// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: https://codemirror.net/5/LICENSE
// Highlighting text that matches the selection
// Defines an option highlightSelectionMatches, which, when enabled,
// will style strings that match the selection throughout the
// document.
// The option can be set to true to simply enable it, or to a
// {minChars, style, wordsOnly, showToken, delay} object to explicitly
// configure it. minChars is the minimum amount of characters that should be
// selected for the behavior to occur, and style is the token style to
// apply to the matches. This will be prefixed by "cm-" to create an
// actual CSS class name. If wordsOnly is enabled, the matches will be
// highlighted only if the selected text is a word. showToken, when enabled,
// will cause the current token to be highlighted when nothing is selected.
// delay is used to specify how much time to wait, in milliseconds, before
// highlighting the matches. If annotateScrollbar is enabled, the occurrences
// will be highlighted on the scrollbar via the matchesonscrollbar addon.

// codemirror: v.5.65.15

(function(mod) {
	if (typeof exports == "object" && typeof module == "object") // CommonJS
		mod(require("../../lib/codemirror"), require("./matchesonscrollbar"));
	else if (typeof define == "function" && define.amd) // AMD
		define(["../../lib/codemirror", "./matchesonscrollbar"], mod);
	else // Plain browser env
		mod(CodeMirror);
})(function(CodeMirror) {
	"use strict";

	var defaults = {
		style: "matchhighlight",
		minChars: 2,
		delay: 100,
		wordsOnly: false,
		annotateScrollbar: false,
		showToken: false,
		trim: true
	}

	function State(options) {
		this.options = {}
		for (var name in defaults)
			this.options[name] = (options && options.hasOwnProperty(name) ? options : defaults)[name]
		this.overlay = this.timeout = null;
		this.matchesonscroll = null;
		this.active = false;
	}

	CodeMirror.defineOption("highlightSelectionMatches", false, function(cm, val, old) {
		if (old && old != CodeMirror.Init) {
			removeOverlay(cm);
			clearTimeout(cm.state.matchHighlighter.timeout);
			cm.state.matchHighlighter = null;
			cm.off("cursorActivity", cursorActivity);
			cm.off("focus", onFocus)
		}
		if (val) {
			var state = cm.state.matchHighlighter = new State(val);
			if (cm.hasFocus()) {
				state.active = true
				highlightMatches(cm)
			} else {
				cm.on("focus", onFocus)
			}
			cm.on("cursorActivity", cursorActivity);
		}
	});

	function cursorActivity(cm) {
		var state = cm.state.matchHighlighter;
		if (state.active || cm.hasFocus()) scheduleHighlight(cm, state)
	}

	function onFocus(cm) {
		var state = cm.state.matchHighlighter
		if (!state.active) {
			state.active = true
			scheduleHighlight(cm, state)
		}
	}

	function scheduleHighlight(cm, state) {
		clearTimeout(state.timeout);
		state.timeout = setTimeout(function() {highlightMatches(cm);}, state.options.delay);
	}

	function addOverlay(cm, query, hasBoundary, style) {
		var state = cm.state.matchHighlighter;
		cm.addOverlay(state.overlay = makeOverlay(query, hasBoundary, style));
		if (state.options.annotateScrollbar && cm.showMatchesOnScrollbar) {
			var searchFor = hasBoundary ? new RegExp((/\w/.test(query.charAt(0)) ? "\\b" : "") +
																							 query.replace(/[\\\[.+*?(){|^$]/g, "\\$&") +
																							 (/\w/.test(query.charAt(query.length - 1)) ? "\\b" : "")) : query;
			state.matchesonscroll = cm.showMatchesOnScrollbar(searchFor, false,
				{className: "CodeMirror-selection-highlight-scrollbar"});
		}
	}

	function removeOverlay(cm) {
		var state = cm.state.matchHighlighter;
		if (state.overlay) {
			cm.removeOverlay(state.overlay);
			state.overlay = null;
			if (state.matchesonscroll) {
				state.matchesonscroll.clear();
				state.matchesonscroll = null;
			}
		}
	}

	function highlightMatches(cm) {
		cm.operation(function() {
			var state = cm.state.matchHighlighter;
			removeOverlay(cm);
			if (!cm.somethingSelected() && state.options.showToken) {
				var re = state.options.showToken === true ? /[\w$]/ : state.options.showToken;
				var cur = cm.getCursor(), line = cm.getLine(cur.line), start = cur.ch, end = start;
				while (start && re.test(line.charAt(start - 1))) --start;
				while (end < line.length && re.test(line.charAt(end))) ++end;
				if (start < end)
					addOverlay(cm, line.slice(start, end), re, state.options.style);
				return;
			}
			var from = cm.getCursor("from"), to = cm.getCursor("to");
			if (from.line != to.line) return;
			if (state.options.wordsOnly && !isWord(cm, from, to)) return;
			var selection = cm.getRange(from, to)
			if (state.options.trim) selection = selection.replace(/^\s+|\s+$/g, "")
			if (selection.length >= state.options.minChars)
				addOverlay(cm, selection, false, state.options.style);
		});
	}

	function isWord(cm, from, to) {
		var str = cm.getRange(from, to);
		if (str.match(/^\w+$/) !== null) {
				if (from.ch > 0) {
						var pos = {line: from.line, ch: from.ch - 1};
						var chr = cm.getRange(pos, from);
						if (chr.match(/\W/) === null) return false;
				}
				if (to.ch < cm.getLine(from.line).length) {
						var pos = {line: to.line, ch: to.ch + 1};
						var chr = cm.getRange(to, pos);
						if (chr.match(/\W/) === null) return false;
				}
				return true;
		} else return false;
	}

	function boundariesAround(stream, re) {
		return (!stream.start || !re.test(stream.string.charAt(stream.start - 1))) &&
			(stream.pos == stream.string.length || !re.test(stream.string.charAt(stream.pos)));
	}

	function makeOverlay(query, hasBoundary, style) {
		return {token: function(stream) {
			if (stream.match(query) &&
					(!hasBoundary || boundariesAround(stream, hasBoundary)))
				return style;
			stream.next();
			stream.skipTo(query.charAt(0)) || stream.skipToEnd();
		}};
	}
});

// #END
