class UserIcon extends View {
	constructor(element) {
		super(element);

		this.onUserUpdateBound = this.onUserUpdate.bind(this);

		if (this.element.hasAttribute("user-id")) {
			TimeCards.dataManager.addDataListener("user", {
				user_id: parseInt(this.element.getAttribute("user-id"))
			}, this.onUserUpdateBound);
		}
		else {
			TimeCards.dataManager.addDataListener("user", {
				is_session_user: true
			}, this.onUserUpdateBound);
		}
	}

	setUser(userId) {
		TimeCards.dataManager.removeDataListener("user", this.onUserUpdateBound);
		TimeCards.dataManager.addDataListener("user", {
			user_id: userId
		}, this.onUserUpdateBound);
	}

	build(element) {
		this.initialsLabel = document.createElement("span");
		this.initialsLabel.className = "initials-label";
		element.appendChild(this.initialsLabel);

		return element;
	}

	onUserUpdate(userId, user) {
		if (user) {
			var initials = user.full_name.substring(0, 1);

			var words = user.full_name.split(" ");
			if (words.length > 1) {
				initials += words[words.length - 1].substring(0, 1);
			}

			initials = initials.toUpperCase();

			this.initialsLabel.innerText = initials;

			var userColor = this.getNameColor(user.full_name);
			this.initialsLabel.style.borderColor = userColor;
			this.element.style.boxShadow = "inset 0 0 0 0.14em " + userColor;
		}
		else {
			TimeCards.dataManager.removeDataListener("user", this.onUserUpdateBound);
		}
	}

	getNameColor(name) {
		var hash = 0;
		do {
			name += "_";
			hash = this.hashCode(name);
		}
		while (("" + hash).length < 10 || hash < 0);

		var hashString = "";
		hashString = ("" + hash).substring(1, 10);

		var r = hashString.substring(0, 3) / 1000 * 225;
		var g = hashString.substring(3, 6) / 1000 * 225;
		var b = hashString.substring(6, 9) / 1000 * 225;

		return "rgb(" + r + ", " + g + ", " + b + ")";
	}

	/**
	 * Returns a hash code from a string
	 * @param  {String} str The string to hash.
	 * @return {Number}    A 32bit integer
	 * @see http://werxltd.com/wp/2010/05/13/javascript-implementation-of-javas-string-hashcode-method/
	 */
	hashCode(str) {
	    let hash = 0;
	    for (let i = 0, len = str.length; i < len; i++) {
	        let chr = str.charCodeAt(i);
	        hash = (hash << 5) - hash + chr;
	        hash |= 0; // Convert to 32bit integer
	    }
	    return hash;
	}
}

UIKit.registerViewType(UserIcon, "user-icon");