<?php

namespace Yajra\DataTables;

use Exception;
use Illuminate\Http\Request;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\UploadedFile;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\QueryException;
use Illuminate\Support\Facades\Storage;
use Illuminate\Database\Eloquent\SoftDeletes;
use Illuminate\Contracts\Validation\Validator;
use Illuminate\Validation\ValidationException;
use Illuminate\Foundation\Validation\ValidatesRequests;

abstract class DataTablesEditor
{
    use ValidatesRequests;

    /**
     * Action performed by the editor.
     *
     * @var string|null
     */
    protected $action = null;

    /**
     * Allowed dataTables editor actions.
     *
     * @var array
     */
    protected $actions = [
        'create',
        'edit',
        'remove',
        'upload',
        'forceDelete',
        'restore',
    ];

    /**
     * @var \Illuminate\Database\Eloquent\Model
     */
    protected $model = null;

    /**
     * Indicates if all mass assignment is enabled on model.
     *
     * @var bool
     */
    protected $unguarded = false;

    /**
     * Upload directory relative to storage path.
     *
     * @var string
     */
    protected $uploadDir = 'editor';

    /**
     * Flag to force delete a model.
     *
     * @var bool
     */
    protected $forceDeleting = false;

    /**
     * Flag to restore a model from deleted state.
     *
     * @var bool
     */
    protected $restoring = false;

    /**
     * Filesystem disk config to use for upload.
     *
     * @var string
     */
    protected $disk = 'public';

    /**
     * Current request data that is being processed.
     *
     * @var array
     */
    protected $currentData = [];

    /**
     * Process dataTables editor action request.
     *
     * @param Request $request
     * @return JsonResponse|mixed
     * @throws DataTablesEditorException
     */
    public function process(Request $request)
    {
        $action = $request->get('action');

        if (! in_array($action, $this->actions)) {
            throw new DataTablesEditorException('Requested action not supported!');
        }

        try {
            return $this->{$action}($request);
        } catch (Exception $exception) {
            $error = config('app.debug')
                ? '<strong>Server Error:</strong> ' . $exception->getMessage()
                : $this->getUseFriendlyErrorMessage();

            app('log')->error($exception);

            return $this->toJson([], [], $error);
        }
    }

    /**
     * @return string
     */
    protected function getUseFriendlyErrorMessage()
    {
        return 'An error occurs while processing your request.';
    }

    /**
     * Display success data in dataTables editor format.
     *
     * @param array $data
     * @param array $errors
     * @param string $error
     * @return JsonResponse
     */
    protected function toJson(array $data, array $errors = [], $error = '')
    {
        $response = [
            'action' => $this->action,
            'data'   => $data,
        ];

        if ($error) {
            $response['error'] = $error;
        }

        if ($errors) {
            $response['fieldErrors'] = $errors;
        }

        return new JsonResponse($response, 200);
    }

    /**
     * Process create action request.
     *
     * @param Request $request
     * @return JsonResponse
     * @throws \Exception
     */
    public function create(Request $request)
    {
        $this->action = $this->action ?? 'create';

        $model      = $this->resolveModel();
        $connection = $model->getConnection();
        $affected   = [];
        $errors     = [];

        $connection->beginTransaction();
        foreach ($request->get('data') as $data) {
            $this->currentData = $data;

            $instance  = $model->newInstance();
            $validator = $this->getValidationFactory()
                              ->make(
                                  $data,
                                  $this->createRules(), $this->messages() + $this->createMessages(),
                                  $this->attributes()
                              );
            if ($validator->fails()) {
                foreach ($this->formatErrors($validator) as $error) {
                    $errors[] = $error;
                }

                continue;
            }

            if (method_exists($this, 'creating')) {
                $data = $this->creating($instance, $data);
            }

            if (method_exists($this, 'saving')) {
                $data = $this->saving($instance, $data);
            }

            $instance->fill($data)->save();

            if (method_exists($this, 'created')) {
                $instance = $this->created($instance, $data);
            }

            if (method_exists($this, 'saved')) {
                $instance = $this->saved($instance, $data);
            }

            $instance->setAttribute('DT_RowId', $instance->getKey());
            $affected[] = $instance;
        }

        if (! $errors) {
            $connection->commit();
        } else {
            $connection->rollBack();
        }

        return $this->toJson($affected, $errors);
    }

    /**
     * Resolve model to used.
     *
     * @return Model|\Illuminate\Database\Eloquent\SoftDeletes
     */
    protected function resolveModel()
    {
        if (! $this->model instanceof Model) {
            $this->model = new $this->model;
        }

        $this->model->unguard($this->unguarded);

        return $this->model;
    }

    /**
     * Get create action validation rules.
     *
     * @return array
     */
    abstract public function createRules();

    /**
     * Get validation messages.
     *
     * @return array
     */
    protected function messages()
    {
        return [];
    }

    /**
     * Get create validation messages.
     *
     * @return array
     * @deprecated deprecated since v1.12.0, please use messages() instead.
     */
    protected function createMessages()
    {
        return [];
    }

    /**
     * Get custom attributes for validator errors.
     *
     * @return array
     */
    public function attributes()
    {
        return [];
    }

    /**
     * @param Validator $validator
     * @return array
     */
    protected function formatErrors(Validator $validator)
    {
        $errors = [];

        collect($validator->errors())->each(function ($error, $key) use (&$errors) {
            $errors[] = [
                'name'   => $key,
                'status' => $error[0],
            ];
        });

        return $errors;
    }

    /**
     * Process restore action request.
     *
     * @param \Illuminate\Http\Request $request
     * @return \Illuminate\Http\JsonResponse
     */
    public function restore(Request $request)
    {
        $this->action = 'restore';

        $this->restoring = true;

        return $this->edit($request);
    }

    /**
     * Process edit action request.
     *
     * @param Request $request
     * @return JsonResponse
     */
    public function edit(Request $request)
    {
        $this->action = $this->action ?? 'edit';

        $connection = $this->getBuilder()->getConnection();
        $affected   = [];
        $errors     = [];

        $connection->beginTransaction();
        foreach ($request->get('data') as $key => $data) {
            $this->currentData = $data;

            $model     = $this->getBuilder()->findOrFail($key);
            $validator = $this->getValidationFactory()
                              ->make(
                                  $data,
                                  $this->editRules($model), $this->messages() + $this->editMessages(),
                                  $this->attributes()
                              );
            if ($validator->fails()) {
                foreach ($this->formatErrors($validator) as $error) {
                    $errors[] = $error;
                }

                continue;
            }

            if (method_exists($this, 'updating')) {
                $data = $this->updating($model, $data);
            }

            if (method_exists($this, 'saving')) {
                $data = $this->saving($model, $data);
            }

            $this->restoring ? $model->restore() : $model->fill($data)->save();

            if (method_exists($this, 'updated')) {
                $model = $this->updated($model, $data);
            }

            if (method_exists($this, 'saved')) {
                $model = $this->saved($model, $data);
            }

            $model->setAttribute('DT_RowId', $model->getKey());
            $affected[] = $model;
        }

        if (! $errors) {
            $connection->commit();
        } else {
            $connection->rollBack();
        }

        return $this->toJson($affected, $errors);
    }

    /**
     * Get elqouent builder of the model.
     *
     * @return \Illuminate\Database\Eloquent\Builder
     */
    protected function getBuilder()
    {
        $model = $this->resolveModel();

        if (in_array(SoftDeletes::class, class_uses($model))) {
            return $model->newQuery()->withTrashed();
        }

        return $model->newQuery();
    }

    /**
     * Get edit action validation rules.
     *
     * @param Model $model
     * @return array
     */
    abstract public function editRules(Model $model);

    /**
     * Get edit validation messages.
     *
     * @return array
     * @deprecated deprecated since v1.12.0, please use messages() instead.
     */
    protected function editMessages()
    {
        return [];
    }

    /**
     * Process force delete action request.
     *
     * @param \Illuminate\Http\Request $request
     * @return \Illuminate\Http\JsonResponse
     * @throws \Exception
     */
    public function forceDelete(Request $request)
    {
        $this->action = 'forceDelete';

        $this->forceDeleting = true;

        return $this->remove($request);
    }

    /**
     * Process remove action request.
     *
     * @param Request $request
     * @return JsonResponse
     * @throws \Exception
     */
    public function remove(Request $request)
    {
        $this->action = $this->action ?? 'remove';

        $connection = $this->getBuilder()->getConnection();
        $affected   = [];
        $errors     = [];

        $connection->beginTransaction();
        foreach ($request->get('data') as $key => $data) {
            $this->currentData = $data;

            $model     = $this->getBuilder()->findOrFail($key);
            $validator = $this->getValidationFactory()
                              ->make(
                                  $data,
                                  $this->removeRules($model), $this->messages() + $this->removeMessages(),
                                  $this->attributes()
                              );
            if ($validator->fails()) {
                foreach ($this->formatErrors($validator) as $error) {
                    $errors[] = $error['status'];
                }

                continue;
            }

            try {
                $deleted = clone $model;
                if (method_exists($this, 'deleting')) {
                    $this->deleting($model, $data);
                }

                $this->forceDeleting ? $model->forceDelete() : $model->delete();

                if (method_exists($this, 'deleted')) {
                    $this->deleted($deleted, $data);
                }
            } catch (QueryException $exception) {
                $error = config('app.debug')
                    ? $exception->getMessage()
                    : $this->removeExceptionMessage($exception, $model);

                $errors[] = $error;
            }

            $affected[] = $deleted;
        }

        if (! $errors) {
            $connection->commit();
        } else {
            $connection->rollBack();
        }

        $response = ['data' => $affected];
        if ($errors) {
            $response['error'] = implode("\n", $errors);
        }

        return $this->toJson($affected, [], $errors ?? '');
    }

    /**
     * Get remove action validation rules.
     *
     * @param Model $model
     * @return array
     */
    abstract public function removeRules(Model $model);

    /**
     * Get remove validation messages.
     *
     * @return array
     * @deprecated deprecated since v1.12.0, please use messages() instead.
     */
    protected function removeMessages()
    {
        return [];
    }

    /**
     * Get remove query exception message.
     *
     * @param QueryException $exception
     * @param Model $model
     * @return string
     */
    protected function removeExceptionMessage(QueryException $exception, Model $model)
    {
        return "Record {$model->getKey()} is protected and cannot be deleted!";
    }

    /**
     * Get dataTables model.
     *
     * @return Model
     */
    public function getModel()
    {
        return $this->model;
    }

    /**
     * Set the dataTables model on runtime.
     *
     * @param Model|string $model
     * @return DataTablesEditor
     */
    public function setModel($model)
    {
        $this->model = $model;

        return $this;
    }

    /**
     * Set model unguard state.
     *
     * @param bool $state
     * @return $this
     */
    public function unguard($state = true)
    {
        $this->unguarded = $state;

        return $this;
    }

    /**
     * Handle uploading of file.
     *
     * @param \Illuminate\Http\Request $request
     * @return \Illuminate\Http\JsonResponse
     */
    public function upload(Request $request)
    {
        $this->action = 'upload';

        $field   = $request->input('uploadField');
        $storage = Storage::disk($this->disk);

        try {
            $rules      = $this->uploadRules();
            $fieldRules = ['upload' => data_get($rules, $field, [])];

            $this->validate($request, $fieldRules, $this->messages(), $this->attributes());

            $uploadedFile = $request->file('upload');
            $filename     = $this->getUploadedFilename($field, $uploadedFile);
            $id           = $storage->putFileAs($this->uploadDir, $uploadedFile, $filename);

            if (method_exists($this, 'uploaded')) {
                $id = $this->uploaded($id);
            }

            return response()->json([
                'action' => $this->action,
                'data'   => [],
                'files'  => [
                    'files' => [
                        $id => [
                            'filename'      => $id,
                            'original_name' => $uploadedFile->getClientOriginalName(),
                            'size'          => $uploadedFile->getSize(),
                            'directory'     => $this->uploadDir,
                            'disk'          => $this->disk,
                            'url'           => $storage->url($id),
                        ],
                    ],
                ],
                'upload' => [
                    'id' => $id,
                ],
            ]);
        } catch (ValidationException $exception) {
            return response()->json([
                'action'      => $this->action,
                'data'        => [],
                'fieldErrors' => [
                    [
                        'name'   => $field,
                        'status' => str_replace('upload', $field, $exception->errors()['upload'][0]),
                    ],
                ],
            ]);
        }
    }

    /**
     * Upload validation rules.
     *
     * @return array
     */
    public function uploadRules()
    {
        return [];
    }

    /**
     * @param string $field
     * @param UploadedFile $uploadedFile
     * @return string
     */
    protected function getUploadedFilename($field, UploadedFile $uploadedFile)
    {
        return date('Ymd_His') . '_' . $uploadedFile->getClientOriginalName();
    }
}
