-- YataiDON-HSS override of PyTaikoGreen/background/bg_collabs/dan.lua: bg_overlay/bg_overlay_2 tile step + scroll period use x2[1]
local DonBGBase       = require("background/bg_objects/donbg/base")
local BGNormal        = require("background/bg_objects/bg_normal")
local Footer          = require("background/bg_objects/footer")
local ChibiController = require("background/bg_objects/chibi")
local DanInfo         = require("background/bg_objects/dan_info")

local COLLAB_PATH     = "background/collab/dan"

-- Custom DonBG: DonBG6 draw-shape but with extra bg_overlay_2 scroll
local DanDonBG        = setmetatable({}, { __index = DonBGBase })
DanDonBG.__index      = DanDonBG

function DanDonBG.new(player_num)
    local self = setmetatable({}, DanDonBG)
    local base = DonBGBase.new(1, player_num, COLLAB_PATH)
    for k, v in pairs(base) do self[k] = v end
    self.overlay_move = tex.get_animation(2)
    local bg_overlay_info = tex.get_texture_info(self.name, "bg_overlay")
    self.bg_overlay_width = bg_overlay_info and bg_overlay_info.x2[1] or 0
    local bg_overlay_2_info = tex.get_texture_info(self.name, "bg_overlay_2")
    self.bg_overlay_2_width = bg_overlay_2_info and bg_overlay_2_info.x2[1] or 0
    self.overlay_move_2 = anim.move(8000, {
        total_distance = -self.bg_overlay_2_width, loop = true
    })
    self._id_bg_overlay   = tex.get_id(self.name, "bg_overlay") or 0
    self._id_bg_overlay_2 = tex.get_id(self.name, "bg_overlay_2") or 0
    self._id_overlay_1    = tex.get_id(self.name, "overlay_1") or 0
    self._id_bg_overlay_3 = tex.get_id(self.name, "bg_overlay_3") or 0
    self._id_overlay_2    = tex.get_id(self.name, "overlay_2") or 0

    self._id_layer_a      = tex.get_id(self.name, "layer_a")
    self._id_layer_b      = tex.get_id(self.name, "layer_b")
    self._id_layer_c      = tex.get_id(self.name, "layer_c")
    self._id_layer_d      = tex.get_id(self.name, "layer_d")
    self._id_petal        = tex.get_id(self.name, "petal")

    -- ROUND 26 (r26-danbg-tiling): DonBGBase:draw() never calls draw_textures
    -- below (that hook does not exist on the base class and is dead code --
    -- true here and in every other bg_collabs/*.lua override, grep shows only
    -- definitions, zero call sites). What it actually renders is
    -- self.states.normal, which DonBGBase.new() just populated from
    -- background/bg_data/donbg.lua's entry for name "0_1" -- generated by
    -- r13-bg's export script from the ARCADE's *plain gameplay* donbg tile
    -- (period=496, vx=-93.29 px/s, an 8 px gradient strip meant to scroll and
    -- wrap every 496 px). Round 19b swapped this folder's `background.png` for
    -- the unrelated 1920x280 donbg_dojo_1p flatten but never touched this
    -- table, so draw_layers was tiling the new full-width art at n=ceil(1920/
    -- 496)+1=5 copies 496 px apart -- exactly the "4-5 vertical seams / sakura
    -- clusters cutting off at boundaries" the user's screenshot showed.
    -- donbg_dojo_1p has no measured scroll (full.py sampled all 10 keyframes
    -- of MC 29, every shape's matrix is identical across frames -- this movie
    -- is not animated in the .nulm at all), so the correct list is exactly
    -- what the dead draw_textures override above already intended: the band
    -- and bg_overlay_3 (round 7's 段位道場 title) each drawn once, period=0.
    -- Bypassing the shared generated table here (instead of hand-editing it)
    -- keeps every OTHER DonBGBase instance -- the plain non-dan gameplay donbg
    -- pool, which legitimately owns and needs that "0_1" period=496 entry --
    -- untouched.
    --
    -- ROUND 76 (r76-gamedan-band-and-autoplay): the "no measured scroll"
    -- sentence above is WRONG, and so is ROUND 35 point 4 which re-derived it.
    -- Both sampled the movie's ROOT node (`#28@0`, character 29) -- which has
    -- only 10 frames and IS constant (tx=960 ty=138 m=[1,0,0,1] on every one of
    -- frames 0..9) -- and never descended into its children. Dumped in full
    -- (`lumen_anim_dump --all --leaves --range 0,1759`, 1760 frames, 47 nodes)
    -- the CHILDREN all scroll, each on its own period:
    --   #6@1  -> -1.500000 px/frame = -90.0000 px/s, wrap 1920 px, loop 1281 f
    --   #10@2 -> -1.200750 px/frame = -72.0450 px/s, wrap 1920 px, loop 1600 f
    --   #16@3 -> -1.091529 px/frame = -65.4918 px/s, wrap 1920 px, loop 1760 f
    --   #27@6 -> -0.750000 px/frame = -45.0000 px/s, wrap  960 px, loop 1281 f
    --   #19@4/#19@5 -> two sakura-petal drifters, 320-frame loop, see below
    -- The picture already changes on FRAME 1 (105,247 px differ from frame 0).
    -- The band is therefore drawn as the real five-layer parallax it is: an
    -- opaque navy seigaiha plate, two cloud silhouette bands, a seigaiha-filled
    -- cloud band, the falling petals, and a sakura-blossom row.
    --
    -- Fail-soft: any layer whose PNG/texture.json entry is missing is simply
    -- left out; with none of them present this degrades to the bare opaque
    -- plate (background.png is fully opaque, alpha 255/255 everywhere), never
    -- to gaps or to the parent's art.
    local back, front = {}, {}
    local function add(list, id, period, vx)
        if id == nil then return end
        table.insert(list, {
            id = id, frame = 0, index = 0, period = period, vx = vx,
            n = (period > 0) and (math.ceil(1920 / period) + 1) or 0,
        })
    end
    add(back, self._id_bg,      0,    0)        -- static plate (donbg_dojo_1p shape rec 0)
    add(back, self._id_layer_a, 1920, -90.0000) -- #6@1  dark cloud silhouettes
    add(back, self._id_layer_b, 1920, -72.0450) -- #10@2 outlined cloud bands
    add(back, self._id_layer_c, 1920, -65.4918) -- #16@3 seigaiha-filled clouds
    -- petals (#19@4/#19@5) are drawn between these two lists -- they sit at
    -- root depths 4 and 5, i.e. under #27@6.
    add(front, self._id_layer_d, 960, -45.0000) -- #27@6 sakura blossom row
    -- ROUND 92 -- user asked for the 段位道場 title not to appear on the play
    -- background (「段位道場這四個字不要出現」). ROUND 7's `bg_overlay_3` draw is
    -- removed rather than the art deleted, so restoring it is one line.
    self._layers_back  = back
    self._layers_front = front
    self.states = { normal = {} }
    for _, l in ipairs(back) do table.insert(self.states.normal, l) end
    for _, l in ipairs(front) do table.insert(self.states.normal, l) end
    -- ROUND 60 (r60-collab-fix-all): DonBGBase now routes collab paths through
    -- the draw_textures contract; dan is the one collab whose correct list is
    -- the hand-built states above, so it opts back into the layer path.
    self.use_layers = true
    return self
end

-- ROUND 76: the two petal drifters. Root depths 4 and 5 place the SAME shape
-- record (480x240, nine sakura petals) 960 px apart and walk both of them from
-- (2073,-218) to (675,525) over 320 frames, then snap back -- measured off the
-- anim dump, and confirmed by pasting shape record 5 centre-registered at the
-- dumped (tx,ty) on top of the plate+tile reconstruction: mean abs error
-- against the cabinet's own render drops from 2.08 to 0.10 at frame 120 and
-- from 2.61 to 0.37 at frame 1759.
--
-- The cabinet clips them to its 1920x276 stage; we have no stage to clip to, so
-- the bottom half of a petal cluster would otherwise fall out of the band and
-- over the play area for ~1.7 s of every 5.33 s cycle. `src`+`y2` crops the
-- draw to the band instead, which is what the stage boundary does.
local PETAL_W, PETAL_H = 480, 240
local PETAL_LOOP_FRAMES = 320
local PETAL_X0, PETAL_Y0 = 2073.0, -218.0
local PETAL_DX, PETAL_DY = -4.36875, 2.321875
local PETAL_GAP = 960.0
-- background.png is 1920x280 pasted at screen y 0 and its row 0 is stage row
-- -2, so screen y = stage y + 2 and the band's bottom edge is screen y 278.
local BAND_Y_CONST = 2.0
local BAND_BOTTOM = 278.0

function DanDonBG:_draw_petals(y)
    if self._id_petal == nil then return end
    local f = (self.elapsed / (1000.0 / 60.0)) % PETAL_LOOP_FRAMES
    local top = (PETAL_Y0 + PETAL_DY * f) - PETAL_H / 2.0 + BAND_Y_CONST + y
    if top >= BAND_BOTTOM then return end
    local h = BAND_BOTTOM - top
    if h > PETAL_H then h = PETAL_H end
    local cx = PETAL_X0 + PETAL_DX * f
    for i = 0, 1 do
        tex.draw_texture(self._id_petal, {
            x = cx - i * PETAL_GAP - PETAL_W / 2.0,
            y = top,
            src = { x = 0, y = 0, width = PETAL_W, height = h },
            y2 = h - PETAL_H,
        })
    end
end

-- ROUND 76: the petals sit between the scrolling cloud bands and the sakura
-- row, so the draw is split rather than left to DonBGBase:draw(). Dan has no
-- fever state (states.fever is nil), so none of the base's crossfade paths
-- applied here anyway.
function DanDonBG:draw(y)
    y = y or 0
    self:draw_layers(self._layers_back or {}, 1.0, y)
    self:_draw_petals(y)
    self:draw_layers(self._layers_front or {}, 1.0, y)
end

function DanDonBG:update(current_time_ms)
    DonBGBase.update(self, current_time_ms)
    self.overlay_move:update(current_time_ms)
    self.overlay_move_2:update(current_time_ms)
end

-- ROUND 19 (r19-dan): `background.png` is now the arcade's own
-- `enso_dani/enso/donbg/donbg_dojo_1p.nulm` band (measured/flattened,
-- scratchpad/r19dn/bake -- 1920x280, navy seigaiha + sakura petals), not the
-- inherited PyTaikoGreen 8px gradient strip. The old tiled overlay draws below
-- (bg_overlay/bg_overlay_2/overlay_1/overlay_2, all still PyTaikoGreen's
-- orange-diagonal art since no arcade source for THOSE specific layers was
-- found) are dropped so they don't paint the wrong pattern back on top; the
-- new band is one static image, not a scrolling composite, so nothing here
-- depends on `self.move` / `self.overlay_move*` any more. `bg_overlay_3`
-- (round 7's 段位道場 title placement) is unchanged and still drawn.
--
-- ROUND 26 (r26-danbg-tiling): DEAD CODE -- DonBGBase:draw() (base.lua) only
-- ever calls draw_layers(self.states...), it has no call to draw_textures on
-- any DonBGBase subclass anywhere in this repo. This method's intent (band +
-- bg_overlay_3, each once) is now what DanDonBG.new() builds directly into
-- self.states above, which IS on the real draw path. Left in place only so a
-- future reader sees what round 19's author meant to happen; do not rely on
-- this function running.
function DanDonBG:draw_textures(fade, y, frame)
    tex.draw_texture(self._id_bg, { y = y })
    tex.draw_texture(self._id_bg_overlay_3)
end

-- Background

local DanBackground = {}
DanBackground.__index = DanBackground

function DanBackground.new(player_num, bpm)
    local self     = setmetatable({}, DanBackground)
    self.donbg     = DanDonBG.new(player_num)
    self.bg_normal = BGNormal.Base.new(0, COLLAB_PATH)
    self.footer    = Footer.new(COLLAB_PATH, 0)
    self.chibi     = ChibiController.new(bpm, COLLAB_PATH, 2)
    self.dan_info  = DanInfo.new()
    return self
end

function DanBackground:update(current_ms, bpm)
    self.donbg:update(current_ms)
    self.chibi:update(current_ms, bpm)
end

function DanBackground:handle_good(player_num) self.chibi:add_chibi(player_num, false) end

function DanBackground:handle_ok(player_num) self.chibi:add_chibi(player_num, false) end

function DanBackground:handle_bad(player_num) self.chibi:add_chibi(player_num, true) end

function DanBackground:handle_drumroll(player_num) end

function DanBackground:handle_balloon(player_num) end

function DanBackground:handle_gauge(player_num, progress, is_clear, is_rainbow)
    self.donbg:set_clear(is_clear)
end

-- ROUND 14 engine binding (ENGINE_BINDINGS.md): DanGameScreen::update pushes the
-- live 段位道場 exam state here every frame. See background/bg_objects/dan_info.lua
-- for what is drawn with it and why the rest of the panel is still the engine's.
function DanBackground:handle_dan(player_num, state)
    self.dan_info:handle(state)
end

function DanBackground:draw_back()
    self.bg_normal:draw()
    self.donbg:draw()
    self.footer:draw()
    self.chibi:draw()
end

-- ROUND 7: the dan soul gauge's separator overlay is drawn by gauge.cpp at a hardcoded
-- fade 0.15; the arcade composites the same 6 px black bands at 0.30 (MAPPING_hud ROUND 5c,
-- shape 33 colour-transform alpha 77/256). GameDanScreen::draw() runs draw_fore() after the
-- gauge, so one more pass at 0.15 composites to 1-(1-0.15)^2 = 0.2775. The overlay is static
-- (it does not depend on the fill), so this needs no gauge state - which is just as well,
-- because Player::update takes the dan_gauge branch and never calls Background:handle_gauge.
function DanBackground:draw_fore()
    if not self._gauge_overlay then
        self._gauge_overlay = tex.load_texture("game/gauge_dan/overlay") or 0
    end
    if self._gauge_overlay ~= 0 then
        tex.draw_texture(self._gauge_overlay, { fade = 0.15 })
    end
end

-- ROUND 90 (r90-danplate-brown-and-place): the 魂ゲージ condition plate MOVED out
-- of draw_fore() into the gauge's own draw slot. On the cabinet it is
-- `gauge_border`, a child of `gauge_mc` inside tamashii_gauge.nulm, and the reference build's
-- datatable/enso_post.bin target 2 puts that whole movie at draw-order row 10 of
-- 29 -- below the notes and below every HUD readout. draw_fore() runs after
-- Player::draw()'s draw_notes(), so from there the plate painted OVER the notes
-- (user report 「魂guage那個白色的景，不應該把音符蓋過去」).
-- DanGameScreen::draw() calls Background::draw_gauge(P1) right after
-- dan_gauge.draw(); background.lua forwards it here.
function DanBackground:draw_gauge(player_num)
    self.dan_info:draw()
end

function DanBackground:destroy()
    self.donbg:destroy()
    self.bg_normal:destroy()
    self.footer:destroy()
    self.chibi:destroy()
end

return DanBackground