--[[
 *
 *  Singe 3
 *  Copyright (C) 2006-2026 Scott Duensing <scott@kangaroopunch.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 *
--]]



-- The bundled game menu.  Everything the menu *is* lives here:  the game list read from every
-- games.dat, the selection and how it moves, the attract video, launching a game and coming back,
-- and the service tools.  Nothing here draws.
--
-- Drawing is a renderer, chosen once at startup by whether this machine has a GPU device:
--
--   Singe/MenuDocument.singe   an RmlUi document, which needs the GPU device the 3D scene uses
--   Singe/MenuOverlay.singe    sprites and fontPrint straight into the overlay, which needs nothing
--
-- The two draw the same menu and take the same keys.  A renderer provides the MENU_RENDER table;
-- see the top of either file for what is in it.

dofile("Singe/Framework.singe")
dofile("Singe/Master.singe")
dofile("Singe/Tools.singe")

local lfs = require("lfs")


function cleanTitle(a)
	local output = string.lower(a)
	output = string.gsub(output, '%p', ' ')
	output = string.gsub(output, '^ +', '')
	output = string.gsub(output, '^the ', '')
	output = string.gsub(output, '^a ', '')
	output = string.gsub(output, '^an ', '')
	return output
end


function compareTitles(a, b)
	return cleanTitle(a.TITLE) < cleanTitle(b.TITLE)
end


-- Makes a game the selection, wrapping at either end of the list, and shows it.
function gameSelect(index)
	if index < 1 then
		index = GAME_COUNT
	elseif index > GAME_COUNT then
		index = 1
	end
	unloadGameAssets()
	GAME_SELECTED = index
	loadGameAssets()
end


-- Starts the selected game.  The menu comes back from the top when it ends.
function gameStart()
	SHUTDOWN_FROM_PUSH = true
	scriptPush(GAME_LIST[GAME_SELECTED])
end


function loadGameAssets()
	local game = GAME_LIST[GAME_SELECTED]

	-- An entry without an attract clip, or naming one that is not there, shows its art and no
	-- video rather than taking the whole menu down with a videoLoad that cannot open it.
	if menuFileExists(game.ATTRACT) then
		VIDEO_ATTRACT = videoLoad(game.ATTRACT)
		if game.AUDIO_TRACK then
			videoSetAudioTrack(VIDEO_ATTRACT, game.AUDIO_TRACK)
		end
		videoPlay(VIDEO_ATTRACT)
		videoSeek(VIDEO_ATTRACT, game.ATTRACT_START or 0)
	else
		debugPrint("Menu:  " .. tostring(game.TITLE) .. " has no attract clip to play.")
	end
	MENU_RENDER.showGame(game)
end


-- Where a game's art should be when it is not there.  Extracted with the other support files, so
-- it is always present whatever a game does or does not ship.
MENU_MISSING_ART = "Singe/missing.png"


-- Whether a name is a file the engine can open.  Asked of the index rather than of the file:
-- io.open, which this used to use, has to hand Lua a real file it can read with the C library, so
-- every picture it was asked about was unpacked out of the .game into data/<game>/cache first --
-- and the menu asks about two of them for every game in the library, none of which it then opens
-- that way:  the sprite loader and the document's texture loader both read straight out of the
-- database.  lfs.attributes goes through the same virtual filesystem and answers from the index,
-- opening nothing.
function menuFileExists(file)
	local path  = tostring(file or "")
	local found = (path ~= "") and lfs.attributes(path) or nil

	return (found ~= nil) and (found.mode ~= "directory")
end


-- A readable art path:  the game's own when it can be opened, the missing-art picture when not.
function menuArtPath(file)
	local path = tostring(file or "")

	if not menuFileExists(path) then
		if path ~= "" then
			debugPrint("Menu:  cannot read " .. path .. ";  showing the missing-art picture.")
		end
		return MENU_MISSING_ART
	end

	return path
end


-- How far left and right move.  A page is a screenful, which is what the renderer answers, but in a
-- library smaller than a screenful every press then lands on the first game or the last and nothing
-- in between can be reached that way at all.  A third of the library is never more than three
-- presses from one end to the other, whatever size it is.
function pageStep()
	return math.max(1, math.min(MENU_RENDER.pageSize(), math.floor(GAME_COUNT / 3)))
end


-- The game page takes input once the backdrop has finished the intro and settled on the grid.
function menuActive()
	return (not toolsActive()) and MENU_RENDER.backdropReady()
end


-- In MODE_FULL every key arrives here as its keysym rather than as a switch, which is what the
-- account tool's typing needs;  the switches it still cares about are the pad's, which keep working.
function onKeyPressed(keysym, scancode)
	if toolsActive() then
		toolsTyped(keysym)
	end
end


function onInputPressed(what)

	-- The service tools take every switch while they are up, including the one that closes them.
	if toolsActive() then
		toolsInput(what)
		return
	end

	-- Are we displaying the grid background?
	if menuActive() then

		if what == SWITCH_SERVICE then
			toolsBegin()
		elseif what == SWITCH_UP then
			gameSelect(GAME_SELECTED - 1)
		elseif what == SWITCH_DOWN then
			gameSelect(GAME_SELECTED + 1)
		elseif what == SWITCH_LEFT then
			-- A page back, wrapping to the end from the first game.
			if GAME_SELECTED == 1 then
				gameSelect(GAME_COUNT)
			else
				gameSelect(math.max(1, GAME_SELECTED - pageStep()))
			end
		elseif what == SWITCH_RIGHT then
			if GAME_SELECTED == GAME_COUNT then
				gameSelect(1)
			else
				gameSelect(math.min(GAME_COUNT, GAME_SELECTED + pageStep()))
			end
		elseif what == SWITCH_START1 or what == SWITCH_START2 or what == SWITCH_BUTTON1 or what == SWITCH_BUTTON2 or what == SWITCH_BUTTON3 or what == SWITCH_BUTTON4 then
			gameStart()
		end

	end

end


function onOverlayUpdate()

	-- The intro, then the grid behind the menu, and the overlay cleared ready to be drawn into.
	MENU_RENDER.backdrop()

	-- The network never blocks the frame;  it makes progress here instead.
	masterPump()

	if toolsActive() then
		toolsUpdate()
		MENU_RENDER.tools()
		return(OVERLAY_UPDATED)
	end

	-- Are we displaying the grid background?
	if menuActive() then
		-- The page keys take the details over from the walk they do by themselves;  the walk picks
		-- up from wherever they leave it once its pause is up.  They arrive as a scancode rather
		-- than a switch because they are not one:  a cabinet has no page keys and loses nothing.
		local key = keyboardGetLastDown()

		if key == SCANCODE.PAGEDOWN.value then
			MENU_RENDER.scrollDetails(1)
		elseif key == SCANCODE.PAGEUP.value then
			MENU_RENDER.scrollDetails(-1)
		end

		-- The attract clip runs between the two frames the game's entry names.
		if VIDEO_ATTRACT and GAME_LIST[GAME_SELECTED].ATTRACT_END then
			if videoGetFrame(VIDEO_ATTRACT) > GAME_LIST[GAME_SELECTED].ATTRACT_END then
				videoSeek(VIDEO_ATTRACT, GAME_LIST[GAME_SELECTED].ATTRACT_START or 0)
			end
		end
		MENU_RENDER.frame()
	end

	return(OVERLAY_UPDATED)

end


function onShutdown()
	-- With no games found there is no renderer and nothing was loaded;  quitting is all there is.
	if MENU_RENDER == nil then
		return
	end
	unloadGameAssets()
	saveConfig(not SHUTDOWN_FROM_PUSH)
	MENU_RENDER.finish()
	if SND_INTRO_VOICE ~= SOUND_ERROR_INVALID then
		-- A game started before the intro's sound had finished;  it wants the speakers to itself.
		soundStop(SND_INTRO_VOICE)
	end
	if SND_INTRO then
		soundUnload(SND_INTRO)
	end
	if SND_CLICK then
		soundUnload(SND_CLICK)
	end
end


function saveConfig(showIntro)
	if GAME_COUNT > 0 then
		-- Save what game we're currently viewing
		local cfg = io.open(CONFIG_FILE, "w")
		if cfg then
			cfg:write("GAME_SELECTED = " .. GAME_SELECTED .. "\n")
			cfg:write("SHOW_INTRO = " .. tostring(showIntro) .. "\n")
			-- The file is written whole, so a renderer forced here has to be written back or it
			-- would last exactly one run.
			if MENU_OVERLAY then
				cfg:write("MENU_OVERLAY = true\n")
			end
			cfg:close()
		else
			debugPrint("Unable to write " .. CONFIG_FILE)
		end
	end
end


function unloadGameAssets()
	-- Nothing is loaded when there are no games.
	if VIDEO_ATTRACT then
		videoUnload(VIDEO_ATTRACT)
		VIDEO_ATTRACT = nil
	end
	MENU_RENDER.hideGame()
end


-- Adds the entries of one games.dat.  container is the game database the file came from, or nil.
local function loadGamesDat(source, container)
	GAMES = {}
	local ok, err = pcall(dofile, source)
	if not ok then
		debugPrint(source .. ":  " .. tostring(err) .. "  Skipped.")
		GAMES = {}
		return
	end
	for _, value in pairs(GAMES or {}) do
		if container then
			-- Packed game:  the engine opens its files through the database, and so does the menu.
			value.CONTAINER = container
			for _, key in ipairs({ "CABINET", "MARQUEE", "ATTRACT" }) do
				if value[key] and value[key]:sub(1, 6):lower() ~= "singe/" then
					value[key] = container .. "/" .. value[key]
				end
			end
		end
		table.insert(GAME_LIST, value)
		GAME_COUNT = GAME_COUNT + 1
	end
	GAMES = {}
end

-- Search for games.dat files in subdirectories and inside .game databases.
--
-- The extension is tested before the mode, and that order matters:  the engine presents a packed
-- game through the VFS, so lfs.attributes reports a .game as a *directory*, not a file.  Testing
-- the mode first sent every container down the loose-directory branch, which loads its games.dat
-- with no container -- and then every CABINET, MARQUEE and ATTRACT path in it named a file that
-- exists only inside the database.  A packed library could not show a single piece of its art.
GAME_LIST     = {}
GAME_COUNT    = 0
for dir in lfs.dir(".") do
	if dir ~= "." and dir ~= ".." then
		local dirattr = lfs.attributes(dir)
		if dir:sub(-5):lower() == ".game" then
			loadGamesDat(dir .. "/games.dat", dir)
		elseif dirattr and (dirattr.mode == "directory") then
			for file in lfs.dir(dir .. "/.") do
				if file == "games.dat" then
					loadGamesDat(dir .. "/games.dat", nil)
				end
			end
		end
	end
end
table.sort(GAME_LIST, compareTitles)

if GAME_COUNT == 0 then
	debugPrint("No games found!  Exiting.")
	singeQuit()
else
	overlaySetResolution(discGetWidth(), discGetHeight())

	-- Three frames of Singe/menuBackground.mkv:  where the menu may take the screen, where the
	-- grid section it loops begins, and its last frame.  The first two are not the same moment --
	-- the menu comes up while the music is still fading out behind it, and only then does the
	-- picture start repeating.  All three come from util/renderMenuVideo.py, which prints them
	-- when it makes the video;  the grid section is a whole number of turns of the grid, so
	-- playing it over and over has no seam in it.  A renderer that draws its own grid uses none
	-- of them:  it knows where its own logo went.
	DISC_MENU_FRAME = 222
	DISC_GRID_START = 300
	DISC_LAST_FRAME = 419

	SHUTDOWN_FROM_PUSH = false

	-- The service tools share this click with the audio delay tool.
	SND_CLICK = soundLoad("Singe/click.wav")

	-- The intro's sound.  It belongs to the menu rather than to either renderer:  one draws the
	-- intro and the other plays a recording of it, and both want the same sound over the top at
	-- the same moment.  Keeping it out of the video is also what stops it being stored twice.
	SND_INTRO = soundLoad("Singe/menuIntro.flac")
	SND_INTRO_VOICE = SOUND_ERROR_INVALID

	-- Load configuration
	SHOW_INTRO = true
	CONFIG_FILE = singeGetDataPath() .. "menu.dat"
	local confattr = lfs.attributes(CONFIG_FILE)
	if confattr then
		dofile(CONFIG_FILE)
		-- A damaged menu.dat must not take the menu down with it.
		GAME_SELECTED = tonumber(GAME_SELECTED) or 1
		if GAME_SELECTED > GAME_COUNT then
			GAME_SELECTED = GAME_COUNT
		end
	else
		GAME_SELECTED = 1
	end

	-- The renderer.  A GUI document is drawn through the GPU device the 3D scene uses, so without
	-- one there is no document to build and guiNew would end the script rather than answer false;
	-- the overlay renderer needs nothing but the overlay every game already draws into.  Set
	-- MENU_OVERLAY = true in menu.dat to use it on a machine that has a GPU, which is how the
	-- overlay path gets tested.
	if singeHasGpu() and not MENU_OVERLAY then
		dofile("Singe/MenuDocument.singe")
	else
		dofile("Singe/MenuOverlay.singe")
	end
	MENU_RENDER.begin()
	MENU_RENDER.layout()
	MENU_RENDER.buildList()

	MENU_RENDER.backdropBegin(SHOW_INTRO)
	if SHOW_INTRO then
		SND_INTRO_VOICE = soundPlay(SND_INTRO)
	end

	-- Prime the pump
	gameSelect(GAME_SELECTED)
end