/* global window, XMLHttpRequest */

module.exports = function(options, logger) {

    var AbstractFileManager = require("../less/environment/abstract-file-manager.js");

    var fileCache = {};

    // TODOS - move log somewhere. pathDiff and doing something similar in node. use pathDiff in the other browser file for the initial load
    var FileManager = function() {
    };

    FileManager.prototype = new AbstractFileManager();

    FileManager.prototype.alwaysMakePathsAbsolute = function alwaysMakePathsAbsolute() {
        return true;
    };
    FileManager.prototype.join = function join(basePath, laterPath) {
        if (!basePath) {
            return laterPath;
        }
        return this.extractUrlParts(laterPath, basePath).path;
    };
    FileManager.prototype.doXHR = function doXHR(url, type, callback, errback) {

        var xhr = new XMLHttpRequest();
        var async = options.isFileProtocol ? options.fileAsync : true;

        if (typeof xhr.overrideMimeType === 'function') {
            xhr.overrideMimeType('text/css');
        }
        logger.debug("XHR: Getting '" + url + "'");
        xhr.open('GET', url, async);
        xhr.setRequestHeader('Accept', type || 'text/x-less, text/css; q=0.9, */*; q=0.5');
        xhr.send(null);

        function handleResponse(xhr, callback, errback) {
            if (xhr.status >= 200 && xhr.status < 300) {
                callback(xhr.responseText,
                    xhr.getResponseHeader("Last-Modified"));
            } else if (typeof errback === 'function') {
                errback(xhr.status, url);
            }
        }

        if (options.isFileProtocol && !options.fileAsync) {
            if (xhr.status === 0 || (xhr.status >= 200 && xhr.status < 300)) {
                callback(xhr.responseText);
            } else {
                errback(xhr.status, url);
            }
        } else if (async) {
            xhr.onreadystatechange = function () {
                if (xhr.readyState == 4) {
                    handleResponse(xhr, callback, errback);
                }
            };
        } else {
            handleResponse(xhr, callback, errback);
        }
    };
    FileManager.prototype.supports = function(filename, currentDirectory, options, environment) {
        return true;
    };

    FileManager.prototype.clearFileCache = function() {
        fileCache = {};
    };

    FileManager.prototype.loadFile = function loadFile(filename, currentDirectory, options, environment) {
        // TODO: Add prefix support like less-node?
        // What about multiple paths?

        if (currentDirectory && !this.isPathAbsolute(filename)) {
            filename = currentDirectory + filename;
        }

        filename = options.ext ? this.tryAppendExtension(filename, options.ext) : filename;

        options = options || {};

        // sheet may be set to the stylesheet for the initial load or a collection of properties including
        // some context variables for imports
        var hrefParts = this.extractUrlParts(filename, window.location.href);
        var href      = hrefParts.url;
        var self      = this;
        
        return new Promise(function(resolve, reject) {
            if (options.useFileCache && fileCache[href]) {
                try {
                    var lessText = fileCache[href];
                    return resolve({ contents: lessText, filename: href, webInfo: { lastModified: new Date() }});
                } catch (e) {
                    return reject({ filename: href, message: "Error loading file " + href + " error was " + e.message });
                }
            }

            self.doXHR(href, options.mime, function doXHRCallback(data, lastModified) {
                // per file cache
                fileCache[href] = data;

                // Use remote copy (re-parse)
                resolve({ contents: data, filename: href, webInfo: { lastModified: lastModified }});
            }, function doXHRError(status, url) {
                reject({ type: 'File', message: "'" + url + "' wasn't found (" + status + ")", href: href });
            });
        });
    };

    return FileManager;
};
