// Choose one of an array
var randomChoice = function(vals) {
	return vals[Math.floor(Math.random() * vals.length)];
};

// Set up the general narrative manager
// -----------------------------------------------------------------------
var StoryManager = {};
StoryManager.storylets = {};

StoryManager.getAllStorylets = function() {
	let allStorylets = [];
	for (let key in this.storylets) {
		let storylets = this.storylets[key].generate();
		for (let i in storylets) allStorylets.push(storylets[i]);
	}
	return allStorylets;
}

StoryManager.getStorylets = function(n=null, tag=null, respect_interrupt=true) 
{
	/* 
		Get n storylets, prioritizing the highest-priority ones first.

		n: if not null, return at most n storylets
		tag: Only get storylets matching this tag
		respect_interrupt: if true, any interrupt storylet overrides n and priority

		For now assume that priorities are integers, but it would be nice
		to be more flexible.

	*/
	let allStorylets;
	if (tag == null) allStorylets = this.getAllStorylets();
	// TODO: get tagged storylets

	// Check for interruptions
	// TODO: Handle more than one interruption
	if (respect_interrupt)
		for (let i in allStorylets)
			if (allStorylets[i].interrupt) return [allStorylets[i]];

	// Get n stories in priority order
	if (n != null) {
		n = Math.min(n, allStorylets.length);
		if (n == 0) return [];
	}
	else n = allStorylets.length;
	let selectedStorylets = [];
	// First sort by ascending priority:
	allStorylets.sort((a, b) => b.priority - a.priority);

	let currentPriority = allStorylets[0].priority;
	while (selectedStorylets.length < n) {
		let priorityStorylets = allStorylets.filter(s => s.priority==currentPriority);
		priorityStorylets.sort((a, b) => (Math.random() - Math.random()));
		let nAdd = Math.min(n - selectedStorylets.length, priorityStorylets.length);
		for (let i=0; i<nAdd; i++) selectedStorylets.push(priorityStorylets.pop());
		currentPriority--;
	}
	return selectedStorylets;
}

window.SM = StoryManager;