<?php

declare(strict_types=1);

namespace DTS;

use DTS\Bookmark;

class BookmarkRepository implements \Iterator
{
    private string $pathToRepository;

    private array $repository = [];

    private int $position = 0;

    function __construct(string $pathToRepository)
    {
        $this->pathToRepository = $pathToRepository;

        $this->load();
    }

    public function sort(bool $asc = true): BookmarkRepository
    {
        usort($this->repository, function ($a, $b) use ($asc) {
            return $asc ? $a->addedAt <=> $b->addedAt
                : $b->addedAt <=> $a->addedAt;
        });

        return $this;
    }

    public function filter(string $tag): BookmarkRepository
    {
        $this->repository = array_filter(
            $this->repository,
            fn($bookmark) => $bookmark->tag === $tag
        );

        return $this;
    }

    public function find(string $id): ?Bookmark
    {
        $index = $this->findBookmarkIndex($id);

        return $this->repository[$index] ?? null;
    }

    public function add(Bookmark $bookmark): bool
    {
        $this->repository[] = $bookmark;

        return $this->save();
    }

    public function update(Bookmark $bookmark): bool
    {
        $index = $this->findBookmarkIndex($bookmark->id);

        if ($index !== null) {
            $this->repository[$index] = $bookmark;

            return $this->save();
        }

        return false;
    }

    public function delete(Bookmark $bookmark): bool
    {
        $index = $this->findBookmarkIndex($bookmark->id);

        if ($index !== null) {
            unset($this->repository[$index]);

            return $this->save();
        }

        return false;
    }

    public function current(): mixed
    {
        return $this->repository[$this->position];
    }

    public function key(): mixed
    {
        return $this->position;
    }

    public function next(): void
    {
        ++$this->position;
    }

    public function rewind(): void
    {
        $this->position = 0;
    }

    public function valid(): bool
    {
        return isset($this->repository[$this->position]);
    }

    private function findBookmarkIndex(string $id): ?int
    {
        foreach ($this->repository as $index => $bookmark) {
            if ($bookmark->id == $id) {
                return $index;
            }
        }

        return null;
    }

    private function load(): void
    {
        if (!is_file($this->pathToRepository) || !is_readable($this->pathToRepository)) {
            throw new \Exception("Unable to locate repository {$this->pathToRepository}");
        }

        if (($fp = fopen($this->pathToRepository, 'r')) === FALSE) {
            throw new \Exception("Unable to read from repository {$this->pathToRepository}");
        }

        while (($data = fgetcsv($fp)) !== FALSE) {
            $bookmark = new Bookmark();

            $bookmark->id = $data[0];
            $bookmark->url = $data[1];
            $bookmark->title = $data[2];
            $bookmark->tag = $data[3];
            $bookmark->addedAt = $data[4];

            $this->repository[] = $bookmark;
        }

        fclose($fp);
    }

    private function save(): bool
    {
        if (($fp = fopen($this->pathToRepository, 'w')) === FALSE) {
            throw new \Exception("Unable to open repository {$this->pathToRepository}");
        }

        $success = true;

        foreach ($this->repository as $bookmark) {
            $success = $success && fputcsv($fp, [
                $bookmark->id,
                $bookmark->url,
                $bookmark->title,
                $bookmark->tag,
                $bookmark->addedAt,
            ]) !== false;
        }

        fclose($fp);

        return $success;
    }
}