<?php

namespace MintyPHP\Service;

class TenantFaviconService
{
    private const MAX_SIZE = 5242880; // 5 MB
    private const SIZES = [
        16 => 'favicon-16x16.png',
        32 => 'favicon-32x32.png',
        96 => 'favicon-96x96.png',
        180 => 'apple-touch-icon.png',
        192 => 'web-app-manifest-192x192.png',
        512 => 'web-app-manifest-512x512.png',
    ];

    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 storageDir(string $uuid): string
    {
        return self::storageBase() . '/tenants/' . $uuid . '/favicon';
    }

    public static function publicDir(string $uuid): string
    {
        return rtrim(dirname(__DIR__, 2) . '/web/favicon/tenants/' . $uuid, '/');
    }

    public static function hasFavicon(string $uuid): bool
    {
        if (!self::isValidUuid($uuid)) {
            return false;
        }
        $path = self::publicDir($uuid) . '/favicon-32x32.png';
        return is_file($path);
    }

    public static function delete(string $uuid): void
    {
        if (!self::isValidUuid($uuid)) {
            return;
        }
        foreach (self::storageDirs($uuid) as $dir) {
            if (!is_dir($dir)) {
                continue;
            }
            $matches = glob($dir . '/*') ?: [];
            foreach ($matches as $file) {
                if (is_file($file)) {
                    @unlink($file);
                }
            }
        }
        $public = self::publicDir($uuid);
        foreach (self::SIZES as $file) {
            $target = $public . '/' . $file;
            if (is_file($target)) {
                @unlink($target);
            }
        }
    }

    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);
        if ($mime !== 'image/png') {
            return ['ok' => false, 'error' => t('Invalid image file')];
        }
        if (!self::canResize()) {
            return ['ok' => false, 'error' => t('Upload failed')];
        }

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

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

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

        foreach (self::SIZES as $size => $fileName) {
            $target = $publicDir . '/' . $fileName;
            if (!self::resizeSquare($originalPath, $target, $size)) {
                return ['ok' => false, 'error' => t('Upload failed')];
            }
            @chmod($target, 0644);
        }

        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 !== '') {
                    return $mime;
                }
            }
        }
        return 'application/octet-stream';
    }

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

    private static function loadImage(string $path)
    {
        if (function_exists('imagecreatefrompng')) {
            return imagecreatefrompng($path);
        }
        return false;
    }

    private static function resizeSquare(string $sourcePath, string $targetPath, int $size): bool
    {
        $src = self::loadImage($sourcePath);
        if (!$src) {
            return false;
        }
        $srcWidth = imagesx($src);
        $srcHeight = imagesy($src);
        if ($srcWidth === 0 || $srcHeight === 0) {
            imagedestroy($src);
            return false;
        }

        $cropSize = min($srcWidth, $srcHeight);
        $srcX = (int) round(($srcWidth - $cropSize) / 2);
        $srcY = (int) round(($srcHeight - $cropSize) / 2);

        $dst = imagecreatetruecolor($size, $size);
        imagealphablending($dst, false);
        imagesavealpha($dst, true);
        $transparent = imagecolorallocatealpha($dst, 0, 0, 0, 127);
        imagefilledrectangle($dst, 0, 0, $size, $size, $transparent);

        imagecopyresampled(
            $dst,
            $src,
            0,
            0,
            $srcX,
            $srcY,
            $size,
            $size,
            $cropSize,
            $cropSize
        );

        $saved = false;
        if (function_exists('imagepng')) {
            $saved = imagepng($dst, $targetPath, 6);
        }

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

        return $saved;
    }

    private static function storageDirs(string $uuid): array
    {
        $dirs = [self::storageDir($uuid)];
        $legacy = self::legacyStorageDir($uuid);
        if ($legacy !== $dirs[0]) {
            $dirs[] = $legacy;
        }
        return $dirs;
    }

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