-- Reads tools/catalog.lua and stamps out the -srv/-log longrun pairs and
-- agetty-tty1..6 under services/. Authored/run on the Windows box with
-- lua55; portable enough to rerun on a real Linux target later. Files are
-- written with explicit "\n" line endings in binary mode so Windows doesn't
-- translate them to CRLF.
--
-- Usage: lua55 tools/gen-services.lua

local script_dir = arg[0]:match("^(.*)[/\\][^/\\]*$") or "."
local repo_root = script_dir .. "/.."
local services_dir = repo_root .. "/services"

local catalog = dofile(script_dir .. "/catalog.lua")

local function is_windows()
	return package.config:sub(1, 1) == "\\"
end

local function mkdir_p(path)
	if is_windows() then
		local winpath = path:gsub("/", "\\")
		os.execute('if not exist "' .. winpath .. '" mkdir "' .. winpath .. '" >nul 2>nul')
	else
		os.execute('mkdir -p "' .. path .. '"')
	end
end

local function dirname(path)
	return path:match("^(.*)[/\\][^/\\]*$") or "."
end

local function write_file(path, content)
	mkdir_p(dirname(path))
	local f = assert(io.open(path, "wb"))
	f:write(content)
	f:close()
end

local function touch(path)
	write_file(path, "")
end

local function lua_array_literal(items)
	local parts = {}
	for i, v in ipairs(items) do
		parts[i] = string.format("%q", v)
	end
	return "{ " .. table.concat(parts, ", ") .. " }"
end

local function render_srv_run(argv)
	return string.format(
		"#!/usr/bin/lua\nlocal s6 = require(\"s6lua\")\ns6.exec(%s)\n",
		lua_array_literal(argv)
	)
end

local function render_finish(tag)
	return string.format(
		"#!/usr/bin/lua\nlocal s6 = require(\"s6lua\")\ns6.log(%q, \"exited (code=%%s signal=%%s)\", arg[1], arg[2])\n",
		tag
	)
end

local function render_log_run(log_dir)
	return string.format(
		"#!/usr/bin/lua\nlocal s6 = require(\"s6lua\")\ns6.mkdirp(%q)\ns6.exec({ \"/usr/bin/s6-log\", \"-b\", \"n20\", \"s10000000\", %q })\n",
		log_dir, log_dir
	)
end

local function render_agetty_run(n)
	return render_srv_run({ "/sbin/agetty", "tty" .. tostring(n), "38400", "linux" })
end

for _, d in ipairs(catalog.daemons) do
	local srv_dir = services_dir .. "/" .. d.srv
	local log_svc_dir = services_dir .. "/" .. d.log

	write_file(srv_dir .. "/type", "longrun\n")
	write_file(srv_dir .. "/run", render_srv_run(d.argv))
	write_file(srv_dir .. "/finish", render_finish(d.key))
	write_file(srv_dir .. "/producer-for", d.log .. "\n")
	for _, dep in ipairs(d.deps) do
		touch(srv_dir .. "/dependencies.d/" .. dep)
	end

	write_file(log_svc_dir .. "/type", "longrun\n")
	write_file(log_svc_dir .. "/run", render_log_run(d.log_dir))
	write_file(log_svc_dir .. "/consumer-for", d.srv .. "\n")
	write_file(log_svc_dir .. "/pipeline-name", d.key .. "\n")

	print("generated " .. d.srv .. " / " .. d.log)
end

if catalog.ttys and #catalog.ttys > 0 then
	local ttys_dir = services_dir .. "/ttys"
	write_file(ttys_dir .. "/type", "bundle\n")
	for _, n in ipairs(catalog.ttys) do
		local name = "agetty-tty" .. tostring(n)
		local dir = services_dir .. "/" .. name
		write_file(dir .. "/type", "longrun\n")
		write_file(dir .. "/run", render_agetty_run(n))
		touch(ttys_dir .. "/contents.d/" .. name)
		print("generated " .. name)
	end
end

print("done")