document.addEventListener('DOMContentLoaded', async () => {
    const urlParams = new URLSearchParams(window.location.search);
    const fileId = urlParams.get('id');
    const key = urlParams.get('key');

    if (fileId && key) {
        displayFileDetails(fileId, key);
    } else {
        document.getElementById('upload__form').style.display = 'block';
        setupUploadForm();
    }
});

const baseUrl = window.location.origin;
const CHUNK_SIZE = 100 * 1024 * 1024; // 100 MB

async function displayFileDetails(fileId, key) {
    try {
        const response = await fetch(`${baseUrl}/get/${fileId}?key=${key}`, {
            method: 'GET',
        });

        const fileDetails = document.getElementById('file__details');
        const fileNameElement = document.getElementById('file__name');
        const fileSizeElement = document.getElementById('file__size');
        const downloadButton = document.getElementById('download__btn');
        const copyButton = document.getElementById('copy__btn');

        if (!response.ok) {
            fileDetails.textContent = `Error: ${response.statusText}`;
            fileDetails.style.display = 'flex';
            return;
        }

        const contentType = response.headers.get('Content-Type');
        
        if (contentType && contentType.includes('application/json')) {
            const result = await response.json();
            const downloadUrl = `${baseUrl}/download/${fileId}?key=${key}`;
            const pageUrl = `${baseUrl}/?id=${fileId}&key=${key}`;
            fileNameElement.textContent = `${result.fileName}`;
            fileSizeElement.textContent = `${result.fileSize}`;
            downloadButton.innerHTML = `<a href="${downloadUrl}">Download</a>`;
            copyButton.onclick = () => {
                navigator.clipboard.writeText(pageUrl);
                copyButton.textContent = 'Copied!';
            };
        } else {
            const result = await response.text();
            fileDetails.textContent = result;
        }

        fileDetails.style.display = 'flex';
    } catch (error) {
        console.error('Error:', error);
        document.getElementById('file__details').textContent = 'An error occurred. Please try again.';
        document.getElementById('file__details').style.display = 'flex';
    }
}

function setupUploadForm() {
    const fileInput = document.querySelector('.upload__input');
    const overlayText = document.querySelector('.upload__input__overlay__text');

    fileInput.addEventListener('change', () => {
        if (fileInput.files.length > 0) {
            overlayText.textContent = fileInput.files[0].name;
        } else {
            overlayText.textContent = 'Choose a file or drag it here';
        }
    });

    document.getElementById('upload__form').addEventListener('submit', async (event) => {
        event.preventDefault();

        const file = fileInput.files[0];

        if (!file) {
            console.log('No file selected.');
            return;
        }

        const progressBar = document.getElementById('upload__progress');
        const progressFill = document.getElementById('progress__fill');
        const uploadButton = document.getElementById('upload__btn');

        uploadButton.style.display = 'none';
        progressBar.style.display = 'block';
        fileInput.disabled = true;

        try {
            await uploadFileInChunks(file, progressFill);
        } catch (error) {
            console.error('Error:', error);
            document.getElementById('upload__result').textContent = 'An error occurred. Please try again.';
            document.getElementById('upload__result').classList.add('upload__result__visible');
        } finally {
            progressBar.style.display = 'none';
            uploadButton.style.display = 'inline-block';
            fileInput.disabled = false;
        }
    });
}

async function uploadFileInChunks(file, progressFill) {
    const fileSize = file.size;
    const chunkCount = Math.ceil(fileSize / CHUNK_SIZE);
    const uploadId = generateUploadId();
    let uploadedSize = 0;

    for (let chunkIndex = 0; chunkIndex < chunkCount; chunkIndex++) {
        const start = chunkIndex * CHUNK_SIZE;
        const end = Math.min(start + CHUNK_SIZE, fileSize);
        const chunk = file.slice(start, end);

        const formData = new FormData();
        formData.append('chunk', chunk);
        formData.append('uploadId', uploadId);
        formData.append('chunkIndex', chunkIndex);
        formData.append('chunkCount', chunkCount);
        formData.append('fileName', file.name);

        const response = await fetch(`${baseUrl}/upload_chunk`, {
            method: 'POST',
            body: formData,
        });

        if (!response.ok) {
            throw new Error(`Error uploading chunk ${chunkIndex}: ${response.statusText}`);
        }

        uploadedSize += chunk.size;
        const progress = Math.round((uploadedSize / fileSize) * 100);
        progressFill.style.width = `${progress}%`;
    }

    // Call upload_complete endpoint
    const completeFormData = new FormData();
    completeFormData.append('uploadId', uploadId);
    completeFormData.append('chunkCount', chunkCount);
    completeFormData.append('fileName', file.name);

    const completeResponse = await fetch(`${baseUrl}/upload_complete`, {
        method: 'POST',
        body: completeFormData,
    });

    if (!completeResponse.ok) {
        throw new Error(`Error completing upload: ${completeResponse.statusText}`);
    }

    const result = await completeResponse.json();
    const pageUrl = `${baseUrl}/?id=${result.id}&key=${result.key}`;
    window.location.href = pageUrl;
}

function generateUploadId() {
    return Math.random().toString(36).substr(2, 9);
}