gen1recomp/src/import/gba/bag_chrome_extract.lua

-- Bake FRLG bag chrome + item icons into CacheFS (data/generated/gba/items/bag/).
-- BG tilemap, male/female bag sprites, 24×24 item icons from sItemIconTable.

local Versions = require("src.import.gba.versions")
local Lz77 = require("src.import.gba.lz77")

local BagChromeExtract = {}

BagChromeExtract.CACHE_SUB = "items/bag"
BagChromeExtract.FORMAT_VERSION = 4
BagChromeExtract.ITEM_PC_SUB = "items/item_pc"

local function default_cache_root()
  local ok, Extract = pcall(require, "src.import.gba.extract_island1")
  if ok and Extract and Extract.CACHE_ROOT then
    return Extract.CACHE_ROOT
  end
  return "data/generated/gba"
end

local function bgr555_to_rgb8(c)
  c = (tonumber(c) or 0) % 32768
  local r5 = c % 32
  local g5 = math.floor(c / 32) % 32
  local b5 = math.floor(c / 1024) % 32
  return math.floor(r5 * 255 / 31 + 0.5),
    math.floor(g5 * 255 / 31 + 0.5),
    math.floor(b5 * 255 / 31 + 0.5)
end

local ffi
do
  local ok, mod = pcall(require, "ffi")
  if ok and mod and mod.new and mod.string then ffi = mod end
end

local bit = rawget(_G, "bit") or rawget(_G, "bit32")
if not bit then
  local ok, mod = pcall(require, "bit")
  if ok and mod then bit = mod end
end

local static_icon_buf = nil
local function get_icon_buf(size)
  if not ffi then return nil end
  if not static_icon_buf then
    static_icon_buf = ffi.new("uint8_t[?]", math.max(size or 2304, 4096))
  end
  return static_icon_buf
end

local function byte_len(buf)
  if type(buf) == "string" then return #buf end
  if type(buf) ~= "table" then return 0 end
  return buf._len or #buf
end

local function decode_tile_4bpp(tileBytes, out, baseX, baseY, stride, hflip, vflip)
  local isStr = type(tileBytes) == "string"
  for row = 0, 7 do
    local srcRow = vflip and (7 - row) or row
    for bx = 0, 3 do
      local byte
      if isStr then
        byte = string.byte(tileBytes, srcRow * 4 + bx + 1) or 0
      else
        byte = tileBytes[srcRow * 4 + bx + 1] or 0
      end
      local p0 = byte % 16
      local p1 = math.floor(byte / 16) % 16
      local x0 = bx * 2
      local x1 = x0 + 1
      if hflip then
        x0, x1 = 7 - x0, 7 - x1
      end
      out[(baseY + row) * stride + (baseX + x0) + 1] = p0
      out[(baseY + row) * stride + (baseX + x1) + 1] = p1
    end
  end
end

local function load_pal_banks(bytes, count)
  local banks = {}
  local isStr = type(bytes) == "string"
  local n = count or math.floor(byte_len(bytes) / 32)
  for b = 0, n - 1 do
    local colors = {}
    local off = b * 32
    for c = 0, 15 do
      local b0, b1
      if isStr then
        b0 = string.byte(bytes, off + c * 2 + 1) or 0
        b1 = string.byte(bytes, off + c * 2 + 2) or 0
      else
        b0 = bytes[off + c * 2 + 1] or 0
        b1 = bytes[off + c * 2 + 2] or 0
      end
      colors[c] = b0 + b1 * 256
    end
    banks[b] = colors
  end
  return banks
end

local function bake_tiles_rgba(gfx, banks, W, H, entryAt)
  local isStr = type(gfx) == "string"
  local tileCount = math.floor(byte_len(gfx) / 32)
  local chunks = {}
  local tmp = {}
  for ty = 0, math.floor(H / 8) - 1 do
    for tx = 0, math.floor(W / 8) - 1 do
      local entry = entryAt(tx, ty) or 0
      local tileId = entry % 1024
      local hflip = math.floor(entry / 1024) % 2 == 1
      local vflip = math.floor(entry / 2048) % 2 == 1
      local bank = banks[math.floor(entry / 4096) % 16] or banks[0]
      if tileId >= tileCount then tileId = 0 end
      local tile = {}
      local base = tileId * 32
      for i = 1, 32 do
        tile[i] = isStr and (string.byte(gfx, base + i) or 0) or (gfx[base + i] or 0)
      end
      for i = 1, 64 do tmp[i] = 0 end
      decode_tile_4bpp(tile, tmp, 0, 0, 8, hflip, vflip)
      for row = 0, 7 do
        for col = 0, 7 do
          local c = bank and bank[tmp[row * 8 + col + 1] or 0] or 0
          local r, g, b = bgr555_to_rgb8(c)
          chunks[(ty * 8 + row) * W + tx * 8 + col + 1] = string.char(r, g, b, 255)
        end
      end
    end
  end
  return table.concat(chunks)
end

local function map_entry(map, tx, ty)
  local mi = (ty * 32 + tx) * 2 + 1
  if type(map) == "string" then
    return (string.byte(map, mi) or 0) + (string.byte(map, mi + 1) or 0) * 256
  end
  return (map[mi] or 0) + (map[mi + 1] or 0) * 256
end

local function bake_bg_rgba(gfx, banks, map, W, H)
  return bake_tiles_rgba(gfx, banks, W, H, function(tx, ty)
    return map_entry(map, tx, ty)
  end)
end

local function female_banks(palBytes, femaleBytes)
  local banks = load_pal_banks(palBytes)
  local over = load_pal_banks(femaleBytes, 1)
  if over[0] then banks[0] = over[0] end
  return banks
end

local function bake_red_arrow(gfx, palBytes)
  local W, H = 16, 32
  local pal = load_pal_banks(palBytes, 1)[0] or {}
  local pixels = {}
  for i = 1, W * H do pixels[i] = 0 end
  local ti = 0
  local isStr = type(gfx) == "string"
  for ty = 0, 3 do
    for tx = 0, 1 do
      local tile = {}
      local base = ti * 32
      for i = 1, 32 do
        tile[i] = isStr and (string.byte(gfx, base + i) or 0) or (gfx[base + i] or 0)
      end
      decode_tile_4bpp(tile, pixels, tx * 8, ty * 8, W, false, false)
      ti = ti + 1
    end
  end
  local chunks = {}
  for i = 1, W * H do
    local idx = pixels[i] or 0
    if idx == 0 then
      chunks[i] = string.char(0, 0, 0, 0)
    else
      local r, g, b = bgr555_to_rgb8(pal[idx] or 0)
      chunks[i] = string.char(r, g, b, 255)
    end
  end
  return table.concat(chunks)
end

--- 64×256 sheet: 4 pocket frames × 64×64 (8×8 tiles each). Color0 transparent.
local function bake_bag_sprite(gfx, palBytes)
  local W, H = 64, 256
  local banks = load_pal_banks(palBytes, 1)
  local pal = banks[0] or {}
  local tileCount = math.floor(byte_len(gfx) / 32)
  local pixels = {}
  for i = 1, W * H do pixels[i] = 0 end
  local ti = 0
  local isStr = type(gfx) == "string"
  for frame = 0, 3 do
    for ty = 0, 7 do
      for tx = 0, 7 do
        if ti < tileCount then
          local tile = {}
          local base = ti * 32
          for i = 1, 32 do
            tile[i] = isStr and (string.byte(gfx, base + i) or 0) or (gfx[base + i] or 0)
          end
          decode_tile_4bpp(tile, pixels, tx * 8, frame * 64 + ty * 8, W, false, false)
        end
        ti = ti + 1
      end
    end
  end
  local chunks = {}
  for i = 1, W * H do
    local idx = pixels[i] or 0
    if idx == 0 then
      chunks[i] = string.char(0, 0, 0, 0)
    else
      local r, g, b = bgr555_to_rgb8(pal[idx] or 0)
      chunks[i] = string.char(r, g, b, 255)
    end
  end
  return table.concat(chunks), W, H, 4
end

--- 24×24 item icon (3×3 tiles). Color0 transparent.
local function bake_icon_rgba(gfx, palBytes)
  local W, H = 24, 24
  local banks = load_pal_banks(palBytes, 1)
  local pal = banks[0] or {}
  local rgb = {}
  for c = 0, 15 do
    local r, g, b = bgr555_to_rgb8(pal[c] or 0)
    rgb[c] = { r, g, b }
  end

  local total_bytes = W * H * 4
  local buf = get_icon_buf(total_bytes)
  local isStr = type(gfx) == "string"
  local band = bit and bit.band
  local rshift = bit and bit.rshift
  local tileCount = math.floor(byte_len(gfx) / 32)

  if buf and band and rshift then
    local ti = 0
    for ty = 0, 2 do
      for tx = 0, 2 do
        local tileOff = ti * 32
        for row = 0, 7 do
          for bx = 0, 3 do
            local byte = 0
            if ti < tileCount then
              local bi = tileOff + row * 4 + bx
              if isStr then
                byte = string.byte(gfx, bi + 1) or 0
              else
                byte = gfx[bi + 1] or 0
              end
            end
            local p0 = band(byte, 0x0F)
            local p1 = rshift(byte, 4)
            local x0 = tx * 8 + bx * 2
            local y0 = ty * 8 + row

            local offset0 = (y0 * W + x0) * 4
            if p0 == 0 then
              buf[offset0] = 0; buf[offset0 + 1] = 0; buf[offset0 + 2] = 0; buf[offset0 + 3] = 0
            else
              local c = rgb[p0] or rgb[0]
              buf[offset0] = c[1]; buf[offset0 + 1] = c[2]; buf[offset0 + 2] = c[3]; buf[offset0 + 3] = 255
            end

            local offset1 = (y0 * W + x0 + 1) * 4
            if p1 == 0 then
              buf[offset1] = 0; buf[offset1 + 1] = 0; buf[offset1 + 2] = 0; buf[offset1 + 3] = 0
            else
              local c = rgb[p1] or rgb[0]
              buf[offset1] = c[1]; buf[offset1 + 1] = c[2]; buf[offset1 + 2] = c[3]; buf[offset1 + 3] = 255
            end
          end
        end
        ti = ti + 1
      end
    end
    return ffi.string(buf, total_bytes)
  end

  local pixels = {}
  for i = 1, W * H do pixels[i] = 0 end
  local ti = 0
  for ty = 0, 2 do
    for tx = 0, 2 do
      if ti < tileCount then
        local tile = {}
        local base = ti * 32
        for i = 1, 32 do
          tile[i] = isStr and (string.byte(gfx, base + i) or 0) or (gfx[base + i] or 0)
        end
        decode_tile_4bpp(tile, pixels, tx * 8, ty * 8, W, false, false)
      end
      ti = ti + 1
    end
  end
  local chunks = {}
  for i = 1, W * H do
    local idx = pixels[i] or 0
    if idx == 0 then
      chunks[i] = string.char(0, 0, 0, 0)
    else
      local r, g, b = bgr555_to_rgb8(pal[idx] or 0)
      chunks[i] = string.char(r, g, b, 255)
    end
  end
  return table.concat(chunks)
end

-- src/item_menu_icons.c:121 sOamData_SwapLine, :129 sAnims_SwapLine
local function bake_swap_line(gfx, palBytes)
  local W, H = 32, 16
  local pal = load_pal_banks(palBytes, 1)[0] or {}
  local pixels = {}
  for i = 1, W * H do pixels[i] = 0 end
  local isStr = type(gfx) == "string"
  for frame = 0, 1 do
    for t = 0, 3 do
      local tile = {}
      local base = (frame * 4 + t) * 32
      for i = 1, 32 do
        tile[i] = isStr and (string.byte(gfx, base + i) or 0) or (gfx[base + i] or 0)
      end
      decode_tile_4bpp(tile, pixels, frame * 16 + (t % 2) * 8, math.floor(t / 2) * 8, W, false, false)
    end
  end
  local chunks = {}
  for i = 1, W * H do
    local idx = pixels[i] or 0
    if idx == 0 then
      chunks[i] = string.char(0, 0, 0, 0)
    else
      local r, g, b = bgr555_to_rgb8(pal[idx] or 0)
      chunks[i] = string.char(r, g, b, 255)
    end
  end
  return table.concat(chunks)
end

local function gba_to_file(ptr)
  ptr = tonumber(ptr) or 0
  if ptr < 0x08000000 or ptr >= 0x0A000000 then return nil end
  return ptr - 0x08000000
end

function BagChromeExtract.run(rom, cache, opts)
  opts = opts or {}
  local cacheRoot = opts.cacheRoot or default_cache_root()
  local root = cacheRoot .. "/" .. BagChromeExtract.CACHE_SUB
  local W = opts.width or 240
  local H = opts.height or 160
  local progress = opts.progress

  local function get(i) return rom:get(i) end
  local function lz(off)
    local ok, out = pcall(Lz77.decompressString, rom, off)
    if ok and out then return out end
    return Lz77.decompress(get, off)
  end
  local function readBytes(off, len)
    if rom.readBytes then return rom:readBytes(off, len) end
    local out = {}
    for i = 1, len do out[i] = rom:get(off + i - 1) or 0 end
    return out
  end
  local function u32(off)
    if rom.u32 then return rom:u32(off) end
    return (rom:get(off) or 0)
      + (rom:get(off + 1) or 0) * 256
      + (rom:get(off + 2) or 0) * 65536
      + (rom:get(off + 3) or 0) * 16777216
  end

  local gfx = lz(Versions.BAG_BG_GFX)
  local pal = lz(Versions.BAG_BG_PAL)
  local map = lz(Versions.BAG_BG_TILEMAP)
  local femalePal = lz(Versions.BAG_BG_PAL_FEMALE)
  local maleBanks = load_pal_banks(pal)
  local femaleBanks = female_banks(pal, femalePal)
  cache:write(root .. "/bg.rgba", bake_bg_rgba(gfx, maleBanks, map, W, H))
  cache:write(root .. "/bg_female.rgba", bake_bg_rgba(gfx, femaleBanks, map, W, H))

  local LW, LH = Versions.BAG_LIST_TILES_W, Versions.BAG_LIST_TILES_H
  local listMap = readBytes(Versions.BAG_LIST_TILEMAP, LW * LH * 2)
  local function list_entry(tx, ty)
    local i = (ty * LW + tx) * 2 + 1
    if type(listMap) == "string" then
      return (string.byte(listMap, i) or 0) + (string.byte(listMap, i + 1) or 0) * 256
    end
    return (listMap[i] or 0) + (listMap[i + 1] or 0) * 256
  end
  local function blank_entry() return Versions.BAG_LIST_BLANK_TILE end
  cache:write(root .. "/list.rgba", bake_tiles_rgba(gfx, maleBanks, LW * 8, LH * 8, list_entry))
  cache:write(root .. "/list_female.rgba", bake_tiles_rgba(gfx, femaleBanks, LW * 8, LH * 8, list_entry))
  cache:write(root .. "/list_blank.rgba", bake_tiles_rgba(gfx, maleBanks, LW * 8, LH * 8, blank_entry))
  cache:write(root .. "/list_blank_female.rgba", bake_tiles_rgba(gfx, femaleBanks, LW * 8, LH * 8, blank_entry))
  -- src/item_menu.c:1118
  cache:write(root .. "/desc_sel.rgba", bake_tiles_rgba(gfx, maleBanks, W, 48, function(tx, ty)
    return map_entry(map, tx, ty + 14) % 4096 + 2 * 4096
  end))

  -- src/item_menu.c:569
  local pcMap = lz(Versions.BAG_BG_ITEM_PC_TILEMAP)
  cache:write(root .. "/bg_itempc.rgba", bake_bg_rgba(gfx, maleBanks, pcMap, W, H))
  cache:write(root .. "/bg_itempc_female.rgba", bake_bg_rgba(gfx, femaleBanks, pcMap, W, H))

  -- src/item_pc.c:435 ItemPc_LoadGraphics, :748 ItemPc_SetMessageWindowPalette
  local pcRoot = cacheRoot .. "/" .. BagChromeExtract.ITEM_PC_SUB
  local ipcGfx = lz(Versions.ITEM_PC_TILES)
  local ipcBanks = load_pal_banks(lz(Versions.ITEM_PC_BG_PALS), 3)
  local ipcMap = lz(Versions.ITEM_PC_TILEMAP)
  for name, msgPal in pairs({ bg = 1, bg_submenu = 2 }) do
    cache:write(pcRoot .. "/" .. name .. ".rgba", bake_tiles_rgba(ipcGfx, ipcBanks, W, H, function(tx, ty)
      local e = map_entry(ipcMap, tx, ty)
      if ty >= 14 then e = e % 4096 + msgPal * 4096 end
      return e
    end))
  end

  cache:write(root .. "/swap_line.rgba", bake_swap_line(lz(Versions.BAG_SWAP_GFX),
    lz(Versions.BAG_SWAP_PAL)))

  local arrowGfx = lz(Versions.RED_ARROW_OTHER_GFX)
  local arrowPal = readBytes(Versions.RED_ARROW_PAL, 32)
  cache:write(root .. "/red_arrow.rgba", bake_red_arrow(arrowGfx, arrowPal))

  local maleGfx = lz(Versions.BAG_MALE_GFX)
  local femaleGfx = lz(Versions.BAG_FEMALE_GFX)
  local sprPal = lz(Versions.BAG_SPRITE_PAL)
  local maleRgba, bw, bh, frames = bake_bag_sprite(maleGfx, sprPal)
  local femaleRgba = bake_bag_sprite(femaleGfx, sprPal)
  cache:write(root .. "/bag_male.rgba", maleRgba)
  cache:write(root .. "/bag_female.rgba", femaleRgba)

  local itemCount = Versions.ITEMS_COUNT or 375
  local tableOff = Versions.ITEM_ICON_TABLE
  local iconDir = root .. "/icons"
  local baked, failed = 0, 0
  local uniqGfx = {}

  for id = 0, itemCount do
    if progress and id % 50 == 0 then
      progress("icons", id, itemCount + 1)
    end
    local entryOff = tableOff + id * 8
    local gfxPtr = u32(entryOff)
    local palPtr = u32(entryOff + 4)
    local gfxOff = gba_to_file(gfxPtr)
    local palOff = gba_to_file(palPtr)
    if gfxOff and palOff then
      local ok, err = pcall(function()
        local key = string.format("%08x:%08x", gfxPtr, palPtr)
        local rgba = uniqGfx[key]
        if not rgba then
          local igfx = lz(gfxOff)
          local ipal = lz(palOff)
          rgba = bake_icon_rgba(igfx, ipal)
          uniqGfx[key] = rgba
        end
        cache:write(string.format("%s/%d.rgba", iconDir, id), rgba)
        baked = baked + 1
      end)
      if not ok then
        failed = failed + 1
        if failed <= 3 then
          print("[bag_chrome] icon " .. id .. " fail: " .. tostring(err))
        end
      end
    else
      failed = failed + 1
    end
  end
  if progress then progress("icons", itemCount + 1, itemCount + 1) end

  local manifest = string.format([[
return {
  format_version = %d,
  width = %d,
  height = %d,
  bagW = %d,
  bagH = %d,
  bagFrames = %d,
  listW = %d,
  listH = %d,
  iconW = 24,
  iconH = 24,
  itemCount = %d,
  iconsBaked = %d,
  iconsFailed = %d,
}
]],
    BagChromeExtract.FORMAT_VERSION, W, H, bw, bh, frames or 4,
    LW * 8, LH * 8, itemCount, baked, failed)
  cache:write(root .. "/manifest.lua", manifest)

  print(string.format("[bag_chrome] bg + bag sprites + %d icons (%d fail) → %s",
    baked, failed, root))
  return {
    root = root,
    width = W,
    height = H,
    iconsBaked = baked,
    iconsFailed = failed,
  }
end

function BagChromeExtract.ready(cache, cacheRoot)
  local root = (cacheRoot or default_cache_root()) .. "/" .. BagChromeExtract.CACHE_SUB
  local need = root .. "/bg.rgba"
  if cache and cache.exists and cache:exists(need) then
    return cache:exists(root .. "/icons/4.rgba")
  end
  return false
end

return BagChromeExtract