<?php

namespace Laravel\Nova\Fields;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\Relation;
use Illuminate\Http\Request;
use Illuminate\Support\Str;
use Laravel\Nova\Contracts\FilterableField;
use Laravel\Nova\Contracts\QueryBuilder;
use Laravel\Nova\Contracts\RelatableField;
use Laravel\Nova\Fields\Filters\EloquentFilter;
use Laravel\Nova\Http\Requests\NovaRequest;
use Laravel\Nova\Http\Requests\ResourceIndexRequest;
use Laravel\Nova\Resource;
use Laravel\Nova\Rules\Relatable;
use Laravel\Nova\TrashedStatus;
use Laravel\Nova\Util;

/**
 * @method static static make(mixed $name, string|null $attribute = null, string|null $resource = null)
 */
class BelongsTo extends Field implements FilterableField, RelatableField
{
    use AssociatableRelation;
    use DeterminesIfCreateRelationCanBeShown;
    use EloquentFilterable;
    use FormatsRelatableDisplayValues;
    use Peekable;
    use ResolvesReverseRelation;
    use Searchable;
    use SupportsDependentFields;

    /**
     * The field's component.
     *
     * @var string
     */
    public $component = 'belongs-to-field';

    /**
     * The class name of the related resource.
     *
     * @var class-string<\Laravel\Nova\Resource>
     */
    public $resourceClass;

    /**
     * The URI key of the related resource.
     *
     * @var string
     */
    public $resourceName;

    /**
     * The resolved BelongsTo Resource.
     *
     * @var \Laravel\Nova\Resource|null
     */
    public $belongsToResource;

    /**
     * The name of the Eloquent "belongs to" relationship.
     *
     * @var string
     */
    public $belongsToRelationship;

    /**
     * The key of the related Eloquent model.
     *
     * @var string|int|null
     */
    public $belongsToId;

    /**
     * Indicates if the related resource can be viewed.
     *
     * @var bool|null
     */
    public $viewable;

    /**
     * The callback that should be run when the field is filled.
     *
     * @var \Closure(\Laravel\Nova\Http\Requests\NovaRequest, mixed):void
     */
    public $filledCallback;

    /**
     * The attribute that is the inverse of this relationship.
     *
     * @var string
     */
    public $inverse;

    /**
     * The displayable singular label of the relation.
     *
     * @var string
     */
    public $singularLabel;

    /**
     * Indicates whether the field should display the "With Trashed" option.
     *
     * @var bool
     */
    public $displaysWithTrashed = true;

    /**
     * Create a new field.
     *
     * @param  string  $name
     * @param  string|null  $attribute
     * @param  class-string<\Laravel\Nova\Resource>|null  $resource
     * @return void
     */
    public function __construct($name, $attribute = null, $resource = null)
    {
        parent::__construct($name, $attribute);

        $resource = $resource ?? ResourceRelationshipGuesser::guessResource($name);

        $this->resourceClass = $resource;
        $this->resourceName = $resource::uriKey();
        $this->belongsToRelationship = $this->attribute = $attribute ?? ResourceRelationshipGuesser::guessRelation($name);
        $this->singularLabel = $name;
    }

    /**
     * Get the relationship name.
     *
     * @return string
     */
    public function relationshipName()
    {
        return $this->belongsToRelationship;
    }

    /**
     * Get the relationship type.
     *
     * @return string
     */
    public function relationshipType()
    {
        return 'belongsTo';
    }

    /**
     * Determine if the field should be displayed for the given request.
     *
     * @param  \Illuminate\Http\Request&\Laravel\Nova\Http\Requests\NovaRequest  $request
     * @return bool
     */
    public function authorize(Request $request)
    {
        return $this->isNotRedundant($request) && parent::authorize($request);
    }

    /**
     * Determine if the field is not redundant.
     *
     * Ex: Is this a "user" belongs to field in a blog post list being shown on the "user" detail page.
     *
     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
     * @return bool
     */
    public function isNotRedundant(NovaRequest $request)
    {
        return ! $request instanceof ResourceIndexRequest || ! $this->isReverseRelation($request);
    }

    /**
     * Resolve the field's value.
     *
     * @param  mixed  $resource
     * @param  string|null  $attribute
     * @return void
     */
    public function resolve($resource, $attribute = null)
    {
        $value = null;

        if ($resource instanceof Resource || $resource instanceof Model) {
            if ($resource->relationLoaded($this->attribute)) {
                $value = $resource->getRelation($this->attribute);
            } else {
                $value = $resource->{$this->attribute}()->withoutGlobalScopes()->getResults();
            }
        }

        if ($value) {
            $this->belongsToResource = new $this->resourceClass($value);

            $this->belongsToId = Util::safeInt($value->getKey());

            $this->value = $this->formatDisplayValue($this->belongsToResource);

            $this->viewable = ($this->viewable ?? true) && $this->belongsToResource->authorizedToView(app(NovaRequest::class));
        }
    }

    /**
     * Resolve dependent field value.
     *
     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
     * @return mixed
     */
    public function resolveDependentValue(NovaRequest $request)
    {
        return $this->belongsToId ?? $this->resolveDefaultValue($request);
    }

    /**
     * Define the callback that should be used to resolve the field's value.
     *
     * @param  callable  $displayCallback
     * @return $this
     */
    public function displayUsing(callable $displayCallback)
    {
        return $this->display($displayCallback);
    }

    /**
     * Get the validation rules for this field.
     *
     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
     * @return array
     */
    public function getRules(NovaRequest $request)
    {
        $query = $this->buildAssociatableQuery(
            $request, $request->{$this->attribute.'_trashed'} === 'true'
        )->toBase();

        return array_merge_recursive(parent::getRules($request), [
            $this->attribute => array_filter([
                $this->nullable ? 'nullable' : 'required',
                new Relatable($request, $query),
            ]),
        ]);
    }

    /**
     * Hydrate the given attribute on the model based on the incoming request.
     *
     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
     * @param  \Illuminate\Database\Eloquent\Model|\Laravel\Nova\Support\Fluent  $model
     * @return void
     */
    public function fill(NovaRequest $request, $model)
    {
        $foreignKey = $this->getRelationForeignKeyName($model->{$this->attribute}());

        parent::fillInto($request, $model, $foreignKey);

        if ($model->isDirty($foreignKey)) {
            $model->unsetRelation($this->attribute);
        }

        if (is_callable($this->filledCallback)) {
            call_user_func($this->filledCallback, $request, $model);
        }
    }

    /**
     * Hydrate the given attribute on the model based on the incoming request.
     *
     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
     * @param  \Illuminate\Database\Eloquent\Model|\Laravel\Nova\Support\Fluent  $model
     * @return mixed
     */
    public function fillForAction(NovaRequest $request, $model)
    {
        if ($request->exists($this->attribute)) {
            $value = $request[$this->attribute];

            $model->{$this->attribute} = $this->resourceClass::newModel()->query()->find($value);
        }
    }

    /**
     * Hydrate the given attribute on the model based on the incoming request.
     *
     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
     * @param  string  $requestAttribute
     * @param  \Illuminate\Database\Eloquent\Model|\Laravel\Nova\Support\Fluent  $model
     * @param  string  $attribute
     * @return mixed
     */
    protected function fillAttributeFromRequest(NovaRequest $request, $requestAttribute, $model, $attribute)
    {
        if ($request->exists($requestAttribute)) {
            $value = $request[$requestAttribute];

            $relation = Relation::noConstraints(function () use ($model) {
                return $model->{$this->attribute}();
            });

            if ($this->isValidNullValue($value)) {
                $relation->dissociate();
            } else {
                $relation->associate($relation->getQuery()->withoutGlobalScopes()->find($value));
            }
        }
    }

    /**
     * Build an associatable query for the field.
     *
     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
     * @param  bool  $withTrashed
     * @return \Laravel\Nova\Contracts\QueryBuilder
     */
    public function buildAssociatableQuery(NovaRequest $request, $withTrashed = false)
    {
        $model = forward_static_call(
            [$resourceClass = $this->resourceClass, 'newModel']
        );

        $query = app()->make(QueryBuilder::class, [$resourceClass]);

        $request->first === 'true'
                        ? $query->whereKey($model->newQueryWithoutScopes(), $request->current)
                        : $query->search(
                            $request, $model->newQuery(), $request->search,
                            [], [], TrashedStatus::fromBoolean($withTrashed)
                        );

        return $query->tap(function ($query) use ($request, $model) {
            if (is_callable($this->relatableQueryCallback)) {
                call_user_func($this->relatableQueryCallback, $request, $query);

                return;
            }

            forward_static_call($this->associatableQueryCallable($request, $model), $request, $query, $this);
        });
    }

    /**
     * Get the associatable query method name.
     *
     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
     * @param  \Illuminate\Database\Eloquent\Model  $model
     * @return array
     */
    protected function associatableQueryCallable(NovaRequest $request, $model)
    {
        return ($method = $this->associatableQueryMethod($request, $model))
                    ? [$request->resource(), $method]
                    : [$this->resourceClass, 'relatableQuery'];
    }

    /**
     * Get the associatable query method name.
     *
     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
     * @param  \Illuminate\Database\Eloquent\Model  $model
     * @return string|null
     */
    protected function associatableQueryMethod(NovaRequest $request, $model)
    {
        $method = 'relatable'.Str::plural(class_basename($model));

        if (method_exists($request->resource(), $method)) {
            return $method;
        }
    }

    /**
     * Format the given associatable resource.
     *
     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
     * @param  mixed  $resource
     * @return array
     */
    public function formatAssociatableResource(NovaRequest $request, $resource)
    {
        return array_filter([
            'avatar' => $resource->resolveAvatarUrl($request),
            'display' => $this->formatDisplayValue($resource),
            'subtitle' => $resource->subtitle(),
            'value' => Util::safeInt($resource->getKey()),
        ]);
    }

    /**
     * Specify if the related resource can be viewed.
     *
     * @param  bool  $value
     * @return $this
     */
    public function viewable($value = true)
    {
        $this->viewable = $value;

        return $this;
    }

    /**
     * Specify a callback that should be run when the field is filled.
     *
     * @param  \Closure(\Laravel\Nova\Http\Requests\NovaRequest, mixed):void  $callback
     * @return $this
     */
    public function filled($callback)
    {
        $this->filledCallback = $callback;

        return $this;
    }

    /**
     * Set the value for the field.
     *
     * @param  mixed  $value
     * @return void
     */
    public function setValue($value)
    {
        $this->belongsToId = Util::safeInt($value);
        $this->value = $value;
    }

    /**
     * Set the attribute name of the inverse of the relationship.
     *
     * @param  string  $inverse
     * @return $this
     */
    public function inverse($inverse)
    {
        $this->inverse = $inverse;

        return $this;
    }

    /**
     * Set the displayable singular label of the resource.
     *
     * @param  string  $singularLabel
     * @return $this
     */
    public function singularLabel($singularLabel)
    {
        $this->singularLabel = $singularLabel;

        return $this;
    }

    /**
     * hides the "With Trashed" option.
     *
     * @return $this
     */
    public function withoutTrashed()
    {
        $this->displaysWithTrashed = false;

        return $this;
    }

    /**
     * Return the sortable uri key for the field.
     *
     * @return string
     */
    public function sortableUriKey()
    {
        $request = app(NovaRequest::class);

        return $this->getRelationForeignKeyName($request->newResource()->resource->{$this->attribute}());
    }

    /**
     * Make the field filter.
     *
     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
     * @return \Laravel\Nova\Fields\Filters\Filter|null
     */
    protected function makeFilter(NovaRequest $request)
    {
        if ($request->viaRelationship()
            && ($request->relationshipType ?? null) === 'hasMany'
            && $this->resourceClass::uriKey() === $request->viaResource
        ) {
            return null;
        }

        return new EloquentFilter($this);
    }

    /**
     * Define filterable attribute.
     *
     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
     * @return string
     */
    protected function filterableAttribute(NovaRequest $request)
    {
        return $this->getRelationForeignKeyName($request->newResource()->resource->{$this->attribute}());
    }

    /**
     * Define the default filterable callback.
     *
     * @return callable(\Laravel\Nova\Http\Requests\NovaRequest, \Illuminate\Database\Eloquent\Builder, mixed, string):void
     */
    protected function defaultFilterableCallback()
    {
        return function (NovaRequest $request, $query, $value, $attribute) {
            $query->where($attribute, '=', $value);
        };
    }

    /**
     * Prepare the field for JSON serialization.
     *
     * @return array
     */
    public function serializeForFilter()
    {
        return transform($this->jsonSerialize(), function ($field) {
            return [
                'debounce' => $field['debounce'],
                'displaysWithTrashed' => $field['displaysWithTrashed'],
                'label' => $this->resourceClass::label(),
                'resourceName' => $field['resourceName'],
                'searchable' => $field['searchable'],
                'withSubtitles' => $field['withSubtitles'],
                'uniqueKey' => $field['uniqueKey'],
            ];
        });
    }

    /**
     * Prepare the field for JSON serialization.
     *
     * @return array<string, mixed>
     */
    public function jsonSerialize(): array
    {
        return with(app(NovaRequest::class), function ($request) {
            $viewable = ! is_null($this->viewable) ? $this->viewable : $this->resourceClass::authorizedToViewAny($request);

            return array_merge([
                'belongsToId' => $this->belongsToId,
                'relationshipType' => $this->relationshipType(),
                'belongsToRelationship' => $this->belongsToRelationship,
                'debounce' => $this->debounce,
                'displaysWithTrashed' => $this->displaysWithTrashed,
                'label' => $this->resourceClass::label(),
                'peekable' => $this->isPeekable($request),
                'hasFieldsToPeekAt' => $this->hasFieldsToPeekAt($request),
                'resourceName' => $this->resourceName,
                'reverse' => $this->isReverseRelation($request),
                'searchable' => $this->isSearchable($request),
                'withSubtitles' => $this->withSubtitles,
                'showCreateRelationButton' => $this->createRelationShouldBeShown($request),
                'singularLabel' => $this->singularLabel,
                'viewable' => $viewable,
            ], parent::jsonSerialize());
        });
    }
}