<?php

namespace Encore\Admin;

use Closure;
use Encore\Admin\Exception\Handler;
use Encore\Admin\Form\Builder;
use Encore\Admin\Form\Field;
use Encore\Admin\Form\HasHooks;
use Encore\Admin\Form\Row;
use Encore\Admin\Form\Tab;
use Illuminate\Contracts\Support\Renderable;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations;
use Illuminate\Database\Eloquent\SoftDeletes;
use Illuminate\Http\Request;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\MessageBag;
use Illuminate\Support\Str;
use Illuminate\Validation\Validator;
use Spatie\EloquentSortable\Sortable;
use Symfony\Component\HttpFoundation\Response;

/**
 * Class Form.
 *
 * @method Field\Text           text($column, $label = '')
 * @method Field\Checkbox       checkbox($column, $label = '')
 * @method Field\Radio          radio($column, $label = '')
 * @method Field\Select         select($column, $label = '')
 * @method Field\MultipleSelect multipleSelect($column, $label = '')
 * @method Field\Textarea       textarea($column, $label = '')
 * @method Field\Hidden         hidden($column, $label = '')
 * @method Field\Id             id($column, $label = '')
 * @method Field\Ip             ip($column, $label = '')
 * @method Field\Url            url($column, $label = '')
 * @method Field\Color          color($column, $label = '')
 * @method Field\Email          email($column, $label = '')
 * @method Field\Mobile         mobile($column, $label = '')
 * @method Field\Slider         slider($column, $label = '')
 * @method Field\File           file($column, $label = '')
 * @method Field\Image          image($column, $label = '')
 * @method Field\Date           date($column, $label = '')
 * @method Field\Datetime       datetime($column, $label = '')
 * @method Field\Time           time($column, $label = '')
 * @method Field\Year           year($column, $label = '')
 * @method Field\Month          month($column, $label = '')
 * @method Field\DateRange      dateRange($start, $end, $label = '')
 * @method Field\DateTimeRange  datetimeRange($start, $end, $label = '')
 * @method Field\TimeRange      timeRange($start, $end, $label = '')
 * @method Field\Number         number($column, $label = '')
 * @method Field\Currency       currency($column, $label = '')
 * @method Field\HasMany        hasMany($relationName, $label = '', $callback)
 * @method Field\SwitchField    switch($column, $label = '')
 * @method Field\Display        display($column, $label = '')
 * @method Field\Rate           rate($column, $label = '')
 * @method Field\Divider        divider($title = '')
 * @method Field\Password       password($column, $label = '')
 * @method Field\Decimal        decimal($column, $label = '')
 * @method Field\Html           html($html, $label = '')
 * @method Field\Tags           tags($column, $label = '')
 * @method Field\Icon           icon($column, $label = '')
 * @method Field\Embeds         embeds($column, $label = '', $callback)
 * @method Field\MultipleImage  multipleImage($column, $label = '')
 * @method Field\MultipleFile   multipleFile($column, $label = '')
 * @method Field\Captcha        captcha($column, $label = '')
 * @method Field\Listbox        listbox($column, $label = '')
 * @method Field\Table          table($column, $label, $builder)
 * @method Field\Timezone       timezone($column, $label = '')
 * @method Field\KeyValue       keyValue($column, $label = '')
 * @method Field\ListField      list($column, $label = '')
 */
class Form implements Renderable
{
    use HasHooks;

    /**
     * Remove flag in `has many` form.
     */
    const REMOVE_FLAG_NAME = '_remove_';

    /**
     * Eloquent model of the form.
     *
     * @var Model
     */
    protected $model;

    /**
     * @var \Illuminate\Validation\Validator
     */
    protected $validator;

    /**
     * @var Builder
     */
    protected $builder;

    /**
     * Data for save to current model from input.
     *
     * @var array
     */
    protected $updates = [];

    /**
     * Data for save to model's relations from input.
     *
     * @var array
     */
    protected $relations = [];

    /**
     * Input data.
     *
     * @var array
     */
    protected $inputs = [];

    /**
     * Available fields.
     *
     * @var array
     */
    public static $availableFields = [];

    /**
     * Form field alias.
     *
     * @var array
     */
    public static $fieldAlias = [];

    /**
     * Ignored saving fields.
     *
     * @var array
     */
    protected $ignored = [];

    /**
     * Collected field assets.
     *
     * @var array
     */
    protected static $collectedAssets = [];

    /**
     * @var Form\Tab
     */
    protected $tab = null;

    /**
     * Field rows in form.
     *
     * @var array
     */
    public $rows = [];

    /**
     * @var bool
     */
    protected $isSoftDeletes = false;

    /**
     * Initialization closure array.
     *
     * @var []Closure
     */
    protected static $initCallbacks;

    /**
     * Create a new form instance.
     *
     * @param $model
     * @param \Closure $callback
     */
    public function __construct($model, Closure $callback = null)
    {
        $this->model = $model;

        $this->builder = new Builder($this);

        if ($callback instanceof Closure) {
            $callback($this);
        }

        $this->isSoftDeletes = in_array(SoftDeletes::class, class_uses_deep($this->model));

        $this->callInitCallbacks();
    }

    /**
     * Initialize with user pre-defined default disables, etc.
     *
     * @param Closure $callback
     */
    public static function init(Closure $callback = null)
    {
        static::$initCallbacks[] = $callback;
    }

    /**
     * Call the initialization closure array in sequence.
     */
    protected function callInitCallbacks()
    {
        if (empty(static::$initCallbacks)) {
            return;
        }

        foreach (static::$initCallbacks as $callback) {
            call_user_func($callback, $this);
        }
    }

    /**
     * @param Field $field
     *
     * @return $this
     */
    public function pushField(Field $field)
    {
        $field->setForm($this);

        $this->builder->fields()->push($field);

        return $this;
    }

    /**
     * @return Model
     */
    public function model()
    {
        return $this->model;
    }

    /**
     * @return Builder
     */
    public function builder()
    {
        return $this->builder;
    }

    /**
     * Generate a edit form.
     *
     * @param $id
     *
     * @return $this
     */
    public function edit($id)
    {
        $this->builder->setMode(Builder::MODE_EDIT);
        $this->builder->setResourceId($id);

        $this->setFieldValue($id);

        return $this;
    }

    /**
     * Use tab to split form.
     *
     * @param string  $title
     * @param Closure $content
     *
     * @return $this
     */
    public function tab($title, Closure $content, $active = false)
    {
        $this->getTab()->append($title, $content, $active);

        return $this;
    }

    /**
     * Get Tab instance.
     *
     * @return Tab
     */
    public function getTab()
    {
        if (is_null($this->tab)) {
            $this->tab = new Tab($this);
        }

        return $this->tab;
    }

    /**
     * Destroy data entity and remove files.
     *
     * @param $id
     *
     * @return mixed
     */
    public function destroy($id)
    {
        try {
            if (($ret = $this->callDeleting($id)) instanceof Response) {
                return $ret;
            }

            collect(explode(',', $id))->filter()->each(function ($id) {
                $builder = $this->model()->newQuery();

                if ($this->isSoftDeletes) {
                    $builder = $builder->withTrashed();
                }

                $model = $builder->with($this->getRelations())->findOrFail($id);

                if ($this->isSoftDeletes && $model->trashed()) {
                    $this->deleteFiles($model, true);
                    $model->forceDelete();

                    return;
                }

                $this->deleteFiles($model);
                $model->delete();
            });

            if (($ret = $this->callDeleted()) instanceof Response) {
                return $ret;
            }

            $response = [
                'status'  => true,
                'message' => trans('admin.delete_succeeded'),
            ];
        } catch (\Exception $exception) {
            $response = [
                'status'  => false,
                'message' => $exception->getMessage() ?: trans('admin.delete_failed'),
            ];
        }

        return response()->json($response);
    }

    /**
     * Remove files in record.
     *
     * @param Model $model
     * @param bool  $forceDelete
     */
    protected function deleteFiles(Model $model, $forceDelete = false)
    {
        // If it's a soft delete, the files in the data will not be deleted.
        if (!$forceDelete && $this->isSoftDeletes) {
            return;
        }

        $data = $model->toArray();

        $this->builder->fields()->filter(function ($field) {
            return $field instanceof Field\File;
        })->each(function (Field\File $file) use ($data) {
            $file->setOriginal($data);

            $file->destroy();
        });
    }

    /**
     * Store a new record.
     *
     * @return \Illuminate\Http\RedirectResponse|\Illuminate\Routing\Redirector|\Illuminate\Http\JsonResponse
     */
    public function store()
    {
        $data = \request()->all();

        // Handle validation errors.
        if ($validationMessages = $this->validationMessages($data)) {
            return back()->withInput()->withErrors($validationMessages);
        }

        if (($response = $this->prepare($data)) instanceof Response) {
            return $response;
        }

        DB::transaction(function () {
            $inserts = $this->prepareInsert($this->updates);

            foreach ($inserts as $column => $value) {
                $this->model->setAttribute($column, $value);
            }

            $this->model->save();

            $this->updateRelation($this->relations);
        });

        if (($response = $this->callSaved()) instanceof Response) {
            return $response;
        }

        if ($response = $this->ajaxResponse(trans('admin.save_succeeded'))) {
            return $response;
        }

        return $this->redirectAfterStore();
    }

    /**
     * Get ajax response.
     *
     * @param string $message
     *
     * @return bool|\Illuminate\Http\JsonResponse
     */
    protected function ajaxResponse($message)
    {
        $request = Request::capture();

        // ajax but not pjax
        if ($request->ajax() && !$request->pjax()) {
            return response()->json([
                'status'  => true,
                'message' => $message,
            ]);
        }

        return false;
    }

    /**
     * Prepare input data for insert or update.
     *
     * @param array $data
     *
     * @return mixed
     */
    protected function prepare($data = [])
    {
        if (($response = $this->callSubmitted()) instanceof Response) {
            return $response;
        }

        $this->inputs = array_merge($this->removeIgnoredFields($data), $this->inputs);

        if (($response = $this->callSaving()) instanceof Response) {
            return $response;
        }

        $this->relations = $this->getRelationInputs($this->inputs);

        $this->updates = Arr::except($this->inputs, array_keys($this->relations));
    }

    /**
     * Remove ignored fields from input.
     *
     * @param array $input
     *
     * @return array
     */
    protected function removeIgnoredFields($input)
    {
        Arr::forget($input, $this->ignored);

        return $input;
    }

    /**
     * Get inputs for relations.
     *
     * @param array $inputs
     *
     * @return array
     */
    protected function getRelationInputs($inputs = [])
    {
        $relations = [];

        foreach ($inputs as $column => $value) {
            if (!method_exists($this->model, $column)) {
                continue;
            }

            $relation = call_user_func([$this->model, $column]);

            if ($relation instanceof Relations\Relation) {
                $relations[$column] = $value;
            }
        }

        return $relations;
    }

    /**
     * Handle update.
     *
     * @param int  $id
     * @param null $data
     *
     * @return bool|\Illuminate\Contracts\Routing\ResponseFactory|\Illuminate\Http\JsonResponse|\Illuminate\Http\RedirectResponse|\Illuminate\Http\Response|mixed|null|Response
     */
    public function update($id, $data = null)
    {
        $data = ($data) ?: request()->all();

        $isEditable = $this->isEditable($data);

        if (($data = $this->handleColumnUpdates($id, $data)) instanceof Response) {
            return $data;
        }

        /* @var Model $this->model */
        $builder = $this->model();

        if ($this->isSoftDeletes) {
            $builder = $builder->withTrashed();
        }

        $this->model = $builder->with($this->getRelations())->findOrFail($id);

        $this->setFieldOriginalValue();

        // Handle validation errors.
        if ($validationMessages = $this->validationMessages($data)) {
            if (!$isEditable) {
                return back()->withInput()->withErrors($validationMessages);
            }

            return response()->json(['errors' => Arr::dot($validationMessages->getMessages())], 422);
        }

        if (($response = $this->prepare($data)) instanceof Response) {
            return $response;
        }

        DB::transaction(function () {
            $updates = $this->prepareUpdate($this->updates);

            foreach ($updates as $column => $value) {
                /* @var Model $this->model */
                $this->model->setAttribute($column, $value);
            }

            $this->model->save();

            $this->updateRelation($this->relations);
        });

        if (($result = $this->callSaved()) instanceof Response) {
            return $result;
        }

        if ($response = $this->ajaxResponse(trans('admin.update_succeeded'))) {
            return $response;
        }

        return $this->redirectAfterUpdate($id);
    }

    /**
     * Get RedirectResponse after store.
     *
     * @return \Illuminate\Http\RedirectResponse
     */
    protected function redirectAfterStore()
    {
        $resourcesPath = $this->resource(0);

        $key = $this->model->getKey();

        return $this->redirectAfterSaving($resourcesPath, $key);
    }

    /**
     * Get RedirectResponse after update.
     *
     * @param mixed $key
     *
     * @return \Illuminate\Http\RedirectResponse
     */
    protected function redirectAfterUpdate($key)
    {
        $resourcesPath = $this->resource(-1);

        return $this->redirectAfterSaving($resourcesPath, $key);
    }

    /**
     * Get RedirectResponse after data saving.
     *
     * @param string $resourcesPath
     * @param string $key
     *
     * @return \Illuminate\Http\RedirectResponse|\Illuminate\Routing\Redirector
     */
    protected function redirectAfterSaving($resourcesPath, $key)
    {
        if (request('after-save') == 1) {
            // continue editing
            $url = rtrim($resourcesPath, '/')."/{$key}/edit";
        } elseif (request('after-save') == 2) {
            // continue creating
            $url = rtrim($resourcesPath, '/').'/create';
        } elseif (request('after-save') == 3) {
            // view resource
            $url = rtrim($resourcesPath, '/')."/{$key}";
        } else {
            $url = request(Builder::PREVIOUS_URL_KEY) ?: $resourcesPath;
        }

        admin_toastr(trans('admin.save_succeeded'));

        return redirect($url);
    }

    /**
     * Check if request is from editable.
     *
     * @param array $input
     *
     * @return bool
     */
    protected function isEditable(array $input = [])
    {
        return array_key_exists('_editable', $input);
    }

    /**
     * Handle updates for single column.
     *
     * @param int   $id
     * @param array $data
     *
     * @return array|\Illuminate\Contracts\Routing\ResponseFactory|\Illuminate\Http\Response|Response
     */
    protected function handleColumnUpdates($id, $data)
    {
        $data = $this->handleEditable($data);

        $data = $this->handleFileDelete($data);

        $data = $this->handleFileSort($data);

        if ($this->handleOrderable($id, $data)) {
            return response([
                'status'  => true,
                'message' => trans('admin.update_succeeded'),
            ]);
        }

        return $data;
    }

    /**
     * Handle editable update.
     *
     * @param array $input
     *
     * @return array
     */
    protected function handleEditable(array $input = [])
    {
        if (array_key_exists('_editable', $input)) {
            $name = $input['name'];
            $value = $input['value'];

            Arr::forget($input, ['pk', 'value', 'name']);
            Arr::set($input, $name, $value);
        }

        return $input;
    }

    /**
     * @param array $input
     *
     * @return array
     */
    protected function handleFileDelete(array $input = [])
    {
        if (array_key_exists(Field::FILE_DELETE_FLAG, $input)) {
            $input[Field::FILE_DELETE_FLAG] = $input['key'];
            unset($input['key']);
        }

        request()->replace($input);

        return $input;
    }

    /**
     * @param array $input
     *
     * @return array
     */
    protected function handleFileSort(array $input = [])
    {
        if (!array_key_exists(Field::FILE_SORT_FLAG, $input)) {
            return $input;
        }

        $sorts = array_filter($input[Field::FILE_SORT_FLAG]);

        if (empty($sorts)) {
            return $input;
        }

        foreach ($sorts as $column => $order) {
            $input[$column] = $order;
        }

        request()->replace($input);

        return $input;
    }

    /**
     * Handle orderable update.
     *
     * @param int   $id
     * @param array $input
     *
     * @return bool
     */
    protected function handleOrderable($id, array $input = [])
    {
        if (array_key_exists('_orderable', $input)) {
            $model = $this->model->find($id);

            if ($model instanceof Sortable) {
                $input['_orderable'] == 1 ? $model->moveOrderUp() : $model->moveOrderDown();

                return true;
            }
        }

        return false;
    }

    /**
     * Update relation data.
     *
     * @param array $relationsData
     *
     * @return void
     */
    protected function updateRelation($relationsData)
    {
        foreach ($relationsData as $name => $values) {
            if (!method_exists($this->model, $name)) {
                continue;
            }

            $relation = $this->model->$name();

            $oneToOneRelation = $relation instanceof Relations\HasOne
                || $relation instanceof Relations\MorphOne
                || $relation instanceof Relations\BelongsTo;

            $prepared = $this->prepareUpdate([$name => $values], $oneToOneRelation);

            if (empty($prepared)) {
                continue;
            }

            switch (true) {
                case $relation instanceof Relations\BelongsToMany:
                case $relation instanceof Relations\MorphToMany:
                    if (isset($prepared[$name])) {
                        $relation->sync($prepared[$name]);
                    }
                    break;
                case $relation instanceof Relations\HasOne:

                    $related = $this->model->$name;

                    // if related is empty
                    if (is_null($related)) {
                        $related = $relation->getRelated();
                        $qualifiedParentKeyName = $relation->getQualifiedParentKeyName();
                        $localKey = Arr::last(explode('.', $qualifiedParentKeyName));
                        $related->{$relation->getForeignKeyName()} = $this->model->{$localKey};
                    }

                    foreach ($prepared[$name] as $column => $value) {
                        $related->setAttribute($column, $value);
                    }

                    $related->save();
                    break;
                case $relation instanceof Relations\BelongsTo:
                case $relation instanceof Relations\MorphTo:

                    $parent = $this->model->$name;

                    // if related is empty
                    if (is_null($parent)) {
                        $parent = $relation->getRelated();
                    }

                    foreach ($prepared[$name] as $column => $value) {
                        $parent->setAttribute($column, $value);
                    }

                    $parent->save();

                    // When in creating, associate two models
                    $foreignKeyMethod = (app()->version() < '5.8.0') ? 'getForeignKey' : 'getForeignKeyName';
                    if (!$this->model->{$relation->{$foreignKeyMethod}()}) {
                        $this->model->{$relation->{$foreignKeyMethod}()} = $parent->getKey();

                        $this->model->save();
                    }

                    break;
                case $relation instanceof Relations\MorphOne:
                    $related = $this->model->$name;
                    if (is_null($related)) {
                        $related = $relation->make();
                    }
                    foreach ($prepared[$name] as $column => $value) {
                        $related->setAttribute($column, $value);
                    }
                    $related->save();
                    break;
                case $relation instanceof Relations\HasMany:
                case $relation instanceof Relations\MorphMany:

                    foreach ($prepared[$name] as $related) {
                        /** @var Relations\Relation $relation */
                        $relation = $this->model()->$name();

                        $keyName = $relation->getRelated()->getKeyName();

                        $instance = $relation->findOrNew(Arr::get($related, $keyName));

                        if ($related[static::REMOVE_FLAG_NAME] == 1) {
                            $instance->delete();

                            continue;
                        }

                        Arr::forget($related, static::REMOVE_FLAG_NAME);

                        $instance->fill($related);

                        $instance->save();
                    }

                    break;
            }
        }
    }

    /**
     * Prepare input data for update.
     *
     * @param array $updates
     * @param bool  $oneToOneRelation If column is one-to-one relation.
     *
     * @return array
     */
    protected function prepareUpdate(array $updates, $oneToOneRelation = false)
    {
        $prepared = [];

        /** @var Field $field */
        foreach ($this->builder->fields() as $field) {
            $columns = $field->column();

            // If column not in input array data, then continue.
            if (!Arr::has($updates, $columns)) {
                continue;
            }

            if ($this->isInvalidColumn($columns, $oneToOneRelation || $field->isJsonType)) {
                continue;
            }

            $value = $this->getDataByColumn($updates, $columns);

            $value = $field->prepare($value);

            if (is_array($columns)) {
                foreach ($columns as $name => $column) {
                    Arr::set($prepared, $column, $value[$name]);
                }
            } elseif (is_string($columns)) {
                Arr::set($prepared, $columns, $value);
            }
        }

        return $prepared;
    }

    /**
     * @param string|array $columns
     * @param bool         $containsDot
     *
     * @return bool
     */
    protected function isInvalidColumn($columns, $containsDot = false)
    {
        foreach ((array) $columns as $column) {
            if ((!$containsDot && Str::contains($column, '.')) ||
                ($containsDot && !Str::contains($column, '.'))) {
                return true;
            }
        }

        return false;
    }

    /**
     * Prepare input data for insert.
     *
     * @param $inserts
     *
     * @return array
     */
    protected function prepareInsert($inserts)
    {
        if ($this->isHasOneRelation($inserts)) {
            $inserts = Arr::dot($inserts);
        }

        foreach ($inserts as $column => $value) {
            if (is_null($field = $this->getFieldByColumn($column))) {
                unset($inserts[$column]);
                continue;
            }

            $inserts[$column] = $field->prepare($value);
        }

        $prepared = [];

        foreach ($inserts as $key => $value) {
            Arr::set($prepared, $key, $value);
        }

        return $prepared;
    }

    /**
     * Is input data is has-one relation.
     *
     * @param array $inserts
     *
     * @return bool
     */
    protected function isHasOneRelation($inserts)
    {
        $first = current($inserts);

        if (!is_array($first)) {
            return false;
        }

        if (is_array(current($first))) {
            return false;
        }

        return Arr::isAssoc($first);
    }

    /**
     * Ignore fields to save.
     *
     * @param string|array $fields
     *
     * @return $this
     */
    public function ignore($fields)
    {
        $this->ignored = array_merge($this->ignored, (array) $fields);

        return $this;
    }

    /**
     * @param array        $data
     * @param string|array $columns
     *
     * @return array|mixed
     */
    protected function getDataByColumn($data, $columns)
    {
        if (is_string($columns)) {
            return Arr::get($data, $columns);
        }

        if (is_array($columns)) {
            $value = [];
            foreach ($columns as $name => $column) {
                if (!Arr::has($data, $column)) {
                    continue;
                }
                $value[$name] = Arr::get($data, $column);
            }

            return $value;
        }
    }

    /**
     * Find field object by column.
     *
     * @param $column
     *
     * @return mixed
     */
    protected function getFieldByColumn($column)
    {
        return $this->builder->fields()->first(
            function (Field $field) use ($column) {
                if (is_array($field->column())) {
                    return in_array($column, $field->column());
                }

                return $field->column() == $column;
            }
        );
    }

    /**
     * Set original data for each field.
     *
     * @return void
     */
    protected function setFieldOriginalValue()
    {
//        static::doNotSnakeAttributes($this->model);

        $values = $this->model->toArray();

        $this->builder->fields()->each(function (Field $field) use ($values) {
            $field->setOriginal($values);
        });
    }

    /**
     * Set all fields value in form.
     *
     * @param $id
     *
     * @return void
     */
    protected function setFieldValue($id)
    {
        $relations = $this->getRelations();

        $builder = $this->model();

        if ($this->isSoftDeletes) {
            $builder = $builder->withTrashed();
        }

        $this->model = $builder->with($relations)->findOrFail($id);

        $this->callEditing();

//        static::doNotSnakeAttributes($this->model);

        $data = $this->model->toArray();

        $this->builder->fields()->each(function (Field $field) use ($data) {
            if (!in_array($field->column(), $this->ignored)) {
                $field->fill($data);
            }
        });
    }

    /**
     * Add a fieldset to form.
     *
     * @param string  $title
     * @param Closure $setCallback
     *
     * @return Field\Fieldset
     */
    public function fieldset(string $title, Closure $setCallback)
    {
        $fieldset = new Field\Fieldset();

        $this->html($fieldset->start($title))->plain();

        $setCallback($this);

        $this->html($fieldset->end())->plain();

        return $fieldset;
    }

    /**
     * Don't snake case attributes.
     *
     * @param Model $model
     *
     * @return void
     */
    protected static function doNotSnakeAttributes(Model $model)
    {
        $class = get_class($model);

        $class::$snakeAttributes = false;
    }

    /**
     * Get validation messages.
     *
     * @param array $input
     *
     * @return MessageBag|bool
     */
    public function validationMessages($input)
    {
        $failedValidators = [];

        /** @var Field $field */
        foreach ($this->builder->fields() as $field) {
            if (!$validator = $field->getValidator($input)) {
                continue;
            }

            if (($validator instanceof Validator) && !$validator->passes()) {
                $failedValidators[] = $validator;
            }
        }

        $message = $this->mergeValidationMessages($failedValidators);

        return $message->any() ? $message : false;
    }

    /**
     * Merge validation messages from input validators.
     *
     * @param \Illuminate\Validation\Validator[] $validators
     *
     * @return MessageBag
     */
    protected function mergeValidationMessages($validators)
    {
        $messageBag = new MessageBag();

        foreach ($validators as $validator) {
            $messageBag = $messageBag->merge($validator->messages());
        }

        return $messageBag;
    }

    /**
     * Get all relations of model from callable.
     *
     * @return array
     */
    public function getRelations()
    {
        $relations = $columns = [];

        /** @var Field $field */
        foreach ($this->builder->fields() as $field) {
            $columns[] = $field->column();
        }

        foreach (Arr::flatten($columns) as $column) {
            if (Str::contains($column, '.')) {
                list($relation) = explode('.', $column);

                if (method_exists($this->model, $relation) &&
                    $this->model->$relation() instanceof Relations\Relation
                ) {
                    $relations[] = $relation;
                }
            } elseif (method_exists($this->model, $column) &&
                !method_exists(Model::class, $column)
            ) {
                $relations[] = $column;
            }
        }

        return array_unique($relations);
    }

    /**
     * Set action for form.
     *
     * @param string $action
     *
     * @return $this
     */
    public function setAction($action)
    {
        $this->builder()->setAction($action);

        return $this;
    }

    /**
     * Set field and label width in current form.
     *
     * @param int $fieldWidth
     * @param int $labelWidth
     *
     * @return $this
     */
    public function setWidth($fieldWidth = 8, $labelWidth = 2)
    {
        $this->builder()->fields()->each(function ($field) use ($fieldWidth, $labelWidth) {
            /* @var Field $field  */
            $field->setWidth($fieldWidth, $labelWidth);
        });

        $this->builder()->setWidth($fieldWidth, $labelWidth);

        return $this;
    }

    /**
     * Set view for form.
     *
     * @param string $view
     *
     * @return $this
     */
    public function setView($view)
    {
        $this->builder()->setView($view);

        return $this;
    }

    /**
     * Set title for form.
     *
     * @param string $title
     *
     * @return $this
     */
    public function setTitle($title = '')
    {
        $this->builder()->setTitle($title);

        return $this;
    }

    /**
     * Add a row in form.
     *
     * @param Closure $callback
     *
     * @return $this
     */
    public function row(Closure $callback)
    {
        $this->rows[] = new Row($callback, $this);

        return $this;
    }

    /**
     * Tools setting for form.
     *
     * @param Closure $callback
     */
    public function tools(Closure $callback)
    {
        $callback->call($this, $this->builder->getTools());
    }

    /**
     * @param Closure|null $callback
     *
     * @return Form\Tools
     */
    public function header(Closure $callback = null)
    {
        if (func_num_args() == 0) {
            return $this->builder->getTools();
        }

        $callback->call($this, $this->builder->getTools());
    }

    /**
     * Disable form submit.
     *
     * @param bool $disable
     *
     * @return $this
     *
     * @deprecated
     */
    public function disableSubmit(bool $disable = true)
    {
        $this->builder()->getFooter()->disableSubmit($disable);

        return $this;
    }

    /**
     * Disable form reset.
     *
     * @param bool $disable
     *
     * @return $this
     *
     * @deprecated
     */
    public function disableReset(bool $disable = true)
    {
        $this->builder()->getFooter()->disableReset($disable);

        return $this;
    }

    /**
     * Disable View Checkbox on footer.
     *
     * @param bool $disable
     *
     * @return $this
     */
    public function disableViewCheck(bool $disable = true)
    {
        $this->builder()->getFooter()->disableViewCheck($disable);

        return $this;
    }

    /**
     * Disable Editing Checkbox on footer.
     *
     * @param bool $disable
     *
     * @return $this
     */
    public function disableEditingCheck(bool $disable = true)
    {
        $this->builder()->getFooter()->disableEditingCheck($disable);

        return $this;
    }

    /**
     * Disable Creating Checkbox on footer.
     *
     * @param bool $disable
     *
     * @return $this
     */
    public function disableCreatingCheck(bool $disable = true)
    {
        $this->builder()->getFooter()->disableCreatingCheck($disable);

        return $this;
    }

    /**
     * Footer setting for form.
     *
     * @param Closure $callback
     */
    public function footer(Closure $callback = null)
    {
        if (func_num_args() == 0) {
            return $this->builder()->getFooter();
        }

        call_user_func($callback, $this->builder()->getFooter());
    }

    /**
     * Get current resource route url.
     *
     * @param int $slice
     *
     * @return string
     */
    public function resource($slice = -2)
    {
        $segments = explode('/', trim(app('request')->getUri(), '/'));

        if ($slice != 0) {
            $segments = array_slice($segments, 0, $slice);
        }

        return implode('/', $segments);
    }

    /**
     * Render the form contents.
     *
     * @return string
     */
    public function render()
    {
        try {
            return $this->builder->render();
        } catch (\Exception $e) {
            return Handler::renderException($e);
        }
    }

    /**
     * Get or set input data.
     *
     * @param string $key
     * @param null   $value
     *
     * @return array|mixed
     */
    public function input($key, $value = null)
    {
        if (is_null($value)) {
            return Arr::get($this->inputs, $key);
        }

        return Arr::set($this->inputs, $key, $value);
    }

    /**
     * Register builtin fields.
     *
     * @return void
     */
    public static function registerBuiltinFields()
    {
        $map = [
            'button'         => Field\Button::class,
            'checkbox'       => Field\Checkbox::class,
            'color'          => Field\Color::class,
            'currency'       => Field\Currency::class,
            'date'           => Field\Date::class,
            'dateRange'      => Field\DateRange::class,
            'datetime'       => Field\Datetime::class,
            'dateTimeRange'  => Field\DatetimeRange::class,
            'datetimeRange'  => Field\DatetimeRange::class,
            'decimal'        => Field\Decimal::class,
            'display'        => Field\Display::class,
            'divider'        => Field\Divider::class,
            'embeds'         => Field\Embeds::class,
            'email'          => Field\Email::class,
            'file'           => Field\File::class,
            'hasMany'        => Field\HasMany::class,
            'hidden'         => Field\Hidden::class,
            'id'             => Field\Id::class,
            'image'          => Field\Image::class,
            'ip'             => Field\Ip::class,
            'mobile'         => Field\Mobile::class,
            'month'          => Field\Month::class,
            'multipleSelect' => Field\MultipleSelect::class,
            'number'         => Field\Number::class,
            'password'       => Field\Password::class,
            'radio'          => Field\Radio::class,
            'rate'           => Field\Rate::class,
            'select'         => Field\Select::class,
            'slider'         => Field\Slider::class,
            'switch'         => Field\SwitchField::class,
            'text'           => Field\Text::class,
            'textarea'       => Field\Textarea::class,
            'time'           => Field\Time::class,
            'timeRange'      => Field\TimeRange::class,
            'url'            => Field\Url::class,
            'year'           => Field\Year::class,
            'html'           => Field\Html::class,
            'tags'           => Field\Tags::class,
            'icon'           => Field\Icon::class,
            'multipleFile'   => Field\MultipleFile::class,
            'multipleImage'  => Field\MultipleImage::class,
            'captcha'        => Field\Captcha::class,
            'listbox'        => Field\Listbox::class,
            'table'          => Field\Table::class,
            'timezone'       => Field\Timezone::class,
            'keyValue'       => Field\KeyValue::class,
            'list'           => Field\ListField::class,
        ];

        foreach ($map as $abstract => $class) {
            static::extend($abstract, $class);
        }
    }

    /**
     * Register custom field.
     *
     * @param string $abstract
     * @param string $class
     *
     * @return void
     */
    public static function extend($abstract, $class)
    {
        static::$availableFields[$abstract] = $class;
    }

    /**
     * Set form field alias.
     *
     * @param string $field
     * @param string $alias
     *
     * @return void
     */
    public static function alias($field, $alias)
    {
        static::$fieldAlias[$alias] = $field;
    }

    /**
     * Remove registered field.
     *
     * @param array|string $abstract
     */
    public static function forget($abstract)
    {
        Arr::forget(static::$availableFields, $abstract);
    }

    /**
     * Find field class.
     *
     * @param string $method
     *
     * @return bool|mixed
     */
    public static function findFieldClass($method)
    {
        // If alias exists.
        if (isset(static::$fieldAlias[$method])) {
            $method = static::$fieldAlias[$method];
        }

        $class = Arr::get(static::$availableFields, $method);

        if (class_exists($class)) {
            return $class;
        }

        return false;
    }

    /**
     * Collect assets required by registered field.
     *
     * @return array
     */
    public static function collectFieldAssets()
    {
        if (!empty(static::$collectedAssets)) {
            return static::$collectedAssets;
        }

        $css = collect();
        $js = collect();

        foreach (static::$availableFields as $field) {
            if (!method_exists($field, 'getAssets')) {
                continue;
            }

            $assets = call_user_func([$field, 'getAssets']);

            $css->push(Arr::get($assets, 'css'));
            $js->push(Arr::get($assets, 'js'));
        }

        return static::$collectedAssets = [
            'css' => $css->flatten()->unique()->filter()->toArray(),
            'js'  => $js->flatten()->unique()->filter()->toArray(),
        ];
    }

    /**
     * Getter.
     *
     * @param string $name
     *
     * @return array|mixed
     */
    public function __get($name)
    {
        return $this->input($name);
    }

    /**
     * Setter.
     *
     * @param string $name
     * @param mixed  $value
     *
     * @return array
     */
    public function __set($name, $value)
    {
        return Arr::set($this->inputs, $name, $value);
    }

    /**
     * Generate a Field object and add to form builder if Field exists.
     *
     * @param string $method
     * @param array  $arguments
     *
     * @return Field
     */
    public function __call($method, $arguments)
    {
        if ($className = static::findFieldClass($method)) {
            $column = Arr::get($arguments, 0, ''); //[0];

            $element = new $className($column, array_slice($arguments, 1));

            $this->pushField($element);

            return $element;
        }

        admin_error('Error', "Field type [$method] does not exist.");

        return new Field\Nullable();
    }
}