-- YataiDON-HSS override of PyTaikoGreen/background/bg_objects/bg_fever.lua
--
-- ROUND 12.  The cabinet's gogo/clear backdrop is
-- enso/background/bg_fever_a_{01,02,03}.nulm: a 1920x540 stage (the lower half
-- of the screen, same anchor as bg_nomal) made of one static plate plus one to
-- three named `scroll_*_mc` strips, each sliding at a constant px/frame with a
-- fixed repeat period.  There is no flipbook anywhere in it, so the whole rig
-- ports as: plate + per-strip {tile, period, px/s}, replayed here.
--
-- The measured numbers live in Scripts/background/bg_data/bg_fever.lua,
-- generated by scratchpad/r12bg/bgfever.py.  If that table is missing this
-- falls back to drawing the static plate only -- never to the parent's art,
-- because Graphics/background/bg_fever/* is fully ours (every texture name the
-- generated id map declares is either a shipped layer or an 8x8 transparent
-- stub).
local ok, DATA = pcall(require, "background/bg_data/bg_fever")
if not ok or type(DATA) ~= "table" then DATA = {} end
-- per-element replay of the cabinet movie (koi, fans, tops... each on its own
-- loop) when bg_data/bg_anim/bg_fever_N.lua has been exported; the layer lists
-- above stay as the fallback.  The rise/fall wipe is still this file's fade.
local ok_anim, BGAnim = pcall(require, "background/bg_objects/bg_anim")
if not ok_anim or type(BGAnim) ~= "table" then BGAnim = nil end

local ArcadeBGFever = {}
ArcadeBGFever.__index = ArcadeBGFever

-- The cabinet wipes normal->fever over `normal_fever` (root frames 1..29 at
-- 60 fps).  We cannot reproduce the wipe with one texture, so it is a fade of
-- the same length, and `transitioned` flips when it ends -- that is the flag
-- background.lua uses to stop drawing bg_normal underneath.
--
-- ROUND 52 (r52-lua-divergence-fixes): the wipe now runs on BOTH edges and is
-- re-triggerable, matching the reference build `EnsoGraphicBgFever::Process`
-- (EnsoGraphicBgFever.obj.c:297-308): the cached flag at +88 is compared
-- against `IsNormaClear` EVERY frame, and each change of state GotoAndPlay's a
-- clip -- `normal_fever` on the rising edge, `fever_normal` on the falling
-- edge.  The old `started`/`transitioned` one-way latch meant only the FIRST
-- clear ever wiped and a gauge dropping below the norma hard-cut the fever
-- backdrop in a single frame.  `stop()` is the falling-edge clip (a fade of
-- the same 29-frame length, from wherever the current fade sits, so an edge
-- mid-wipe reverses smoothly), and `start()` re-arms after it.
-- `is_visible()` is the new flag background.lua uses to keep drawing this
-- object while the exit fade is still alive.
local TRANSITION_MS = 29000 / 60

function ArcadeBGFever.new(index, path)
    local self = setmetatable({}, ArcadeBGFever)
    self.name = "bg_fever_" .. index
    self.path = path or "background"
    tex.load_folder(self.path, "bg_fever/" .. self.name)

    self.transitioned = false
    self.started = false
    self.elapsed = 0
    self.last_ms = nil

    self.fade = anim.fade(TRANSITION_MS, {
        initial_opacity = 0.0,
        final_opacity = 1.0,
        loop = false
    })

    self.anim = nil
    if BGAnim and (path or "background") == "background" then
        self.anim = BGAnim.new(self.name, path)
    end

    self.layers = {}
    local d = DATA[self.name]
    if d and d.layers then
        for _, l in ipairs(d.layers) do
            local id = tex.get_texture(self.path .. "/" .. self.name .. "/" .. l.tex)
            if id then
                local period = l.period or 0
                table.insert(self.layers, {
                    id = id,
                    period = period,
                    vx = l.vx or 0,
                    -- enough copies to cover 1920 px whatever the phase
                    n = (period > 0) and (math.ceil(1920 / period) + 1) or 0
                })
            end
        end
    end
    if #self.layers == 0 then
        -- fail soft: the generated table is missing or named textures this
        -- folder does not have.  Draw the one name every slot ships.
        local id = tex.get_texture(self.path .. "/" .. self.name .. "/background")
        if id then table.insert(self.layers, {id = id, period = 0, vx = 0, n = 0}) end
    end

    return self
end

function ArcadeBGFever:start()
    if self.started then return end
    self.started = true
    self.transitioned = false
    -- `normal_fever`: wipe in from wherever the (possibly mid-exit) fade sits.
    local from = self.fade and self.fade.attribute or 0.0
    self.fade = anim.fade(TRANSITION_MS, {
        initial_opacity = from,
        final_opacity = 1.0,
        loop = false
    })
    self.fade:start()
end

-- ROUND 52: falling edge (`fever_normal`).  Re-arms start() for the next clear.
function ArcadeBGFever:stop()
    if not self.started then return end
    self.started = false
    self.transitioned = false
    local from = self.fade and self.fade.attribute or 1.0
    self.fade = anim.fade(TRANSITION_MS, {
        initial_opacity = from,
        final_opacity = 0.0,
        loop = false
    })
    self.fade:start()
end

-- ROUND 52: true while anything of this backdrop is on screen -- entering,
-- steady, or exiting.  background.lua draws bg_normal beneath whenever the
-- fever plate is not yet (or no longer) fully opaque.
function ArcadeBGFever:is_visible()
    if self.started then return true end
    return (self.fade.attribute or 0) > 0.001 and not self.fade.is_finished
end

function ArcadeBGFever:update(current_time_ms)
    if self.last_ms then
        local dt = current_time_ms - self.last_ms
        if dt > 0 and dt < 500 then self.elapsed = self.elapsed + dt end
    end
    self.last_ms = current_time_ms
    if self.anim then self.anim:update(current_time_ms) end

    if not self.transitioned then
        self.fade:update(current_time_ms)
        if self.started and self.fade.is_finished then self.transitioned = true end
    end
end

function ArcadeBGFever:draw()
    local fade = self.transitioned and 1.0 or self.fade.attribute
    if self.anim then
        self.anim:draw(fade)
        return
    end

    -- back to front, in the cabinet's own depth order: the static art is NOT
    -- all behind the strips (bg_fever_a_02's spinning tops sit in front of an
    -- opaque checker strip), so the order in the table is load-bearing.
    for _, l in ipairs(self.layers) do
        if l.period > 0 then
            local off = (self.elapsed / 1000.0) * l.vx
            off = off % l.period
            if off > 0 then off = off - l.period end
            for i = 0, l.n do
                tex.draw_texture(l.id, { x = off + i * l.period, fade = fade })
            end
        else
            tex.draw_texture(l.id, { fade = fade })
        end
    end
end

function ArcadeBGFever:destroy()
    tex.unload_folder(self.path, "bg_fever/" .. self.name)
    if self.anim then self.anim:destroy() end
end

local BGFever = {}
BGFever.Base = ArcadeBGFever
BGFever.Arcade = ArcadeBGFever

function BGFever.create(index, path)
    return ArcadeBGFever.new(index, path)
end

return BGFever