// Main application state
let appState = {
    commits: [],
    episodes: [],
    currentScale: 'week',
    clusterWindow: 240,
    selectedEpisode: null,
    filteredCommits: [],
    searchQuery: '',
    darkMode: false
};

// DOM elements
const elements = {
    fileInput: document.getElementById('file-input'),
    dropZone: document.getElementById('drop-zone'),
    controls: document.getElementById('controls'),
    stats: document.getElementById('stats'),
    visualization: document.getElementById('visualization'),
    details: document.getElementById('details'),
    clusterSlider: document.getElementById('cluster-slider'),
    clusterValue: document.getElementById('cluster-value'),
    scaleWeek: document.getElementById('scale-week'),
    scaleMonth: document.getElementById('scale-month'),
    scaleOverall: document.getElementById('scale-overall'),
    searchInput: document.getElementById('search-input'),
    totalCommits: document.getElementById('total-commits'),
    totalEpisodes: document.getElementById('total-episodes'),
    dateRange: document.getElementById('date-range'),
    episodesList: document.getElementById('episodes-list'),
    selectedEpisodeTitle: document.getElementById('selected-episode-title'),
    commitDetails: document.getElementById('commit-details'),
    exportJson: document.getElementById('export-json'),
    exportMd: document.getElementById('export-md'),
    themeToggle: document.getElementById('theme-toggle'),
    timeline: document.getElementById('timeline')
};

// Initialize the application
function init() {
    setupEventListeners();
    checkDarkModePreference();
}

// Set up event listeners
function setupEventListeners() {
    // File input handling
    elements.fileInput.addEventListener('change', handleFileSelect);
    
    // Drag and drop handling
    elements.dropZone.addEventListener('dragover', (e) => {
        e.preventDefault();
        elements.dropZone.classList.add('active');
    });
    
    elements.dropZone.addEventListener('dragleave', () => {
        elements.dropZone.classList.remove('active');
    });
    
    elements.dropZone.addEventListener('drop', (e) => {
        e.preventDefault();
        elements.dropZone.classList.remove('active');
        if (e.dataTransfer.files.length) {
            elements.fileInput.files = e.dataTransfer.files;
            handleFileSelect({ target: elements.fileInput });
        }
    });
    
    // Controls
    elements.clusterSlider.addEventListener('input', () => {
        const value = parseInt(elements.clusterSlider.value);
        elements.clusterValue.textContent = `${value} min`;
        appState.clusterWindow = value;
        processCommits();
    });
    
    elements.scaleWeek.addEventListener('click', () => {
        setActiveScale('week');
        renderTimeline();
    });
    
    elements.scaleMonth.addEventListener('click', () => {
        setActiveScale('month');
        renderTimeline();
    });
    
    elements.scaleOverall.addEventListener('click', () => {
        setActiveScale('overall');
        renderTimeline();
    });
    
    elements.searchInput.addEventListener('input', (e) => {
        appState.searchQuery = e.target.value.toLowerCase();
        filterCommits();
    });
    
    // Export buttons
    elements.exportJson.addEventListener('click', exportEpisodesJson);
    elements.exportMd.addEventListener('click', exportEpisodesMarkdown);
    
    // Theme toggle
    elements.themeToggle.addEventListener('click', toggleDarkMode);
}

// Check user's dark mode preference
function checkDarkModePreference() {
    const prefersDark = window.matchMedia('(prefers-color-scheme: dark)').matches;
    if (prefersDark) {
        document.documentElement.classList.add('dark');
        appState.darkMode = true;
        elements.themeToggle.innerHTML = feather.icons['sun'].toSvg();
    } else {
        elements.themeToggle.innerHTML = feather.icons['moon'].toSvg();
    }
}

// Toggle dark mode
function toggleDarkMode() {
    appState.darkMode = !appState.darkMode;
    if (appState.darkMode) {
        document.documentElement.classList.add('dark');
        elements.themeToggle.innerHTML = feather.icons['sun'].toSvg();
    } else {
        document.documentElement.classList.remove('dark');
        elements.themeToggle.innerHTML = feather.icons['moon'].toSvg();
    }
}

// Set active scale and update UI
function setActiveScale(scale) {
    appState.currentScale = scale;
    elements.scaleWeek.classList.remove('active');
    elements.scaleMonth.classList.remove('active');
    elements.scaleOverall.classList.remove('active');
    
    if (scale === 'week') {
        elements.scaleWeek.classList.add('active');
    } else if (scale === 'month') {
        elements.scaleMonth.classList.add('active');
    } else {
        elements.scaleOverall.classList.add('active');
    }
}

// Handle file selection
function handleFileSelect(event) {
    const file = event.target.files[0];
    if (!file) return;

    // Show loading state
    elements.dropZone.innerHTML = `
        <div class="flex flex-col items-center justify-center space-y-4">
            <div class="animate-spin rounded-full h-12 w-12 border-t-2 border-b-2 border-indigo-600"></div>
            <p class="text-gray-600 dark:text-gray-400">Processing ${file.name}...</p>
        </div>
    `;

    const reader = new FileReader();
    reader.onload = (e) => {
        try {
            // Try to parse as JSON regardless of file extension
            const data = JSON.parse(e.target.result);
            parseCommitData(data);
        } catch (error) {
            console.error("File parse error:", error);
            showError(`Failed to parse file (${error.message}). Please ensure it contains valid JSON data.`);
            resetDropZoneUI();
        }
    };

    reader.onerror = () => {
        showError("Error reading file. Please try again.");
        resetDropZoneUI();
    };

    reader.readAsText(file);
}

function showError(message) {
    // Create or update error message element
    let errorEl = document.getElementById('error-message');
    if (!errorEl) {
        errorEl = document.createElement('div');
        errorEl.id = 'error-message';
        elements.dropZone.parentNode.insertBefore(errorEl, elements.dropZone.nextSibling);
    }

    errorEl.className = 'mt-4 p-4 bg-red-100 dark:bg-red-900 text-red-700 dark:text-red-100 rounded-md';
    errorEl.innerHTML = `
        <div class="flex items-center">
            <i data-feather="alert-circle" class="w-5 h-5 mr-2"></i>
            <span>${message}</span>
        </div>
    `;
    feather.replace();
}

function resetDropZoneUI() {
    elements.dropZone.innerHTML = `
        <div class="flex flex-col items-center justify-center space-y-4">
            <i data-feather="upload" class="w-12 h-12 text-indigo-600 dark:text-indigo-400"></i>
            <h2 class="text-xl font-semibold text-gray-800 dark:text-gray-200">Drag & Drop your commit file here</h2>
            <p class="text-gray-600 dark:text-gray-400">or</p>
            <label class="cursor-pointer bg-indigo-600 hover:bg-indigo-700 text-white px-4 py-2 rounded-md transition-colors">
                <input type="file" id="file-input" class="hidden" accept=".json,.txt">
                <span>Select File</span>
            </label>
            <p class="text-sm text-gray-500 dark:text-gray-400">Supports .json or .txt files with commit data</p>
        </div>
    `;
    feather.replace();
}
// Parse commit data from different formats
function parseCommitData(data) {
    let commits = [];
    
    if (!data) {
        showError("File appears to be empty.");
        return;
    }
    
    if (Array.isArray(data)) {
// Check if it's the slim format or GitHub format
        if (data[0]?.hash || data[0]?.author_name) {
            // Slim format
            commits = data.map(item => ({
                hash: item.hash,
                author_name: item.author_name,
                author_email: item.author_email,
                date_iso: item.date_iso,
                message: item.message
            }));
        } else if (data[0]?.sha || data[0]?.commit?.author) {
            // GitHub format
            commits = data.map(item => ({
                hash: item.sha,
                author_name: item.commit.author.name,
                author_email: item.commit.author.email,
                date_iso: item.commit.author.date,
                message: item.commit.message
            }));
        } else {
            showError("Unsupported JSON format detected.");
            return;
        }
    } else {
        showError("File should contain an array of commit objects.");
        return;
    }
    
    // Sort commits by date
    commits.sort((a, b) => new Date(a.date_iso) - new Date(b.date_iso));
    
    appState.commits = commits;
    processCommits();
}

// Process commits into episodes based on clustering window
function processCommits() {
    if (appState.commits.length === 0) return;
    
    const episodes = [];
    let currentEpisode = null;
    const windowMs = appState.clusterWindow * 60 * 1000;
    
    for (let i = 0; i < appState.commits.length; i++) {
        const commit = appState.commits[i];
        const commitDate = new Date(commit.date_iso);
        
        if (!currentEpisode) {
            // Start new episode
            currentEpisode = {
                title: commit.message.split('\n')[0].substring(0, 60),
                start: commit.date_iso,
                end: commit.date_iso,
                commits: [commit]
            };
        } else {
            const prevCommitDate = new Date(appState.commits[i-1].date_iso);
            const timeDiff = commitDate - prevCommitDate;
            
            if (timeDiff > windowMs) {
                // Close current episode and start a new one
                episodes.push(currentEpisode);
                currentEpisode = {
                    title: commit.message.split('\n')[0].substring(0, 60),
                    start: commit.date_iso,
                    end: commit.date_iso,
                    commits: [commit]
                };
            } else {
                // Add to current episode
                currentEpisode.commits.push(commit);
                currentEpisode.end = commit.date_iso;
                // Update title if this commit's message is shorter
                const firstLine = commit.message.split('\n')[0].substring(0, 60);
                if (firstLine.length < currentEpisode.title.length) {
                    currentEpisode.title = firstLine;
                }
            }
        }
    }
    
    // Add the last episode
    if (currentEpisode) {
        episodes.push(currentEpisode);
    }
    
    appState.episodes = episodes;
    appState.filteredCommits = [...appState.commits];
    
    updateUI();
    renderTimeline();
    renderEpisodesList();
}

// Filter commits based on search query
function filterCommits() {
    if (!appState.searchQuery) {
        appState.filteredCommits = [...appState.commits];
    } else {
        appState.filteredCommits = appState.commits.filter(commit => 
            commit.message.toLowerCase().includes(appState.searchQuery) || 
            commit.author_name.toLowerCase().includes(appState.searchQuery)
        );
    }
    
    // Re-process commits with current cluster window
    processCommits();
}

// Update UI elements with stats
function updateUI() {
    // Show controls and visualization
    elements.controls.classList.remove('hidden');
    elements.stats.classList.remove('hidden');
    elements.visualization.classList.remove('hidden');
    elements.details.classList.remove('hidden');
    
    // Update stats
    elements.totalCommits.textContent = appState.commits.length;
    elements.totalEpisodes.textContent = appState.episodes.length;
    
    if (appState.commits.length > 0) {
        const firstDate = new Date(appState.commits[0].date_iso);
        const lastDate = new Date(appState.commits[appState.commits.length - 1].date_iso);
        elements.dateRange.textContent = `${formatDate(firstDate)} → ${formatDate(lastDate)}`;
    }
}

// Format date for display
function formatDate(date) {
    return date.toLocaleDateString('en-US', { year: 'numeric', month: 'short', day: 'numeric' });
}

// Render D3 timeline
function renderTimeline() {
    if (appState.episodes.length === 0) return;
    
    // Clear previous timeline
    elements.timeline.innerHTML = '';
    
    // Get dimensions
    const width = elements.timeline.clientWidth;
    const height = elements.timeline.clientHeight;
    const margin = { top: 20, right: 30, bottom: 30, left: 40 };
    const innerWidth = width - margin.left - margin.right;
    const innerHeight = height - margin.top - margin.bottom;
    
    // Parse dates
    const firstCommit = new Date(appState.commits[0].date_iso);
    const lastCommit = new Date(appState.commits[appState.commits.length - 1].date_iso);
    
    // Create SVG
    const svg = d3.select(elements.timeline)
        .append('svg')
        .attr('width', width)
        .attr('height', height);
    
    const g = svg.append('g')
        .attr('transform', `translate(${margin.left}, ${margin.top})`);
    
    // Create scales based on current time scale
    let xScale;
    let xAxis;
    let timeFormat;
    
    if (appState.currentScale === 'week') {
        // Group by week
        xScale = d3.scaleTime()
            .domain([d3.timeWeek.floor(firstCommit), d3.timeWeek.ceil(lastCommit)])
            .range([0, innerWidth]);
        xAxis = d3.axisBottom(xScale)
            .tickFormat(d3.timeFormat('%V (week %V)'));
    } else if (appState.currentScale === 'month') {
        // Group by month
        xScale = d3.scaleTime()
            .domain([d3.timeMonth.floor(firstCommit), d3.timeMonth.ceil(lastCommit)])
            .range([0, innerWidth]);
        xAxis = d3.axisBottom(xScale)
            .tickFormat(d3.timeFormat('%b %Y'));
    } else {
        // Overall view
        xScale = d3.scaleTime()
            .domain([firstCommit, lastCommit])
            .range([0, innerWidth]);
        xAxis = d3.axisBottom(xScale);
    }
    
    // Create y scale for commit density
    const maxCommits = d3.max(appState.episodes, d => d.commits.length);
    const yScale = d3.scaleLinear()
        .domain([0, maxCommits])
        .range([innerHeight, 0]);
    
    // Add axes
    g.append('g')
        .attr('class', 'axis axis-x')
        .attr('transform', `translate(0, ${innerHeight})`)
        .call(xAxis);
    
    g.append('g')
        .attr('class', 'axis axis-y')
        .call(d3.axisLeft(yScale)
            .ticks(5)
            .tickFormat(d => Math.floor(d) === d ? d : ''));
    
    // Add grid lines
    g.append('g')
        .attr('class', 'grid')
        .call(d3.axisLeft(yScale)
            .ticks(5)
            .tickSize(-innerWidth)
            .tickFormat(''));
    
    // Add episodes as rectangles or density plots
    if (appState.currentScale === 'overall') {
        // Show individual episodes as rectangles
        appState.episodes.forEach(episode => {
            const start = new Date(episode.start);
            const end = new Date(episode.end);
            
            g.append('rect')
                .attr('class', 'episode-rect')
                .attr('x', xScale(start))
                .attr('y', yScale(episode.commits.length))
                .attr('width', Math.max(1, xScale(end) - xScale(start)))
                .attr('height', innerHeight - yScale(episode.commits.length))
                .attr('data-id', episode.start)
                .on('mouseover', function() {
                    d3.select(this).attr('fill-opacity', 0.4);
                    showTooltip(episode, d3.event.pageX, d3.event.pageY);
                })
                .on('mouseout', function() {
                    d3.select(this).attr('fill-opacity', 0.2);
                    hideTooltip();
                })
                .on('click', () => selectEpisode(episode));
        });
        
        // Add commit circles
        appState.commits.forEach(commit => {
            g.append('circle')
                .attr('class', 'commit-circle')
                .attr('cx', xScale(new Date(commit.date_iso)))
                .attr('cy', innerHeight - 10)
                .attr('r', 3)
                .attr('data-hash', commit.hash)
                .on('mouseover', function() {
                    d3.select(this).attr('r', 5);
                })
                .on('mouseout', function() {
                    d3.select(this).attr('r', 3);
                });
        });
    } else {
        // Show aggregated density for week/month view
        const timeBins = {};
        const timeKeyFn = appState.currentScale === 'week' ? 
            d => d3.timeWeek.floor(new Date(d.date_iso)).getTime() : 
            d => d3.timeMonth.floor(new Date(d.date_iso)).getTime();
        
        appState.commits.forEach(commit => {
            const key = timeKeyFn(commit);
            if (!timeBins[key]) {
                timeBins[key] = 0;
            }
            timeBins[key]++;
        });
        
        const maxBinValue = d3.max(Object.values(timeBins));
        const binYScale = d3.scaleLinear()
            .domain([0, maxBinValue])
            .range([innerHeight, 0]);
        
        Object.entries(timeBins).forEach(([time, count]) => {
            const date = new Date(parseInt(time));
            
            g.append('rect')
                .attr('class', 'episode-rect')
                .attr('x', xScale(date))
                .attr('y', binYScale(count))
                .attr('width', appState.currentScale === 'week' ? innerWidth / 52 : innerWidth / 12)
                .attr('height', innerHeight - binYScale(count))
                .attr('fill-opacity', 0.3);
        });
    }
}

// Show tooltip for episode
function showTooltip(episode, x, y) {
    const tooltip = d3.select('body').append('div')
        .attr('class', 'tooltip')
        .style('left', `${x + 10}px`)
        .style('top', `${y + 10}px`)
        .html(`
            <div class="font-semibold text-indigo-600 dark:text-indigo-400">${episode.title}</div>
            <div>${formatDate(new Date(episode.start))} → ${formatDate(new Date(episode.end))}</div>
            <div>${episode.commits.length} commits</div>
        `);
    
    tooltip.transition().duration(200).style('opacity', 1);
}

// Hide tooltip
function hideTooltip() {
    d3.select('.tooltip').remove();
}

// Render episodes list
function renderEpisodesList() {
    elements.episodesList.innerHTML = '';
    
    appState.episodes.forEach((episode, index) => {
        const episodeElement = document.createElement('div');
        episodeElement.className = 'episode-item';
        if (appState.selectedEpisode && appState.selectedEpisode.start === episode.start) {
            episodeElement.classList.add('active');
        }
        episodeElement.innerHTML = `
            <div class="font-medium text-indigo-600 dark:text-indigo-400">${index + 1}. ${episode.title}</div>
            <div class="text-sm text-gray-500 dark:text-gray-400">
                ${formatDate(new Date(episode.start))} → ${formatDate(new Date(episode.end))}
                <span class="float-right">${episode.commits.length} commits</span>
            </div>
        `;
        episodeElement.addEventListener('click', () => selectEpisode(episode));
        elements.episodesList.appendChild(episodeElement);
    });
}

// Select an episode to view its commits
function selectEpisode(episode) {
    appState.selectedEpisode = episode;
    renderSelectedEpisode();
    renderEpisodesList();
}

// Render selected episode details
function renderSelectedEpisode() {
    if (!appState.selectedEpisode) return;
    
    const episode = appState.selectedEpisode;
    elements.selectedEpisodeTitle.textContent = episode.title;
    
    // Render commit table
    elements.commitDetails.innerHTML = `
        <table class="min-w-full divide-y divide-gray-200 dark:divide-gray-700">
            <thead class="bg-gray-50 dark:bg-gray-800">
                <tr>
                    <th class="px-4 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider">Date</th>
                    <th class="px-4 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider">Hash</th>
                    <th class="px-4 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider">Author</th>
                    <th class="px-4 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider">Message</th>
                </tr>
            </thead>
            <tbody class="bg-white dark:bg-gray-800 divide-y divide-gray-200 dark:divide-gray-700">
                ${episode.commits.map(commit => `
                    <tr class="commit-row">
                        <td class="px-4 py-3 whitespace-nowrap text-sm text-gray-500 dark:text-gray-400">
                            ${formatDateTime(new Date(commit.date_iso))}
                        </td>
                        <td class="px-4 py-3 whitespace-nowrap text-sm font-mono text-indigo-600 dark:text-indigo-400">
                            <button class="copy-hash" data-hash="${commit.hash}" title="Copy hash">
                                ${commit.hash.substring(0, 7)}
                            </button>
                        </td>
                        <td class="px-4 py-3 whitespace-nowrap text-sm text-gray-500 dark:text-gray-400">
                            ${commit.author_name}
                        </td>
                        <td class="px-4 py-3 text-sm text-gray-800 dark:text-gray-200">
                            ${commit.message.split('\n')[0].substring(0, 80)}
                            ${commit.message.split('\n')[0].length > 80 ? '...' : ''}
                        </td>
                    </tr>
                `).join('')}
            </tbody>
        </table>
    `;
    
    // Add event listeners for copy hash buttons
    document.querySelectorAll('.copy-hash').forEach(button => {
        button.addEventListener('click', (e) => {
            const hash = e.target.getAttribute('data-hash');
            navigator.clipboard.writeText(hash).then(() => {
                const originalText = e.target.textContent;
                e.target.textContent = 'Copied!';
                setTimeout(() => {
                    e.target.textContent = originalText;
                }, 2000);
            });
        });
    });
}

// Format date and time for display
function formatDateTime(date) {
    return date.toLocaleString('en-US', {
        year: 'numeric',
        month: 'short',
        day: 'numeric',
        hour: '2-digit',
        minute: '2-digit'
    });
}

// Export episodes as JSON
function exportEpisodesJson() {
    if (!appState.episodes.length) return;
    
    const exportData = {
        repository: "local-export",
        generated_at: new Date().toISOString(),
        time_window_minutes: appState.clusterWindow,
        episodes: appState.episodes
    };
    
    const blob = new Blob([JSON.stringify(exportData, null, 2)], { type: 'application/json' });
    const url = URL.createObjectURL(blob);
    
    const a = document.createElement('a');
    a.href = url;
    a.download = `git-odyssey-episodes-${new Date().toISOString().split('T')[0]}.md`;
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    URL.revokeObjectURL(url);
}

// Format duration for display
function formatDuration(ms) {
    const minutes = Math.floor(ms / 60000);
    const hours = Math.floor(minutes / 60);
    const days = Math.floor(hours / 24);
    
    if (days > 0) return `${days}d ${hours % 24}h`;
    if (hours > 0) return `${hours}h ${minutes % 60}m`;
    return `${minutes}m`;
`git-odyssey-episodes-${new Date().toISOString().split('T')[0]}.json`;
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    URL.revokeObjectURL(url);
}

// Export episodes as Markdown
function exportEpisodesMarkdown() {
    if (!appState.episodes.length) return;
    
    let markdown = `# Git Odyssey Export\n\n`;
    markdown += `- **Total Episodes**: ${appState.episodes.length}\n`;
    markdown += `- **Total Commits**: ${appState.commits.length}\n`;
    markdown += `- **Date Range**: ${formatDate(new Date(appState.commits[0].date_iso))} → ${formatDate(new Date(appState.commits[appState.commits.length - 1].date_iso))}\n`;
    markdown += `- **Cluster Window**: ${appState.clusterWindow} minutes\n\n`;
    
    appState.episodes.forEach((episode, index) => {
        markdown += `## Episode ${index + 1}: ${episode.title}\n\n`;
        markdown += `- **Date Range**: ${formatDate(new Date(episode.start))} → ${formatDate(new Date(episode.end))}\n`;
        markdown += `- **Duration**: ${formatDuration(new Date(episode.end) - new Date(episode.start))}\n`;
        markdown += `- **Commits**: ${episode.commits.length}\n\n`;
        
        markdown += `### Commits\n\n`;
        markdown += `| Date | Hash | Author | Message |\n`;
        markdown += `|------|------|--------|---------|\n`;
        
        episode.commits.forEach(commit => {
            const shortHash = commit.hash.substring(0, 7);
            const firstLine = commit.message.split('\n')[0];
            markdown += `| ${formatDateTime(new Date(commit.date_iso))} | ${shortHash} | ${commit.author_name} | ${firstLine.substring(0, 60)}${firstLine.length > 60 ? '...' : ''} |\n`;
        });
        
        markdown += '\n';
    });
    
    const blob = new Blob([markdown], { type: 'text/markdown' });
    const url = URL.createObjectURL(blob);
    
    const a = document.createElement('a');
    a.href = url;
    a.download =