#!/bin/env lua
-- This source code form is subject to the terms of the MPL-v2 https://mozilla.org/MPL/2.0/ --
-- Any documentation generated is licensed under PDL-v1 https://www.openoffice.org/licenses/PDL.html
local sourceFileName = assert(arg[1])
local textFileName   = assert(arg[2])

local sourceFile = assert(io.open(sourceFileName))
local tf = assert(io.open(textFileName, "w"))

local cmdArgs = {}
for i=1,#arg do
	if skipNext then
		skipNext = false
	else
		local a = arg[i]
		if a == "-e" or a == "--ext" then
			cmdArgs.ext = arg[i+1]
			skipNext = true
		end
	end
end

local ext = cmdArgs.ext or sourceFileName:match("[^.]+$")
local marker

if ext == "c" then
	marker = "//%*"
elseif ext == "lua" then
	marker = "--%*"
else
	error("Unkown extension", ext)
end

local name = sourceFileName:match("([^/]+)%.%w+$")
local functions = {}
local description = {}

function bold(str)
	return "\\fB"..str.."\\fR"
end
function italic(str)
	return "\\fI"..str.."\\fR"
end

for line in sourceFile:lines() do
	local s, e = line:find("^%s*"..marker.."%s*") 
	if s then
		local str = line:sub(e+1)
		s, e = str:find("%w%([^)]*%)")
		if s then
			local proto = str:sub(1, e)
			local returnProto = ""
			local des = str:sub(e+2)
			if proto:match("^[%w|,[%]:.]+ ") then
				returnProto = proto:match("^([^(]+) ")--:gsub("%w+", italic("%1")):gsub("%|", " | "):gsub(",", ", ").." "
				returnProto = returnProto:gsub("^(%w+)", bold("%1")):gsub("| (%w+)", "| "..bold("%1")):gsub(", (%w+)", ", "..bold("%1")):gsub("%[(%w+)", "["..bold("%1"))
				returnProto = returnProto:gsub(" %w+", italic("%1"))
				returnProto = returnProto.." "
				proto = proto:gsub("^([^(]+) (%w+)", "%2")
			end
			proto = proto:gsub("%w+[,)%]]?", function(word)
				if word:match("[,)%]]") then
					return italic(word:sub(1, -2)) .. word:sub(-1)
				else
					return bold(word)
				end
			end)
			des = des:gsub("%*%*([%w$.]+)%*%*", italic("%1"))
			des = des:gsub("%*([%w$.]+)%*", bold("%1"))
			table.insert(functions, {
				proto = proto,
				returnProto = returnProto,
				des = des
			})
		else
			s, e = str:find("^%.%w+")
			if e then
				local cmd = str:sub(2, e)
				local txt = str:sub(e+1):gsub("^%s+", "")
				if cmd == "name" then
					name = name .. " - " .. txt
				elseif cmd == "desc" then
					txt = txt:gsub("%*%*([%w$.]+)%*%*", italic("%1"))
					txt = txt:gsub("%*([%w$.]+)%*", bold("%1"))
					table.insert(description, txt)
				end
			end
		end
	end
end

table.sort(functions, function(a, b)
	return a.proto < b.proto
end)
for f,func in pairs(functions) do
	func.proto = func.returnProto..func.proto
end

tf:write(".TH thornWM 3\n.SH NAME\n"..name.."\n")

tf:write(".SH SYNOPSIS\n")
for f,func in pairs(functions) do
	tf:write(".TP\n")
	tf:write(func.proto.."\n")
end

tf:write(".SH DESCRIPTION\n")
tf:write(table.concat(description, "\n").."\n")
for f,func in pairs(functions) do
	tf:write(".TP\n"..func.proto.."\n")
	tf:write(func.des.."\n")
end

tf:write(".SH COPYRIGHT\nThe contents of this Documentation are subject to the Public Documentation License Version 1.0\n")