extends SceneTree

# Usage:
#   godot --headless --path demo --script scripts/export_map.gd -- SEED DEPTH [LEVELS] OUT.map
#
# Generates N dungeons (seeds SEED..SEED+N-1, depths DEPTH..DEPTH+N-1),
# stacks them vertically, and writes one Standard Quake .map file.
#
# Chasms on non-bottom levels are real holes — no floor brush, and the
# level below has its ceiling drilled out at the same (x,y) so the shaft
# stays open all the way down until it hits a non-chasm floor. Chasms on
# the bottom level get a local pit floor at CHASM_TOP so you don't fall
# into the void.

const TILE_SIZE := 64
const HEIGHT := 128
const WALL_THICKNESS := 64
const TEXTURE := "__TB_empty"

const FLOOR_TOP := 0
const WATER_TOP := -32
const CHASM_TOP := -128
const PIT_BOTTOM := CHASM_TOP - WALL_THICKNESS   # = -192
const WALL_TOP := HEIGHT + WALL_THICKNESS        # = 192

# Per-level Z offset. Each level's brushes get translated by
# -level_index * LEVEL_SPACING. Sized so level N+1's ceiling top sits at
# or below level N's PIT_BOTTOM — no overlap, no z-fighting.
const LEVEL_SPACING := 384

# terrain_t
const T_NOTHING     := 0
const T_FLOOR       := 1
const T_WALL        := 2
const T_DOOR        := 3
const T_CORRIDOR    := 4
const T_LIQUID      := 5
const T_BRIDGE      := 6
const T_STAIRS_UP   := 7
const T_STAIRS_DOWN := 8

# liquid_t
const L_WATER := 1
const L_CHASM := 3

enum Kind { EMPTY, WALL, FLOOR, WATER, CHASM }

func _init() -> void:
	var args := OS.get_cmdline_user_args()
	var seed: int
	var depth: int
	var levels: int
	var out_path: String
	match args.size():
		3:
			seed = int(args[0])
			depth = int(args[1])
			levels = 1
			out_path = args[2]
		4:
			seed = int(args[0])
			depth = int(args[1])
			levels = int(args[2])
			out_path = args[3]
		_:
			push_error("usage: -- SEED DEPTH [LEVELS] OUT.map")
			quit(1)
			return

	if levels < 1:
		push_error("levels must be >= 1")
		quit(1)
		return

	var grids: Array = []
	for k in range(levels):
		var gen := BrogueGen.new()
		grids.append(gen.generate(seed + k, depth + k))
		gen.free()

	var f := FileAccess.open(out_path, FileAccess.WRITE)
	if f == null:
		push_error("cannot open %s for write" % out_path)
		quit(1)
		return

	var brush_count := _write_map(f, grids, seed, depth)
	f.close()
	print("wrote %s — %d levels, %d brushes" % [out_path, levels, brush_count])
	quit(0)

func _write_map(f: FileAccess, grids: Array, seed: int, depth: int) -> int:
	f.store_string("// Game: FuncGodot\n")
	f.store_string("// Format: Valve\n")
	f.store_string("// Generated by brogue-genesis — seed: %d, depth: %d, levels: %d\n" % [
		seed, depth, grids.size(),
	])
	f.store_string("{\n")
	f.store_string("\"classname\" \"worldspawn\"\n")

	var count := 0
	var w: int = grids[0]["width"]
	var h: int = grids[0]["height"]
	# Per-(x,y) flag: "some level above has a chasm here, so our ceiling
	# is drilled out so the shaft stays open". Accumulates top-down.
	var chasm_above := PackedByteArray()
	chasm_above.resize(w * h)

	for k in range(grids.size()):
		var grid: Dictionary = grids[k]
		var is_bottom := (k == grids.size() - 1)
		var z_offset := -k * LEVEL_SPACING
		count += _write_level(f, grid, z_offset, chasm_above, is_bottom)
		# Update chasm_above for the next level using THIS level's chasms.
		_propagate_chasms(grid, chasm_above)

	f.store_string("}\n")
	return count

func _write_level(f: FileAccess, grid: Dictionary, z_off: int,
				chasm_above: PackedByteArray, is_bottom: bool) -> int:
	var w: int = grid["width"]
	var h: int = grid["height"]
	var terrain: PackedByteArray = grid["terrain"]
	var liquid: PackedByteArray = grid["liquid"]

	var count := 0
	var ts := TILE_SIZE

	# Pass 1 — floors / walls, row-merged by kind.
	for gy in range(h):
		var run_start := 0
		var run_kind := _kind(terrain, liquid, w, 0, gy)
		for gx in range(1, w + 1):
			var cur: int = Kind.EMPTY
			if gx < w:
				cur = _kind(terrain, liquid, w, gx, gy)
			if cur == run_kind and gx < w:
				continue
			var x0 := run_start * ts
			var x1 := gx * ts
			var y0 := gy * ts
			var y1 := (gy + 1) * ts
			match run_kind:
				Kind.WALL:
					count += _emit_box(f, x0, y0, z_off + PIT_BOTTOM,
										x1, y1, z_off + WALL_TOP)
				Kind.FLOOR:
					count += _emit_box(f, x0, y0, z_off + PIT_BOTTOM,
										x1, y1, z_off + FLOOR_TOP)
				Kind.WATER:
					count += _emit_box(f, x0, y0, z_off + PIT_BOTTOM,
										x1, y1, z_off + WATER_TOP)
				Kind.CHASM:
					# Non-bottom chasms are real holes — no floor. Bottom
					# chasms get a local pit floor so the player doesn't
					# fall into empty void.
					if is_bottom:
						count += _emit_box(f, x0, y0, z_off + PIT_BOTTOM,
											x1, y1, z_off + CHASM_TOP)
				_:
					pass
			run_start = gx
			run_kind = cur

	# Pass 2 — ceilings, row-merged by "is ceiling present here?". A
	# ceiling is present if the cell has floor-like terrain AND no level
	# above has drilled a chasm through it.
	for gy in range(h):
		var run_start := 0
		var run_has := _has_ceiling(terrain, chasm_above, w, 0, gy)
		for gx in range(1, w + 1):
			var cur := false
			if gx < w:
				cur = _has_ceiling(terrain, chasm_above, w, gx, gy)
			if cur == run_has and gx < w:
				continue
			if run_has:
				var x0 := run_start * ts
				var x1 := gx * ts
				var y0 := gy * ts
				var y1 := (gy + 1) * ts
				count += _emit_box(f, x0, y0, z_off + HEIGHT,
									x1, y1, z_off + WALL_TOP)
			run_start = gx
			run_has = cur

	return count

# Record any chasm cells at this level into the running mask so the NEXT
# level knows to drill its ceiling there.
func _propagate_chasms(grid: Dictionary, chasm_above: PackedByteArray) -> void:
	var w: int = grid["width"]
	var h: int = grid["height"]
	var terrain: PackedByteArray = grid["terrain"]
	var liquid: PackedByteArray = grid["liquid"]
	for gy in range(h):
		for gx in range(w):
			var idx := gy * w + gx
			if terrain[idx] == T_LIQUID and liquid[idx] == L_CHASM:
				chasm_above[idx] = 1

# Draw kind for floor/wall emission.
func _kind(terrain: PackedByteArray, liquid: PackedByteArray,
			w: int, x: int, y: int) -> int:
	var idx := y * w + x
	var t: int = terrain[idx]
	match t:
		T_NOTHING:  return Kind.EMPTY
		T_WALL:     return Kind.WALL
		T_LIQUID:
			var liq: int = liquid[idx]
			if liq == L_CHASM: return Kind.CHASM
			if liq == L_WATER: return Kind.WATER
			return Kind.FLOOR  # lava / brimstone sit at floor level
		_:          return Kind.FLOOR

# Ceiling emitted when the cell is floor-like AND no chasm sits above it.
# Walls and empty cells don't get ceilings either (wall brush already
# reaches WALL_TOP; empty is empty).
func _has_ceiling(terrain: PackedByteArray, chasm_above: PackedByteArray,
					w: int, x: int, y: int) -> bool:
	var idx := y * w + x
	if chasm_above[idx] != 0:
		return false
	var t: int = terrain[idx]
	return t != T_NOTHING and t != T_WALL

# Standard Quake brush: 6 axis-aligned planes, 3 points per plane, inward
# normals per TrenchBroom convention. Mirrors libd's emit_solid_box.
func _emit_box(f: FileAccess, x0: int, y0: int, z0: int,
				x1: int, y1: int, z1: int) -> int:
	if x0 >= x1 or y0 >= y1 or z0 >= z1:
		return 0
	f.store_string("{\n")
	# Valve 220 texture axes per face normal (Quake convention).
	# X-facing walls: U=Y, V=-Z. Y-facing walls: U=X, V=-Z. Z-facing: U=X, V=-Y.
	var ax_x := "[ 0 1 0 0 ] [ 0 0 -1 0 ]"
	var ax_y := "[ 1 0 0 0 ] [ 0 0 -1 0 ]"
	var ax_z := "[ 1 0 0 0 ] [ 0 -1 0 0 ]"
	# -X
	_face(f, x0, y0, z0, x0, y1, z0, x0, y0, z1, ax_x)
	# +X
	_face(f, x1, y0, z0, x1, y0, z1, x1, y1, z0, ax_x)
	# -Y
	_face(f, x0, y0, z1, x1, y0, z1, x0, y0, z0, ax_y)
	# +Y
	_face(f, x0, y1, z0, x1, y1, z0, x0, y1, z1, ax_y)
	# -Z
	_face(f, x0, y0, z0, x1, y0, z0, x0, y1, z0, ax_z)
	# +Z
	_face(f, x0, y0, z1, x0, y1, z1, x1, y0, z1, ax_z)
	f.store_string("}\n")
	return 1

func _face(f: FileAccess, x1: int, y1: int, z1: int,
			x2: int, y2: int, z2: int,
			x3: int, y3: int, z3: int, axes: String) -> void:
	f.store_string("( %d %d %d ) ( %d %d %d ) ( %d %d %d ) %s %s 0 1 1\n" % [
		x1, y1, z1, x2, y2, z2, x3, y3, z3, TEXTURE, axes,
	])