/***********/
/* HELPERS */
/***********/

/*	Toggle the current state, as represented in the AKS object. (Nothing actually
	happens until the UI state is updated, killSticky() is called (if needed),
	and the new settings are saved in storage.)

	What “toggle the current state” actually means depends on the current mode.

	[1]	In blacklist mode, toggleState() does one of the following:

	(a) (if stickies are not being killed on the current page) adds a matching 
		pattern (if one is not already there), and removes all applicable 
		exclusion patterns; or,
	(b) (if stickies are being killed on the current page) removes all 
		applicable matching patterns.

	[2] In whitelist mode, toggleState() does one of the following:

	(a) (if stickies are not being killed on the current page) removes all 
		applicable exclusion patterns; or,
	(b) (if stickies are being killed on the current page) adds an exclusion
		pattern.
	*/
function toggleState() {
	if (AKS.mode == "blacklist") {
		if (!AKS.pageMatched || AKS.pageExcluded) {
		/*	In this case, stickies are NOT being killed. We must add a matching
			pattern, and remove all applicable exclusion patterns. */
			if (!AKS.pageMatched) {
				addPatternForCurrentTab(AKS.matchingPatterns);
			}
			if (AKS.pageExcluded) {
				disablePatternsForCurrentTab(AKS.exclusionPatterns);
			}
		} else {
		/*	In this case, stickies ARE being killed. We must remove all
			applicable matching patterns. */
			disablePatternsForCurrentTab(AKS.matchingPatterns);
		}
	} else { // if whitelist mode
		if (AKS.pageExcluded) {
		/*	In this case, stickies are NOT being killed. We must remove all
			applicable exclusion patterns. */
			disablePatternsForCurrentTab(AKS.exclusionPatterns);
		} else {
		/*	In this case, stickies ARE being killed. We must add an exclusion
			pattern. */
			addPatternForCurrentTab(AKS.exclusionPatterns);
		}
	}
	recalculatePatternEffects();
}

/*	Given a patterns list (whether matching or exclusion), enables all patterns
	that match the current page URL, if any. If none are found, adds a new 
	pattern for the current tab.
	*/
function addPatternForCurrentTab(patterns) {
	/*	First, we see if there are already any existing but commented-out 
		patterns that match the active tab. If so, we enable them all. */
	var existingPatternsFound = false;
	for (var i = 0; i < patterns.length; i++) {
		if (patterns[i] && patterns[i].hasPrefix("#")) {
			// Strip the leading comment characters and whitespace.
			let uncommentedPattern = patterns[i].replace(/^#[#\s]*/, "");
			// Check if the pattern matches the active tab’s URL.
			if (AKS.activeTabLocation.match(new RegExp(uncommentedPattern))) {
				// If so, replace the commented pattern.
				patterns[i] = uncommentedPattern;
				existingPatternsFound = true;
			}
		}
	}
	if (existingPatternsFound) return;

	/*	If no existing but commented-out patterns have been found, then we’ve
		got to add a new pattern. */
	let dtf = new Intl.DateTimeFormat([], 
		{ month: 'short', day: 'numeric', year: 'numeric', hour: 'numeric', minute: 'numeric', second: 'numeric' });
	patterns.push("## " + dtf.format(new Date()) + " - " + AKS.activeTabLocation);
	patterns.push(regExpForCurrentTab());
	patterns.push("");
}

/*	Given a patterns list (whether matching or exclusion), disables all patterns
	that match the current page URL.
	*/
function disablePatternsForCurrentTab(patterns) {
	for (var i = 0; i < patterns.length; i++) {
		if (patterns[i] && AKS.activeTabLocation.match(new RegExp(patterns[i])))
			patterns[i] = "# " + patterns[i];
	}
}

/*	Creates a regexp that matches the current page URL. This regexp will match
	all pages on the same domain.
	*/
function regExpForCurrentTab() {
	let a = document.createElement("A");
	a.href = AKS.activeTabLocation;
	return ".*" + a.host.replace(/\./g, "\\.") + ".*";
}

/*	Recalculates the values of AKS.pageMatched and AKS.pageExcluded, based on
	the contents of the matching and exclusion patterns lists.
	*/
function recalculatePatternEffects() {
	AKS.pageMatched = false;
	AKS.pageExcluded = false;
	for (let pattern of AKS.matchingPatterns) {
		if (pattern &&
			!pattern.hasPrefix("#") &&
			AKS.activeTabLocation.match(new RegExp(pattern))) {
			AKS.pageMatched = true;
			break;
		}
	}
	for (let pattern of AKS.exclusionPatterns) {
		if (pattern &&
			!pattern.hasPrefix("#") &&
			AKS.activeTabLocation.match(new RegExp(pattern))) {
			AKS.pageExcluded = true;
			break;
		}
	}
}

/*	Updates the values of properties of the AKS object on the basis of the 
	provided result object. Called after a document.querySelector to storage (to retrieve the
	result object).

	Updated properties are: the current mode, the matching and exclusion 
	patterns lists, and the ‘pageMatched’ and ‘pageExcluded’ properties (which
	are computed from the patterns lists).
	*/
function updateState(result) {
	AKS.mode = result.mode || "blacklist";
	AKS.matchingPatterns = (AKS.mode == "whitelist") ?
						   [ ".*" ] :
						   (typeof result.matchingPatterns != "undefined" ?
							result.matchingPatterns.split("\n") :
							[ ]);
	AKS.exclusionPatterns = typeof result.exclusionPatterns != "undefined" ?
							result.exclusionPatterns.split("\n") :
							[ ];
	recalculatePatternEffects();
}

/*	Updates the state of all UI elements to reflect the current values of the
	AKS object (see updateState()).
	*/
function updateUIState() {
	// The big button.
	let mainButton = document.querySelector("button.main-button");
	// The block containing the mode indicator and the “Killing stickies?” label.
	let info = document.querySelector(".info");
	// The “Killing stickies?” label.
	let statusLabel = document.querySelector(".info .status-display");
	// The “Mode:” label.
	let modeLabel = document.querySelector(".info .mode-display");

	var active, whitelist;

	/*	The extension (and thus the main button) is shown as ‘active’ if:
		(a) Blacklist mode is active, the current page is matched, and NOT
			excluded; or,
		(b) Whitelist mode is active, and the current page is NOT excluded.
		*/
	if (AKS.mode == "blacklist") {
		if (AKS.pageMatched && !AKS.pageExcluded) {
			active = true;
		} else {
			active = false;
		}
	} else {
		if (!AKS.pageExcluded) {
			active = false;
		} else {
			active = true;
		}
	}

	mainButton.classList.toggle("active", active);
	statusLabel.classList.toggle("active", active);

	mainButton.classList.toggle("whitelist", (AKS.mode == "whitelist"));
	info.classList.toggle("whitelist", (AKS.mode == "whitelist"));

	mainButton.dataset["tooltip"] = active ? 
									"Click to stop killing stickies on this page" :
									"Click to kill stickies on this page";
	modeLabel.dataset["tooltip"] = (AKS.mode == "whitelist") ?
								   "Stickies are killed *except* on sites you exclude" :
								   "Stickies are killed *only* on specified sites";
}

/*	Updates the tooltip text and position, as specified by the given element
	(in the element’s data-tooltip and data-tooltip-position-y attributes).
	*/
function updateTooltip(element) {
	let tooltip = document.querySelector(".tooltip");
	tooltip.innerHTML = element.dataset["tooltip"].replace(/\*(.+?)\*/, "<strong>$1</strong>");
	tooltip.style.top = element.dataset["tooltipPositionY"];
}

/******************/
/* INITIALIZATION */
/******************/

function initialize() {
	window.AKS = { };
	
	// Update version.
	document.querySelector(".info-header .version").innerHTML = chrome.runtime.getManifest().version;

	// Retrieve saved settings.
	chrome.tabs.query({currentWindow: true, active: true}, (tabs) => {
		AKS.activeTabLocation = tabs[0].url;
		AKS.activeTabID = tabs[0].id;
		chrome.storage.sync.get([ "matchingPatterns", "exclusionPatterns", "mode" ], (result) => {
			updateState(result);
			updateUIState();
		});
	});

	// Listener for main button.
	document.querySelector("button.main-button").addActivateEvent((event) => {
		/*	This doesn’t actually kill the stickies yet; that’s below, in the 
			callback to storage.sync.set. */
		toggleState();

		// Prepare the changes for saving.
		var changes = {
			"exclusionPatterns": AKS.exclusionPatterns.join("\n"),
			"mode": AKS.mode
		};
		if (AKS.mode == "blacklist")
			changes.matchingPatterns = AKS.matchingPatterns.join("\n");

		// Save the changes.
		chrome.storage.sync.set(changes, () => {
			// Update the UI, once changes are saved.
			updateUIState();
			let reloadButton = document.querySelector("button.reload-button");

			/*	If need be, actually kill stickies on the current page. 
				Otherwise, show the reload button. */
			let shouldKillSticky = AKS.pageMatched && !AKS.pageExcluded;
			if (AKS.pageMatched && !AKS.pageExcluded) {
				chrome.tabs.executeScript(null, { code: 'killSticky()' });
				reloadButton.classList.toggle("active", false);
			} else {
				reloadButton.classList.toggle("active", true);
			}

			// Update the tooltip for the main button.
			updateTooltip(event.target);

			// Update the page action (toolbar) icon.
			updateIcon(shouldKillSticky, AKS.activeTabID);
		});
	});

	// Listener for Options button.
	document.querySelector("button.options-button").addActivateEvent(() => {
		chrome.runtime.openOptionsPage(null);
	});
	
	// Listener for the Help button.
	document.querySelector("button.help-button").addActivateEvent(() => {
		// TODO: code!
	});

	// Listener for reload button (appears when sticky-killing is toggled OFF).
	document.querySelector("button.reload-button").addActivateEvent(() => {
		chrome.tabs.update(null, { url: AKS.activeTabLocation });
		window.close();
	});

	// Listeners to show/hide tooltips.
	document.querySelectorAll("button, .mode-display").forEach(element => {
		let tooltip = document.querySelector(".tooltip");
		element.addEventListener("mouseenter", (event) => {
			tooltip.classList.toggle("active", true);
			updateTooltip(event.target);
		});
		element.addEventListener("mouseleave", (event) => {
			tooltip.classList.toggle("active", false);
		});
	});
}

initialize();