<?php
namespace DatabaseHelper;

use DatabaseHelper\enums\CascadeTypes;
use DatabaseHelper\enums\CharsetTypes;
use DatabaseHelper\enums\CollationTypes;
use DatabaseHelper\enums\ColumnTypes;
use DatabaseHelper\enums\EngineTypes;
use DatabaseHelper\interfaces\TableBlueprint;
use InvalidArgumentException;

class Table implements TableBlueprint
{
    public string $tableName;

    public array $columns = [];

    public array $primaryKey;

    public array $foreignKeys = [];

    // Table settings
    protected EngineTypes $engine = EngineTypes::INNODB;
    protected CharsetTypes $charset = CharsetTypes::UTF8;
    protected CollationTypes $collation = CollationTypes::UTF8_GENERAL_CI;

    public function __construct(string $tableName) {
        $this->tableName = $tableName;
    }

    public function column(string $name, ColumnTypes $type, mixed $default = null, bool $nullable = false, bool $unique = false): TableBlueprint {
        if(isset($this->columns[$name]))
            throw new InvalidArgumentException('Column name already exists.');

        $this->columns[$name] = [
            'colName' => $name,
            'defaultVal' => $default,
            'colType' => $type,
            'nullable' => $nullable,
            'unique' => $unique
        ];

        return $this;
    }

    public function primaryColumn(string $name, ColumnTypes $type, bool $autoincrement = false): TableBlueprint {
        if(isset($this->primaryKey))
            throw new InvalidArgumentException('Primary column already exists.');

        $this->primaryKey = [
            'colName' => $name,
            'colType' => $type,
            'autoincrement' => $autoincrement
        ];

        return $this->column($name, $type);
    }

    public function foreignColumn(TableBlueprint $foreignTable, CascadeTypes $onDelete, CascadeTypes $onUpdate): TableBlueprint {
        $colName = $foreignTable->primaryKey['colName'];
        if(isset($this->columns[$colName]))
            throw new InvalidArgumentException('Column name already exists.');

        $this->foreignKeys[] = [
            'colName' => $colName,
            'tableName' => $foreignTable->tableName,
            'onDelete' => $onDelete,
            'onUpdate' => $onUpdate
        ];

        $this->columns[$colName] = $foreignTable->columns[$colName];
        return $this;
    }

    public function engine(EngineTypes $engine): TableBlueprint {
        $this->engine = $engine;
        return $this;
    }

    public function charset(CharsetTypes $charset): TableBlueprint {
        $this->charset = $charset;
        return $this;
    }

    public function collation(CollationTypes $collation): TableBlueprint {
        $this->collation = $collation;
        return $this;
    }

    public function toSql(): string {
        $sql = "CREATE TABLE `{$this->tableName}` (\n";

        if (!empty($this->primaryKey)) {
            $sql .= "  `{$this->primaryKey['colName']}` {$this->primaryKey['colType']->value}";
            if ($this->primaryKey['autoincrement'])
                $sql .= " AUTO_INCREMENT";
            $sql .= " NOT NULL,\n";
        }

        foreach ($this->columns as $column) {
            if ($column['colName'] !== $this->primaryKey['colName']) {
                $sql .= "  `{$column['colName']}` {$column['colType']->value}";

                if (!$column['nullable'])
                    $sql .= " NOT NULL";

                if ($column['unique'])
                    $sql .= " UNIQUE";

                if ($column['defaultVal'] !== null) {
                    $default = is_string($column['defaultVal']) ? "'{$column['defaultVal']}'" : $column['defaultVal'];
                    $sql .= " DEFAULT $default";
                }

                $sql .= ",\n";
            }
        }

        if (!empty($this->primaryKey))
            $sql .= "  PRIMARY KEY (`{$this->primaryKey['colName']}`),\n";

        foreach ($this->foreignKeys as $foreignKey) {
            $sql .= "  FOREIGN KEY (`{$foreignKey['colName']}`) REFERENCES `{$foreignKey['tableName']}` (`{$foreignKey['colName']}`)";
            $sql .= " ON DELETE {$foreignKey['onDelete']->type()} ON UPDATE {$foreignKey['onUpdate']->type()},\n";
        }

        $sql = rtrim($sql, ",\n") . "\n";
        $sql .= ") ENGINE={$this->engine->type()} CHARSET={$this->charset->type()} COLLATE={$this->collation->type()};";

        return $sql;
    }

    public function create(): void {
        $sql = $this->toSql();
        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');
        dbDelta($sql);
    }
}