<?php

class ImageHandler {
    private $upload_path;
    private $allowed_types;
    private $max_size;

    public function __construct() {
        $this->upload_path = UPLOAD_PATH;
        $this->allowed_types = ALLOWED_IMAGE_TYPES;
        $this->max_size = MAX_IMAGE_SIZE;

        if (!file_exists($this->upload_path)) {
            mkdir($this->upload_path, 0755, true);
        }
    }

    public function upload($file, $optimize = true) {
        if (!isset($file['tmp_name']) || !is_uploaded_file($file['tmp_name'])) {
            throw new Exception('No file uploaded');
        }

        // Validate file
        $this->validateFile($file);

        // Generate unique filename
        $extension = pathinfo($file['name'], PATHINFO_EXTENSION);
        $filename = uniqid() . '_' . time() . '.' . $extension;
        $filepath = $this->upload_path . '/' . $filename;

        // Move and optimize
        if (move_uploaded_file($file['tmp_name'], $filepath)) {
            if ($optimize) {
                $this->optimizeImage($filepath);
            }
            return $filename;
        }

        throw new Exception('Failed to move uploaded file');
    }

    private function validateFile($file) {
        // Check file size
        if ($file['size'] > $this->max_size) {
            throw new Exception('File size exceeds limit');
        }

        // Check file type
        $finfo = finfo_open(FILEINFO_MIME_TYPE);
        $mime_type = finfo_file($finfo, $file['tmp_name']);
        finfo_close($finfo);

        if (!in_array($mime_type, $this->allowed_types)) {
            throw new Exception('Invalid file type');
        }
    }

    private function optimizeImage($filepath) {
        $image = null;
        $mime = mime_content_type($filepath);

        switch ($mime) {
            case 'image/jpeg':
                $image = imagecreatefromjpeg($filepath);
                imagejpeg($image, $filepath, 85); // 85% quality
                break;
            case 'image/png':
                $image = imagecreatefrompng($filepath);
                imagepng($image, $filepath, 8); // Compression level 8
                break;
            case 'image/webp':
                $image = imagecreatefromwebp($filepath);
                imagewebp($image, $filepath, 85);
                break;
        }

        if ($image) {
            imagedestroy($image);
        }
    }

    public function createThumbnail($filename, $width = 200, $height = 200) {
        $source_path = $this->upload_path . '/' . $filename;
        $thumb_path = $this->upload_path . '/thumbnails/' . $filename;

        if (!file_exists(dirname($thumb_path))) {
            mkdir(dirname($thumb_path), 0755, true);
        }

        $source_image = imagecreatefromstring(file_get_contents($source_path));
        $source_width = imagesx($source_image);
        $source_height = imagesy($source_image);

        $thumb = imagecreatetruecolor($width, $height);
        imagecopyresampled($thumb, $source_image, 0, 0, 0, 0, $width, $height, $source_width, $source_height);

        $mime = mime_content_type($source_path);
        switch ($mime) {
            case 'image/jpeg':
                imagejpeg($thumb, $thumb_path, 85);
                break;
            case 'image/png':
                imagepng($thumb, $thumb_path, 8);
                break;
            case 'image/webp':
                imagewebp($thumb, $thumb_path, 85);
                break;
        }

        imagedestroy($source_image);
        imagedestroy($thumb);

        return 'thumbnails/' . $filename;
    }
}