local outdir = arg[1]

function string.trim(self)
	return self:gsub("^%s+", ""):gsub("%s+$", "")
end

local escapes = {
	["\\"] = "\\",
	["n"] = "\n",
	["t"] = "\t",
	["r"] = "\r"
}
local docs = {}
local cdoc
local cfunc
local function parse_string(str, close, noesc)
	local s = ""
	local esc = false
	repeat
		local c = str.read()
		if not esc then
			if (c ~= "\\" or noesc) then
				s = s .. c
			else
				esc = true
			end
		else
			if (escapes[c]) then
				s = s .. escapes[c]
			else
				return nil, "invalid escape"
			end
		end
	until str.peek(#close) == close or str.peek(#close) == ""
	str.seek(#close)
	return s
end

local function parse_dec(str)
	local num = ""
	repeat
		num = num .. str.read()
	until not str.peek():match("%d") or str.peek() == ""
	return tonumber(num, 10)
end

local function parse_hex(str)
	if not str.peek():match("%x") then
		return nil, "malformed hex"
	end
	local num = ""
	repeat
		num = num .. str.read()
	until not str.peek():match("%x") or str.peek() == ""
	return tonumber(num, 16)
end
local ln = 0
local function parse_line(line)
	local args = {}
	local idx = 1
	local str = {
		peek = function(amt)
			amt = amt or 1
			return line:sub(idx, idx+amt-1)
		end,
		read = function(amt)
			amt = amt or 1
			local data = line:sub(idx, idx+amt-1)
			idx = idx + amt
			return data
		end,
		seek = function(amt)
			amt = amt or 0
			idx = idx + amt
			return idx
		end
	}
	local function lassert(a, b)
		return assert(a, "line #"..ln..": "..(b or "unknown error"))
	end
	while str.peek() ~= "" do
		if (str.peek() == "\"") then
			str.seek(1)
			args[#args+1] = lassert(parse_string(str, "\"", false))
		elseif (str.peek(2) == "0x") then
			str.seek(2)
			args[#args+1] = lassert(parse_hex(str))
		elseif (str.peek(1):match("%d")) then
			args[#args+1] = lassert(parse_dec(str))
		elseif (str.peek() == "'") then
			str.seek(1)
			args[#args+1] = lassert(parse_string(str, "'", false))
		elseif (str.peek() == " ") then
			--do nothing
		else
			args[#args+1] = lassert(parse_string(str, " ", true))
		end
	end
	return args
end
local function is_comment(line)
	if (line:trim():sub(1, 2) == "--") then
		return true, line:sub(3)
	end
end
for line in io.stdin:lines() do
	ln = ln+1
	local com, rline = is_comment(line)
	if (com) then
		if (rline:match("^%-@module")) then
			local args = parse_line(rline:sub(10))
			if (cdoc) then
				if (cfunc) then
					cdoc.methods[#cdoc.methods+1] = cfunc
					cfunc = nil
				end
				docs[#docs+1] = cdoc
			end
			cdoc = {
				type = "module",
				methods = {},
				name = args[2],
				mod = args[1]
			}
		elseif (rline:match("^%-@section")) then
			local args = parse_line(rline:sub(11))
			if (cdoc) then
				if (cfunc) then
					cdoc.methods[#cdoc.methods+1] = cfunc
					cfunc = nil
				end
				docs[#docs+1] = cdoc
			end
			cdoc = {
				type = "generic",
				methods = {},
				name = args[2],
				mod = args[1]
			}
		elseif (rline:match("^%-@page")) then
			if (cfunc) then
				cdoc.methods[#cdoc.methods+1] = cfunc
			end
			local args = parse_line(rline:sub(8))
			cfunc = {
				type = "page",
				doc = {},
				name = args[1],
				print_name = args[2]
			}
		elseif (rline:match("^%-@arg") and cfunc.type == "func") then
			local args = parse_line(rline:sub(7))
			cfunc.args[#cfunc.args+1] = {
				name = args[1],
				type = args[2],
				doc = args[3]
			}
		elseif (rline:match("^%-@return") and cfunc.type == "func") then
			local args = parse_line(rline:sub(10))
			cfunc.ret[#cfunc.ret+1] = {
				type = args[1],
				doc = args[2],
			}
		elseif (rline:match("^%-@doc")) then
			local args = parse_line(rline:sub(7))
			cfunc.doc[#cfunc.doc+1] = {
				doc = args[1],
			}
		elseif (rline:match("^%-@see")) then
			local args = parse_line(rline:sub(7))
			cfunc.doc[#cfunc.doc+1] = {
				doc = "See \27_S"..args[1].."\27_E"
			}
		elseif (rline:match("^%-@note")) then
			local args = parse_line(rline:sub(8))
			cfunc.doc[#cfunc.doc+1] = {
				doc = "NOTE: "..args[1]
			}
		elseif (rline:match("^%-@desc")) then
			local args = parse_line(rline:sub(8))
			cfunc.doc[#cfunc.doc+1] = {
				doc = args[1]
			}
		elseif (rline:match("^%-@vararg")) then
			cfunc.vararg = true
		elseif (rline:match("^%-@varret")) then
			cfunc.varret = true
		elseif (rline:match("^%-@func")) then
			if (cfunc) then
				cdoc.methods[#cdoc.methods+1] = cfunc
			end
			local args = parse_line(rline:sub(8))
			cfunc = {
				type = "func",
				doc = {},
				name = args[1],
				ret = {},
				args = {}
			}
		end
	else
		io.stderr:write(line.."\n")
	end
end

if (cfunc) then
	cdoc.methods[#cdoc.methods+1] = cfunc
end
if (cdoc) then
	docs[#docs+1] = cdoc
end
for i=1, #docs do
	os.execute("mkdir -p \""..outdir.."/"..docs[i].mod:trim().."\"")
	for j=1, #docs[i].methods do
		local docc = ""
		local f = io.open(outdir.."/"..docs[i].mod:trim().."/"..docs[i].methods[j].name:trim()..".tdf", "wb")
		if (docs[i].methods[j].type == "func") then
			local argtext = ""
			local fun = docs[i].mod.."."..docs[i].methods[j].name.."("
			if (#docs[i].methods[j].args > 0) then
				for k=1, #docs[i].methods[j].args do
					fun = fun .. docs[i].methods[j].args[k].name..":"..docs[i].methods[j].args[k].type .. ", "
					argtext = argtext .. docs[i].methods[j].args[k].name .. " - " .. docs[i].methods[j].args[k].doc .. "\n"
				end
				if (docs[i].methods[j].vararg) then
					fun = fun .. "..."
				else
					fun = fun:sub(1, #fun-2)
				end
			else
				argtext = "No arguments"
			end
			fun = fun .. ")"

			local rettext = ""
			if (#docs[i].methods[j].ret > 0) then
				fun = fun .. ":"
				for k=1, #docs[i].methods[j].ret do
					fun = fun .. docs[i].methods[j].ret[k].type .. ", "
					rettext = rettext .. docs[i].methods[j].ret[k].type .. " - " .. docs[i].methods[j].ret[k].doc .. "\n"
				end
				if (docs[i].methods[j].varret) then
					fun = fun .. "..."
				else
					fun = fun:sub(1, #fun-2)
				end
			else
				rettext = "No return."
			end
			docc = docc .. fun .. "\n\nArguments:\n"..argtext.."\n\nReturns:\n"..rettext.."\n\n"
		else
			docc = docc .. docs[i].methods[j].print_name .. "\n\n"
		end
		for k=1, #docs[i].methods[j].doc do
			docc = docc..docs[i].methods[j].doc[k].doc .. "\n"
		end
		f:write(docc)
		f:close()
	end
end