPath = $this->getSqlPathWithFileName( $relativeJsonPath, $sqlPath );
                }
            } else {
                // Allow to specify a folder and build the name from the json filename
                if ( is_dir( $sqlPath ) ) {
                    $sqlPath .= '/' . $platform;
                    $directory = $sqlPath;
                    $sqlPath = $this->getSqlPathWithFileName( $relativeJsonPath, $sqlPath );
                } elseif ( count( $platforms ) > 1 ) {
                    $directory = dirname( $sqlPath ) . '/' . $platform;
                    $sqlPath = $directory . '/' . pathinfo( $sqlPath, PATHINFO_FILENAME ) . '.sql';
                } else {
                    $directory = false;
                }
 
                // The directory for the platform might not exist.
                if ( $directory !== false && !is_dir( $directory )
                    && !mkdir( $directory ) && !is_dir( $directory )
                ) {
                    $this->error( "Cannot create $directory for $platform" );
 
                    continue;
                }
            }
 
            $this->writeSchema( $platform, $jsonPath, $relativeJsonPath, $sqlPath );
        }
    }
 
    private function getSqlPathWithFileName( string $relativeJsonPath, string $sqlPath ): string {
        $jsonFilename = pathinfo( $relativeJsonPath, PATHINFO_FILENAME );
        if ( str_starts_with( $jsonFilename, 'tables' ) ) {
            $sqlFileName = $jsonFilename . '-generated.sql';
        } else {
            $sqlFileName = $jsonFilename . '.sql';
        }
 
        return $sqlPath . '/' . $sqlFileName;
    }
 
    private function writeSchema(
        string $platform,
        string $jsonPath,
        string $relativeJsonPath,
        string $sqlPath
    ): void {
        $abstractSchemaChange = $this->getSchema( $jsonPath );
 
        $sql =
            "-- This file is automatically generated using maintenance/$this->scriptName.\n" .
            "-- Source: $relativeJsonPath\n" .
            "-- Do not modify this file directly.\n" .
            "-- See https://www.mediawiki.org/wiki/Manual:Schema_changes\n";
 
        $sql .= $this->generateSchema( $platform, $abstractSchemaChange );
 
        // Give a hint, if nothing changed
        if ( is_readable( $sqlPath ) ) {
            $oldSql = file_get_contents( $sqlPath );
            if ( $oldSql === $sql ) {
                $this->output( "Schema change is unchanged.\n" );
            }
        }
 
        file_put_contents( $sqlPath, $sql );
        $this->output( 'Schema change generated and written to ' . $sqlPath . "\n" );
    }
 
    abstract protected function generateSchema( string $platform, array $schema ): string;
 
    private function getSchema( string $jsonPath ): array {
        $json = file_get_contents( $jsonPath );
 
        if ( !$json ) {
            $this->fatalError(
                "'$jsonPath' does not exist!\n"
            );
        }
 
        $abstractSchema = json_decode( $json, true );
 
        if ( json_last_error() !== JSON_ERROR_NONE ) {
            $this->fatalError(
                "'$jsonPath' seems to be invalid json. Check the syntax and try again!\n" . json_last_error_msg()
            );
        }
 
        $validator = new AbstractSchemaValidator( function ( string $msg ): void {
            $this->fatalError( $msg );
        } );
        try {
            $validator->validate( $jsonPath );
        } catch ( AbstractSchemaValidationError $e ) {
            $this->fatalError( $e->getMessage() );
        }
 
        return $abstractSchema;
    }
}