/* cgit.js: javacript functions for cgit
 *
 * Copyright (C) 2006-2018 cgit Development Team <cgit@lists.zx2c4.com>
 *
 * Licensed under GNU General Public License v2
 *   (see LICENSE.txt for full license text)
 */

(function () {

/* This follows the logic and suffixes used in ui-shared.c */

var age_classes = [ "age-mins", "age-hours", "age-days",    "age-weeks",    "age-months",    "age-years" ];
var age_suffix =  [ "min.",     "hours",     "days",        "weeks",        "months",        "years",         "years" ];
var age_next =    [ 60,         3600,        24 * 3600,     7 * 24 * 3600,  30 * 24 * 3600,  365 * 24 * 3600, 365 * 24 * 3600 ];
var age_limit =   [ 7200,       24 * 7200,   7 * 24 * 7200, 30 * 24 * 7200, 365 * 25 * 7200, 365 * 25 * 7200 ];
var update_next = [ 10,         5 * 60,      1800,          24 * 3600,      24 * 3600,       24 * 3600,       24 * 3600 ];

function render_age(e, age) {
	var t, n;

	for (n = 0; n < age_classes.length; n++)
		if (age < age_limit[n])
			break;

	t = Math.round(age / age_next[n]) + " " + age_suffix[n];

	if (e.textContent != t) {
		e.textContent = t;
		if (n == age_classes.length)
			n--;
		if (e.className != age_classes[n])
			e.className = age_classes[n];
	}
}

function aging() {
	var n, next = 24 * 3600,
	    now_ut = Math.round((new Date().getTime() / 1000));

	for (n = 0; n < age_classes.length; n++) {
		var m, elems = document.getElementsByClassName(age_classes[n]);

		if (elems.length && update_next[n] < next)
			next = update_next[n];

		for (m = 0; m < elems.length; m++) {
			var age = now_ut - elems[m].getAttribute("data-ut");

			/* A commit dated ahead of the viewer's clock would
			 * otherwise render as a negative age; ui-shared.c
			 * clamps the same way. */
			if (age < 0)
				age = 0;

			render_age(elems[m], age);
		}
	}

	/*
	 * We only need to come back when the age might have changed.
	 * Eg, if everything is counted in hours already, once per
	 * 5 minutes is accurate enough.
	 */

	window.setTimeout(aging, next * 1000);
}

document.addEventListener("DOMContentLoaded", function() {
	/* we can do the aging on DOM content load since no layout dependency */
	aging();
}, false);

})();

/* Selects marked data-autosubmit reload the page with the new setting.
 * Wired here instead of inline onchange handlers, which a strict
 * Content-Security-Policy blocks. Without scripting the forms keep
 * their noscript reload button. */

(function () {

document.addEventListener("DOMContentLoaded", function () {
	var i, els = document.querySelectorAll("select[data-autosubmit]");

	for (i = 0; i < els.length; i++)
		els[i].addEventListener("change", function () {
			this.form.submit();
		});
}, false);

})();

/* Wash a faded highlight over the source line targeted by the URL
 * fragment, #n231, or over a range like #n5-n12. The line anchors live
 * in the number gutter, so this measures the anchor and lays a
 * full-width bar across the code at the same height. Without JS the
 * CSS :target rule still tints the line number itself. */

(function () {

var bar = null;

function place() {
	var m, a, b, table, box, ra, rb, top, bottom;

	if (bar) {
		bar.remove();
		bar = null;
	}
	m = /^#n(\d+)(?:-n?(\d+))?$/.exec(location.hash);
	if (!m)
		return;
	a = document.getElementById("n" + m[1]);
	if (!a)
		return;
	b = (m[2] && document.getElementById("n" + m[2])) || a;
	table = a.closest("table");
	if (!table)
		return;
	box = table.getBoundingClientRect();
	ra = a.getBoundingClientRect();
	rb = b.getBoundingClientRect();
	top = Math.min(ra.top, rb.top) - box.top;
	bottom = Math.max(ra.bottom, rb.bottom) - box.top;
	bar = document.createElement("div");
	bar.className = "line-hl";
	bar.style.top = top + "px";
	bar.style.height = (bottom - top) + "px";
	table.appendChild(bar);
	/* The browser only scrolls to fragments that name a real id, so
	 * bring ranges into view ourselves. */
	if (m[2])
		a.scrollIntoView({ block: "center" });
}

document.addEventListener("DOMContentLoaded", place, false);
window.addEventListener("hashchange", place, false);

})();

/* Colour theme toggle: cycles auto -> light -> dark and remembers the
 * choice. "auto" leaves the page following the system preference via CSS. */

(function () {

var KEY = "cgit-theme";
var ORDER = [ "auto", "light", "dark" ];
var ICONS = {
	auto:  '<svg viewBox="0 0 24 24"><circle cx="12" cy="12" r="9"/><path d="M12 3a9 9 0 0 0 0 18z" fill="currentColor" stroke="none"/></svg>',
	light: '<svg viewBox="0 0 24 24"><circle cx="12" cy="12" r="5"/><path d="M12 1v3M12 20v3M4.2 4.2l2.1 2.1M17.7 17.7l2.1 2.1M1 12h3M20 12h3M4.2 19.8l2.1-2.1M17.7 6.3l2.1-2.1"/></svg>',
	dark:  '<svg viewBox="0 0 24 24"><path d="M21 12.8A9 9 0 1 1 11.2 3 7 7 0 0 0 21 12.8z"/></svg>'
};

function saved() {
	try { return localStorage.getItem(KEY); } catch (e) { return null; }
}

function persist(value) {
	try { localStorage.setItem(KEY, value); } catch (e) { }
}

function apply(theme, btn) {
	var html = document.documentElement;
	if (theme === "auto")
		html.removeAttribute("data-theme");
	else
		html.setAttribute("data-theme", theme);
	/* Keep the standalone page background in sync with the choice. */
	html.style.colorScheme = (theme === "auto") ? "" : theme;
	if (btn) {
		btn.innerHTML = ICONS[theme];
		btn.title = "Colour theme: " + theme;
	}
}

var theme = saved();
if (ORDER.indexOf(theme) < 0)
	theme = "auto";

/* Settled here rather than on DOMContentLoaded. This file is fetched from
 * <head> and runs before the body is parsed, so the choice lands on <html>
 * ahead of the first paint and the page never shows the other theme first.
 * The marker sits on <html> for the same reason, since div#cgit does not
 * exist yet. cgit-js reserves the toggle's column so revealing the button
 * below does not shift the header. */
apply(theme, null);
document.documentElement.classList.add("cgit-js");

document.addEventListener("DOMContentLoaded", function () {
	var root = document.getElementById("cgit");
	if (!root)
		return;
	var btn = root.querySelector(".theme-toggle");
	if (!btn)
		return;

	apply(theme, btn);
	btn.hidden = false;
	btn.addEventListener("click", function () {
		theme = ORDER[(ORDER.indexOf(theme) + 1) % ORDER.length];
		persist(theme);
		apply(theme, btn);
	});
}, false);

})();