Handy = {}

Handy.Locations = {

    /**
     * The database instance we'll be using.
     */
    database: false,

    /**
     * This function sets up the database, initialising it if needed, and then making it
     * available to the other methods.
     */
    init_database: function() {

        // Setup the database.
        this.database = Ti.Database.install('db/locations.sqlite3', 'portfolio.sqlite3');

        // Done here.
        return true;

    },

    search: function(lat, long) {

        Ti.API.info("Searching for " + lat + "/" + long);

    },

    /**
     * Retreives a location. First, it will try to retreive the data from the cache,
     * but will fall back to an API request if the information is old, or not yet cached.
     */
    get: function(id) {

        // Setup the database if necessary.
        if (!this.database) {
            this.init_database();
        }

        Ti.API.info("Locations: Retreiving " + id);

        // Try to get the location from the cache.
        var results = this.database.execute('SELECT * FROM "locations" WHERE id=?', id);

        // If we have the location in the cache...
        if (results.isValidRow()) {

            Ti.API.info("Locations: Got location from cache.")

            // Get the time the location was cached.
            var date = JSON.parse(results.fieldByName('date'));

            // Get the current time.
            var current_date = new Date;
            var unixtime = parseInt(current_date.getTime() / 1000);

            // Check if the record is over our expiry time...
            if ((date + Ti.App.Properties.getInt('cache_expiry')) < unixtime) {

                // Attempt to refresh the data...
                if (this.refresh(id)) {

                    // Now re-run this method and return the data.
                    return this.get(id);

                // ... if the refresh failed, just return the current data.
                } else {

                    // Parse the data record.
                    var data = JSON.parse(results.fieldByName('data'));

                    // Mark the data as old.
                    data.old = true;

                    // Done.
                    return data;
                }

            // ... if the record hasn't expired, just send it back.
            } else {

                return JSON.parse(results.fieldByName('data'));

            }

        }

        // If we don't get the result in the cache...
        if (!results.isValidRow()) {

            Ti.API.info("Locations: Requested location is not cached. Requesting from the web.");

            // If we don't have a network connection, we'll just bail out.
            if (!Ti.Network.online) {

                Ti.API.info("Locations: No network connection, refresh aborted.")

                return false;
            }

            Ti.API.info("Locations: Making an API request for newer data.")

            // Grab the username and password of the current user.
            var username = Ti.App.Properties.getString('auth_username');
            var password = Ti.App.Properties.getString('auth_password')

            // Create the HTTP request.
            var xhr = Titanium.Network.createHTTPClient();

            // Pass it the database.
            xhr.database = this.database;

            // Handle the event when the ULR has loaded.
            xhr.onload = function() {

                // Parse the response.
                var response = JSON.parse(this.responseText);

                // Grab the current unixtime.
                var current_date = new Date;
                var unixtime = parseInt(current_date.getTime() / 1000);

                Ti.API.info("Locations: Got location data. Storing data in cache.");

                // Generate our query, escaping any quotes in the JSON.
                var query = 'INSERT INTO "locations" (id, date, data) VALUES (' + id + ', ' + unixtime + ", '" + JSON.stringify(response.objects[0]).replace("'", "''") + "')";

                // Execute the query.
                this.database.execute(query);

                // We're done.
                return response.objects[0];

            };

            // Setup the URL for the HTTP request.
            xhr.open('GET', Ti.App.Properties.getString('location_uri') + id);

            // Encode the username/password and set the header.
            var auth_string = 'Basic ' + Ti.Utils.base64encode(username + ':' + password);
            xhr.setRequestHeader('Authorization', auth_string);

            // Perform the request.
            xhr.send();
        }

        results.close();
    },

    /**
     * Refreshes the cached version of a a location.
     */
    refresh: function(id) {

        Ti.API.info("Locations: Refreshing location " + id)

        // If we don't have a network connection, we'll just bail out.
        if (!Ti.Network.online) {

            Ti.API.info("Locations: No network connection, refresh aborted.")

            return false;
        }

        Ti.API.info("Locations: Making an API request for newer data.")

        // Grab the username and password of the current user.
        var username = Ti.App.Properties.getString('auth_username');
        var password = Ti.App.Properties.getString('auth_password')

        // Create the HTTP request.
        var xhr = Titanium.Network.createHTTPClient();

        // Pass it the database.
        xhr.database = this.database;

        // Handle the event when the ULR has loaded.
        xhr.onload = function() {

            // Parse the response.
            var response = JSON.parse(this.responseText);

            // Grab the current unixtime.
            var current_date = new Date;
            var unixtime = parseInt(current_date.getTime() / 1000);

            Ti.API.info("Locations: Got location data. Storing data in cache.");

            // Generate our query, escaping any quotes in the JSON.
            var query = 'UPDATE "locations" SET date=' + unixtime + ", data='" + JSON.stringify(response.objects[0]).replace("'", "''") + "' WHERE id=" + id;

            // Execute the query.
            this.database.execute(query);

            // We're done.
            return true;
        };

        // Setup the URL for the HTTP request.
        xhr.open('GET', Ti.App.Properties.getString('location_uri') + id);

        // Encode the username/password and set the header.
        var auth_string = 'Basic ' + Ti.Utils.base64encode(username + ':' + password);
        xhr.setRequestHeader('Authorization', auth_string);

        // Perform the request.
        xhr.send();

    }

}