title: $:/plugins/local/org-gtd/library.js
type: application/javascript
module-type: library

/*\
title: $:/plugins/local/org-gtd/library.js
type: application/javascript
module-type: library
\*/
(function() {
"use strict";

var TODO_STATES = ["TODO","NEXT","WAIT","DONE"],
	TODO_LOOKUP = Object.create(null),
	HEADING_PATTERN = /^(\*+)\s+(?:(TODO|NEXT|WAIT|DONE)\s+)?(.*)$/,
	TAG_PATTERN = /\s+:([A-Za-z0-9_@#%+.-]+(?::[A-Za-z0-9_@#%+.-]+)*):\s*$/,
	DATE_PATTERN = /\b(SCHEDULED|DEADLINE):\s*<([0-9]{4}-[0-9]{2}-[0-9]{2})(?:\s+[^>]*)?>/g;

TODO_STATES.forEach(function(state) {
	TODO_LOOKUP[state] = true;
});

function parseHeading(line,lineIndex) {
	var match = HEADING_PATTERN.exec(line),
		tagMatch,
		title,
		tags = [];
	if(!match) {
		return null;
	}
	title = match[3];
	tagMatch = TAG_PATTERN.exec(title);
	if(tagMatch) {
		tags = tagMatch[1].split(":");
		title = title.substring(0,tagMatch.index).trim();
	}
	return {
		level: match[1].length,
		state: match[2] || "",
		title: title,
		tags: tags,
		line: lineIndex,
		sourceLine: lineIndex + 1,
		endLine: lineIndex,
		scheduled: "",
		deadline: ""
	};
}

function parse(text) {
	var lines = (text || "").split("\n"),
		headings = [],
		current = null;
	lines.forEach(function(line,index) {
		var heading = parseHeading(line,index),
			match;
		if(heading) {
			if(current) {
				current.endLine = index - 1;
			}
			headings.push(heading);
			current = heading;
			return;
		}
		if(current) {
			DATE_PATTERN.lastIndex = 0;
			while((match = DATE_PATTERN.exec(line)) !== null) {
				if(match[1] === "SCHEDULED") {
					current.scheduled = match[2];
				} else {
					current.deadline = match[2];
				}
			}
		}
	});
	if(current) {
		current.endLine = lines.length - 1;
	}
	for(var index = 0; index < headings.length; index++) {
		var heading = headings[index],
			nextIndex = index + 1;
		while(nextIndex < headings.length && headings[nextIndex].level > heading.level) {
			nextIndex++;
		}
		heading.subtreeEndLine = nextIndex < headings.length ? headings[nextIndex].line - 1 : lines.length - 1;
	}
	return {lines: lines,headings: headings};
}

function headingAtLine(parsed,line) {
	var result = null;
	parsed.headings.forEach(function(heading) {
		if(heading.line <= line && heading.subtreeEndLine >= line) {
			if(!result || heading.level >= result.level) {
				result = heading;
			}
		}
	});
	return result;
}

function cycleState(line) {
	var heading = parseHeading(line,0),
		stars,
		nextState,
		rest;
	if(!heading) {
		return null;
	}
	stars = new Array(heading.level + 1).join("*");
	if(heading.state) {
		nextState = TODO_STATES[(TODO_STATES.indexOf(heading.state) + 1) % TODO_STATES.length];
		rest = line.replace(/^(\*+)\s+(?:TODO|NEXT|WAIT|DONE)\s+/,"$1 " + nextState + " ");
	} else {
		rest = line.replace(/^(\*+)\s+/,"$1 TODO ");
	}
	return {line: rest,state: nextState || "TODO",level: stars.length};
}

function dateToTime(value) {
	var match = /^(\d{4})-(\d{2})-(\d{2})$/.exec(value || ""),
		date;
	if(!match) {
		return NaN;
	}
	date = new Date(Number(match[1]),Number(match[2]) - 1,Number(match[3]));
	if(date.getFullYear() !== Number(match[1]) || date.getMonth() !== Number(match[2]) - 1 || date.getDate() !== Number(match[3])) {
		return NaN;
	}
	return date.getTime();
}

exports.TODO_STATES = TODO_STATES;
exports.TODO_LOOKUP = TODO_LOOKUP;
exports.parseHeading = parseHeading;
exports.parse = parse;
exports.headingAtLine = headingAtLine;
exports.cycleState = cycleState;
exports.dateToTime = dateToTime;

})();