<?php

namespace App\Models;

use App\Enumerations\ContentStatuses;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Support\Facades\DB;

/**
 * Class Content
 */
class Content extends Model
{
    public $timestamps = true;
    protected $fillable = [
        'user_id',
        'module_handler',
        'published_from',
        'published_to',
        'title_photo',
        'title',
        'url',
        'meta_keywords',
        'meta_description',
        'content',
        'module_settings',
        'status'
    ];
    protected $guarded = [];
    const STATUS_DELETED = 'deleted';
    const STATUS_DRAFT = 'draft';
    const STATUS_PROTECTED = 'protected';
    const STATUS_PUBLIC = 'public';

    /**
     * Getter for query with setup filter for non-deleted and non-draft pages
     */
    protected function getPageQuery()
    {
        return Content::where('status', '!=', Content::STATUS_DELETED)
                      ->where('status', '!=', Content::STATUS_DRAFT);
    }

    /**
     * Getter for homepage content page
     *
     * @return Content
     */
    public function getHomepage()
    {
        return $this->getPageQuery()
                    ->where('is_homepage', 1)
                    ->first();
    }

    /**
     * Getter for any page specified by its url.
     *
     * @param $url
     *
     * @return Content
     */
    public function getByURL($url)
    {
        return $this->getPageQuery()
                    ->where('url', $url)
                    ->first();
    }

    /**
     * Getter for overview of all content pages.
     *
     * These content pages may be filtered by using some handler
     *
     * @param bool $handler
     * @param bool $status
     * @param bool $joinAuthor
     *
     * @return
     */
    public function getOverview($handler = false, $status = false, $joinAuthor = false)
    {
        $query = DB::table('contents')
                   ->select('contents.*', 'modules.name AS module_name')
                   ->where('contents.status', '<>', self::STATUS_DELETED)
                   ->join('modules', 'modules.handler', '=', 'contents.module_handler')
                   ->orderBy('created_at', 'DESC');

        // filter results using handler
        if ($handler) {
            $query = $query->where('module_handler', $handler);
        }

        // join user email and user name to results when needed
        if ($joinAuthor) {
            $query = $query->join('users', 'users.id', '=', 'contents.user_id')
                           ->addSelect('users.name AS author_name')
                           ->addSelect('users.email AS author_email');
        }

        // add filtering by status
        if (in_array($status, ContentStatuses::getSimple())) {
            $query = $query->where('contents.status', $status);
        }

        return $query;
    }

    /**
     * Updates current model with information about changed columns
     *
     * @param array  $fields
     * @param array  $request
     * @param string $revisionId
     *
     * @return int number of changed columns
     */
    public function updateWithHistory(array $fields, array $request, $revisionId = null)
    {
        if (!$revisionId) {
            $revisionId = uniqid();
        }

        $changed = 0;

        foreach ($fields as $fieldDB => $fieldRequest) {
            // ignore non-existing fields
            if ((!isset($this->$fieldDB) && !is_null($this->$fieldDB)) || (!isset($request[$fieldRequest]) && !is_null($request[$fieldRequest]))) {
                continue;
            }

            // remove any whitespaces around real content
            if (!is_null($request[$fieldRequest]))
            $request[$fieldRequest] = trim($request[$fieldRequest]);

            if (trim($this->$fieldDB) != $request[$fieldRequest]) {

                // setup history object
                $history = [
                    'user_id'    => \Auth::user()->id,
                    'content_id' => $this->id,
                    'edit_batch' => $revisionId,
                    'column'     => $fieldRequest,
                    'old_value'  => $this->$fieldDB,
                    'new_value'  => $request[$fieldRequest]
                ];

                // save history
                ContentHistory::create($history);

                // save change into database
                $this->$fieldDB = $request[$fieldRequest];

                $changed++;
            }
        }

        $this->save();

        return [$revisionId, $changed];
    }

    /**
     * Mark relationship with its historical records
     *
     * @return \Illuminate\Database\Eloquent\Relations\HasMany
     */
    public function history()
    {
        return $this->hasMany('App\Models\ContentHistory');
    }

    /**
     * Mark relationship with users table
     *
     * @return \Illuminate\Database\Eloquent\Relations\BelongsTo
     */
    public function author()
    {
        return $this->belongsTo('App\Models\User', 'user_id');
    }
}