<?php
/**
 * Classes to create relation schema in Dia format.
 */

declare(strict_types=1);

namespace PhpMyAdmin\Plugins\Schema\Dia;

use PhpMyAdmin\Plugins\Schema\ExportRelationSchema;

use function in_array;

/**
 * Dia Relation Schema Class
 *
 * Purpose of this class is to generate the Dia XML Document
 * which is used for representing the database diagrams in Dia IDE
 * This class uses Database Table and Reference Objects of Dia and with
 * the combination of these objects actually helps in preparing Dia XML.
 *
 * Dia XML is generated by using XMLWriter php extension and this class
 * inherits ExportRelationSchema class has common functionality added
 * to this class
 *
 * @property Dia $diagram
 */
class DiaRelationSchema extends ExportRelationSchema
{
    /** @var TableStatsDia[] */
    private $tables = [];

    /** @var RelationStatsDia[] Relations */
    private $relations = [];

    /** @var float */
    private $topMargin = 2.8222000598907471;

    /** @var float */
    private $bottomMargin = 2.8222000598907471;

    /** @var float */
    private $leftMargin = 2.8222000598907471;

    /** @var float */
    private $rightMargin = 2.8222000598907471;

    /** @var int */
    public static $objectId = 0;

    /**
     * Upon instantiation This outputs the Dia XML document
     * that user can download
     *
     * @see Dia
     * @see TableStatsDia
     * @see RelationStatsDia
     *
     * @param string $db database name
     */
    public function __construct($db)
    {
        parent::__construct($db, new Dia());

        $this->setShowColor(isset($_REQUEST['dia_show_color']));
        $this->setShowKeys(isset($_REQUEST['dia_show_keys']));
        $this->setOrientation((string) $_REQUEST['dia_orientation']);
        $this->setPaper((string) $_REQUEST['dia_paper']);

        $this->diagram->startDiaDoc(
            $this->paper,
            $this->topMargin,
            $this->bottomMargin,
            $this->leftMargin,
            $this->rightMargin,
            $this->orientation
        );

        $alltables = $this->getTablesFromRequest();

        foreach ($alltables as $table) {
            if (isset($this->tables[$table])) {
                continue;
            }

            $this->tables[$table] = new TableStatsDia(
                $this->diagram,
                $this->db,
                $table,
                $this->pageNumber,
                $this->showKeys,
                $this->offline
            );
        }

        $seen_a_relation = false;
        foreach ($alltables as $one_table) {
            $exist_rel = $this->relation->getForeigners($this->db, $one_table, '', 'both');
            if (! $exist_rel) {
                continue;
            }

            $seen_a_relation = true;
            foreach ($exist_rel as $master_field => $rel) {
                /* put the foreign table on the schema only if selected
                 * by the user
                 * (do not use array_search() because we would have to
                 * to do a === false and this is not PHP3 compatible)
                 */
                if ($master_field !== 'foreign_keys_data') {
                    if (in_array($rel['foreign_table'], $alltables)) {
                        $this->addRelation(
                            $one_table,
                            $master_field,
                            $rel['foreign_table'],
                            $rel['foreign_field'],
                            $this->showKeys
                        );
                    }

                    continue;
                }

                foreach ($rel as $one_key) {
                    if (! in_array($one_key['ref_table_name'], $alltables)) {
                        continue;
                    }

                    foreach ($one_key['index_list'] as $index => $one_field) {
                        $this->addRelation(
                            $one_table,
                            $one_field,
                            $one_key['ref_table_name'],
                            $one_key['ref_index_list'][$index],
                            $this->showKeys
                        );
                    }
                }
            }
        }

        $this->drawTables();

        if ($seen_a_relation) {
            $this->drawRelations();
        }

        $this->diagram->endDiaDoc();
    }

    /**
     * Output Dia Document for download
     */
    public function showOutput(): void
    {
        $this->diagram->showOutput($this->getFileName('.dia'));
    }

    /**
     * Defines relation objects
     *
     * @see    TableStatsDia::__construct(),RelationStatsDia::__construct()
     *
     * @param string $masterTable  The master table name
     * @param string $masterField  The relation field in the master table
     * @param string $foreignTable The foreign table name
     * @param string $foreignField The relation field in the foreign table
     * @param bool   $showKeys     Whether to display ONLY keys or not
     */
    private function addRelation(
        $masterTable,
        $masterField,
        $foreignTable,
        $foreignField,
        $showKeys
    ): void {
        if (! isset($this->tables[$masterTable])) {
            $this->tables[$masterTable] = new TableStatsDia(
                $this->diagram,
                $this->db,
                $masterTable,
                $this->pageNumber,
                $showKeys
            );
        }

        if (! isset($this->tables[$foreignTable])) {
            $this->tables[$foreignTable] = new TableStatsDia(
                $this->diagram,
                $this->db,
                $foreignTable,
                $this->pageNumber,
                $showKeys
            );
        }

        $this->relations[] = new RelationStatsDia(
            $this->diagram,
            $this->tables[$masterTable],
            $masterField,
            $this->tables[$foreignTable],
            $foreignField
        );
    }

    /**
     * Draws relation references
     *
     * connects master table's master field to
     * foreign table's foreign field using Dia object
     * type Database - Reference
     *
     * @see    RelationStatsDia::relationDraw()
     */
    private function drawRelations(): void
    {
        foreach ($this->relations as $relation) {
            $relation->relationDraw($this->showColor);
        }
    }

    /**
     * Draws tables
     *
     * Tables are generated using Dia object type Database - Table
     * primary fields are underlined and bold in tables
     *
     * @see    TableStatsDia::tableDraw()
     */
    private function drawTables(): void
    {
        foreach ($this->tables as $table) {
            $table->tableDraw($this->showColor);
        }
    }
}