<?php

namespace Common\Files\Traits;

use DB;
use Illuminate\Database\Eloquent\Collection;

trait HandlesEntryPaths
{
    public function getPathAttribute($value)
    {
        if ( ! $value) $value = '';

        $parts = explode('/', $value);

        $parts = array_map(function($part) {
            return $this->decodePathId($part);
        }, array_filter($parts));

        return implode('/', $parts);
    }

    public function setPathAttribute($value)
    {
        if ( ! $value) $value = '';

        $this->attributes['path'] = $this->encodePath($value);
    }

    /**
     * @param string $oldPath
     * @param string $newPath
     * @param null $entryIds
     */
    public function updatePaths($oldPath, $newPath, $entryIds = null)
    {
        $oldPath = $this->encodePath($oldPath);
        $newPath = $this->encodePath($newPath);

        $query = $this->newQuery();

        if ($entryIds) {
            $query->whereIn('id', $entryIds);
        }

        $query->where('path', 'LIKE', "$oldPath%")
            ->update(['path' => DB::raw("REPLACE(path, '$oldPath', '$newPath')")]);
    }

    /**
     * Get all children of current entry.
     *
     * @return Collection
     */
    public function findChildren()
    {
        if ( ! $this->exists) return collect();

        return $this->where('path', 'like', $this->attributes['path'].'%')->get();
    }

    /**
     * Generate full path for current entry, based on its parent.
     */
    public function generatePath()
    {
        if ( ! $this->exists) return;

        $this->path = $this->id;

        if ($this->parent_id) {
            $parent = $this->find($this->parent_id);
            $this->path = "{$parent->path}/$this->path";
        }

        $this->save();
    }

    private function encodePath($path)
    {
        $parts = explode('/', (string) $path);

        $parts = array_filter($parts);

        $parts = array_map(function($part) {
            return $this->encodePathId($part);
        }, $parts);

        return implode('/', $parts);
    }

    private function encodePathId($id) {
        return base_convert($id, 10, 36);
    }

    private function decodePathId($id) {
        return base_convert($id, 36, 10);
    }
}
