'use strict';

var headlessBrowsers = [
    'Chrome',
    'Chromium',
    'ChromeCanary',
    'Firefox',
    'FirefoxDeveloper',
    'FirefoxAurora',
    'FirefoxNightly',
];

var DetectBrowsers = function (config, logger) {
    var fs = require('fs'),
        os = require('os'),
        which = require('which'),
        browsers = require('./browsers'),
        log = logger.create('framework.detect-browsers');

    /**
     * Returns all browser names found on the current system.
     *
     * @param {!Object} browsers The object with all browsers fro the browsers directory.
     * @returns {Array}
     */
    function getInstalledBrowsers (browsers) {
        var i, length,
            browserNames = Object.keys(browsers),
            result = [];

        // only use one firefox version on linux
        if (process.platform === 'linux') {
            browserNames = browserNames.filter(function (name) {
                return name !== 'firefoxAurora' && name !== 'firefoxNightly';
            });
        }

        // iterate over all browsers in the browsers folder
        for (i = 0, length = browserNames.length; i < length; i++) {
            var browser = browsers[browserNames[i]],
                browserPaths = browser.DEFAULT_CMD[process.platform] || [],
                y, paths = browserPaths.length;

            if (process.env[browser.ENV_CMD]) {
                log.info('which.sync(process.env[browser.ENV_CMD]): ', which.sync(process.env[browser.ENV_CMD]));
            }
            if (process.env[browser.ENV_CMD] && which.sync(process.env[browser.ENV_CMD])) {
                result.push(browser.name);
                continue;
            }

            // iterate over all browser paths
            for (y = 0; y < paths; y++) {
                try {
                    var browserLocated = fs.existsSync(browserPaths[y]) || which.sync(browserPaths[y]);

                    // don't use Edge on operating systems other than Windows 10
                    // (the launcher would be found, but would fail to run)
                    var useBrowser = browser.name !== 'Edge' || process.platform === 'win32' && /^1\d/.test(os.release());

                    if (browserLocated && useBrowser && result.indexOf(browser.name) < 0) {
                        // add browser when found in file system or when env variable is set
                        result.push(browser.name);

                        // set env variable on win32 when it does not exist yet
                        if (process.platform === 'win32') {
                            process.env[browser.ENV_CMD] = browserPaths[y];
                        }

                        break;
                    }
                } catch (e) {
                    // which.sync() failed to find the browser.
                }
            }
        }

        return result;
    }

    config = config || {};
    config.detectBrowsers = config.detectBrowsers || {};
    config.plugins = config.plugins || [];

    if (config.detectBrowsers.enabled === false) {
        log.info('Detecting browsers is disabled. The browsers of the browsers array are used.');
        return;
    }

    var availableBrowsers = getInstalledBrowsers(browsers);

    if (config.detectBrowsers.preferHeadless) {
        availableBrowsers = availableBrowsers.map(function (browser) {
            return headlessBrowsers.indexOf(browser) >= 0 ? browser + 'Headless' : browser;
        });
    }

    // override the browsers in the config only when browsers where find by this plugin
    if (availableBrowsers.length >= 0) {
        // check for PhantomJS option
        if (config.detectBrowsers.usePhantomJS !== false) {
            availableBrowsers.push('PhantomJS');
        }

        if (config.detectBrowsers.postDetection && typeof config.detectBrowsers.postDetection === 'function') {
            //Add specific process to manage browsers list
            availableBrowsers = config.detectBrowsers.postDetection(availableBrowsers);
        }

        var browserList = config.browsers || [];
        if (availableBrowsers.length > 0) {
            config.browsers = browserList.concat(
                availableBrowsers.filter(function (browser) {
                    return browserList.indexOf(browser) === -1;
                })
            );
        }
        log.info('The following browsers will be used:', config.browsers);
    } else {
        log.warn('No browsers were detected. The browsers of the browsers array are used.');
    }
};

// inject karma runner config
DetectBrowsers.$inject = ['config', 'logger'];

// PUBLISH DI MODULE
module.exports = {
    'framework:detectBrowsers': ['factory', DetectBrowsers]
};