<?php

namespace App\Tables;

use Illuminate\Contracts\Support\Arrayable;
use JsonSerializable;
use MightyPork\Exceptions\SimpleValidationException;
use MightyPork\Exceptions\NotApplicableException;
use MightyPork\Utils\Utils;

/**
 * Helper class representing one column in a data table.
 *
 * @property-read bool $id_modified
 * @property-read bool $type_modified
 * @property-read bool $name_modified
 * @property-read bool $title_modified
 *
 * @property-read string $id_orig
 * @property-read string $type_orig
 * @property-read string $name_orig
 * @property-read string $title_orig
 */
class Column implements JsonSerializable, Arrayable
{
    const colTypes = [
        'int', 'bool', 'float', 'string'
    ];

    // marked public to make keyBy() work

    public $id;
    public $type;
    public $name;
    public $title;

    /** @var bool - column is marked to be deleted by a changeset */
    public $toRemove = false;

    /** @var bool - column is new in this changeset */
    public $isNew = false;

    /** @var array - original attrib values if edited in a changeset */
    private $orig_attribs = [];
    /** @var array - list of attrib names that are modified by a changeset */
    private $modified_attribs = [];

    /**
     * Mark for removal (used in editing GUI)
     */
    public function markForRemoval()
    {
        $this->toRemove = true;
    }

    /**
     * Mark this column as new
     */
    public function markAsNew()
    {
        $this->isNew = true;
    }

    /**
     * Modify by a changeset
     *
     * @param array $columnObject
     */
    public function modifyByChangeset(array $columnObject)
    {
        foreach ((array)$columnObject as $key => $value) {
            if ($value != $this->$key) {
                $this->modified_attribs[] = $key;
                $this->orig_attribs[$key] = $this->$key;
                $this->$key = $value;
            }
        }
    }

    public function __get($name)
    {
        if (ends_with($name, '_modified')) {
            $basename = str_replace('_modified', '', $name);
            if (property_exists($this, $basename)) {
                return in_array($basename, $this->modified_attribs);
            }
        }

        if (ends_with($name, '_orig')) {
            $basename = str_replace('_orig', '', $name);
            if (property_exists($this, $basename)) {
                return $this->orig_attribs[$basename];
            }
        }

        throw new NotApplicableException("No such column property: $name");
    }

    /**
     * @param $columns
     * @return Column[]
     */
    public static function columnsFromJson($columns)
    {
        if (is_string($columns)) {
            $columns = json_decode($columns);
        }

        return array_map(function ($x) {
            return new Column($x);
        }, $columns);
    }

    /**
     * Set column ID
     * @param string $id - GCID
     */
    public function setID($id)
    {
        $this->id = $id;
    }

    /**
     * Create from object or array
     *
     * @param object|array $obj
     */
    public function __construct($obj, $allowEmptyName=false)
    {
        $b = objBag($obj);

        if (!$allowEmptyName && (!$b->has('name') || $b->name == '')) {
            throw new NotApplicableException('Missing name in column');
        }

        if (!$b->has('type')) {
            throw new NotApplicableException('Missing type in column');
        }

        if ($b->name[0] == '_') { // would cause problems with selects (see: _id / GRID)
            throw new NotApplicableException("Column name can't start with underscore.");
        }

        if (!in_array($b->type, self::colTypes)) {
            throw new NotApplicableException("\"$b->type\" is not a valid column type.");
        }

        $this->id = $b->get('id', null);
        $this->name = $b->name;
        $this->type = $b->type;
        $this->title = $b->title ?: $b->name;
    }

    /**
     * @return array with keys {name, title, type}
     */
    public function toArray()
    {
        return [
            'id' => $this->id,
            'name' => $this->name,
            'title' => $this->title,
            'type' => $this->type,
            '_new' => $this->isNew,
            '_remove' => $this->toRemove,
            '_changed' => $this->modified_attribs,
            '_orig' => $this->orig_attribs,
        ];
    }

    /**
     * Convert a value to the target type, validating it in the process
     *
     * @param mixed $value
     * @return bool|float|int|string
     */
    public function cast($value)
    {
        switch ($this->type) {
            case 'int':
                if (is_null($value)) return 0;
                if (is_int($value)) return $value;
                if (is_float($value)) return round($value);
                if (is_numeric($value)) return intval($value);
                throw new SimpleValidationException($this->id, "Could not convert value \"$value\" to int!");

            case 'float':
                if (is_null($value)) return 0;
                if (is_int($value) || is_float($value)) return (float)$value;
                if (is_numeric($value)) return floatval($value);
                throw new SimpleValidationException($this->id, "Could not convert value \"$value\" to float!");

            case 'bool':
                if (is_null($value)) return false;
                return Utils::parseBool($value);

            case 'string':
                if (is_null($value)) return "";
                return "$value";

            default:
                throw new \LogicException("Illegal column type: \"$this->type\"");
        }
    }

    /**
     * Specify data which should be serialized to JSON
     * @link http://php.net/manual/en/jsonserializable.jsonserialize.php
     * @return mixed data which can be serialized by <b>json_encode</b>,
     * which is a value of any type other than a resource.
     * @since 5.4.0
     */
    public function jsonSerialize()
    {
        return $this->toArray();
    }
}