#!/usr/bin/env lua5.1

local utils = {}
function utils.join_table(table, separator)
	local string = ""
	for i=1,#table do
		string = string .. table[i] .. separator
	end
	return string
end

local env_string = ""
local netns_string = ""
local USE_NETNS = os.getenv "USE_NETNS"
if USE_NETNS ~= nil then
	env_string = env_string .. "USE_NETNS="..USE_NETNS.." "
	netns_string = "ip netns exec "..USE_NETNS.." "
end
local dependencies_string = ""
local DEPENDENCIES = os.getenv "DEPENDENCIES"
if DEPENDENCIES ~= nil then
	env_string = env_string .. "DEPENDENCIES='"..DEPENDENCIES.."' "
	for dep in string.gmatch(DEPENDENCIES, "[%w-]+") do
		dependencies_string = dependencies_string .. "sv status "..dep.." || exit 1\n"
	end
end

local user = arg[1]
local container_name = arg[2]
local image_name = arg[3]

local group = user
local GROUP = os.getenv "GROUP"
if GROUP ~= nil then
	env_string = env_string .. "GROUP="..GROUP.." "
	group = GROUP
end

local arguments = {unpack(arg, 4)}
for i=1,#arguments do
	arguments[i] = "'"..arguments[i].."'"
end

local prefix = [[
#!/bin/sh
# Generated with ]]..utils.join_table({env_string..arg[0], user, container_name, image_name, unpack(arguments)}, " ")..[[

]]..dependencies_string..[[

IMAGE=']]..image_name..[['

CONTAINER_NAME=']]..container_name..[['

export USER=']]..user..[['

export GROUP=']]..group..[['

export HOME="/home/$USER"
cd "$HOME"
]]

local run_script = prefix..[[

chpst -u "$USER:$GROUP" podman pull "$IMAGE" 2>/dev/stdout || exit $?
chpst -u "$USER:$GROUP" podman image prune -f 2>/dev/stdout || exit $?

exec ]]..netns_string..[[chpst -u "$USER:$GROUP" podman run --tty --rm \
	--name="$CONTAINER_NAME" \
	--replace \
]]..utils.join_table(arguments, " ")..[[ \
	"$IMAGE" 2>/dev/stdout
]]
local finish_script = prefix..[[

chpst -u "$USER:$GROUP" podman stop --ignore "$CONTAINER_NAME" 2>/dev/stdout || exit $?
chpst -u "$USER:$GROUP" podman rm --force --ignore "$CONTAINER_NAME" 2>/dev/stdout || exit $?
]]

local function write_script(file_name, content)
	local file = io.open(file_name, "w+")
	file:write(content)
	file:close()
	os.execute("chmod +x '"..file_name.."'")
end

write_script("run", run_script)
write_script("finish", finish_script)