<?php

namespace PrelandAdmin;

use FilesystemIterator;
use RecursiveDirectoryIterator;
use RecursiveIteratorIterator;
use RuntimeException;
use ZipArchive;

/**
 * Файловый контракт Set демонстрационных изображений Index.
 * Перенесено из API 591a67cc8302 components/indpic/IndpicSetStorage.php (preland#22).
 *
 * Компонент не знает о БД: он только проверяет и атомарно заменяет содержимое
 * каталогов `images/indpic/<номер>`. Это позволяет одинаково применять его к
 * Set, добавленному через SFTP или ZIP CPanel.
 */
final class IndpicSetStorage
{
    /** @var array<string, array{width: int, height: int}> */
    private const DIMENSIONS = [
        '01_desk_1-source.avif' => ['width' => 1696, 'height' => 920],
        '01_desk_1-source.webp' => ['width' => 1696, 'height' => 920],
        '01_desk_1-source.jpg' => ['width' => 1696, 'height' => 920],
        '01_desk_2-result.avif' => ['width' => 1696, 'height' => 920],
        '01_desk_2-result.webp' => ['width' => 1696, 'height' => 920],
        '01_desk_2-result.jpg' => ['width' => 1696, 'height' => 920],
        '01_desk_3-thumb.avif' => ['width' => 200, 'height' => 200],
        '01_desk_3-thumb.webp' => ['width' => 200, 'height' => 200],
        '01_desk_3-thumb.jpg' => ['width' => 200, 'height' => 200],
        '01_mob_1-source.avif' => ['width' => 400, 'height' => 217],
        '01_mob_1-source.webp' => ['width' => 400, 'height' => 217],
        '01_mob_1-source.jpg' => ['width' => 400, 'height' => 217],
        '01_mob_2-result.avif' => ['width' => 400, 'height' => 217],
        '01_mob_2-result.webp' => ['width' => 400, 'height' => 217],
        '01_mob_2-result.jpg' => ['width' => 400, 'height' => 217],
        '01_mob_3-thumb.avif' => ['width' => 60, 'height' => 60],
        '01_mob_3-thumb.webp' => ['width' => 60, 'height' => 60],
        '01_mob_3-thumb.jpg' => ['width' => 60, 'height' => 60],
        '02_desk_1-source.avif' => ['width' => 1696, 'height' => 920],
        '02_desk_1-source.webp' => ['width' => 1696, 'height' => 920],
        '02_desk_1-source.jpg' => ['width' => 1696, 'height' => 920],
        '02_desk_2-result.avif' => ['width' => 1696, 'height' => 920],
        '02_desk_2-result.webp' => ['width' => 1696, 'height' => 920],
        '02_desk_2-result.jpg' => ['width' => 1696, 'height' => 920],
        '02_desk_3-thumb.avif' => ['width' => 200, 'height' => 200],
        '02_desk_3-thumb.webp' => ['width' => 200, 'height' => 200],
        '02_desk_3-thumb.jpg' => ['width' => 200, 'height' => 200],
        '02_mob_1-source.avif' => ['width' => 400, 'height' => 217],
        '02_mob_1-source.webp' => ['width' => 400, 'height' => 217],
        '02_mob_1-source.jpg' => ['width' => 400, 'height' => 217],
        '02_mob_2-result.avif' => ['width' => 400, 'height' => 217],
        '02_mob_2-result.webp' => ['width' => 400, 'height' => 217],
        '02_mob_2-result.jpg' => ['width' => 400, 'height' => 217],
        '02_mob_3-thumb.avif' => ['width' => 60, 'height' => 60],
        '02_mob_3-thumb.webp' => ['width' => 60, 'height' => 60],
        '02_mob_3-thumb.jpg' => ['width' => 60, 'height' => 60],
        '03_desk_1-source.avif' => ['width' => 1696, 'height' => 920],
        '03_desk_1-source.webp' => ['width' => 1696, 'height' => 920],
        '03_desk_1-source.jpg' => ['width' => 1696, 'height' => 920],
        '03_desk_2-result.avif' => ['width' => 1696, 'height' => 920],
        '03_desk_2-result.webp' => ['width' => 1696, 'height' => 920],
        '03_desk_2-result.jpg' => ['width' => 1696, 'height' => 920],
        '03_desk_3-thumb.avif' => ['width' => 200, 'height' => 200],
        '03_desk_3-thumb.webp' => ['width' => 200, 'height' => 200],
        '03_desk_3-thumb.jpg' => ['width' => 200, 'height' => 200],
        '03_mob_1-source.avif' => ['width' => 400, 'height' => 217],
        '03_mob_1-source.webp' => ['width' => 400, 'height' => 217],
        '03_mob_1-source.jpg' => ['width' => 400, 'height' => 217],
        '03_mob_2-result.avif' => ['width' => 400, 'height' => 217],
        '03_mob_2-result.webp' => ['width' => 400, 'height' => 217],
        '03_mob_2-result.jpg' => ['width' => 400, 'height' => 217],
        '03_mob_3-thumb.avif' => ['width' => 60, 'height' => 60],
        '03_mob_3-thumb.webp' => ['width' => 60, 'height' => 60],
        '03_mob_3-thumb.jpg' => ['width' => 60, 'height' => 60],
        '04_desk_1-source.avif' => ['width' => 1696, 'height' => 920],
        '04_desk_1-source.webp' => ['width' => 1696, 'height' => 920],
        '04_desk_1-source.jpg' => ['width' => 1696, 'height' => 920],
        '04_desk_2-result.avif' => ['width' => 1696, 'height' => 920],
        '04_desk_2-result.webp' => ['width' => 1696, 'height' => 920],
        '04_desk_2-result.jpg' => ['width' => 1696, 'height' => 920],
        '04_desk_3-thumb.avif' => ['width' => 200, 'height' => 200],
        '04_desk_3-thumb.webp' => ['width' => 200, 'height' => 200],
        '04_desk_3-thumb.jpg' => ['width' => 200, 'height' => 200],
        '04_mob_1-source.avif' => ['width' => 400, 'height' => 217],
        '04_mob_1-source.webp' => ['width' => 400, 'height' => 217],
        '04_mob_1-source.jpg' => ['width' => 400, 'height' => 217],
        '04_mob_2-result.avif' => ['width' => 400, 'height' => 217],
        '04_mob_2-result.webp' => ['width' => 400, 'height' => 217],
        '04_mob_2-result.jpg' => ['width' => 400, 'height' => 217],
        '04_mob_3-thumb.avif' => ['width' => 60, 'height' => 60],
        '04_mob_3-thumb.webp' => ['width' => 60, 'height' => 60],
        '04_mob_3-thumb.jpg' => ['width' => 60, 'height' => 60],
        '05_desk_1-source.avif' => ['width' => 1696, 'height' => 920],
        '05_desk_1-source.webp' => ['width' => 1696, 'height' => 920],
        '05_desk_1-source.jpg' => ['width' => 1696, 'height' => 920],
        '05_desk_2-result.avif' => ['width' => 1696, 'height' => 920],
        '05_desk_2-result.webp' => ['width' => 1696, 'height' => 920],
        '05_desk_2-result.jpg' => ['width' => 1696, 'height' => 920],
        '05_desk_3-thumb.avif' => ['width' => 200, 'height' => 200],
        '05_desk_3-thumb.webp' => ['width' => 200, 'height' => 200],
        '05_desk_3-thumb.jpg' => ['width' => 200, 'height' => 200],
        '05_mob_1-source.avif' => ['width' => 400, 'height' => 217],
        '05_mob_1-source.webp' => ['width' => 400, 'height' => 217],
        '05_mob_1-source.jpg' => ['width' => 400, 'height' => 217],
        '05_mob_2-result.avif' => ['width' => 400, 'height' => 217],
        '05_mob_2-result.webp' => ['width' => 400, 'height' => 217],
        '05_mob_2-result.jpg' => ['width' => 400, 'height' => 217],
        '05_mob_3-thumb.avif' => ['width' => 60, 'height' => 60],
        '05_mob_3-thumb.webp' => ['width' => 60, 'height' => 60],
        '05_mob_3-thumb.jpg' => ['width' => 60, 'height' => 60],
    ];

    private readonly ?\Closure $imageInspector;

    public function __construct(private readonly string $root, ?callable $imageInspector = null)
    {
        $this->imageInspector = $imageInspector === null ? null : \Closure::fromCallable($imageInspector);
    }

    /** @return array<string, array{width: int, height: int}> */
    public static function expectedDimensions(): array
    {
        return self::DIMENSIONS;
    }

    public function isComplete(int $set): bool
    {
        try {
            $this->validateDirectory($set);
            return true;
        } catch (RuntimeException) {
            return false;
        }
    }

    /** @throws RuntimeException если каталог не соответствует контракту Set. */
    public function validateDirectory(int $set): void
    {
        $directory = $this->directory($set);
        if (!is_dir($directory)) {
            throw new RuntimeException("Папка Set {$set} не найдена.");
        }

        $actual = [];
        $errors = [];
        foreach (new FilesystemIterator($directory, FilesystemIterator::SKIP_DOTS) as $item) {
            if ($item->isLink() || !$item->isFile()) {
                $errors[] = "Лишний элемент в Set {$set}: {$item->getFilename()}.";
                continue;
            }
            $actual[$item->getFilename()] = $item->getPathname();
        }

        $expected = self::DIMENSIONS;
        foreach (array_keys($expected) as $filename) {
            if (!isset($actual[$filename])) {
                $errors[] = "Отсутствует обязательный файл {$filename}.";
            }
        }
        foreach (array_keys($actual) as $filename) {
            if (!isset($expected[$filename])) {
                $errors[] = "Лишний файл {$filename}.";
            }
        }

        foreach ($expected as $filename => $dimensions) {
            if (!isset($actual[$filename])) {
                continue;
            }
            try {
                $actualDimensions = $this->dimensions($actual[$filename]);
                if ($actualDimensions !== $dimensions) {
                    $errors[] = sprintf(
                        'Неверный размер %s: %d×%d, ожидалось %d×%d.',
                        $filename,
                        $actualDimensions['width'],
                        $actualDimensions['height'],
                        $dimensions['width'],
                        $dimensions['height']
                    );
                }
            } catch (RuntimeException $exception) {
                $errors[] = $exception->getMessage();
            }
        }

        if ($errors !== []) {
            throw new RuntimeException(implode("\n", $errors));
        }
    }

    /**
     * Полностью и атомарно заменяет Set распакованным ZIP после проверки всех файлов.
     *
     * @throws RuntimeException
     */
    public function replaceFromZip(int $set, string $zipPath): void
    {
        $this->assertSetNumber($set);
        if (!is_file($zipPath)) {
            throw new RuntimeException('ZIP-файл не получен.');
        }
        if (!class_exists(ZipArchive::class)) {
            throw new RuntimeException('На сервере не доступна поддержка ZIP.');
        }

        $stagingParent = $this->root . DIRECTORY_SEPARATOR . '.staging';
        $staging = $stagingParent . DIRECTORY_SEPARATOR . $set . '-' . bin2hex(random_bytes(8));
        $stagedSet = $staging . DIRECTORY_SEPARATOR . $set;
        if (!is_dir($stagingParent) && !mkdir($stagingParent, 0775, true) && !is_dir($stagingParent)) {
            throw new RuntimeException('Не удалось создать staging-каталог Set.');
        }
        if (!mkdir($stagedSet, 0775, true)) {
            throw new RuntimeException('Не удалось подготовить staging-каталог Set.');
        }

        try {
            $this->extractZip($zipPath, $set, $stagedSet);
            $this->validateDirectoryPath($stagedSet, $set);
            $this->activateStagedSet($set, $stagedSet);
        } catch (\Throwable $exception) {
            if (is_dir($staging)) {
                $this->removeDirectory($staging);
            }
            throw $exception instanceof RuntimeException
                ? $exception
                : new RuntimeException('Не удалось заменить Set ZIP-архивом.', 0, $exception);
        }

        if (is_dir($staging)) {
            $this->removeDirectory($staging);
        }
    }

    private function extractZip(string $zipPath, int $set, string $target): void
    {
        $zip = new ZipArchive();
        if ($zip->open($zipPath) !== true) {
            throw new RuntimeException('Не удалось открыть ZIP-архив.');
        }

        try {
            $prefix = $set . '/';
            $files = [];
            $directories = [];
            for ($index = 0; $index < $zip->numFiles; $index++) {
                $name = (string) $zip->getNameIndex($index);
                if ($name === '' || str_contains($name, '\\') || str_starts_with($name, '/') || str_contains($name, '../')) {
                    throw new RuntimeException('ZIP содержит недопустимую структуру файлов.');
                }
                if ($name === $prefix) {
                    $directories[] = $name;
                    continue;
                }
                if (!str_starts_with($name, $prefix) || str_contains(substr($name, strlen($prefix)), '/')) {
                    throw new RuntimeException('ZIP содержит недопустимую структуру файлов.');
                }

                $filename = substr($name, strlen($prefix));
                if (!isset(self::DIMENSIONS[$filename]) || isset($files[$filename])) {
                    throw new RuntimeException('ZIP содержит лишний или повторяющийся файл.');
                }
                $files[$filename] = $index;
            }

            // Некоторые ZIP-клиенты (в частности проводник Windows) не добавляют
            // отдельную запись корневого каталога: достаточно 90 файлов с единым
            // префиксом "<номер Set>/". Вложенные каталоги всё равно отклоняются выше.
            if (count($directories) > 1 || count($files) !== count(self::DIMENSIONS)) {
                throw new RuntimeException("ZIP должен содержать папку {$set} и ровно 90 файлов в ней.");
            }

            foreach (array_keys(self::DIMENSIONS) as $filename) {
                if (!isset($files[$filename])) {
                    throw new RuntimeException("В ZIP отсутствует обязательный файл {$filename}.");
                }
                $stream = $zip->getStream($prefix . $filename);
                if ($stream === false) {
                    throw new RuntimeException("Не удалось прочитать файл {$filename} из ZIP.");
                }
                $destination = $target . DIRECTORY_SEPARATOR . $filename;
                $output = fopen($destination, 'wb');
                if ($output === false) {
                    fclose($stream);
                    throw new RuntimeException("Не удалось подготовить файл {$filename}.");
                }
                $copied = stream_copy_to_stream($stream, $output, 8388609);
                fclose($output);
                fclose($stream);
                if ($copied === false || $copied > 8388608) {
                    throw new RuntimeException("Не удалось распаковать файл {$filename}.");
                }
                chmod($destination, 0644);
            }
        } finally {
            $zip->close();
        }
    }

    private function activateStagedSet(int $set, string $stagedSet): void
    {
        $destination = $this->directory($set);
        $backup = $this->root . DIRECTORY_SEPARATOR . '.backup-' . $set . '-' . bin2hex(random_bytes(8));
        $hadDestination = is_dir($destination);

        if ($hadDestination && !rename($destination, $backup)) {
            throw new RuntimeException('Не удалось подготовить замену текущего Set.');
        }
        if (!rename($stagedSet, $destination)) {
            if ($hadDestination) {
                rename($backup, $destination);
            }
            throw new RuntimeException('Не удалось активировать новый Set.');
        }
        if ($hadDestination) {
            $this->removeDirectory($backup);
        }
    }

    /** @return array{width: int, height: int} */
    private function dimensions(string $path): array
    {
        if ($this->imageInspector !== null) {
            $dimensions = ($this->imageInspector)($path);
            if (!is_array($dimensions) || !isset($dimensions['width'], $dimensions['height'])) {
                throw new RuntimeException('Проверка изображения вернула некорректный размер.');
            }
            return ['width' => (int) $dimensions['width'], 'height' => (int) $dimensions['height']];
        }
        if (!class_exists(\Imagick::class)) {
            throw new RuntimeException('На сервере не доступна проверка изображений Imagick.');
        }

        try {
            $image = new \Imagick();
            $image->readImage($path);
            $format = strtoupper($image->getImageFormat());
            $extension = strtolower(pathinfo($path, PATHINFO_EXTENSION));
            $allowed = ['jpg'=>['JPEG','JPG'], 'webp'=>['WEBP'], 'avif'=>['AVIF','HEIC']];
            if (!in_array($format, $allowed[$extension] ?? [], true) || $image->getNumberImages() !== 1) {
                throw new RuntimeException('Формат изображения не совпадает с расширением либо содержит несколько кадров.');
            }
            $dimensions = ['width' => $image->getImageWidth(), 'height' => $image->getImageHeight()];
            $image->clear();
            $image->destroy();
            return $dimensions;
        } catch (\Throwable $exception) {
            throw new RuntimeException('Файл ' . basename($path) . ' не является корректным изображением.', 0, $exception);
        }
    }

    private function validateDirectoryPath(string $directory, int $set): void
    {
        $storage = new self(dirname($directory), $this->imageInspector);
        $storage->validateDirectory($set);
    }

    private function directory(int $set): string
    {
        $this->assertSetNumber($set);
        return $this->root . DIRECTORY_SEPARATOR . $set;
    }

    private function assertSetNumber(int $set): void
    {
        if ($set < 1 || $set > 9) {
            throw new RuntimeException('Номер Set должен быть от 1 до 9.');
        }
    }

    private function removeDirectory(string $directory): void
    {
        $iterator = new RecursiveIteratorIterator(
            new RecursiveDirectoryIterator($directory, FilesystemIterator::SKIP_DOTS),
            RecursiveIteratorIterator::CHILD_FIRST
        );
        foreach ($iterator as $item) {
            $item->isDir() ? rmdir($item->getPathname()) : unlink($item->getPathname());
        }
        rmdir($directory);
    }
}