-- YataiDON-HSS override of PyTaikoGreen/background/bg_objects/fever.lua: bounce total_distance 50*screen_scale
--
-- ROUND 52 (r52-lua-divergence-fixes): the 魂-max crowd is now EDGE-DRIVEN on
-- both sides and re-triggerable, matching the reference build `EnsoGraphicFeverEffect::Process`
-- (EnsoGraphicFeverEffect.obj.c:123-129): the cached flag at +88 is compared
-- against `IsTamashiiMax` every frame and each change plays a clip --
-- `normal_fever` rising, `fever_normal` falling.  The skin used to pop the
-- crowd in and out in a single frame (draw gated on the raw is_rainbow flag in
-- background.lua) and never replayed the entrance on a re-max.  The entry/exit
-- clips themselves are not exported (the cabinet's 40-frame 1920x540 flipbook
-- stays out -- ROUND 12 trade), so both edges are an alpha ramp of the same
-- 29-frame length BgFever's measured wipe uses (a documented stand-in, not a
-- measured FeverEffect number).  `is_visible()` replaces background.lua's
-- is_rainbow draw gate so the exit ramp actually gets drawn.
local FEVER_EDGE_MS = 29000 / 60

local BaseFever = {}
BaseFever.__index = BaseFever

function BaseFever.new(index, bpm, path)
    local self = setmetatable({}, BaseFever)
    self.name = "fever_" .. index
    self.path = path or "background"
    tex.load_folder(self.path, "fever/" .. self.name)
    local half_beat = (60000 / bpm) / 2
    self.bounce_up = anim.move(half_beat, {total_distance = 50 * tex.get_screen_scale(), ease_out = "quadratic"})
    self.bounce_down = anim.move(half_beat, {total_distance = 50 * tex.get_screen_scale(), ease_in = "quadratic", delay = half_beat})
    -- ROUND 60: nil = missing.  id 0 is a VALID texture id (the global
    -- name->id map starts at 0), so "or 0" hid real textures and, worse, made
    -- a missing folder draw texture id 0 (an unrelated sheet).
    self._id_overlay_l = tex.get_id(self.name, "overlay_l")
    self._id_overlay_r = tex.get_id(self.name, "overlay_r")
    self._id_overlay   = tex.get_id(self.name, "overlay")
    self.active = false
    self.edge_fade = anim.fade(FEVER_EDGE_MS, {initial_opacity = 0.0, final_opacity = 0.0})
    return self
end

function BaseFever:start()
    if self.active then return end
    self.active = true
    local from = self.edge_fade and self.edge_fade.attribute or 0.0
    self.edge_fade = anim.fade(FEVER_EDGE_MS, {initial_opacity = from, final_opacity = 1.0})
    self.edge_fade:start()
    self.bounce_up:start()
    self.bounce_down:start()
end

-- ROUND 52: falling edge (`fever_normal`); re-arms start().
function BaseFever:stop()
    if not self.active then return end
    self.active = false
    local from = self.edge_fade and self.edge_fade.attribute or 1.0
    self.edge_fade = anim.fade(FEVER_EDGE_MS, {initial_opacity = from, final_opacity = 0.0})
    self.edge_fade:start()
end

function BaseFever:is_visible()
    if self.active then return true end
    return (self.edge_fade.attribute or 0) > 0.001 and not self.edge_fade.is_finished
end

function BaseFever:alpha()
    if self.active and self.edge_fade.is_finished then return 1.0 end
    return self.edge_fade.attribute or 0.0
end

function BaseFever:update(current_time_ms, bpm)
    self.edge_fade:update(current_time_ms)
    self.bounce_up:update(current_time_ms)
    self.bounce_down:update(current_time_ms)
    if self.bounce_down.is_finished then
        local half_beat = (60000 / bpm) / 2
        self.bounce_up = anim.move(half_beat, {total_distance = 50 * tex.get_screen_scale(), ease_out = "quadratic"})
        self.bounce_down = anim.move(half_beat, {total_distance = 50 * tex.get_screen_scale(), ease_in = "quadratic", delay = half_beat})
        self.bounce_up:start()
        self.bounce_down:start()
    end
end

function BaseFever:destroy()
    tex.unload_folder(self.path, "fever/" .. self.name)
end

local Fever0 = setmetatable({}, {__index = BaseFever})
Fever0.__index = Fever0

function Fever0.new(index, bpm, path)
    local self = setmetatable({}, Fever0)
    local base = BaseFever.new(index, bpm, path)
    for k, v in pairs(base) do self[k] = v end
    return self
end

function Fever0:draw()
    local a = self:alpha()
    if a <= 0.001 then return end
    local y = self.bounce_down.attribute - self.bounce_up.attribute
    -- ROUND 60 (r60-collab-fix-all): fail soft when the folder shipped no art.
    if self._id_overlay_l then tex.draw_texture(self._id_overlay_l, {y = y, fade = a}) end
    if self._id_overlay_r then tex.draw_texture(self._id_overlay_r, {y = y, fade = a}) end
end

-- Fever1 and Fever2 share the same draw as Fever0
local Fever1 = setmetatable({}, {__index = Fever0})
Fever1.__index = Fever1
function Fever1.new(index, bpm, path)
    local self = setmetatable({}, Fever1)
    local base = BaseFever.new(index, bpm, path)
    for k, v in pairs(base) do self[k] = v end
    return self
end
function Fever1:draw() Fever0.draw(self) end

local Fever2 = setmetatable({}, {__index = Fever0})
Fever2.__index = Fever2
function Fever2.new(index, bpm, path)
    local self = setmetatable({}, Fever2)
    local base = BaseFever.new(index, bpm, path)
    for k, v in pairs(base) do self[k] = v end
    return self
end
function Fever2:draw() Fever0.draw(self) end

local Fever3 = setmetatable({}, {__index = BaseFever})
Fever3.__index = Fever3

function Fever3.new(index, bpm, path)
    local self = setmetatable({}, Fever3)
    local base = BaseFever.new(index, bpm, path)
    for k, v in pairs(base) do self[k] = v end
    return self
end

function Fever3:draw()
    local a = self:alpha()
    if a <= 0.001 then return end
    -- ROUND 60: fail soft on a missing fever folder (see Fever0:draw).
    if not self._id_overlay then return end
    local y = self.bounce_down.attribute - self.bounce_up.attribute
    tex.draw_texture(self._id_overlay, {y = y, fade = a})
end

local Fever = {}
Fever.Base = BaseFever
Fever.Fever0 = Fever0
Fever.Fever1 = Fever1
Fever.Fever2 = Fever2
Fever.Fever3 = Fever3

function Fever.create(index, bpm, path)
    local map = {Fever0, Fever1, Fever2, Fever3}
    return map[index + 1].new(index, bpm, path)
end

return Fever