extends Node

var shader_material = load('res://palette_mat.tres')

# Portability for GLES2 vs GLES3 stuff
const INDEX_FORMAT := Image.FORMAT_L8


# Offsets

# Glyphs
const offset_glyphs_small := 0x1FF000  # 0x100 entries, 2bpp
const offset_glyphs_dialog := 0x03E800  # 0x100 entries, 1bpp
const offset_glyphs_kanji := 0x1BD000  # 0x1AA entries, 1bpp

# Images
const offset_title_ffv := 0x031243  # Type 02 headed compression, expands to 0x1000 bytes
const offset_title_dragon := 0x032D22  # Type 02 compression, expands to 0x1200 bytes
const offset_title_dragon_OAM := 0x033342  # Type 02 headed compression, expands to 0x0120 bytes

const offset_locations_bg_palettes := 0x03BB00  # 2bytes * 128 colors * 43 sets
const offset_worldmap_blocks := 0x0FF0C0  # 0x0FF3C0 0x0FF6C0
const offset_worldmap_tile_palettes := 0x0FF9C0  # 0x0FFAC0 0x0FFBC0  Length 0x100
const offset_worldmap_palettes := 0x0FFCC0  # 0x0FFDC0 0x0FFEC0  Length 0x100
const offset_worldmap_tiles := 0x1B8000  # 0x1BA000 0x1BC000

const offset_Character_Battle_Sprite_Tiles := 0x120000
const offset_Character_Battle_Sprite_Palettes := 0x14A3C0
const offset_Character_Battle_Sprite_Layouts := 0x14B997
const num_Character_Battle_Sprite_Layouts := 11

const offset_Character_Battle_Sprite_Disabled_Palette := 0x00F867
const offset_Character_Battle_Sprite_Stone_Palette := 0x00F807

const offset_Tiles_Fist := 0x11D710  # 3bpp tile

# Arrays to store sprites in
var worldmap_palette_imgs = []
var worldmap_palette_textures = []
var worldmap_tile_individual_imgs = []
var worldmap_tile_atlas_textures = []
var worldmap_block_tile_ids = []
var worldmap_block_individual_imgs = []
var worldmap_block_individual_textures = []
var worldmap_block_atlas_imgs = []
var worldmap_block_atlas_textures = []
# var worldmap_tile_atlas_textures = []

#var character_battle_sprite_tiles = []
#var character_battle_sprite_palette_imgs = []
var character_battle_sprite_palette_textures = []
var character_battle_sprite_palette_disabled_texture: ImageTexture
var character_battle_sprite_palette_stone_texture: ImageTexture
var weapon_textures = {}

func ByteArray(size: int) -> PoolByteArray:
	var arr := PoolByteArray()
	arr.resize(size)
	return arr

func texture_from_image(image: Image, flags: int = 0) -> ImageTexture:
	var tex = ImageTexture.new()
	tex.create_from_image(image, flags)
	return tex

func bgr555_to_color(short: int) -> Color:
	var color = Color()
	color.a = 1
	color.r = ((short & 0x1F) / 31.0)
	color.g = (((short >> 5) & 0x1F) / 31.0)
	color.b = (((short >> 10) & 0x1F) / 31.0)
	return color

func generate_palette_rgbf(rom: File, offset: int, length: int = 16) -> Image:
	rom.seek(offset)
	var img := Image.new()
	var rows := length/16
	img.create(16, rows, false, Image.FORMAT_RGBF)
	img.lock()
	for y in rows:
		for x in 16:
			var color = bgr555_to_color(rom.get_16())
			img.set_pixel(x, y, color)
	img.unlock()
	return img

func generate_palette_rgb8(rom: File, offset: int, length: int = 16) -> Image:
	# Safe for GLES2 only!
	# Implicit sRGB -> linear conversion on ImageTexture creation from RGB8 Image ruins this in GLES3 mode
	rom.seek(offset)
	var data = ByteArray(length*3)
	# img.lock()
	for i in length:
		var color := bgr555_to_color(rom.get_16())
		var j: int = i*3
		data[j] = color.r8
		data[j+1] = color.g8
		data[j+2] = color.b8
	var img := Image.new()
	img.create_from_data(16, length/16, false, Image.FORMAT_RGB8, data)
	return img

func generate_palette_rgb5_a1(rom: File, offset: int, length: int = 16) -> Image:
	var data = ByteArray(length*2)
	rom.seek(offset)
	for i in range(length):
		var bgr555 := rom.get_16()
		var r := bgr555 & 0x1F
		var g := (bgr555 >> 5) & 0x1F
		var b := (bgr555 >> 10) & 0x1F
		var rgb5_a1 := (r << 11) | (g << 6) | (b << 1) | 1
		data[i*2] = rgb5_a1 & 0xFF
		data[(i*2)+1] = rgb5_a1 >> 8
	var img := Image.new()
	img.create_from_data(16, length/16, false, Image.FORMAT_RGBA5551, data)
	return img

func generate_palette(rom: File, offset: int, length: int = 16) -> Image:
	if length < 16:
		length = 16
	return generate_palette_rgb8(rom, offset, length)

func gba_4bpp_to_tile(data: PoolByteArray) -> Image:
	var tdata := ByteArray(64)
	for i in range(32):
		tdata[i*2] = data[i] % 16
		tdata[i*2+1] = data[i] / 16
	var tile := Image.new()
	tile.create_from_data(8, 8, false, INDEX_FORMAT, tdata)
	return tile

func snes_mode7_to_tile(data: PoolByteArray) -> Image:
	# Easy one, it's just straight data left-to-right, top-to-bottom
	var tile := Image.new()
	tile.create_from_data(8, 8, false, INDEX_FORMAT, data)
	return tile

func snes_mode7_compressed_to_tile(data: PoolByteArray, tile_palette: int = 0) -> Image:
	# 4 bits per pixel.
	var tdata := ByteArray(64)
	for i in 32:
		var b := data[i]
		var j: int = i*2
		tdata[j] = (b & 0x0F) | tile_palette
		tdata[j+1] = (b >> 4) | tile_palette
	return snes_mode7_to_tile(tdata)

func snes_4plane_to_tile(data: PoolByteArray) -> Image:
	var tdata := ByteArray(64)
	for i in range(64):
		var j = (i/8)*2
		var x = 7 - (i%8)
		tdata[i] = (data[j] >> x & 1) | ((data[j+1] >> x & 1)<<1) | ((data[j+16] >> x & 1)<<2) | ((data[j+17] >> x & 1)<<3)
	var tile := Image.new()
	tile.create_from_data(8, 8, false, INDEX_FORMAT, tdata)
	return tile

func snes_3plane_to_tile(data: PoolByteArray) -> Image:
	var tdata := ByteArray(64)
	for i in range(64):
		var j = (i/8)*2
		var x = 7 - (i%8)
		tdata[i] = (data[j] >> x & 1) | ((data[j+1] >> x & 1)<<1) | ((data[(i/8)+16] >> x & 1)<<2)
	var tile := Image.new()
	tile.create_from_data(8, 8, false, INDEX_FORMAT, tdata)
	return tile

func snes_2plane_to_tile(data: PoolByteArray) -> Image:
	var tdata := ByteArray(64)
	for i in range(64):
		var j = (i/8)*2
		var x = 7 - (i%8)
		tdata[i] = (data[j] >> x & 1) | ((data[j+1] >> x & 1)<<1)
	var tile := Image.new()
	tile.create_from_data(8, 8, false, INDEX_FORMAT, tdata)
	return tile

func snes_1plane_to_tile(data: PoolByteArray) -> Image:
	var tdata := ByteArray(64)
	for i in range(64):
		var x = 7 - (i%8)
		tdata[i] = (data[i/8] >> x & 1)
	var tile := Image.new()
	tile.create_from_data(8, 8, false, INDEX_FORMAT, tdata)
	return tile

func snes_get_tile(rom: File, offset: int, length: int) -> Image:
	rom.seek(offset)
	var data := rom.get_buffer(length)
	var planes := length / 8
	match planes:
		4:
			return snes_4plane_to_tile(data)
		3:
			return snes_3plane_to_tile(data)
		2:
			return snes_2plane_to_tile(data)
		_:
			return snes_1plane_to_tile(data)


func make_tile_atlas(tile_images) -> Image:
	var r := Rect2(0, 0, 8, 8)
	var image = Image.new()
	image.create(128, 128, false, INDEX_FORMAT)
	var tile = 0
	for y in tile_images.size()/16:
		for x in 16:
			image.blit_rect(tile_images[tile], r, Vector2(x*8, y*8))
			tile += 1
	return image


func snes_load_worldmap(rom: File):
	# Load Worldmap Graphics
	var worldmap_tile_counts = [256, 256, 128]  # Only 128 underwater tiles
	for world_ts in 3:  # Bartz/Combined World, Galuf World, Underwater  (world tilesets, not to be confused with the 5 world maps)
		var tile_count: int = worldmap_tile_counts[world_ts]
		var image := generate_palette(rom, offset_worldmap_palettes + (world_ts*0x100), 0x100)
		worldmap_palette_imgs.append(image)
		worldmap_palette_textures.append(texture_from_image(image))

		var tile_palettes = []
		rom.seek(offset_worldmap_tile_palettes + (world_ts*0x100))
		for pal in 256:
			tile_palettes.append(rom.get_8())

		var tile_images = []
		# var tile_textures = []
		rom.seek(offset_worldmap_tiles + (world_ts*0x2000))
		for tile in tile_count:
			var tiledata := rom.get_buffer(32)
			image = snes_mode7_compressed_to_tile(tiledata, tile_palettes[tile])
			tile_images.append(image)
			# tile_textures.append(texture_from_image(image))
		worldmap_tile_individual_imgs.append(tile_images)
		worldmap_tile_atlas_textures.append(texture_from_image(make_tile_atlas(tile_images)))


		# Block definitions
		var block_images = []
		var block_textures = []
		var block_bank_start: int = offset_worldmap_blocks + (world_ts*0x300)
		var block_tile_ids := PoolByteArray()
		for block in 0xC0:  # 192 blocks per world tileset
			image = Image.new()
			image.create(16, 16, false, INDEX_FORMAT)
			for tile in 4:
				rom.seek(block_bank_start + block + (tile * 0xC0))  # Horrible interleaving scheme
				var src_idx := rom.get_8()
				block_tile_ids.append(src_idx)
				if src_idx < tile_count:
					image.blit_rect(tile_images[src_idx], Rect2(0, 0, 8, 8), Vector2((tile%2)*8, (tile/2)*8))
			block_images.append(image)
			block_textures.append(texture_from_image(image))
		worldmap_block_individual_imgs.append(block_images)
		worldmap_block_individual_textures.append(block_textures)
		worldmap_block_tile_ids.append(block_tile_ids)
		# Make block atlas
		image = Image.new()
		image.create(16*16, 16*12, false, INDEX_FORMAT)
		for block in 0xC0:
			image.blit_rect(block_images[block], Rect2(0, 0, 16, 16), Vector2((block%16)*16, (block/16)*16))
		worldmap_block_atlas_imgs.append(image)
		worldmap_block_atlas_textures.append(texture_from_image(image))

		# # DEBUG: Make tile atlas
		# image = Image.new()
		# image.create(16*8, (tile_count/16)*8, false, INDEX_FORMAT)
		# for tile in tile_count:
		# 	image.blit_rect(tile_images[tile], Rect2(0, 0, 8, 8), Vector2((tile%16)*8, (tile/16)*8))
		# worldmap_tile_atlas_textures.append(texture_from_image(image))

	MapLoader.update_worldmap_block_tile_ids(worldmap_block_tile_ids)


func load_snes_rom(rom: File):
	# Load Battle sprites
	rom.seek(offset_Character_Battle_Sprite_Layouts)
	var battle_strip_layouts = rom.get_buffer(num_Character_Battle_Sprite_Layouts * 6)
	# Character Battle Sprite Tiles
	for strip in range(0, 22*5):
		var tiles = []
		for i in range(0, 32*48, 32):
			tiles.append(snes_get_tile(rom, offset_Character_Battle_Sprite_Tiles + (strip*32*48) + i, 32))
		var strip_image = Image.new()
		strip_image.create(16, 24 * num_Character_Battle_Sprite_Layouts, false, INDEX_FORMAT)
		for i in range(6 * num_Character_Battle_Sprite_Layouts):
			strip_image.blit_rect(tiles[battle_strip_layouts[i]], Rect2(0, 0, 8, 8), Vector2((i%2) * 8, (i/2) * 8))
		strip_images.append(strip_image)
		strip_textures.append(texture_from_image(strip_image))

	# Character Battle Sprite Palettes
	for palette in range(0, 22*5):
		character_battle_sprite_palette_textures.append(texture_from_image(generate_palette(rom, offset_Character_Battle_Sprite_Palettes + (palette*32))))
	character_battle_sprite_palette_disabled_texture = texture_from_image(generate_palette(rom, offset_Character_Battle_Sprite_Disabled_Palette))
	character_battle_sprite_palette_stone_texture = texture_from_image(generate_palette(rom, offset_Character_Battle_Sprite_Stone_Palette))

	weapon_textures['Fist'] = texture_from_image(snes_get_tile(rom, offset_Tiles_Fist, 24))

	snes_load_worldmap(rom)


const gba_marker := 'FINAL FANTASY V      ADVANCE    SYGMAB'
const gba_marker_pos_US := 0x12FE10
const gba_marker_pos_EU := 0x131294
const gba_offset_battle_sprite_tiles := 504
const gba_offset_battle_sprite_palettes := 1064
const gba_offset_battle_sprite_layouts := 9435
func load_gba_rom(filename: String):
	var rom := File.new()
	var offset_marker: int
	var result = rom.open(filename, File.READ)
	if result != 0:
		print_debug('ROM failed to open: ', result)
		return

	rom.seek(gba_marker_pos_US)
	if rom.get_buffer(len(gba_marker)).get_string_from_ascii() == gba_marker:
		offset_marker = gba_marker_pos_US
	else:
		rom.seek(gba_marker_pos_EU)
		if rom.get_buffer(len(gba_marker)).get_string_from_ascii() == gba_marker:
			offset_marker = gba_marker_pos_EU
		else:
			print_debug('ROM does not match known US/EU ROMs, aborting')
			return

	# Battle Sprite Tiles
	rom.seek(offset_marker + gba_offset_battle_sprite_layouts)
	var battle_strip_layouts = rom.get_buffer(num_Character_Battle_Sprite_Layouts * 6)
	for strip in range(0, 26*5):
		var tiles = []
		rom.seek(offset_marker + gba_offset_battle_sprite_tiles + strip*4)
		var address = rom.get_32() - 0x08000000
		var tiledata = CommonGBA.LZ77_decompress(rom, address)
		tiledata.append(0)  # Slicing to end of array causes an engine crash. For shame!
		for i in range(8, 57*32+8, 32):
			tiles.append(gba_4bpp_to_tile(tiledata.subarray(i, i+32)))
		var strip_image = Image.new()
		strip_image.create(16, 24 * num_Character_Battle_Sprite_Layouts, false, INDEX_FORMAT)
		for i in range(6 * num_Character_Battle_Sprite_Layouts):
			strip_image.blit_rect(tiles[battle_strip_layouts[i]], Rect2(0, 0, 8, 8), Vector2((i%2) * 8, (i/2) * 8))
		strip_images.append(strip_image)
		strip_textures.append(texture_from_image(strip_image))

	# Character Battle Sprite Palettes
	for palette in range(0, 26*5):
		rom.seek(offset_marker + gba_offset_battle_sprite_palettes + palette*4)
		character_battle_sprite_palette_textures.append(texture_from_image(generate_palette(rom, rom.get_32() - 0x08000000 + 8)))
#	character_battle_sprite_palette_disabled_texture = texture_from_image(generate_palette(rom, offset_Character_Battle_Sprite_Disabled_Palette))
#	character_battle_sprite_palette_stone_texture = texture_from_image(generate_palette(rom, offset_Character_Battle_Sprite_Stone_Palette))


var strip_images = []
var strip_textures = []
# func _ready():
	#pass