local DonBGBase        = require("background/bg_objects/donbg/base")
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/imas_sidem"
local MAX_DANCERS      = 3

-- Custom DonBG: 16*scale tiled background with 8x scale scroll
local ImasSidemDonBG   = setmetatable({}, { __index = DonBGBase })
ImasSidemDonBG.__index = ImasSidemDonBG

function ImasSidemDonBG.new(player_num)
    local self = setmetatable({}, ImasSidemDonBG)
    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(3000, { total_distance = -bg_width * sc * 8, loop = true })
    return self
end

function ImasSidemDonBG: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
        })
    end
end

-- BGNormal: looping 4-frame screen texture change
local ImasSidemBGNormal = {}
ImasSidemBGNormal.__index = ImasSidemBGNormal

function ImasSidemBGNormal.new()
    local self = setmetatable({}, ImasSidemBGNormal)
    self.name = "bg_0"
    tex.load_folder(COLLAB_PATH, "bg_normal/" .. self.name)
    self.screen_change = anim.texture_change(8000, {
        { 0, 2000, 0 }, { 2000, 4000, 1 }, { 4000, 6000, 2 }, { 6000, 8000, 3 }
    }, { loop = true })
    self._id_bg      = tex.get_id(self.name, "background") or 0
    self._id_screen  = tex.get_id(self.name, "screen") or 0
    self._id_overlay = tex.get_id(self.name, "overlay") or 0
    return self
end

function ImasSidemBGNormal:update(current_time_ms)
    self.screen_change:update(current_time_ms)
end

function ImasSidemBGNormal:draw()
    tex.draw_id(self._id_bg)
    tex.draw_id(self._id_screen, { frame = self.screen_change.attribute })
    tex.draw_id(self._id_overlay)
end

function ImasSidemBGNormal:destroy()
    tex.unload_folder(COLLAB_PATH, "bg_normal/" .. self.name)
end

-- BGFever: same screen texture change + overlay_2; immediately transitioned
local ImasSidemBGFever = {}
ImasSidemBGFever.__index = ImasSidemBGFever

function ImasSidemBGFever.new()
    local self = setmetatable({}, ImasSidemBGFever)
    self.name = "bg_fever_0"
    tex.load_folder(COLLAB_PATH, "bg_fever/" .. self.name)
    self.transitioned = true
    self.screen_change = anim.texture_change(8000, {
        { 0, 2000, 0 }, { 2000, 4000, 1 }, { 4000, 6000, 2 }, { 6000, 8000, 3 }
    }, { loop = true })
    self._id_bg       = tex.get_id(self.name, "background") or 0
    self._id_screen   = tex.get_id(self.name, "screen") or 0
    self._id_overlay  = tex.get_id(self.name, "overlay") or 0
    self._id_overlay2 = tex.get_id(self.name, "overlay_2") or 0
    return self
end

function ImasSidemBGFever:start() end -- already transitioned

function ImasSidemBGFever:update(current_time_ms)
    self.screen_change:update(current_time_ms)
end

function ImasSidemBGFever:draw()
    tex.draw_id(self._id_bg)
    tex.draw_id(self._id_screen,   { frame = self.screen_change.attribute })
    tex.draw_id(self._id_overlay)
    tex.draw_id(self._id_overlay2)
end

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

-- Fever: same 2-frame overlay as imas collab (2-beat cycle)
local ImasSidemFever = {}
ImasSidemFever.__index = ImasSidemFever

function ImasSidemFever.new(bpm)
    local self = setmetatable({}, ImasSidemFever)
    local base = Fever.Base.new(0, bpm, COLLAB_PATH)
    for k, v in pairs(base) do self[k] = v end
    local total = 120000 / bpm
    self.texture_change = anim.texture_change(total, {
        { 0,         total / 2, 0 },
        { total / 2, total,     1 }
    }, { loop = true })
    return self
end

function ImasSidemFever:start()
    Fever.Base.start(self)
end

function ImasSidemFever:update(current_time_ms, bpm)
    Fever.Base.update(self, current_time_ms, bpm)
    self.texture_change:update(current_time_ms)
end

function ImasSidemFever:draw()
    local y = self.bounce_down.attribute - self.bounce_up.attribute
    tex.draw_id(self._id_overlay, { y = y, frame = self.texture_change.attribute })
end

-- Background

local ImasSidemBackground = {}
ImasSidemBackground.__index = ImasSidemBackground

function ImasSidemBackground.new(player_num, bpm)
    local self          = setmetatable({}, ImasSidemBackground)
    self.donbg          = ImasSidemDonBG.new(player_num)
    self.bg_normal      = ImasSidemBGNormal.new()
    self.bg_fever       = ImasSidemBGFever.new()
    self.footer         = Footer.new(COLLAB_PATH, 0)
    self.fever          = ImasSidemFever.new(bpm)
    self.dancer         = Dancer.BaseDancerGroup.new(0, bpm, MAX_DANCERS, COLLAB_PATH)
    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 ImasSidemBackground:update(current_ms, bpm)
    self.donbg:update(current_ms)
    self.bg_normal: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 ImasSidemBackground:handle_good(player_num) self.chibi:add_chibi(player_num, false) end

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

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

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

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

function ImasSidemBackground: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 ImasSidemBackground: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 ImasSidemBackground:draw_fore() end

function ImasSidemBackground: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 ImasSidemBackground