function toDate(s) {
    return Date.parse(s) ? new Date(s).toJSON().replace(/T|\.\d+Z$/g, ' ').trim() : s;
}

function getHeader(name, headers) {
    var ret = '';

    headers.some(function(header) {
        if (header.name.toLowerCase() === name.toLowerCase()) {
            ret = header.value.toLowerCase();
            return true;
        }
    });

    return ret;
}

function parseUrl(href) {
    var url = {};
    try {
        url = new (window.URL || window.webkitURL)(href);
    } catch (e) {}

    return url;
}

function processRequest(url, headers) {
    var mineTypes = {
        'text/css': 'css',
        'text/javascript': 'js',
        'application/javascript': 'js',
        'application/x-javascript': 'js',
        'application/json': 'js'
    };

    var type;
    var contentType = getHeader('content-type', headers);

    for (var mineType in mineTypes) {
        if (mineTypes.hasOwnProperty(mineType)) {
            if (contentType.indexOf(mineType) !== -1) {
                type = mineTypes[mineType];
                break;
            }
        }
    }

    var parsedUrl = parseUrl(url);

    if (/\.(md|markdown)$/i.test(parsedUrl.pathname)
    && contentType.match(/(plain|markdown)/)) {
        type = 'markdown';
    }

    headers = headers.map(function(header) {
        var name = header.name;
        var value = header.value;

        switch (name.toLowerCase()) {
            case 'content-length':
                value = (parseInt(value, 10) / 1024).toFixed(1) + 'K';
                break;
            case 'date':
            case 'expires':
            case 'last-modified':
                value = toDate(value);
                break;
            default:
                break;
        }

        return {
            name: name,
            value: value
        };
    });

    return {
        url: url,
        type: type,
        contentType: contentType,
        headers: headers
    };
}

function setOptions(options, keep) {
    chrome.storage.sync.set(options);
    chrome.contextMenus.removeAll();

    if (options.enabled) {
        chrome.browserAction.setIcon({
            path: {
                19: 'icon/icon_48.png',
                38: 'icon/icon_128.png'
            }
        });

        // enable html pretty
        if (~options.formatTypes.indexOf('html')) {
            chrome.contextMenus.create({
                id: 'PrettyPageSource',
                type: 'normal',
                title: 'Pretty Page Source',
                contexts: ['page']
            });
        }
    } else {
        chrome.browserAction.setIcon({
            path: {
                19: 'icon/icon_disabled.png',
                38: 'icon/icon_disabled.png'
            }
        });
    }

    if (!keep) {
        chrome.tabs.reload({
            bypassCache: false
        });
    }
}

// click right context menu
chrome.contextMenus.onClicked.addListener(function(info, tab) {
    var tabId = tab.id;

    chrome.tabs.sendMessage(tabId, {
        action: 'prettyDocument'
    });
});

// init options
chrome.storage.sync.get(function(options) {
    if (!options || Object.keys(options).length !== 9) {
        options = {
            enabled: true,
            theme: 'dabblet',
            fontSize: '14px',
            indent: 4,
            customCSS: '',
            headers: true,
            unicode: true,
            bugFree: false,
            formatTypes: ['js', 'css', 'markdown']
        };
    }

    setOptions(options, true);
});

// cache requests
var cacheRequests = {};
chrome.webRequest.onHeadersReceived.addListener(function(details) {
    var url = details.url;
    var tabId = details.tabId;
    var headers = details.responseHeaders;
    var request = processRequest(url, headers);

    cacheRequests[tabId] = request;

    if (request.type && !request.contentType.includes('charset')) {
        headers = headers.map(function(header) {
            if (header.name.toLowerCase() === 'content-type') {
                header.value = request.contentType + '; charset=utf-8';
            }
            return header;
        });

        return { responseHeaders: headers };
    }

    return {};
}, {
    urls: ['<all_urls>'],
    types: ['main_frame']
}, ['blocking', 'responseHeaders']);

// message listener
chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) {
    var url = sender.url;
    var action = request.action;

    // clean cache headers
    var tab = sender.tab || {};

    if (action === 'request') {
        sendResponse(cacheRequests[tab.id] || { url: url });
    }

    try {
        delete cacheRequests[tab.id];
    } catch (e) {}

    if (action === 'prettify') {
        var worker = new Worker('worker.js');

        worker.onerror = function(e) {
            console.error(e);
            worker.terminate();
            worker = null;
            sendResponse();
        };
        worker.onmessage = function(e) {
            worker.terminate();
            worker = null;
            sendResponse(e.data);
        };

        request.language = navigator.language;

        worker.postMessage(request);

        return true;
    }
});

// popup readme
chrome.runtime.onInstalled.addListener(function(details) {
    if (details.reason === 'install') {
        chrome.tabs.create({
            url: 'https://gitee.com/tankunpeng/fex-format',
            active: true
        });
    }
});