/** 
 * jspsych plugin for categorization trials with feedback and animated stimuli
 * Josh de Leeuw
 *
 * documentation: https://github.com/jodeleeuw/jsPsych/wiki/jspsych-categorize-animation
 **/

(function($) {
	jsPsych["categorize-animation"] = (function() {

		var plugin = {};

		plugin.create = function(params) {

			params = jsPsych.pluginAPI.enforceArray(params, ['key_answer', 'text_answer', 'choices', 'data']);

			var trials = new Array(params.stimuli.length);
			for (var i = 0; i < trials.length; i++) {
				trials[i] = {};
				trials[i].stims = params.stimuli[i];
				trials[i].sequence_reps = params.sequence_reps || 1;
				trials[i].key_answer = params.key_answer[i];
				trials[i].text_answer = (typeof params.text_answer === 'undefined') ? "" : params.text_answer[i];
				trials[i].choices = params.choices;
				trials[i].correct_text = params.correct_text || "Correct.";
				trials[i].incorrect_text = params.incorrect_text || "Wrong.";
				trials[i].allow_response_before_complete = params.allow_response_before_complete || false;
				trials[i].frame_time = params.frame_time || 500;
				trials[i].timing_feedback_duration = params.timing_feedback_duration || 2000;
				trials[i].prompt = (typeof params.prompt === 'undefined') ? '' : params.prompt;
			}
			return trials;
		};

		plugin.trial = function(display_element, trial) {

			// if any trial variables are functions
			// this evaluates the function and replaces
			// it with the output of the function
			trial = jsPsych.pluginAPI.normalizeTrialVariables(trial);

			var animate_frame = -1;
			var reps = 0;

			var showAnimation = true;

			var responded = false;
			var timeoutSet = false;


			var startTime = (new Date()).getTime();

			// show animation
			var animate_interval = setInterval(function() {
				display_element.html(""); // clear everything
				animate_frame++;
				if (animate_frame == trial.stims.length) {
					animate_frame = 0;
					reps++;
					// check if reps complete //
					if (trial.sequence_reps != -1 && reps >= trial.sequence_reps) {
						// done with animation
						showAnimation = false;
					}
				}

				if (showAnimation) {
					display_element.append($('<img>', {
						"src": trial.stims[animate_frame],
						"class": 'jspsych-categorize-animation-stimulus'
					}));
				}

				if (!responded && trial.allow_response_before_complete) {
					// in here if the user can respond before the animation is done
					if (trial.prompt !== "") {
						display_element.append(trial.prompt);
					}
				} else if (!responded) {
					// in here if the user has to wait to respond until animation is done.
					// if this is the case, don't show the prompt until the animation is over.
					if (!showAnimation) {
						if (trial.prompt !== "") {
							display_element.append(trial.prompt);
						}
					}
				} else {
					// user has responded if we get here.

					// show feedback
					var feedback_text = "";
					if (block.data[block.trial_idx].correct) {
						feedback_text = trial.correct_text.replace("%ANS%", trial.text_answer);
					} else {
						feedback_text = trial.incorrect_text.replace("%ANS%", trial.text_answer);
					}
					display_element.append(feedback_text);

					// set timeout to clear feedback
					if (!timeoutSet) {
						timeoutSet = true;
						setTimeout(function() {
							endTrial();
						}, trial.timing_feedback_duration);
					}
				}


			}, trial.frame_time);


			var keyboard_listener;

			var after_response = function(info) {
				// ignore the response if animation is playing and subject
				// not allowed to respond before it is complete
				if (!trial.allow_response_before_complete && showAnimation) {
					return false;
				}

				var correct = false;
				if (trial.key_answer == info.key) {
					correct = true;
				}

				responded = true;

				var trial_data = {
					"stimulus": trial.stims[0],
					"rt": info.rt,
					"correct": correct,
					"key_press": info.key
				};

				jsPsych.data.write($.extend({}, trial_data, trial.data));

				jsPsych.pluginAPI.cancelKeyboardResponse(keyboard_listener);

			}

			jsPsych.pluginAPI.getKeyboardResponse(after_response, trial.choices, 'date', true);

			function endTrial() {
				clearInterval(animate_interval); // stop animation!
				display_element.html(''); // clear everything
				if (trial.timing_post_trial > 0) {
					setTimeout(function() {
						jsPsych.finishTrial();
					}, trial.timing_post_trial);
				} else {
					jsPsych.finishTrial();
				}
			}
		};

		return plugin;
	})();
})(jQuery);