document.addEventListener('DOMContentLoaded', () => {
    const dropZone = document.getElementById('dropZone');
    const fileInput = document.getElementById('fileInput');
    const browseBtn = document.getElementById('browseBtn');
    const progressContainer = document.getElementById('progressContainer');
    const uploadProgress = document.getElementById('uploadProgress');
    const progressText = document.getElementById('progressText');
    const errorContainer = document.getElementById('errorContainer');
    const resultContainer = document.getElementById('resultContainer');
    const downloadLink = document.getElementById('downloadLink');
    const copyBtn = document.getElementById('copyBtn');
    const copySuccess = document.getElementById('copySuccess');

    // Исправление 1: Предотвращаем всплытие события для кнопки
    browseBtn.addEventListener('click', (e) => {
        e.stopPropagation(); // Блокируем всплытие события
        fileInput.click();
    });

    // Исправление 2: Убрали прямой вызов click из dropZone
    dropZone.addEventListener('click', (e) => {
        // Открываем только при клике на саму зону, но не на её дочерние элементы
        if (e.target === dropZone) {
            fileInput.click();
        }
    });

    fileInput.addEventListener('change', handleFileSelect);

    ['dragenter', 'dragover', 'dragleave', 'drop'].forEach(eventName => {
        dropZone.addEventListener(eventName, preventDefaults, false);
    });

    function preventDefaults(e) {
        e.preventDefault();
        e.stopPropagation();
    }

    ['dragenter', 'dragover'].forEach(eventName => {
        dropZone.addEventListener(eventName, () => {
            dropZone.classList.add('drag-over');
        }, false);
    });

    ['dragleave', 'drop'].forEach(eventName => {
        dropZone.addEventListener(eventName, () => {
            dropZone.classList.remove('drag-over');
        }, false);
    });

    dropZone.addEventListener('drop', handleDrop, false);
    copyBtn.addEventListener('click', copyToClipboard);

    function handleFileSelect(e) {
        if (e.target.files.length > 0) {
            processFile(e.target.files[0]);
        }
    }

    function handleDrop(e) {
        const files = e.dataTransfer.files;
        if (files.length > 0) {
            processFile(files[0]);
        }
    }

    function processFile(file) {
        hideError();
        resultContainer.style.display = 'none';

        // Исправление 3: Синхронизация лимита с сообщением (150MB)
        if (file.size > 150 * 1024 * 1024) {
            showError('File is too large. Maximum size: 150MB');
            return;
        }
	
	// Проверка на русские буквы в имени файла (добавленный блок)
	const russianLettersRegex = /[а-яёА-ЯЁ]/;
	if (russianLettersRegex.test(file.name)) {
	    showError('File name contains Russian letters. Please rename the file using only English characters.');
	    return;
	}
	
	// 1. Добавляем список разрешенных MIME-типов
        const allowedMimeTypes = [
            "application/pdf",
            "text/plain",
            "image/jpeg",
            "image/png",
            "image/gif",
            "image/bmp",
            "audio/mpeg",
            "video/mp4",
            "application/zip",
            "application/x-tar",
            "application/gzip",
            "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
            "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
        ];

        // 2. Проверяем MIME-тип файла
        if (!allowedMimeTypes.includes(file.type)) {
            showError(`Unsupported file type: ${file.type || 'unknown type'}. Allowed types: ${allowedMimeTypes.join(', ')}`);
            return;
        }

        progressContainer.style.display = 'block';
        uploadProgress.style.width = '0%';
        progressText.textContent = '0%';

        uploadFile(file);
    }

    function uploadFile(file) {
        const formData = new FormData();
        formData.append('file', file);

        const xhr = new XMLHttpRequest();

        // Исправление 4: Добавили обработку ошибок для Safari
        xhr.onreadystatechange = function() {
            if (xhr.readyState === 4) {
                if (xhr.status === 0) {
                    showError('Network error or blocked by browser');
                }
            }
        };

        xhr.upload.addEventListener('progress', (e) => {
            if (e.lengthComputable) {
                const percent = Math.round((e.loaded / e.total) * 100);
                uploadProgress.style.width = `${percent}%`;
                progressText.textContent = `${percent}%`;
            }
        });

        xhr.addEventListener('load', () => {
            if (xhr.status >= 200 && xhr.status < 300) {
                try {
                    const response = JSON.parse(xhr.responseText);
                    showResult(response.s3_key);
                } catch (e) {
                    showError('Error processing server response');
                }
            } else {
                try {
                    const errorResponse = JSON.parse(xhr.responseText);
                    showError(errorResponse.detail || 'File upload error');
                } catch {
                    showError(`Error ${xhr.status}: ${xhr.statusText}`);
                }
            }
        });

        xhr.addEventListener('error', () => {
            showError('Network error. Check your internet connection');
        });

        xhr.addEventListener('abort', () => {
            showError('Upload canceled');
        });

        xhr.open('POST', '/api/v1/upload', true);
        xhr.send(formData);
    }

    function showResult(s3Key) {
        const downloadUrl = `https://app.nonstudents.online/api/v1/download/${s3Key}`;
        downloadLink.value = downloadUrl;
        resultContainer.style.display = 'block';
        progressContainer.style.display = 'none';
    }

    function copyToClipboard() {
        downloadLink.select();
        document.execCommand('copy');
        copySuccess.style.display = 'flex';
        setTimeout(() => {
            copySuccess.style.display = 'none';
        }, 2000);
    }

    function showError(message) {
        errorContainer.textContent = message;
        errorContainer.style.display = 'block';
        progressContainer.style.display = 'none';
    }

    function hideError() {
        errorContainer.style.display = 'none';
        errorContainer.textContent = '';
    }
});