// Background service worker for Auto Cover Generator

// 1. Native Click Behavior
chrome.sidePanel.setPanelBehavior({ openPanelOnActionClick: true });

const openTabs = new Set();

// 2. Click Handler (Native behavior handles opening, we just manage content)
// Note: chrome.action.onClicked is ignored when openPanelOnActionClick is true.

// 3. Tab State Management
// Monitor all tab changes to ensure correct panel is shown
chrome.runtime.onInstalled.addListener(() => {
    initializeAllTabs();
});

chrome.runtime.onStartup.addListener(() => {
    initializeAllTabs();
});

async function initializeAllTabs() {
    const tabs = await chrome.tabs.query({});
    for (const tab of tabs) {
        await checkAndSetSidePanel(tab.id);
    }
}

// 4. Tab Activation / Isolation Logic
chrome.tabs.onActivated.addListener(async (activeInfo) => {
    const tabId = activeInfo.tabId;
    await checkAndSetSidePanel(tabId);
});

chrome.tabs.onUpdated.addListener(async (tabId, changeInfo, tab) => {
    if (changeInfo.status === 'complete' || changeInfo.url) {
        await checkAndSetSidePanel(tabId);
    }
});

async function checkAndSetSidePanel(tabId) {
    try {
        const tab = await chrome.tabs.get(tabId);
        if (!tab) return; // Tab doesn't exist

        // If we don't have permission to see the URL, it's definitely not Gemini (since we have host_permissions for Gemini).
        // So undefined tab.url means "Restricted/Other Site".
        const isGemini = tab.url && tab.url.startsWith('https://gemini.google.com/');

        if (isGemini) {
            // Enable and set path for Gemini
            await chrome.sidePanel.setOptions({
                tabId: tabId,
                path: 'sidepanel/panel.html',
                enabled: true
            });
        } else {
            // Disable for all other sites - this CLOSES the panel if open
            // and ensures it stays closed when returning to the tab (until clicked manually)
            await chrome.sidePanel.setOptions({
                tabId: tabId,
                enabled: false
            });
        }

    } catch (e) {
        // Tab might be closed or we heavily failed access
        console.log('Cannot access tab or set panel', e);
    }
}

chrome.runtime.onInstalled.addListener(() => {
    chrome.sidePanel.setOptions({ enabled: false });
});

chrome.tabs.onRemoved.addListener((tabId) => {
    openTabs.delete(tabId);
});

// 4. Message Routing
chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
    // Forward messages to content script
    if (message.action === 'generateCover' || message.action === 'removeObjectFromImage') {
        chrome.tabs.query({ active: true, currentWindow: true }, (tabs) => {
            if (tabs[0]) {
                chrome.tabs.sendMessage(tabs[0].id, message, (response) => {
                    sendResponse(response);
                });
            }
        });
        return true;
    }

    if (message.action === 'downloadImage') {
        const url = message.url;
        const timestamp = new Date().toISOString().replace(/[:.]/g, '-');
        const filename = `gemini_gen_${timestamp}.png`;

        chrome.downloads.download({
            url: url,
            filename: filename,
            conflictAction: 'uniquify'
        }, (downloadId) => {
            if (chrome.runtime.lastError) {
                console.error('Download failed:', chrome.runtime.lastError);
            } else {
                console.log('Download started, ID:', downloadId);
            }
        });
        return;
    }

    if (message.action === 'generationError') {
        chrome.runtime.sendMessage(message).catch(() => { });
    }
});

console.log('Auto Cover Generator: Background Service Ready');