-- Drives Hologram Time Traveler (the original or its port) from what the game shows, the same
-- way for both.  The driver file defines what it takes:  a view() of the game's state and
-- ttPress(switch, down) to press or let go of a switch;  this file decides.  The trace lines
-- it prints are what compare.sh diffs.
--
-- The policy:  a coin and START at the attract loop;  in a level, the move the row asks for
-- three frames into its window (a turn first where the row wants a turn and a shot), a wrong
-- one on every fifth move and none on every seventh with misses on;  a cube against the first
-- death with misses on;  at the map, the trader once with misses on (a coin buys a cube) and
-- the timer's own choice otherwise;  a pull at the hellgate's lever;  a coin and START at the
-- continue;  a letter at the board.

TT_FRAMES = tonumber(os.getenv("PORT_FRAMES")) or 60000

local perfect  = (os.getenv("PORT_PERFECT") == "1")
local frames   = 0
local lastLine = nil
local pending  = nil     -- { switch } pressed this frame, let go the next.
local answered = {}      -- Windows answered, by level/segment/move/lives.
local tried    = {}      -- Moves met before, by level/segment/move.
local coined   = false
local started  = false
local cubeUsed = false
local traded   = false
local pulled   = false
local lettered = false
local continues = 0
local turnAt   = nil     -- The frame the turn went in, for the shot after it.

local SWITCH_OF = nil


function ttTraceSeek(frame)
	debugPrint(string.format("TRACE seek %d", frame))
end


local function tap(switch)
	ttPress(switch, true)
	pending = switch
end


-- view:  { flow, screen, step, alt, level, seg, move, moves, frame, score, lives, cubes, credits,
--          window = { from, to }, correct (the row's move, or nil for the tutorial's choice),
--          turned (the turn is in), dying, wizard, mapWait, mapCursor, trader, hellgate,
--          continuing, board }
function ttDrive(view)
	if pending then
		ttPress(pending, false)
		pending = nil
	end
	frames = frames + 1
	if SWITCH_OF == nil then
		SWITCH_OF = { [view.UP] = SWITCH_UP, [view.DOWN] = SWITCH_DOWN, [view.LEFT] = SWITCH_LEFT, [view.RIGHT] = SWITCH_RIGHT, [view.ACTION] = SWITCH_BUTTON1 }
	end
	-- (altState is left out:  the original's LCD drawing steps it while the attract loop shows.)
	local line = string.format("TRACE flow %s screen %s step %s level %s seg %s move %s score %s lives %s cubes %s credits %s",
	                           tostring(view.flow), tostring(view.screen), tostring(view.step), tostring(view.level), tostring(view.seg),
	                           tostring(view.move), tostring(view.score), tostring(view.lives), tostring(view.cubes), tostring(view.credits))

	if line ~= lastLine then
		debugPrint(line .. " disc " .. tostring(view.frame))
		lastLine = line
	end
	if frames >= TT_FRAMES then
		debugPrint("TRACE end after " .. frames .. " frames")
		singeQuit()
		return
	end
	-- The attract loop:  a coin, then START once the credit shows.
	if view.intro then
		if (frames > 200) and not coined then
			coined = true
			tap(SWITCH_COIN1)
			return
		end
		if coined and (frames > 300) and (frames % 40 == 0) and (view.credits > 0) then
			tap(SWITCH_START1)
		end
		return
	end
	-- The continue:  a coin, then START, taken once.
	if view.continuing then
		if (continues < 1) and (frames % 30 == 0) then
			if view.credits == 0 then
				tap(SWITCH_COIN1)
			else
				continues = continues + 1
				tap(SWITCH_START1)
			end
		end
		return
	end
	-- The map:  the trader once (with misses on), else the timer's own choice.
	if view.mapWait then
		if (not perfect) and (not traded) and (view.mapCursor == view.TRADER) then
			traded = true
			tap(SWITCH_BUTTON1)
		end
		return
	end
	-- The trader:  a coin buys a cube.
	if view.trader then
		if (frames % 20 == 0) then
			tap(SWITCH_COIN1)
		end
		return
	end
	-- The hellgate:  one pull at the lever with misses on (a roll can take every life);  the
	-- perfect run lets the clip pass.
	if view.hellgate then
		if (not perfect) and not pulled then
			pulled = true
			tap(SWITCH_BUTTON1)
		end
		return
	end
	pulled = false
	-- The board:  one letter, and the rest to the clip's end.
	if view.board then
		if not lettered then
			lettered = true
			tap(SWITCH_BUTTON1)
		end
		return
	end
	-- A death:  a cube against the first, with misses on.
	if view.dying then
		if (not perfect) and (not cubeUsed) and (view.cubes > 0) then
			cubeUsed = true
			tap(SWITCH_BUTTON2)
		end
		return
	end
	-- A level's window.
	if view.window then
		local moveKey = tostring(view.level) .. "/" .. tostring(view.seg) .. "/" .. tostring(view.move)
		local key     = moveKey .. "/" .. tostring(view.lives)
		local retry   = (tried[moveKey] ~= nil)
		local at      = view.frame

		if (at >= view.window[1] + 3) and (at <= view.window[2]) and not answered[key] then
			local correct = view.correct

			if correct == nil then
				-- The tutorial's choice:  the sign post's right skips it, nothing plays it.
				answered[key] = true
				tried[moveKey] = true
				if perfect then
					tap(SWITCH_RIGHT)
				end
				return
			end
			if correct == view.NOMOVE then
				-- A row that wants nothing.
				answered[key] = true
				return
			end
			local missed = (not perfect) and (view.move % 7 == 0) and (view.move % 5 ~= 0) and not retry
			local wrong  = (not perfect) and (view.move % 5 == 0) and not retry

			if missed then
				answered[key] = true
				tried[moveKey] = true
				return
			end
			if (correct == view.TURNRIGHTSHOOT) or (correct == view.TURNLEFTSHOOT) then
				-- A turn, then the shot two frames on.
				if not view.turned then
					if turnAt == nil then
						turnAt = at
						tap(wrong and SWITCH_UP or ((correct == view.TURNRIGHTSHOOT) and SWITCH_RIGHT or SWITCH_LEFT))
						if wrong then
							answered[key] = true
							tried[moveKey] = true
							turnAt = nil
						end
					end
				elseif at >= turnAt + 2 then
					answered[key] = true
					tried[moveKey] = true
					turnAt = nil
					tap(SWITCH_BUTTON1)
				end
				return
			end
			answered[key] = true
			tried[moveKey] = true
			local switch = SWITCH_OF[correct]

			if wrong then
				switch = (correct == view.UP) and SWITCH_DOWN or SWITCH_UP
			end
			if switch then
				tap(switch)
			end
		end
	end
end