extends Node

# World Map Block Properties
# 3 bytes
# Byte0: movement properties
#	0x01 = passable on foot
#	0x02 = passable on chocobo?
#	0x04 = passable on black chocobo
#	0x08 = passable on hiryuu?
#	0x10 = passable in submarine? set on deep water tiles, and all undersea tiles that aren't cliffs
#	0x20 = passable in ship? set on deep water tiles only (not undersea) - can submerge?
#	0x40 = passable in airship? Pretty much every tile aboveground has this. No undersea.
#	0x80 = only set on clear sea floor. Submarine pathable/can surface?
# Byte1: movement properties
#	0x01 = (water flips) can move from this block rightwards
#	0x02 = (water flips) can move from this block leftwards
#	0x04 = (water flips) can move from this block downwards
#	0x08 = (water flips) can move from this block upwards
#	0x10 = Chocobo can't land/dismount. most aboveground water tiles
#	0x20 = Black Chocobo can't land.
#	0x40 = Hiryuu can't land.
#	0x80 = Airship can't land.
# Byte2: movement properties
#	0x01 = Set on forests, deep water, void.
#	0x02 = Set on deep water, void, desert.
#	0x04 = Only set on diagonal land corners and Galuf World swamp
#	0x08 = No hits.
#	0x10 = Mountains and Exdeath's Castle
#	0x20 = Set on first two rows of forests, also waterfall, but not lower bounds of forests
#	0x40 = Shallow water.
#	0x80 =

# Vehicle landing bit masks: [00 10 20 40 00 00 80] - & with Byte1, if 1, can't land
# Vehicle IDs: [None,  Chocobo,  BlkChocobo,  Hiryuu,  Submarine,  Ship,  Airship]

# Worldmap animations
# World 1 (and probably 3)
# Sea tiles and waterfall tiles have a scrolling effect in tile data
# This may require setting up a proper tile indirect lookup shader
# Shifting sands and the portal have cycling palettes: $6C and $6D swap every frame, $51 through $55 scroll left (i.e. $55->$54, $51->$55)
# This will be best hardcoded as a 10 palette cycle
# World 2:
# Sea tiles have a horizontal scrolling effect in tile data (addresses $1880, $18C0, $1C80, $1CC0)
# ASM at C09660  BF 21 86 7F    LDA $7F8621,X
# Probably going to shader this effect instead of storing hundreds of frames
# No palette cycling

enum FlagsBlockPathing {
	PATHABLE_FOOT = 0x001,
	PATHABLE_CHOCOBO = 0x002,
	PATHABLE_BLACK_CHOCOBO = 0x004,
	PATHABLE_HIRYUU = 0x008,
	PATHABLE_SUBMARINE = 0x010,
	PATHABLE_SHIP = 0x020,
	PATHABLE_AIRSHIP = 0x040,
	SURFACEABLE = 0x080,
	LANDABLE_CHOCOBO = 0x100,
	LANDABLE_BLACK_CHOCOBO = 0x200,
	LANDABLE_HIRYUU = 0x400,
	LANDABLE_AIRSHIP = 0x800,
}

class WorldMap:
	const block_width := 256
	const block_height := 256
	const tile_width := block_width * 2
	const tile_height := block_height * 2
	var blockmap: PoolByteArray
	var block_tile_ids: PoolByteArray
	var block_pathing: PoolIntArray

	func get_block_tiles(id: int) -> PoolByteArray:
		var i = id * 4
		return self.block_tile_ids.subarray(i, i+4)

	func get_block_pathing_flags(id: int) -> int:
		return block_pathing[id]

	func make_tile_atlas() -> Image:
		var image := Image.new()
		var data := PoolByteArray()
		data.resize(tile_width*tile_height)
		var block_tile := 0
		for y_off in range(0, tile_height*tile_width, tile_width):
			for x_off in range(0, tile_width, 2):
				data[y_off + x_off] = self.block_tile_ids[block_tile]
				block_tile += 1
				data[y_off + x_off + 1] = self.block_tile_ids[block_tile]
				block_tile += 1
				data[y_off + tile_width + x_off] = self.block_tile_ids[block_tile]
				block_tile += 1
				data[y_off + tile_width + x_off + 1] = self.block_tile_ids[block_tile]
				block_tile += 1
		return image

var worldmaps = [WorldMap.new(), WorldMap.new(), WorldMap.new(), WorldMap.new(), WorldMap.new()]

var worldmap_block_properties = []
var worldmap_block_pathings = []
func load_worldmap_block_properties(rom: File):
	rom.seek(0x0FEA00)
	for world_ts in 3:
		var ts_properties = PoolIntArray()
		var ts_pathings = PoolIntArray()
		for block in 0xC0:
			var properties := rom.get_16() + (rom.get_8() << 16)
			ts_properties.append(properties)
			var pathings := properties >> 16  # First 8 pathable flags map directly
			pathings |= (((properties >> 12) & 0xF) ^ 0xF) << 8  # Next 4 flags (can land) are taken from high bits of second byte and inverted
			ts_pathings.append(pathings)
		worldmap_block_properties.append(ts_properties)
		worldmap_block_pathings.append(ts_pathings)
	worldmaps[0].block_pathing = worldmap_block_pathings[0]
	worldmaps[1].block_pathing = worldmap_block_pathings[1]
	worldmaps[2].block_pathing = worldmap_block_pathings[0]
	worldmaps[3].block_pathing = worldmap_block_pathings[2]
	worldmaps[4].block_pathing = worldmap_block_pathings[2]


func load_worldmaps(rom: File):
	var chunk_addresses = PoolIntArray()
	chunk_addresses.resize(0x500)  # 5 worldmaps * 256 chunks
	rom.seek(0x0FE000)
	for id in range(0, 0x434):
		chunk_addresses[id] = rom.get_16() + 0x070000
	for id in range(0x434, 0x500):
		chunk_addresses[id] = rom.get_16() + 0x080000

	for worldmap_id in 5:  # Bartz World, Galuf World, Combined World, Underwater Galuf World, Underwater Combined World
		# Worldmap chunks have a basic compression.
		# Repeated blocks along a row are run-length-encoded (RLE)
		# Certain blocks (mountains) expand to 1x3
		var blockmap = PoolByteArray()
		blockmap.resize(WorldMap.block_height * WorldMap.block_width)
		for chunk_id in range(worldmap_id*0x100, (worldmap_id+1)*0x100):
			rom.seek(chunk_addresses[chunk_id])
			while blockmap.size() < 256:
				var b := rom.get_8()
				if b >= 0xC0:  # RLE
					var count := b-0xBF
					var block = rom.get_8()
					for i in count:
						blockmap.append(block)
				else:
					blockmap.append(b)
					if b == 0x0C or b == 0x1C or b == 0x2C:
						# Mountain blocks expand to a 1x3
						blockmap.append(b+1)
						blockmap.append(b+2)
		worldmaps[worldmap_id].blockmap = blockmap

func update_worldmap_block_tile_ids(worldmap_block_tile_ids: Array):
	# Called by SpriteLoader
	worldmaps[0].block_tile_ids = worldmap_block_tile_ids[0]
	worldmaps[1].block_tile_ids = worldmap_block_tile_ids[1]
	worldmaps[2].block_tile_ids = worldmap_block_tile_ids[0]
	worldmaps[3].block_tile_ids = worldmap_block_tile_ids[2]
	worldmaps[4].block_tile_ids = worldmap_block_tile_ids[2]

func load_snes_rom(rom: File):
	load_worldmap_block_properties(rom)
	load_worldmaps(rom)