local lfs = require("lfs")

local enableDebug = true
local enableImGui = false
local flatpakSteam = true

-- Name of your local workshop container
local workshopName = "MyModWorkshop"

-- Mods live here inside the git repo
local repoModsDir = "mods"

local isWindows = package.config:sub(1, 1) == "\\"
local sep = isWindows and "\\" or "/"

local homeDir = isWindows and os.getenv("userprofile") or os.getenv("HOME")
local flatpakSteamVar = not isWindows and os.getenv("HOME") .. "/.var/app/com.valvesoftware.Steam"

-- Launch via Steam
local pzCacheRoot
local pzExecutable
if isWindows then
	pzCacheRoot = (homeDir .. "\\Zomboid")
	pzExecutable = "steam.exe -applaunch 108600"
else
	pzExecutable = flatpakSteam and "flatpak run com.valvesoftware.Steam -applaunch 108600" or "steam -applaunch 108600"
	pzCacheRoot = flatpakSteam and (flatpakSteamVar .. "/Zomboid") or (homeDir .. "/Zomboid")
end

-- Final destination: Workshop/<Name>/Contents/mods
local pzModsDir = pzCacheRoot .. sep .. "Workshop" .. sep .. workshopName .. sep .. "Contents" .. sep .. "mods"

-- =========================
-- File helpers
-- =========================

local function copyFile(src, dst)
	local inFile = assert(io.open(src, "rb"))
	local data = inFile:read("*all")
	inFile:close()

	local outFile = assert(io.open(dst, "wb"))
	outFile:write(data)
	outFile:close()
end

local function mkdir(path)
	if isWindows then
		os.execute(string.format('mkdir "%s" 2>nul', path))
	else
		os.execute(string.format('mkdir -p "%s"', path))
	end
end

local function copyDir(src, dst)
	mkdir(dst)
	for name in lfs.dir(src) do
		if name ~= "." and name ~= ".." then
			local srcPath = src .. sep .. name
			local dstPath = dst .. sep .. name
			local attr = lfs.attributes(srcPath)
			if attr.mode == "directory" then
				copyDir(srcPath, dstPath)
			else
				copyFile(srcPath, dstPath)
			end
		end
	end
end

-- =========================
-- Safety helpers
-- =========================

local function normalizePath(path)
	path = path:gsub("\\", "/")
	return path:gsub("/+$", "")
end

local function isRootPath(path)
	if path == "/" then
		return true
	end
	if path:match("^[A-Za-z]:$") then
		return true
	end
	return false
end
local function isSubPath(child, parent)
	child = normalizePath(child)
	parent = normalizePath(parent)
	return child:sub(1, #parent + 1) == parent .. "/"
end

local function validatePath(target, root, home)
	local t = normalizePath(target)
	local r = normalizePath(root)
	local h = normalizePath(home)

	assert(t ~= "", "Refusing to delete empty path")
	assert(not isRootPath(t), "Refusing to delete root path")
	assert(t ~= h, "Refusing to delete home directory")
	assert(isSubPath(t, r), "Refusing to delete outside workshop mods")
	assert(#t > #r + 1, "Refusing to delete mods root")
end

-- =========================
-- Discover mods dynamically
-- =========================

local mods = {}

for name in lfs.dir(repoModsDir) do
	if name ~= "." and name ~= ".." then
		local path = repoModsDir .. sep .. name
		local attr = lfs.attributes(path)
		if attr and attr.mode == "directory" then
			table.insert(mods, name)
		end
	end
end

assert(#mods > 0, "No mods found in ./mods directory")

-- =========================
-- Copy mods
-- =========================

print("Installing mods into workshop:")
mkdir(pzModsDir)

for _, modName in ipairs(mods) do
	local src = repoModsDir .. sep .. modName
	local dst = pzModsDir .. sep .. modName
	print("  - " .. modName)
	print("  - copied" .. src .. " to " .. dst)
	validatePath(dst, pzModsDir, homeDir)
	copyDir(src, dst)
end

print("All mods copied successfully!")

-- =========================
-- Launch Project Zomboid
-- =========================

local params = {}
table.insert(params, "-modfolders workshop,mods")

if enableDebug then
	table.insert(params, "-debug")
end
if enableImGui then
	table.insert(params, "-imgui")
end

local cmd = string.format("%s %s", pzExecutable, table.concat(params, " "))

print("Launching:")
print(cmd)
os.execute(cmd)