// DOM Elements
const pdfFileInput = document.getElementById('pdfFile');
const pdfUploadArea = document.getElementById('pdfUploadArea');
const uploadedFileInfo = document.getElementById('uploadedFileInfo');
const fileNameElement = document.getElementById('fileName');
const fileSizeElement = document.getElementById('fileSize');
const removeFileButton = document.getElementById('removeFile');
const uploadProgressBar = document.getElementById('uploadProgressBar');
const uploadPercent = document.getElementById('uploadPercent');
const convertButton = document.getElementById('convertBtn');
const processingState = document.getElementById('processingState');
const initialPreview = document.getElementById('initialPreview');
const resultsSection = document.getElementById('resultsSection');
const processingProgressBar = document.getElementById('processingProgressBar');
const processingPercent = document.getElementById('processingPercent');
const textPreview = document.getElementById('textPreview');
const downloadButton = document.getElementById('downloadBtn');
const newConversionButton = document.getElementById('newConversionBtn');
const copyTextButton = document.getElementById('copyTextBtn');
const toast = document.getElementById('toast');
const toastMessage = document.getElementById('toastMessage');
const sectionCheckboxes = document.querySelectorAll('.section-checkbox');
const sectionLabels = document.querySelectorAll('.section-label');

// Sample resume data for demonstration
const sampleResumeData = {
    contactInfo: "Jane Doe\n(123) 456-7890\njane.doe@email.com\n123 Main Street, New York, NY 10001",
    socialMedia: "LinkedIn: linkedin.com/in/janedoe\nGitHub: github.com/janedoe\nPortfolio: janedoe.dev",
    workExperience: "Senior Software Engineer, Tech Solutions Inc. (2020-Present)\n- Lead development of customer-facing web applications\n- Implemented Agile methodologies improving team productivity by 30%\n- Mentored 5 junior developers\n\nSoftware Developer, Innovate Corp. (2017-2020)\n- Developed and maintained internal tools using React and Node.js\n- Reduced application load time by 40% through performance optimization\n- Collaborated with cross-functional teams to deliver projects on schedule",
    education: "Master of Science in Computer Science\nUniversity of Technology (2015-2017)\nGPA: 3.8/4.0\n\nBachelor of Science in Information Technology\nState College (2011-2015)",
    certifications: "AWS Certified Solutions Architect - Associate\nGoogle Professional Cloud Architect\nScrum Master Certification (CSM)",
    skills: "Programming: JavaScript, Python, Java, C#\nFrameworks: React, Node.js, Angular, .NET\nDatabases: MySQL, MongoDB, PostgreSQL\nTools: Git, Docker, AWS, Jenkins\nSoft Skills: Leadership, Problem-solving, Communication, Team Collaboration",
    summary: "Senior Software Engineer with 8+ years of experience in full-stack development, specializing in scalable web applications. Proven track record of leading cross-functional teams, implementing Agile methodologies, and delivering projects that improve efficiency and user experience. Passionate about mentoring junior developers and staying current with emerging technologies."
};

// Current state
let currentFile = null;
let selectedSections = ['contactInfo', 'socialMedia', 'workExperience', 'education', 'skills', 'summary'];

// Initialize event listeners
function init() {
    // File upload handlers
    pdfFileInput.addEventListener('change', handleFileSelect);
    
    // Drag and drop handlers
    pdfUploadArea.addEventListener('dragover', handleDragOver);
    pdfUploadArea.addEventListener('dragleave', handleDragLeave);
    pdfUploadArea.addEventListener('drop', handleDrop);
    
    // File removal
    removeFileButton.addEventListener('click', removeFile);
    
    // Section selection handlers
    sectionCheckboxes.forEach(checkbox => {
        checkbox.addEventListener('change', updateSectionSelection);
        // Initialize check icons
        if (checkbox.checked) {
            const label = checkbox.nextElementSibling;
            const checkIcon = label.querySelector('.check-icon');
            if (checkIcon) checkIcon.classList.remove('hidden');
        }
    });
    
    // Convert button
    convertButton.addEventListener('click', startConversion);
    
    // Results buttons
    downloadButton.addEventListener('click', downloadTextFile);
    newConversionButton.addEventListener('click', resetToInitialState);
    copyTextButton.addEventListener('click', copyTextToClipboard);
    
    // Initialize with sample text preview
    updateTextPreview();
}

// Handle file selection
function handleFileSelect(event) {
    const file = event.target.files[0];
    if (file && file.type === 'application/pdf') {
        processFile(file);
    } else {
        showToast('Please select a valid PDF file', 'error');
    }
}

// Handle drag over
function handleDragOver(event) {
    event.preventDefault();
    event.stopPropagation();
    pdfUploadArea.classList.add('dragover');
}

// Handle drag leave
function handleDragLeave(event) {
    event.preventDefault();
    event.stopPropagation();
    pdfUploadArea.classList.remove('dragover');
}

// Handle drop
function handleDrop(event) {
    event.preventDefault();
    event.stopPropagation();
    pdfUploadArea.classList.remove('dragover');
    
    const files = event.dataTransfer.files;
    if (files.length > 0) {
        const file = files[0];
        if (file.type === 'application/pdf') {
            processFile(file);
        } else {
            showToast('Please drop a valid PDF file', 'error');
        }
    }
}

// Process the uploaded file
function processFile(file) {
    currentFile = file;
    
    // Update UI with file info
    fileNameElement.textContent = file.name;
    fileSizeElement.textContent = formatFileSize(file.size);
    
    // Show upload progress animation
    uploadedFileInfo.classList.remove('hidden');
    simulateUploadProgress();
    
    // Enable convert button
    convertButton.disabled = false;
    convertButton.classList.remove('opacity-50');
    
    showToast(`File "${file.name}" uploaded successfully`, 'success');
}

// Simulate upload progress
function simulateUploadProgress() {
    let progress = 0;
    const interval = setInterval(() => {
        progress += Math.random() * 15;
        if (progress >= 100) {
            progress = 100;
            clearInterval(interval);
        }
        
        uploadProgressBar.style.width = `${progress}%`;
        uploadPercent.textContent = `${Math.round(progress)}%`;
    }, 100);
}

// Format file size
function formatFileSize(bytes) {
    if (bytes < 1024) return bytes + ' B';
    else if (bytes < 1024 * 1024) return (bytes / 1024).toFixed(1) + ' KB';
    else return (bytes / (1024 * 1024)).toFixed(1) + ' MB';
}

// Remove file
function removeFile() {
    currentFile = null;
    pdfFileInput.value = '';
    uploadedFileInfo.classList.add('hidden');
    convertButton.disabled = true;
    convertButton.classList.add('opacity-50');
}

// Update section selection
function updateSectionSelection(event) {
    const checkbox = event.target;
    const label = checkbox.nextElementSibling;
    const checkIcon = label.querySelector('.check-icon');
    
    if (checkbox.checked) {
        checkIcon.classList.remove('hidden');
        selectedSections.push(checkbox.id);
    } else {
        checkIcon.classList.add('hidden');
        selectedSections = selectedSections.filter(id => id !== checkbox.id);
    }
    
    // Update preview if we have results
    if (resultsSection.classList.contains('hidden') === false) {
        updateTextPreview();
    }
}

// Start the conversion process
function startConversion() {
    if (!currentFile && selectedSections.length === 0) {
        showToast('Please upload a PDF and select at least one section', 'error');
        return;
    }
    
    if (!currentFile) {
        showToast('Please upload a PDF file first', 'error');
        return;
    }
    
    if (selectedSections.length === 0) {
        showToast('Please select at least one section to include', 'error');
        return;
    }
    
    // Hide initial preview and show processing state
    initialPreview.classList.add('hidden');
    processingState.classList.remove('hidden');
    processingState.classList.add('fade-in');
    
    // Start the processing animation
    simulateProcessing();
}

// Simulate AI processing
function simulateProcessing() {
    let progress = 0;
    const steps = document.querySelectorAll('.processing-step');
    
    const interval = setInterval(() => {
        progress += Math.random() * 8;
        if (progress >= 100) {
            progress = 100;
            clearInterval(interval);
            
            // Show results after a brief delay
            setTimeout(showResults, 500);
        }
        
        // Update main progress bar
        processingProgressBar.style.width = `${progress}%`;
        processingPercent.textContent = `${Math.round(progress)}%`;
        
        // Update individual step progress
        const stepProgress = progress / 100;
        steps.forEach((step, index) => {
            const stepNum = parseInt(step.getAttribute('data-step'));
            const stepTarget = stepNum * 25;
            const stepWidth = Math.min(Math.max(0, (progress - (stepTarget - 25)) / 25 * 100), 100);
            step.style.width = `${stepWidth}%`;
        });
    }, 200);
}

// Show results
function showResults() {
    processingState.classList.add('hidden');
    resultsSection.classList.remove('hidden');
    resultsSection.classList.add('fade-in');
    
    updateTextPreview();
    showToast('Resume successfully converted to ATS-optimized text!', 'success');
}

===========================\n";
        text += sampleResumeData.contactInfo + "\n\n";
    }
    
    if (selectedSections.includes('socialMedia')) {
        text += "SOCIAL MEDIA & LINKS\n";
        text += "====================\n";
        text += sampleResumeData.socialMedia + "\n\n";
    }
    
    if (selectedSections.includes('workExperience')) {
        text += "WORK EXPERIENCE\n";
        text += "================\n";
        text += sampleResumeData.workExperience + "\n\n";
    }
    
    if (selectedSections.includes('education')) {
        text += "EDUCATION\n";
        text += "=========\n";
        text += sampleResumeData.education + "\n\n";
    }
    
    if (selectedSections.includes('certifications')) {
        text += "CERTIFICATIONS\n";
        text += "==============\n";
        text += sampleResumeData.certifications + "\n\n";
    }
    
    if (selectedSections.includes('skills')) {
        text += "SKILLS\n";
        text += "======\n";
        text += sampleResumeData.skills + "\n\n";
    }
    
    text += "\n=== END OF RESUME ===";
    text += "\n\n[This resume has been optimized for Applicant Tracking Systems by AI Resume ATS Optimizer]";
    
    textPreview.textContent = text;
}

// Download text file
function downloadTextFile() {
    const text = textPreview.textContent;
    const blob = new Blob([text], { type: 'text/plain' });
    const url = URL.createObjectURL(blob);
    
    const a = document.createElement('a');
    a.href = url;
    a.download = 'ats_optimized_resume.txt';
    document.body.appendChild(a);
    a.click();
    
    setTimeout(() => {
        document.body.removeChild(a);
        URL.revokeObjectURL(url);
    }, 100);
    
    showToast('Text file downloaded successfully!', 'success');
}

// Copy text to clipboard
function copyTextToClipboard() {
    const text = textPreview.textContent;
    
    navigator.clipboard.writeText(text).then(() => {
        showToast('Text copied to clipboard!', 'success');
    }).catch(err => {
        console.error('Failed to copy text: ', err);
        showToast('Failed to copy text to clipboard', 'error');
    });
}

// Reset to initial state
function resetToInitialState() {
    // Reset file
    removeFile();
    
    // Reset sections
    sectionCheckboxes.forEach(checkbox => {
        if (checkbox.id !== 'certifications') {
            checkbox.checked = true;
            const label = checkbox.nextElementSibling;
            const checkIcon = label.querySelector('.check-icon');
            checkIcon.classList.remove('hidden');
        } else {
            checkbox.checked = false;
            const label = checkbox.nextElementSibling;
            const checkIcon = label.querySelector('.check-icon');
            checkIcon.classList.add('hidden');
        }
    });
    
    selectedSections = ['contactInfo', 'socialMedia', 'workExperience', 'education', 'skills', 'summary'];
    
    // Hide results and show initial preview
    resultsSection.classList.add('hidden');
    initialPreview.classList.remove('hidden');
    initialPreview.classList.add('fade-in');
    
    showToast('Ready for a new conversion!', 'success');
}

// Show toast notification
function showToast(message, type = 'success') {
    toastMessage.textContent = message;
    
    // Set color based on type
    if (type === 'error') {
        toast.style.backgroundColor = '#ef4444';
    } else if (type === 'success') {
        toast.style.backgroundColor = '#10b981';
    } else {
        toast.style.backgroundColor = '#3b82f6';
    }
    
    // Show toast
    toast.classList.remove('translate-y-full');
    
    // Hide after 3 seconds
    setTimeout(() => {
        toast.classList.add('translate-y-full');
    }, 3000);
}

// Initialize the application when DOM is loaded
document.addEventListener('DOMContentLoaded', init);

// Add some interactivity to section labels
sectionLabels.forEach(label => {
    label.addEventListener('click', function() {
        this.classList.add('transform', 'scale-[1.02]', 'transition-transform');
        setTimeout(() => {
            this.classList.remove('transform', 'scale-[1.02]');
        }, 150);
    });
});