local DonBGBase       = require("background/bg_objects/donbg/base")
local BGNormal        = require("background/bg_objects/bg_normal")
local Fever           = require("background/bg_objects/fever")
local Footer          = require("background/bg_objects/footer")
local Dancer          = require("background/bg_objects/dancer")
local RendaController = require("background/bg_objects/renda")
local ChibiController = require("background/bg_objects/chibi")

local COLLAB_PATH     = "background/collab/oshiri"
local MAX_DANCERS     = 5

-- Custom DonBG: 16*scale wide tiled background + 3 overlay rows per tile
local OshiriDonBG     = setmetatable({}, { __index = DonBGBase })
OshiriDonBG.__index   = OshiriDonBG

function OshiriDonBG.new(player_num)
    local self = setmetatable({}, OshiriDonBG)
    local base = DonBGBase.new(1, player_num, COLLAB_PATH)
    for k, v in pairs(base) do self[k] = v end
    local bg_width = self.bg_texture and self.bg_texture.width or 0
    local sc = tex.get_screen_scale()
    self.move = anim.move(20000, { total_distance = -bg_width * sc * 8, loop = true })
    self._id_overlay = tex.get_id(self.name, "overlay") or 0
    return self
end

function OshiriDonBG:draw_textures(fade, y, frame)
    local sc = tex.get_screen_scale()
    local bg_width = self.bg_texture and self.bg_texture.width or 0
    for i = 0, math.floor(16 * sc) - 1 do
        tex.draw_id(self._id_bg, {
            frame = frame,
            fade = fade,
            x = (i * bg_width) + self.move.attribute,
            y = y
        })
        for j = 0, 2 do
            tex.draw_id(self._id_overlay, {
                frame = frame,
                fade = fade,
                x = (i * bg_width) + self.move.attribute,
                y = y + (j * 70 * sc)
            })
        end
    end
end

-- BGFever: looping 3-frame overlay; immediately transitioned on start
local OshiriBGFever = {}
OshiriBGFever.__index = OshiriBGFever

function OshiriBGFever.new()
    local self = setmetatable({}, OshiriBGFever)
    self.name = "bg_fever_0"
    tex.load_folder(COLLAB_PATH, "bg_fever/" .. self.name)
    self.transitioned = false
    self.overlay_texture_change = anim.texture_change(2049, {
        { 0, 683, 0 }, { 683, 1366, 1 }, { 1366, 2049, 2 }
    }, { loop = true })
    self._id_bg      = tex.get_id(self.name, "background") or 0
    self._id_overlay = tex.get_id(self.name, "overlay") or 0
    return self
end

function OshiriBGFever:start()
    self.transitioned = true
end

function OshiriBGFever:update(current_time_ms)
    self.overlay_texture_change:update(current_time_ms)
end

function OshiriBGFever:draw()
    tex.draw_id(self._id_bg)
    tex.draw_id(self._id_overlay, { frame = self.overlay_texture_change.attribute })
end

function OshiriBGFever:destroy()
    tex.unload_folder(COLLAB_PATH, "bg_fever/" .. self.name)
end

-- Custom DancerGroup: fixed variant assignment (0, 1, 1, 1, 1), no shuffle
local OshiriDancerGroup = setmetatable({}, { __index = Dancer.BaseDancerGroup })
OshiriDancerGroup.__index = OshiriDancerGroup

function OshiriDancerGroup.new(bpm)
    local self = setmetatable({}, OshiriDancerGroup)
    self.name = "dancer_0"
    self.active_count = 0
    self.path = COLLAB_PATH
    tex.load_folder(COLLAB_PATH, "dancer/" .. self.name)
    self.spawn_positions = { 2, 1, 3, 0, 4 }
    self.active_dancers = {}
    self.max_dancers = MAX_DANCERS
    local BaseDancer = Dancer.Base
    self.dancers = {
        BaseDancer.new(self.name, 0, bpm),
        BaseDancer.new(self.name, 1, bpm),
        BaseDancer.new(self.name, 1, bpm),
        BaseDancer.new(self.name, 1, bpm),
        BaseDancer.new(self.name, 1, bpm),
    }
    self.needs_initial_dancer = true
    return self
end

function OshiriDancerGroup:update(current_time_ms, bpm)
    if self.needs_initial_dancer then
        self.needs_initial_dancer = false
        self:add_dancer()
    end
    Dancer.BaseDancerGroup.update(self, current_time_ms, bpm)
end

-- Background

local OshiriBackground = {}
OshiriBackground.__index = OshiriBackground

function OshiriBackground.new(player_num, bpm)
    local self          = setmetatable({}, OshiriBackground)
    self.donbg          = OshiriDonBG.new(player_num)
    self.bg_normal      = BGNormal.Base.new(0, COLLAB_PATH)
    self.bg_fever       = OshiriBGFever.new()
    self.footer         = Footer.new(COLLAB_PATH, 0)
    self.fever          = Fever.create(3, bpm, COLLAB_PATH)
    self.dancer         = OshiriDancerGroup.new(bpm)
    self.renda          = RendaController.new(COLLAB_PATH, 0)
    self.chibi          = ChibiController.new(bpm, COLLAB_PATH, 0)
    self.is_clear       = false
    self.is_rainbow     = false
    self.last_milestone = 1
    return self
end

function OshiriBackground:update(current_ms, bpm)
    self.donbg:update(current_ms)
    self.bg_fever:update(current_ms)
    self.fever:update(current_ms, bpm)
    self.dancer:update(current_ms, bpm)
    self.renda:update(current_ms)
    self.chibi:update(current_ms, bpm)
end

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

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

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

function OshiriBackground:handle_drumroll(player_num) self.renda:add_renda() end

function OshiriBackground:handle_balloon(player_num) self.renda:add_renda() end

function OshiriBackground:handle_gauge(player_num, progress, is_clear, is_rainbow)
    self.donbg:set_clear(is_clear)
    if is_clear and not self.is_clear then self.bg_fever:start() end
    if is_rainbow and not self.is_rainbow then self.fever:start() end
    self.is_clear   = is_clear
    self.is_rainbow = is_rainbow

    local current_milestone
    if is_clear then
        current_milestone = MAX_DANCERS
    else
        current_milestone = math.min(MAX_DANCERS - 1, math.floor(progress * MAX_DANCERS))
    end
    if current_milestone > self.last_milestone then
        for _ = 1, current_milestone - self.last_milestone do self.dancer:add_dancer() end
        self.last_milestone = current_milestone
    elseif current_milestone < self.last_milestone then
        for _ = 1, self.last_milestone - current_milestone do self.dancer:remove_dancer() end
        self.last_milestone = current_milestone
    end
end

function OshiriBackground:draw_back()
    if self.is_clear then
        if not self.bg_fever.transitioned then
            self.bg_normal:draw()
            self.bg_fever:draw()
        else
            self.bg_fever:draw()
        end
    else
        self.bg_normal:draw()
    end
    self.donbg:draw()
    self.renda:draw()
    self.dancer:draw()
    self.footer:draw()
    if self.is_rainbow then self.fever:draw() end
    self.chibi:draw()
end

function OshiriBackground:draw_fore() end

function OshiriBackground:destroy()
    self.donbg:destroy()
    self.bg_normal:destroy()
    self.bg_fever:destroy()
    self.fever:destroy()
    self.dancer:destroy()
    self.footer:destroy()
    self.renda:destroy()
    self.chibi:destroy()
end

return OshiriBackground