-- 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, "background")
    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_texture(self.path .. "/" .. self.name .. "/bg_overlay") or 0
    self._id_bg_overlay_2 = tex.get_texture(self.path .. "/" .. self.name .. "/bg_overlay_2") or 0
    self._id_overlay_1    = tex.get_texture(self.path .. "/" .. self.name .. "/overlay_1") or 0
    self._id_bg_overlay_3 = tex.get_texture(self.path .. "/" .. self.name .. "/bg_overlay_3") or 0
    self._id_overlay_2    = tex.get_texture(self.path .. "/" .. self.name .. "/overlay_2") or 0

    self._id_layer_a      = tex.get_texture(self.path .. "/" .. self.name .. "/layer_a")
    self._id_layer_b      = tex.get_texture(self.path .. "/" .. self.name .. "/layer_b")
    self._id_layer_c      = tex.get_texture(self.path .. "/" .. self.name .. "/layer_c")
    self._id_layer_d      = tex.get_texture(self.path .. "/" .. self.name .. "/layer_d")
    self._id_petal        = tex.get_texture(self.path .. "/" .. self.name .. "/petal")

    -- hand-built five-layer parallax band; missing layers are simply skipped.
    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 sit between the back and front lists
    add(front, self._id_layer_d, 960, -45.0000) -- #27@6 sakura blossom row
    -- 段位道場 title (bg_overlay_3) intentionally not drawn
    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
    -- use the hand-built layer list above
    self.use_layers = true
    return self
end

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

-- petals sit between the back and front layers
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

-- dead code: DonBGBase:draw() uses self.states, not this hook.
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

-- engine pushes the live 段位道場 exam state here every frame.
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

-- dan soul gauge separator overlay (static, drawn at a hardcoded fade).
function DanBackground:draw_fore()
    if not self._gauge_overlay then
        self._gauge_overlay = tex.get_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

-- dan condition plate, drawn in the gauge's own layer.
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