/*
 * Shared client side code
 */

// Meta functions
class Sakura {
    public static cookiePrefix: string = ""; // Cookie prefix, gets prepended to cookie names
    public static cookiePath: string = "/"; // Cookie path, can in most cases be left untouched
    
    // Get or set a cookie value
    public static cookie(name: string, value: string = null): string {
        // If value is null only get the cookie's value
        if (value) {
            // Delete the old instance
            document.cookie = this.cookiePrefix + name + '=;expires=Thu, 01 Jan 1970 00:00:01 GMT; path=' + this.cookiePath;

            // Assign the cookie
            document.cookie = this.cookiePrefix + name + '=' + value + '; path=' + this.cookiePath;

            // Pass the value through
            return value;
        } else {
            // Perform a regex on document.cookie
            var get = new RegExp('(^|; )' + encodeURIComponent(this.cookiePrefix + name) + '=([^;]*)').exec(document.cookie);

            // If anything was returned return it (professional phrasing)
            return get ? get[2] : '';
        }
    }

    // Unix timestamp
    public static epoch(): number {
        return Math.floor(Date.now() / 1000);
    }

    // Toggle a class
    public static toggleClass(element: HTMLElement, name: string): void {
        // Check if the class already exists and if not add it
        if (element.className.indexOf(name) < 0) {
            element.className += ' ' + name;
        } else { // If so remove it and kill additional spaces
            element.className = element.className.replace(name, '').trim();
        }
    }

    // Remove every element with a specific class name
    public static removeByClass(name: string): void {
        // Get the elements
        var objs = document.getElementsByClassName(name);

        // Use a while loop to remove each element
        while (objs.length > 0) {
            objs[0].parentNode.removeChild(objs[0]);
        }
    }

    // Remove a single element with a specific id
    public static removeById(id: string): void {
        // Get the element
        var obj = document.getElementById(id);

        // If the element exists use the parent node to remove it
        if (typeof (obj) != "undefined" && obj !== null) {
            obj.parentNode.removeChild(obj);
        }
    }

    // Alternative for Math.log2() since it's still experimental
    public static log2(num: number): number {
        return Math.log(num) / Math.log(2);
    }

    // Get the number of unique characters in a string
    public static unique(string: string): number {
        // Store the already found character
        var used: string[] = [];
        
        // The amount of characters we've already found
        var count: number = 0;

        // Count the amount of unique characters
        for (var i = 0; i < string.length; i++) {
            // Check if we already counted this character
            if (used.indexOf(string[i]) == -1) {
                // Push the character into the used array
                used.push(string[i]);

                // Up the count
                count++;
            }
        }

        // Return the count
        return count;
    }

    // Calculate password entropy
    public static entropy(string: string): number {
        // Decode utf-8 encoded characters
        string = utf8.decode(string);

        // Count the unique characters in the string
        var unique: number = this.unique(string);

        // Do the entropy calculation
        return unique * this.log2(256);
    }

    // Validate string lengths
    public static stringLength(string: string, minimum: number, maximum: number): boolean {
        // Get length of string
        var length = string.length;

        // Check if it meets the minimum/maximum
        if (length < minimum || length > maximum) {
            return false;
        }

        // If it passes both return true
        return true;
    }

    // Validate email address formats
    public static validateEmail(email: string): boolean {
        // RFC compliant e-mail address regex
        var re = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,48})+$/;

        // Test it on the email var which'll return a boolean
        return re.test(email);
    }
}

// UTF-8 functions
class utf8 {
    // Encode a utf-8 string
    public static encode(string): string {
        return unescape(encodeURIComponent(string));
    }

    // Decode a utf-8 string
    public static decode(string): string {
        return decodeURIComponent(escape(string));
    }
}