#!/usr/bin/env lua
local basepath = (debug.getinfo(1, "S").source:sub(2):match("(.*[/\\])") or "./"):sub(1,-2)
table.unpack = table.unpack or unpack -- Lua 5.1 compat

function main()
	local dataPath = arg[1]
	local settingPath = p("data","setting")
	local settings = {}
	
	settings.blog_name = readSetting(p(dataPath,settingPath,"blog_name.txt"),removeNewline)
	settings.index_path = readSetting(p(dataPath,settingPath,"index_path.txt"),removeNewline)
	settings.sub_path = readSetting(p(dataPath,settingPath,"sub_path.txt"),removeNewline)
	settings.page_html = readSetting(p(dataPath,settingPath,"page.html"),removeNewline)
	settings.page_path = readSetting(p(dataPath,settingPath,"page_path.txt"),removeNewline)
	settings.post_html = readSetting(p(dataPath,settingPath,"post.html"),removeNewline)
	settings.post_path = readSetting(p(dataPath,settingPath,"post_path.txt"),removeNewline)
	settings.posts_per_page = readSetting(p(dataPath,settingPath,"posts_per_page.txt"),tonumber)
	print("* Settings:")
	for i,s in pairs(settings) do
		print("** " ..i.. ":\n" ..tostring(s))
	end
	print("* Reading post entry list ...")
	local file = io.open(p(dataPath,settings.post_path,"entries.txt"),"r")
	local posts = {}
	for line in file:lines() do
		table.insert(posts,line)
	end
	file:close()
	table.sort(posts)
	tableReverse(posts)
	
	local postnr = settings.posts_per_page
	local post_env = nil
	local pagenr = 0
	local pagef = nil
	local page_env = nil
	local page = nil
	local maxPage = math.ceil(#posts / settings.posts_per_page)
	
	local function dumpPost()
		page = applyEnv(settings.page_html,page_env)
		pagef:write(page)
		pagef:close()
	end
	
	print("* Creating pages ...")
	
	for i,s in ipairs(posts) do
		-- PAGE
		if postnr == settings.posts_per_page then
			postnr = 0
			pagenr = pagenr + 1
			if pagef ~= nil then
				dumpPost()
			end
			print("** Page: " ..tostring(pagenr).. " ...")
			
			page_env = {}
			page_env.BLOG = settings.blog_name
			page_env.PAGE = tostring(pagenr)
			if pagenr > 1 then
				page_env.LINK_PREVIOUS = p(settings.sub_path,settings.page_path,tostring(pagenr - 1).. ".html")
			else
				page_env.LINK_PREVIOUS = p(settings.sub_path,settings.page_path,tostring(pagenr).. ".html")
			end
			
			if pagenr >= maxPage then
				page_env.LINK_NEXT = p(settings.sub_path,settings.page_path,tostring(pagenr).. ".html")
			else
				page_env.LINK_NEXT = p(settings.sub_path,settings.page_path,tostring(pagenr + 1).. ".html")
			end
			page_env.POSTS = ""
			
			pagef = io.open(p(dataPath,settings.page_path,tostring(pagenr).. ".html"),"w")
		end
		
		-- POST
		print("*** " ..s.. " ...")
		local stamp,title = table.unpack(stringSplit(s,"_",1))
		stamp = stringSplit(stamp,"-",1)
		stamp.date = {}
		stamp.date.year = tonumber(string.sub(stamp[1],1,4))
		stamp.date.month = tonumber(string.sub(stamp[1],5,6))
		stamp.date.day = tonumber(string.sub(stamp[1],7,8))
		stamp[1] = nil
		
		stamp.time = {}
		stamp.time.hour = tonumber(string.sub(stamp[2],1,2))
		stamp.time.minute = tonumber(string.sub(stamp[2],3,4))
		stamp[2] = nil
		print("**** Title: " ..title)
		print("**** Date: " ..tableJoin({stamp.date.year,stamp.date.month,stamp.date.day},"/"))
		print("**** Time: " ..tableJoin({stamp.time.hour,stamp.time.minute},":"))
		
		post_env = {}
		post_env.TITLE = title
		post_env.DATE_YEAR = tostring(stamp.date.year)
		post_env.DATE_MONTH = padNumber(stamp.date.month,2)
		post_env.DATE_DAY = padNumber(stamp.date.day,2)
		post_env.TIME_HOUR = padNumber(stamp.time.hour,2)
		post_env.TIME_MINUTE = padNumber(stamp.time.minute,2)
		post_env.LINK_RAW = p(settings.sub_path,settings.post_path,s,"content.html")
		post_env.POST = readFile(p(dataPath,settings.post_path,s,"content.html"))
		page_env.POSTS = page_env.POSTS .. applyEnv(settings.post_html,post_env) .. "\n"
		postnr = postnr + 1
	end
	if pagef ~= nil then dumpPost() end
end

function padNumber(nr,len)
	nr = tostring(nr)
	local curLen = string.len(nr)
	while curLen < len do
		nr = "0" .. nr
		curLen = curLen + 1
	end
	return nr
end

function applyEnv(str,env)
	for i,v in pairs(env) do
		str = string.gsub(str,"%$%$" ..i.. "%$%$",v)
	end
	return str
end

function readSetting(path,converter)
	local data = readFile(path)
	if converter == nil or converter == tostring then
		return data
	end
	return converter(data)
end

function readFile(path)
	local file = io.open(path,"r")
	local data = file:read("*a")
	file:close()
	return data
end

function tableReverse(tbl)
	local start = 1
	local stop = #tbl
	
	while start < stop do
		tbl[start], tbl[stop] = tbl[stop], tbl[start]
		start = start + 1
		stop = stop - 1
	end
end

function stringSplit(str, sep, limit)
	sep = sep or " "
	limit = limit or 0
	
	local splits = 0
	local sep_escaped = sep:gsub("[%(%)%.%%%+%-%*%?%[%]%^%$]","%%%1")
	local parts = {}
	for part in str:gmatch("([^" .. sep_escaped .. "]+)") do
		if limit > 0 and splits > limit then
			parts[splits] = parts[splits] .. sep .. part
		else
			splits = splits + 1
			table.insert(parts, part)
		end
	end
	return parts
end

function tableJoin(tbl, sep)
	local length = #tbl
	if length == 0 then return "" end

	local str = tostring(tbl[1])
	local index = 2
	while index <= length do
		str = str .. sep .. tostring(tbl[index])
		index = index + 1
	end
	return str
end

function pathJoin(...)
	return tableJoin({...},"/")
end
p = pathJoin

function removeNewline(str)
	str = string.gsub(str,"\n","")
	str = string.gsub(str,"\r","")
	return str
end

main()