gma.lua

local OUTPUT_FILE = assert(arg[1], "Missing argument #1 (output file)")
local ADDON_JSON = assert(arg[2], "Missing argument #2 (path to addon.json)")
local PATH_SEP = package.config:sub(1,1)

local function read(path --[[@param path string]]) ---@return string
	local handle = assert(io.open(path, "rb"))
	local content = handle:read("*a")
	handle:close()
	return content
end

local function get_current_dir()
	local dir = os.getenv("PWD") -- Linux
	if dir == nil then
		local cd = io.popen("cd") -- Windows
		dir = cd:read("*l")
		cd:close()
	end

	assert(dir ~= nil, "Can't detect current working directory")



	if dir[#dir] ~= PATH_SEP then
		dir = dir .. PATH_SEP
	end

	return dir
end

local function remove_prefix(orig, prefix)
	local prefixStart, prefixEnd = string.find(orig, prefix, 1, true)

	if prefixStart ~= 1 then return orig end

	return "."..PATH_SEP..orig:sub(prefixEnd + 1)
end

local pattern_escape_replacements = {
	["("] = "%(",
	[")"] = "%)",
	["."] = "%.",
	["%"] = "%%",
	["+"] = "%+",
	["-"] = "%-",
	["*"] = "%*",
	["?"] = "%?",
	["["] = "%[",
	["]"] = "%]",
	["^"] = "%^",
	["$"] = "%$",
	["\0"] = "%z"
}

function string.PatternSafe( str )
	return ( string.gsub( str, ".", pattern_escape_replacements ) )
end

---@generic T, V
---@param t T[]
---@param f fun(v: T, k: integer): V
---@return V[]
local function map(t, f)
	local out = {}
	for k, v in ipairs(t) do out[k] = f(v, k) end
	return out
end

---@param name string
---@param desc string
---@param author string
---@param files { path: string, content: string }[] # List of 'files'
---@param steamid integer? # SteamID64 of person who packed the addon. Defaults 0
---@param timestamp integer? # Timestamp of when addon was packed. Defaults to os.time()
---@return string gma # Packed gma file contents
local function pack(name, desc, author, files, steamid, timestamp)
	return "GMAD"
		.. ("< I1 I8 I8 x z z z I4"):pack(3 --[[version]], steamid or 0, timestamp or os.time(), name, desc, author, 1)
		.. table.concat(map(files, function(v, k)
			return ("< I4 z I8 I4"):pack(k, v.path, #v.content, 0 --[[crc]])
		end))
		.. "\0\0\0\0"
		.. table.concat(map(files, function(v)
			return v.content
		end))
		.. "\0\0\0\0"
end

-- JSON parser originally from qjson.lua
local function decode(json --[[@param json string]]) ---@return table
	local ptr = 0
	local function consume(pattern --[[@param pattern string]]) ---@return string?
		ptr = json:find("%S", ptr) or ptr

		local start, finish, match = json:find(pattern, ptr)
		if start then
			ptr = finish + 1
			return match or true
		end
	end

	local object, array
	local function number() return tonumber(consume("^(%-?%d+%.%d+)") or consume("^(%-?%d+)")) end
	local function bool() return consume("^(true)") or consume("^(false)") end
	local function string() return consume("^\"([^\"]*)\"") end
	local function value() return object() or string() or number() or bool() or array() end

	function object()
		if consume("^{") then
			local fields = {}
			while true do
				if consume("^}") then return fields end
				local key = assert(string(), "Expected field for table")
				assert(consume("^:"))
				fields[key] = assert(value(), "Expected value for field " .. key)
				consume("^,")
			end
		end
	end

	function array()
		if consume("^%[") then
			local values = {}
			while true do
				if consume("^%]") then return values end
				values[#values + 1] = assert(value(), "Expected value for field #" .. #values + 1)
				consume("^,")
			end
		end
	end

	return object() or array()
end

local function wildcard2pattern(s --[[@param s string]])
	return "^%./" .. s:PatternSafe():gsub("%%%*", ".*") .. "$"
end

local function passes_any_filter(path, filter)
	for _, pattern in ipairs(filter) do
		if path:match(pattern) then return true end
	end

	return false
end

-- Retrieved from https://github.com/Facepunch/gmad/blob/master/include/AddonWhiteList.h
local whitelist = map({
	"lua/*.lua",
	"scenes/*.vcd",
	"particles/*.pcf",
	"resource/fonts/*.ttf",
	"scripts/vehicles/*.txt",
	"resource/localization/*/*.properties",
	"maps/*.bsp",
	"maps/*.lmp",
	"maps/*.nav",
	"maps/*.ain",
	"maps/thumb/*.png",
	"sound/*.wav",
	"sound/*.mp3",
	"sound/*.ogg",
	"materials/*.vmt",
	"materials/*.vtf",
	"materials/*.png",
	"materials/*.jpg",
	"materials/*.jpeg",
	"materials/colorcorrection/*.raw",
	"models/*.mdl",
	"models/*.vtx",
	"models/*.phy",
	"models/*.ani",
	"models/*.vvd",
	"gamemodes/*/*.txt",
	"gamemodes/*/*.fgd",
	"gamemodes/*/logo.png",
	"gamemodes/*/icon24.png",
	"gamemodes/*/gamemode/*.lua",
	"gamemodes/*/entities/effects/*.lua",
	"gamemodes/*/entities/weapons/*.lua",
	"gamemodes/*/entities/entities/*.lua",
	"gamemodes/*/backgrounds/*.png",
	"gamemodes/*/backgrounds/*.jpg",
	"gamemodes/*/backgrounds/*.jpeg",
	"gamemodes/*/content/models/*.mdl",
	"gamemodes/*/content/models/*.vtx",
	"gamemodes/*/content/models/*.phy",
	"gamemodes/*/content/models/*.ani",
	"gamemodes/*/content/models/*.vvd",
	"gamemodes/*/content/materials/*.vmt",
	"gamemodes/*/content/materials/*.vtf",
	"gamemodes/*/content/materials/*.png",
	"gamemodes/*/content/materials/*.jpg",
	"gamemodes/*/content/materials/*.jpeg",
	"gamemodes/*/content/materials/colorcorrection/*.raw",
	"gamemodes/*/content/scenes/*.vcd",
	"gamemodes/*/content/particles/*.pcf",
	"gamemodes/*/content/resource/fonts/*.ttf",
	"gamemodes/*/content/scripts/vehicles/*.txt",
	"gamemodes/*/content/resource/localization/*/*.properties",
	"gamemodes/*/content/maps/*.bsp",
	"gamemodes/*/content/maps/*.nav",
	"gamemodes/*/content/maps/*.ain",
	"gamemodes/*/content/maps/thumb/*.png",
	"gamemodes/*/content/sound/*.wav",
	"gamemodes/*/content/sound/*.mp3",
	"gamemodes/*/content/sound/*.ogg",

	-- Immutable version of `data` folder: https://github.com/Facepunch/gmad/commit/d55a4438a5bc0d2f25c02bda1e73e8034fdf736b
	"data_static/*.txt",
	"data_static/*.dat",
	"data_static/*.json",
	"data_static/*.xml",
	"data_static/*.csv",
	"data_static/*.dem",
	"data_static/*.vcd",

	"data_static/*.vtf",
	"data_static/*.vmt",
	"data_static/*.png",
	"data_static/*.jpg",
	"data_static/*.jpeg",

	"data_static/*.mp3",
	"data_static/*.wav",
	"data_static/*.ogg",
}, wildcard2pattern)

do
	---@type string
	local curdir = get_current_dir()

	---@type { title: string?, description: string?, author: string?, ignore: string[]?, authors: string[]? }
	local addon = assert( decode( read(ADDON_JSON) ), "Failed to parse addon.json file" )

	---@type { path: string, content: string }[]
	local files = {}

	---@type string[]
	local blacklist = {}

	if addon.ignore then -- if specified list of files to ignore.
		blacklist = map(addon.ignore, wildcard2pattern)
	end

	print("Got ", #files, " files")
	do
		local dir = assert(io.popen(PATH_SEP == "\\" and "dir /s /b ." or "find . -type f"))

		for path in dir:lines() do
			local normalized = remove_prefix(path, curdir):gsub(PATH_SEP, "/") -- normalize

			print("File",normalized)

			if not passes_any_filter(normalized, whitelist) then
				print("> !Warning: skipping because not whitelisted")
			elseif passes_any_filter(normalized, blacklist) then
				print("> Blacklisted in addon.json")
			else
				files[#files + 1] = {
					path = normalized:sub(3), -- strip initial ./ part
					content = read(path)
				}
				print("> Added to GMA")
			end
		end

		dir:close()
	end


	local handle = assert(io.open(OUTPUT_FILE, "wb"), "Failed to create/overwrite output file")
	handle:write(
		pack(
			addon.title or "No title provided",
			addon.description or "No description provided",
			addon.author or (addon.authors and table.concat(addon.authors, ", ")) or "No author provided",
			files
		)
	)
	handle:close()
end