-- FolderBox rendering (genre kanban), split out of song_select.lua. Shared helpers and
-- the wheel/folder animation state come from box_base.

local base = require("song_select/file_navigator/box_base")

local folder_leg = base.folder_leg
local BOARD_W = base.BOARD_W
local CAP_H = base.CAP_H
local CEN_CLOSED_H, CEN_OPEN_H = base.CEN_CLOSED_H, base.CEN_OPEN_H
local FOLDER_CLOSE_MS, STALE_TIMER_MS = base.FOLDER_CLOSE_MS, base.STALE_TIMER_MS
local draw_board, draw_glow, glow_pulse = base.draw_board, base.draw_glow, base.glow_pulse
local draw_title = base.draw_title
local outline, board_outline = base.outline, base.board_outline
local box_id = base.box_id
local go_get, leg_f, box_fade, fly_offset = base.go_get, base.leg_f, base.box_fade, base.fly_offset
local is_decided = base.is_decided
local wheel_open_t, wheel_close_step = base.wheel_open_t, base.wheel_close_step
local folder_open_timeline, folder_close_timeline = base.folder_open_timeline, base.folder_close_timeline

-- Event/search folders are matched by display name (the engine folds DEFAULT/RECOMMENDED/
-- FAVORITE/DAN/DIFFICULTY into genre frame 0).
local EVENT_FOLDER_NAMES = { ["ドドンと！新曲祭り！"] = true, ["New Songs"] = true, ["New"] = true,
                             ["おすすめ曲"] = true, ["Recommended"] = true, ["推薦歌曲"] = true }
local SORT_FOLDER_NAMES  = { ["曲検索"] = true, ["Search Song"] = true, ["搜尋歌曲"] = true,
                             ["むずかしさで探す"] = true, ["Difficulty Sort"] = true, ["難易度排序"] = true,
                             ["むずかしさからえらぶ"] = true, ["Diff Sort"] = true }
local FOLDER_FRAME_EVENT, FOLDER_FRAME_SORT, FOLDER_FRAME_DANI = 11, 12, 10

local SORT_COLLECTIONS  = { SEARCH = true, DIFFICULTY = true }
local EVENT_COLLECTIONS = { NEW = true, RECOMMENDED = true }

local function folder_frame(box)
    local n = box.text_name
    if n and EVENT_FOLDER_NAMES[n] then return FOLDER_FRAME_EVENT, true end
    local col = box.collection
    if col and col ~= "" then
        if EVENT_COLLECTIONS[col] then return FOLDER_FRAME_EVENT, true end
        if SORT_COLLECTIONS[col]  then return FOLDER_FRAME_SORT, false end
    end
    if box.kind and box:kind() == "dan" then return FOLDER_FRAME_DANI, false end
    if n and SORT_FOLDER_NAMES[n]  then return FOLDER_FRAME_SORT, false end
    return box:genre_frame(), false
end

-- instance_board_pattern: 960x120 strip centred on the board, y follows the title
function SongSelect:draw_pattern(bx, by, p, fade)
    if not self._id_pattern then return end
    tex.draw_texture(self._id_pattern, { x = bx - 480, y = by - 94 * p - 60, fade = fade })
end

-- The genre board title, re-made at the skin_config folder_box_name size.
local FOLDER_TITLE_SIZE = nil
function SongSelect:folder_title(box)
    if FOLDER_TITLE_SIZE == nil then
        local cfg = tex.get_skin_config("folder_box_name")
        FOLDER_TITLE_SIZE = (cfg and cfg.font_size and cfg.font_size > 0) and cfg.font_size or false
    end
    if not FOLDER_TITLE_SIZE then return box:name() end
    local key = box.text_name
    if not key or key == "" then return box:name() end
    local ff = folder_frame(box)
    key = ff .. "\0" .. key
    local t = self._folder_titles[key]
    if t == nil then
        t = text.create_raw_text(box.text_name, FOLDER_TITLE_SIZE, { 255, 255, 255, 255 },
                                 board_outline(ff), false, outline(7.5), 2.0)
        self._folder_titles[key] = t or false
    end
    return t or box:name()
end

function SongSelect:draw_folder_board(box, pb, ch_alpha, ch_off, ta, glow_a)
    local bx, by = box:box_x(), box:box_y()
    local fdx, fdy = fly_offset(box); bx, by = bx + fdx, by + fdy   -- wheel fly-in
    local cen_h = CEN_CLOSED_H + (CEN_OPEN_H - CEN_CLOSED_H) * pb
    local fade = box_fade(box)
    local frame, has_pattern = folder_frame(box)

    -- the genre board furls/unfurls horizontally across the folder transition
    local ltitle = 1.0
    local lf = (box:draw_state() == "open" or is_decided(box)) and leg_f() or nil
    if lf then
        local sx, ba = go_get("genre_board_sx", lf, 1), go_get("genre_board_sx", lf, 2)
        if sx and ba then
            if ba <= 0.0 then return end   -- the board is not on screen
            if sx < 1.0 then               -- furl / unfurl: the open slab alone
                draw_board(self._id_bar_folder, frame, bx, by, CEN_OPEN_H,
                           fade * ba, false, sx)
                return
            end
            ch_alpha = math.min(ch_alpha, go_get("genre_chara_a", lf, 1) or 1.0)
            ta       = math.min(ta,       go_get("genre_intro_a", lf, 1) or 1.0)
            ltitle   = go_get("genre_title_a", lf, 1) or 1.0
        end
    end

    if glow_a > 0 then draw_glow(self._id_glow, bx, by, cen_h, fade * glow_a * glow_pulse()) end
    -- closed folder = bar_genre, open folder = folder_graphic (title band on top)
    if pb <= 0.0 then
        draw_board(self._id_bar_genre, frame, bx, by, cen_h, fade)
    else
        draw_board(self._id_bar_folder, frame, bx, by, cen_h, fade, pb >= 1.0)
        if pb < 1.0 then draw_board(self._id_bar_genre, frame, bx, by, cen_h, fade * (1.0 - pb)) end
    end
    if has_pattern then self:draw_pattern(bx, by, pb, fade) end

    if box:has_box_texture() then
        -- a library-supplied box.png is fitted (aspect kept, shrink only) into the board rect
        if ch_alpha > 0 then
            box:draw_box_texture({ cx = bx, cy = by,
                                   max_w = BOARD_W, max_h = CAP_H * 2 + CEN_OPEN_H,
                                   fade = fade * ch_alpha })
        end
        -- title drawn after the art, matching the cabinet's depth order
        draw_title(self:folder_title(box), bx, by - 94 * pb, fade * ltitle)
        return
    end

    -- characters: texture has L at x=510 and R at x=1410
    if ch_alpha > 0 then
        local slide = 450.0 - ch_off
        local gframe = box:genre_frame()
        tex.draw_texture(self._id_box_chara, { frame = gframe, x = bx - 960 + slide, y = by - 240, x2 = 960 - 1920, fade = fade * ch_alpha,
                                               src = { x = 0, y = 0, width = 960, height = 480 } })
        tex.draw_texture(self._id_box_chara, { frame = gframe, x = bx - slide, y = by - 240, x2 = 960 - 1920, fade = fade * ch_alpha,
                                               src = { x = 960, y = 0, width = 960, height = 480 } })
    end
    -- title rises to y-94 when open; the song count stands in for the intro text
    draw_title(self:folder_title(box), bx, by - 94 * pb, fade * ltitle)
    local n = box.tja_count
    if ta > 0 and n and n > 0 then
        local ckey = frame .. "\0" .. n
        local label = self._count_cache[ckey]
        if not label then
            label = text.create_raw_text(tostring(n) .. " songs", 32, { 255, 255, 255, 255 }, board_outline(frame), false, outline(4.0), 2.0)
            self._count_cache[ckey] = label
        end
        if label then draw_title(label, bx, by + 49 * pb, fade * ta) end
    end
end

function SongSelect:draw_folder_closed(box)
    local key = "f\0" .. box_id(box)
    local e = wheel_close_step(key, FOLDER_CLOSE_MS, STALE_TIMER_MS)
    if e then
        local pb, ch_alpha, ch_off, ta = folder_close_timeline(e)
        self:draw_folder_board(box, pb, ch_alpha, ch_off, ta, pb)
        return
    end
    self:draw_folder_board(box, 0.0, 0.0, 340.0, 0.0, 0.0)
end

function SongSelect:draw_folder_open(box)
    -- remember the decided board: the engine removes it from the wheel while its songs
    -- load, and draw_overlays keeps drawing it until it has furled away
    folder_leg.last_open_id, folder_leg.last_open_box = box_id(box), box
    if is_decided(box) then
        self._dec_frame = self._frame_no
        self:draw_folder_board(box, 1.0, 1.0, 440.0, 1.0, 1.0)
        return
    end
    local key = "f\0" .. box_id(box)
    local t = wheel_open_t(key)
    if t == nil then     -- 508 ms pre-growth hold: fully closed
        self:draw_folder_board(box, 0.0, 0.0, 340.0, 0.0, 0.0)
        return
    end
    local pb, ch_alpha, ch_off, ta = folder_open_timeline(t)
    self:draw_folder_board(box, pb, ch_alpha, ch_off, ta, pb)
end

return { folder_frame = folder_frame }