<?php

namespace App\Classes;

use ArrayAccess;
use Illuminate\Filesystem\FilesystemAdapter;

class MetadataManager implements ArrayAccess
{
    /**
     * Original metadata content
     */
    private array $originalContent = [];

    /**
     * Current metadata content
     */
    private array $content = [];

    public function __construct(protected string $filename, protected FilesystemAdapter $disk)
    {

    }

    /**
     * Return a boolean value indicating if the file actually exists on disk
     */
    public function exists()
    {
        return $this->disk->exists($this->filename);
    }

    /**
     * Set a new array of values
     */
    public function set(array $content): void
    {
        $this->content = $content;
    }

    /**
     * Return a boolean indicating if the file has changed since it was loaded
     */
    public function isDirty(): bool
    {
        $original = collect($this->originalContent);
        $current  = collect($this->content);

        return !$original->diffAssoc($current)->isEmpty() || !$current->diffAssoc($original)->isEmpty();
    }

    /**
     * Store file on disk
     */
    public function save(): bool
    {
        if (!$this->isDirty()) {
            return false;
        }

        $json = json_encode($this->content, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);

        $this->disk->put($this->filename, $json);

        $this->originalContent = $this->content;

        return true;
    }

    public function offsetExists(mixed $offset): bool
    {
        return isset($this->content[$offset]);
    }

    public function &offsetGet(mixed $offset): mixed
    {
        if (!isset($this->content[$offset])) {
            $this->content[$offset] = null;
        }

        return $this->content[$offset];
    }

    public function offsetSet(mixed $offset, mixed $value): void
    {
        if (is_null($offset)) {
            $this->content[] = $value;
        } else {
            $this->content[$offset] = $value;
        }
    }

    public function offsetUnset(mixed $offset): void
    {
        unset($this->content[$offset]);
    }
}