-- accessibility/init.lua — mod entry point.
--
-- This is the ONLY thing the game calls into. main.lua gains exactly one line:
--
--     require("accessibility").initialize()
--
-- placed after console.prepare() and before the first states.switch(). By that
-- point templates are preprocessed, keybindings are loaded, states.setup() has
-- run, and the console canvas exists — everything we patch is ready.
--
-- Everything here is wrapped so that a bug in the mod degrades to "no speech"
-- rather than taking the game down with it.

local accessibility = {}

local speech = require("accessibility.speech")
local stateNames = require("accessibility.stateNames")
local hotkeys = require("accessibility.hotkeys")
local walltones = require("accessibility.walltones")
local menus = require("accessibility.menus")
local testbed = require("accessibility.testbed")

local testbedActive = false

-- States we ship focus descriptors for. Also the list the self-test walks.
local describedStates = {
	"main_menu",
	"settings_menu",
	"load_game",
	"new_game",
	"narration",
	"ingame_dialogue",
	"ingame_observe",
	"actions_menu",
	"worldmap",
	"alchemy_table",
	"journal",
	"character",
	"menu_text",
	"ingame_message",
	"menu_message",
	"inventory",
	"craft",
	"refine",
	"trade",
	"config_menu",
}

local initialized = false

--------------------------------------------------------------------------------
-- Patch registry
--
-- Later phases register their patches here. Each entry is {name, fn}; fn is called
-- inside a pcall during initialize(), and a failure disables only that patch.
--------------------------------------------------------------------------------

local patches = {}

function accessibility.registerPatch(name, fn)
	patches[#patches + 1] = {name = name, fn = fn}
end

local patchResults = {}

local function applyPatches()
	for _, patch in ipairs(patches) do
		local ok, err = pcall(patch.fn)
		patchResults[patch.name] = ok and "ok" or tostring(err)
		if not ok then
			print("[accessibility] patch '" .. patch.name .. "' FAILED: " .. tostring(err))
		end
	end
end

-- Startup self-test output. This is the version-bump canary: when the game
-- updates and something we hook has moved, it shows up here immediately rather
-- than as silence three screens into a playthrough.
function accessibility.selfTest()
	print("[accessibility] --- self test ---")
	print("[accessibility] TTS: " .. (speech.isAvailable() and "available"
		or ("UNAVAILABLE (" .. tostring(speech.getFailureReason()) .. ")")))
	if speech.isAvailable() then
		-- Distinguishes "DLL loaded" from "actually reached a screen reader or SAPI".
		print("[accessibility] speech channel: " .. (speech.hasSpeech() and "yes" or "NO — nothing will be audible"))
	end
	for name, result in pairs(patchResults) do
		print("[accessibility] patch " .. name .. ": " .. result)
	end

	-- Menu focus probes. A renamed local in a future game version surfaces here at
	-- startup rather than as silence mid-playthrough.
	local ok, results = pcall(menus.selfTest, describedStates)
	if ok then
		for _, stateName in ipairs(describedStates) do
			print("[accessibility] menu " .. stateName .. ": " .. tostring(results[stateName]))
		end
	end

	print("[accessibility] --- end self test ---")
end

--------------------------------------------------------------------------------
-- Core hooks into states.lua
--------------------------------------------------------------------------------

local function hookStates()
	local states = require("states")

	-- Screen changes: announce the new screen.
	local realSwitch = states.switch
	states.switch = function(newState, params)
		local result = realSwitch(newState, params)

		-- After the switch, so the state's open() has already set up its focus --
		-- main_menu, for one, only picks selectedOption inside open().
		pcall(function()
			-- Guard against NESTED switches. open() can itself switch state:
			-- ingame.open() sees world.pendingDialogue and goes straight to
			-- ingame_dialogue. Because we announce after realSwitch returns, the
			-- inner announcement ("Conversation") happens first and the outer one
			-- ("Game") then interrupts and clobbers it. If we are no longer the
			-- current state, the inner switch already announced -- stay quiet.
			if states.getCurrent() ~= newState then
				return
			end

			local descriptor = menus.loadDescriptor(newState)

			if descriptor then
				menus.announceScreen(newState)
				if descriptor.onOpen then
					speech.say(descriptor.onOpen, false)
				end
			else
				speech.say(stateNames[newState] or newState, true)
			end
		end)

		return result
	end

	-- Per-frame speech flush. main.lua calls states.update(dt) via a table lookup,
	-- so wrapping the field here avoids editing love.update.
	local realUpdate = states.update
	states.update = function(dt)
		local result = realUpdate(dt)

		-- Poll focus rather than relying on keypress alone.
		--
		-- Focus can move with no key involved: main_menu.mousemoved assigns
		-- selectedOption straight from the cursor position, so wherever the mouse
		-- happens to rest silently overrides the selection -- including at startup,
		-- before the player has touched anything. Polling also closes the race
		-- where a state's open() sets focus after we have already announced.
		--
		-- Cheap: two debug.getupvalue lookups, and only for states we describe.
		pcall(function()
			menus.announceFocusIfChanged(states.getCurrent())
		end)

		pcall(walltones.update)
		pcall(speech.flush)
		if testbedActive then
			pcall(testbed.update, dt)
		end
		return result
	end

	-- Global hotkey layer. Ours are consumed; everything else falls through to the
	-- game untouched.
	local realKeypressed = states.keypressed
	states.keypressed = function(key, scancode)
		local consumed = false
		local ok, result = pcall(hotkeys.keypressed, key, scancode)
		if ok then
			consumed = result
		end

		if consumed then
			return
		end

		pcall(hotkeys.onGameKey)

		local keyResult = realKeypressed(key, scancode)

		-- After the game handler, so we read the focus it just moved to.
		pcall(function()
			menus.announceFocusIfChanged(states.getCurrent())
		end)

		return keyResult
	end

	-- Text entry (character naming) arrives via textinput, not keypressed.
	local realTextinput = states.textinput
	states.textinput = function(text)
		local result = realTextinput(text)

		pcall(function()
			menus.announceFocusIfChanged(states.getCurrent())
		end)

		return result
	end

	-- CRITICAL: re-point the love callbacks at our wrappers.
	--
	-- states.setup() runs before us and does:
	--     love[callback] = love[callback] or states[callback]
	-- which captures the function BY VALUE. main.lua defines love.load, update,
	-- mousepressed, mousereleased and quit itself, but NOT keypressed/textinput --
	-- so those were bound to the original states.keypressed at setup time.
	-- Replacing the states table field alone leaves love.keypressed pointing at
	-- the old function and our wrapper never runs.
	--
	-- states.switch and states.update are unaffected because they are looked up on
	-- the table at call time (from state files and from main.lua's love.update).
	love.keypressed = states.keypressed
	love.textinput = states.textinput
end

--------------------------------------------------------------------------------
-- Entry point
--------------------------------------------------------------------------------

function accessibility.initialize()
	if initialized then
		return
	end
	initialized = true

	accessibility.registerPatch("console", require("accessibility.patches.console"))
	accessibility.registerPatch("popups", require("accessibility.patches.popups"))
	accessibility.registerPatch("slider", require("accessibility.patches.slider"))

	pcall(function()
		require("accessibility.surroundings").registerKeys(hotkeys)
		require("accessibility.tracker").registerKeys(hotkeys)
	end)

	local ok, err = pcall(function()
		speech.initialize()
		walltones.load()
		hookStates()
		applyPatches()
	end)

	if not ok then
		print("[accessibility] initialisation FAILED, game continues unmodified: " .. tostring(err))
		return
	end

	accessibility.selfTest()

	if testbed.isEnabled() then
		testbedActive = true
		testbed.start()
	end
end

return accessibility