<?php

namespace Ulmus\Adapter;

use Ulmus\Migration\FieldDefinition;
use Ulmus\Entity;

class SqlFieldMapper
{
    public string $type;

    public string $length;

    public function __construct(
        public FieldDefinition $field,
    ) {
        $this->map();
    }

    public function map() : void
    {
        $type = $this->field->type;
        $length = $this->field->length;
        
        if ( is_a($type, Entity\Field\Date::class, true) ) {
            $type = "DATE";
        }
        elseif ( is_a($type, Entity\Field\Time::class, true) ) {
            $type = "TIME";
        }
        elseif ( is_a($type, \DateTime::class, true) ) {
            $type = "DATETIME";
        }
        elseif ( enum_exists($type) ) {
            # Haven't found a better way yet to check for BackendEnum without an instance of the object
            if ( ! method_exists($type, 'tryFrom') ) {
                throw new \Ulmus\Exception\BackedEnumRequired(sprintf("You must define your enum as a BackedEnum instead of an UnitEnum for field '%s'.", $this->field->getColumnName()));
            }

            $type = "string";
        }

        switch($type) {
            case "bool":
                $this->type = "TINYINT";
                $this->length = 1;
                break;

            case "array":
                $this->type = "JSON";
                break;

            case "string":
                if ($length && $length <= 255) {
                    $this->type = "VARCHAR";
                    $this->length = $length;
                    break;
                }
                elseif (! $length || ( $length <= 65535 ) ) {
                    $this->type = "TEXT";
                }
                elseif ( $length <= 16777215 ) {
                    $this->type = "MEDIUMTEXT";
                }
                elseif ($length <= 4294967295) {
                    $this->type = "LONGTEXT";
                }
                else {
                    throw new \Exception("A column with a length bigger than 4GB cannot be created.");
                }

                # Length is unnecessary on TEXT fields
                unset($length);

                break;

            case "float":
                $this->type = "DOUBLE";

            default:
                if ($length) {
                    $this->length = $length;
                }

                $this->type ??= strtoupper($type);
        }

        $this->postProcess();
    }

    public function render() : string
    {
        return $this->type . ( isset($this->length) ? "($this->length)" : "" );
    }

    public function postProcess() : void
    {
    }
}