<?php

namespace MintyPHP\Service;

class TenantAvatarService
{
    private const MAX_SIZE = 5242880; // 5 MB
    private const SIZES = [64, 128, 256];
    private const DEFAULT_SIZE = 128;

    public static function isValidUuid(string $uuid): bool
    {
        return (bool) preg_match('/^[a-f0-9-]{36}$/i', $uuid);
    }

    public static function storageBase(): string
    {
        if (defined('APP_STORAGE_PATH') && APP_STORAGE_PATH) {
            return rtrim(APP_STORAGE_PATH, '/');
        }
        return rtrim(dirname(__DIR__, 2) . '/storage', '/');
    }

    public static function tenantDir(string $uuid): string
    {
        return self::storageBase() . '/tenants/' . $uuid . '/avatar';
    }

    public static function findAvatarPath(string $uuid, ?int $size = null): ?string
    {
        if (!self::isValidUuid($uuid)) {
            return null;
        }
        $dirs = self::avatarDirs($uuid);
        foreach ($dirs as $dir) {
            if (!is_dir($dir)) {
                continue;
            }
            if ($size) {
                $size = self::normalizeSize($size);
                $variant = self::findVariantPath($dir, $size);
                if ($variant) {
                    return $variant;
                }
            }
            $defaultVariant = self::findVariantPath($dir, self::DEFAULT_SIZE);
            if ($defaultVariant) {
                return $defaultVariant;
            }
            $original = self::findOriginalPath($dir);
            if ($original) {
                return $original;
            }
        }
        return null;
    }

    public static function hasAvatar(string $uuid): bool
    {
        $path = self::findAvatarPath($uuid);
        return $path ? is_file($path) : false;
    }

    public static function delete(string $uuid): bool
    {
        if (!self::isValidUuid($uuid)) {
            return false;
        }
        foreach (self::avatarDirs($uuid) as $dir) {
            if (!is_dir($dir)) {
                continue;
            }
            $matches = array_merge(
                glob($dir . '/avatar-*.*') ?: [],
                glob($dir . '/avatar.*') ?: [],
                glob($dir . '/original.*') ?: []
            );
            foreach ($matches as $file) {
                if (is_file($file)) {
                    @unlink($file);
                }
            }
        }
        return true;
    }

    public static function saveUpload(string $uuid, array $file): array
    {
        if (!self::isValidUuid($uuid)) {
            return ['ok' => false, 'error' => t('Tenant not found')];
        }
        if (empty($file) || !isset($file['tmp_name'])) {
            return ['ok' => false, 'error' => t('No file uploaded')];
        }
        if (($file['error'] ?? UPLOAD_ERR_NO_FILE) !== UPLOAD_ERR_OK) {
            return ['ok' => false, 'error' => t('Upload failed')];
        }
        if (($file['size'] ?? 0) > self::MAX_SIZE) {
            return ['ok' => false, 'error' => t('File is too large')];
        }

        $tmpPath = $file['tmp_name'];
        $mime = self::detectMime($tmpPath);
        $isSvg = self::isSvgUpload($mime, $tmpPath);
        $ext = self::extensionForMime($mime, $isSvg);
        if (!$ext) {
            return ['ok' => false, 'error' => t('Invalid image file')];
        }
        if ($isSvg && !self::isSafeSvg($tmpPath)) {
            return ['ok' => false, 'error' => t('Invalid image file')];
        }

        $dir = self::tenantDir($uuid);
        if (!is_dir($dir) && !mkdir($dir, 0755, true) && !is_dir($dir)) {
            return ['ok' => false, 'error' => t('Upload failed')];
        }

        self::delete($uuid);
        $originalPath = $dir . '/original.' . $ext;
        if (!move_uploaded_file($tmpPath, $originalPath)) {
            return ['ok' => false, 'error' => t('Upload failed')];
        }
        @chmod($originalPath, 0644);

        $variantExt = function_exists('imagewebp') ? 'webp' : 'jpg';
        if (!$isSvg && self::canResize()) {
            foreach (self::SIZES as $size) {
                $target = $dir . '/avatar-' . $size . '.' . $variantExt;
                self::resizeAndFit($originalPath, $target, $size, $size, $variantExt);
            }
        }

        return ['ok' => true, 'path' => $originalPath, 'mime' => $mime];
    }

    public static function detectMime(string $path): string
    {
        if (function_exists('finfo_open')) {
            $finfo = finfo_open(FILEINFO_MIME_TYPE);
            if ($finfo) {
                $mime = finfo_file($finfo, $path);
                if (is_string($mime) && $mime !== '') {
                    if (self::isSvgUpload($mime, $path)) {
                        return 'image/svg+xml';
                    }
                    return $mime;
                }
            }
        }
        if (self::isSvgUpload('application/octet-stream', $path)) {
            return 'image/svg+xml';
        }
        return 'application/octet-stream';
    }

    private static function extensionForMime(string $mime, bool $isSvg = false): ?string
    {
        if ($isSvg) {
            return 'svg';
        }
        $map = [
            'image/jpeg' => 'jpg',
            'image/png' => 'png',
            'image/webp' => 'webp',
        ];
        return $map[$mime] ?? null;
    }

    private static function isSvgUpload(string $mime, string $path): bool
    {
        if ($mime === 'image/svg+xml') {
            return true;
        }
        $head = @file_get_contents($path, false, null, 0, 1024);
        if (!is_string($head) || $head === '') {
            return false;
        }
        return stripos($head, '<svg') !== false;
    }

    private static function isSafeSvg(string $path): bool
    {
        $contents = @file_get_contents($path);
        if (!is_string($contents) || $contents === '') {
            return false;
        }
        $lower = strtolower($contents);
        if (strpos($lower, '<script') !== false) {
            return false;
        }
        if (strpos($lower, 'onload=') !== false) {
            return false;
        }
        if (strpos($lower, 'javascript:') !== false) {
            return false;
        }
        if (strpos($lower, '<foreignobject') !== false) {
            return false;
        }
        return true;
    }

    private static function normalizeSize(int $size): int
    {
        if (in_array($size, self::SIZES, true)) {
            return $size;
        }
        return self::DEFAULT_SIZE;
    }

    private static function findVariantPath(string $dir, int $size): ?string
    {
        $matches = glob($dir . '/avatar-' . $size . '.*');
        if (!$matches) {
            return null;
        }
        usort($matches, static function ($a, $b) {
            return filemtime($b) <=> filemtime($a);
        });
        return $matches[0] ?? null;
    }

    private static function findOriginalPath(string $dir): ?string
    {
        $matches = glob($dir . '/original.*');
        if (!$matches) {
            return null;
        }
        usort($matches, static function ($a, $b) {
            return filemtime($b) <=> filemtime($a);
        });
        return $matches[0] ?? null;
    }

    private static function canResize(): bool
    {
        return function_exists('imagecreatetruecolor') && function_exists('imagecopyresampled');
    }

    private static function createImageResource(string $path, string $mime)
    {
        if ($mime === 'image/jpeg' && function_exists('imagecreatefromjpeg')) {
            return imagecreatefromjpeg($path);
        }
        if ($mime === 'image/png' && function_exists('imagecreatefrompng')) {
            return imagecreatefrompng($path);
        }
        if ($mime === 'image/webp' && function_exists('imagecreatefromwebp')) {
            return imagecreatefromwebp($path);
        }
        return false;
    }

    private static function resizeAndFit(string $sourcePath, string $targetPath, int $width, int $height, string $ext): bool
    {
        $mime = self::detectMime($sourcePath);
        $src = self::createImageResource($sourcePath, $mime);
        if (!$src) {
            return false;
        }

        $srcWidth = imagesx($src);
        $srcHeight = imagesy($src);
        if ($srcWidth === 0 || $srcHeight === 0) {
            imagedestroy($src);
            return false;
        }

        $scale = min($width / $srcWidth, $height / $srcHeight);
        $dstWidth = (int) round($srcWidth * $scale);
        $dstHeight = (int) round($srcHeight * $scale);
        if ($dstWidth < 1) $dstWidth = 1;
        if ($dstHeight < 1) $dstHeight = 1;

        $dst = imagecreatetruecolor($dstWidth, $dstHeight);
        if ($ext === 'png' || $ext === 'webp') {
            imagealphablending($dst, false);
            imagesavealpha($dst, true);
            $transparent = imagecolorallocatealpha($dst, 0, 0, 0, 127);
            imagefilledrectangle($dst, 0, 0, $dstWidth, $dstHeight, $transparent);
        }

        imagecopyresampled(
            $dst,
            $src,
            0,
            0,
            0,
            0,
            $dstWidth,
            $dstHeight,
            $srcWidth,
            $srcHeight
        );

        $saved = false;
        if ($ext === 'webp' && function_exists('imagewebp')) {
            $saved = imagewebp($dst, $targetPath, 82);
        } elseif ($ext === 'png' && function_exists('imagepng')) {
            $saved = imagepng($dst, $targetPath, 6);
        } else {
            $saved = imagejpeg($dst, $targetPath, 85);
        }

        imagedestroy($src);
        imagedestroy($dst);

        if ($saved) {
            @chmod($targetPath, 0644);
        }
        return $saved;
    }

    private static function avatarDirs(string $uuid): array
    {
        $dirs = [self::tenantDir($uuid)];
        $legacy = self::legacyTenantDir($uuid);
        if ($legacy !== $dirs[0]) {
            $dirs[] = $legacy;
        }
        return $dirs;
    }

    private static function legacyTenantDir(string $uuid): string
    {
        return self::storageBase() . '/tenants/' . $uuid;
    }
}