build.lua

require "LuaTemplates.templates"
require "LuaTemplates.parsers"
require "lfs"

-- Config --

dofile(arg[1] or ".blogrc")

posts_dir = posts_dir or "_posts/"
layouts_dir = layouts_dir or "_layouts/"
-- - -- - -- 

-- Logging --
function make_msg(prefix, name) return function (fmt, ...) print(prefix, string.format(fmt, ...)); end end
msg_info, msg_warn, msg_error = make_msg("II", "info"), make_msg("WW", "warn"), make_msg("EE", "error");
-- -- - -- --

-- Append '/' to end of posts_dir if necessary
posts_dir = posts_dir:gsub("([^/])$", "%1/")

-- Append '/' to end of base_url if necessary
base_url = base_url:gsub("([^/])$", "%1/")

posts = {};


-- Read posts, interpret
for post_filename in lfs.dir(posts_dir:gsub("/$", "")) do
	-- Ignore dotfiles
	if not post_filename:match("^%.") then
		msg_info("Processing %s", post_filename);
		local post_file, err = io.open(posts_dir..post_filename);
		if post_file then
			local post_format = post_filename:match("%.(%w+)") or "text";
			local post = { filename = post_filename, path = posts_dir..post_filename, format = post_format };
			if not parsers[post_format] then
				msg_warn("Post format '%s' not supported", post_format);
			else
				local inside_header, line_num = nil, 0;
				for line in post_file:lines() do
					line_num = line_num + 1;
					if  line:match("^%-%-%-") then
						if not inside_header then
							inside_header = true;
						else
							inside_header = false;
							break;
						end
					elseif not inside_header then
						break;
					else
						local k,v = line:match("^(%w+):%s?(.*)$");
						if k and v then
							post[k] = v;
						else
							msg_warn("Couldn't parse header at line %d", line_num);
						end
					end
				end
			end	
		
			local post_data, err = post_file:read("*a");

			-- Parse post_data according to extension, add to post list
			--msg_info("Parsing %s...", post_filename) --:gsub("%.[^%.]+$", ""):match("[^/]+"));
			post.content = templates.load(parsers[post_format](post_data)):render{ page = post };
			post.shorttitle = post.title:gsub("%W+", "-"):lower():sub(1,45)
			if #post.title:gsub("%W+", "-") > 45 then
				post.shorttitle = post.shorttitle:gsub("%-%w+$", "");
			end
			post.url = base_url..post.shorttitle.."/"
			post.post = post
			post.updated = post.updated or os.date("!%Y-%m-%dT%H:%M:%SZ", lfs.attributes(post.path).modification);
			if post.published then
				if not post.published:match("^%d%d%d%d%-%d%d%-%d%dT%d%d:%d%d%:%d%dZ$") then
					msg_error("Post has invalid published date");
				end
			end
			table.insert(posts, post);
		else	
			msg_error("Failed to open %s, %s", post_filename, err);
		end
	end
end

local layouts = setmetatable({ default = templates.init(layouts_dir.."default.html"); }, 
	{ __index = function (t, k) rawset(t, k, templates.init(layouts_dir..k..".html")); return rawget(t, k); end });

table.sort(posts, function (a, b)
			do return (a.updated or "") < (b.updated or ""); end
			if not a.updated then return true; end
			if not b.updated then return false; end
			local a_year, a_month, a_day = a.updated:match("(%d%d%d%d)%-(%d%d)%-(%d%d)");
			local b_year, b_month, b_day = b.updated:match("(%d%d%d%d)%-(%d%d)%-(%d%d)");
			if b_year >= a_year then return true; end
			if b_month >= a_month then return true; end
			if b_day >= a_day then return true; end
			return false;
		end);

do
	local shorttitles = {};
	for _, post in ipairs(posts) do
		while shorttitles[post.shorttitle] do
			post.shorttitle = post.shorttitle:gsub("%~%d+$", "").."~"..((tonumber(post.shorttitle:match("%~(%d*)$")) or 0) + 1)
			post.url = base_url..post.shorttitle.."/"
		end
		shorttitles[post.shorttitle] = post;
	end
end

msg_info("%s post%s processed", #posts, #posts ~= 1 and "s" or "");

msg_info(" - - - ");

local unpublished = 0;
for n, post in ipairs(posts) do
	if post.content and (not post.layout or layouts[post.layout]) then
		lfs.mkdir(post.shorttitle);
		local outfile, err = io.open(post.shorttitle.."/index.html", "w+");
		if outfile then
			local layout = layouts[post.layout or "default"];
			
			-- Link to the previous and next published posts
			local i = 1;
			repeat
				post.next = posts[n+i];
				i = i + 1;
			until (not post.next) or post.next.published;
			i = 1;
			repeat
				post.previous = posts[n-i];
				i = i + 1;
			until (not post.previous) or post.previous.published;
			
			post.id = n;
			outfile:write(layout:render(post));
			outfile:close();
			if not post.published then
				-- Not published yet, hide it
				--msg_info("Hiding unpublished post");
				unpublished = unpublished + 1;
				posts[n] = nil;
			end
		else
			msg_error("Failed to write HTML: %s", err);
		end
		if post.published then
			msg_info("Published: %s", post.shorttitle);
		else
			msg_info("Generated: %s", post.shorttitle);
		end
	end
end

-- Do main page
local main_tpl = templates.init(layouts_dir.."/main.html");

main_tpl:saverender("index.html", { title = blog_title, posts = posts });

msg_info("%s post%s published, %d post%s unpublished", #posts, #posts ~= 1 and "s" or "", unpublished, unpublished ~= 1 and "s" or "");

msg_info(" - - - ");

-- Do feed
local atom = io.open("feed/atom.xml.new", "w+");
atom:write[[<?xml version="1.0" encoding="UTF-8"?>
	<feed xmlns="http://www.w3.org/2005/Atom">
]]
atom:write("\t<id>", base_url, "</id>\n");
atom:write("\t<title>", blog_title, "</title>\n");
atom:write("\t<subtitle>", blog_subtitle, "</subtitle>\n");
atom:write("\t<link href='", base_url, "feed/atom.xml' rel='self' />\n");
atom:write("\t<link href='", base_url, "' />\n");

atom:write("\t<updated>", os.date "!%Y-%m-%dT%H:%M:%SZ", "</updated>\n");

for n, post in ipairs(posts) do
	if n > 10 then break; end
	if post.published then
		atom:write("<entry>\n");
		atom:write("\t<author>\n\t\t<name>", post.author or default_author or "Unknown Author", "</name>\n\t</author>\n");
		atom:write("\t<id>", post.url, "</id>\n");
		atom:write("\t<title>", post.title, "</title>\n");
		atom:write("\t<published>", post.published, "</published>\n");
		atom:write("\t<updated>", post.updated, "</updated>\n");
		atom:write("\t<link href='", post.url, "' />\n");
		atom:write("\t<content type='html'>\n", post.content:gsub("&", "&amp;"):gsub("<", "&lt;"), "\t</content>\n");
		atom:write("</entry>\n");
	end
end
atom:write("</feed>");
atom:close();
os.rename("feed/atom.xml.new", "feed/atom.xml");

msg_info("ATOM feed written to feed/atom.xml");