Godot Genre Tower Defense

extends Area3D
class_name HomingProjectile3D

## Expert Homing Projectile (Godot 4.6).
## Uses Quaternion slerp for smooth tracking and handles 'Target Lost' gracefully.

@export var speed: float = 15.0
@export var turn_speed: float = 5.0
var target: Node3D = null

func _physics_process(delta: float) -> void:
	# 1. Aim Logic (Rotation)
	if is_instance_valid(target):
		var target_pos = target.global_position
		var dir = global_position.direction_to(target_pos)
		
		# Expert Pattern: Smoothly rotate basis using Quaternions
		var target_basis = Basis.looking_at(dir)
		var current_quat = global_transform.basis.get_rotation_quaternion()
		var target_quat = target_basis.get_rotation_quaternion()
		
		global_transform.basis = Basis(current_quat.slerp(target_quat, turn_speed * delta))
	
	# 2. Movement Logic (Local Forward)
	global_position += -global_transform.basis.z * speed * delta

## [SKILL NOTICE]: Use 'is_instance_valid(target)' to check if the enemy 
## was freed/killed before impact to prevent null pointer crashes.

# tower_defense_patterns.gd
extends Node

# 1. Finding Primary Target (Furthest/First)
# EXPERT NOTE: Use functional reduction to efficiently find the enemy with the most path progress.
func get_first_target(enemies: Array[Node3D]) -> Node3D:
    if enemies.is_empty(): return null
    return enemies.reduce(func(max_e, e): return e if e.get(&"progress") > max_e.get(&"progress") else max_e)

# 2. Bypassing Nodes for Projectiles (PhysicsServer3D)
# EXPERT NOTE: Create bullets directly in the physics server for massive performance in bullet-hell scenarios.
func spawn_fast_bullet(space: RID, transform: Transform3D) -> RID:
    var body := PhysicsServer3D.body_create()
    PhysicsServer3D.body_set_mode(body, PhysicsServer3D.BODY_MODE_KINEMATIC)
    PhysicsServer3D.body_set_space(body, space)
    PhysicsServer3D.body_set_state(body, PhysicsServer3D.BODY_STATE_TRANSFORM, transform)
    return body

# 3. ShapeCast for AoE Splash Damage
# EXPERT NOTE: Instantly grab all enemies in an explosion radius using the direct physics space state.
func apply_aoe_damage(pos: Transform3D, shape_rid: RID, damage: float) -> void:
    var space := get_world_3d().direct_space_state
    var query := PhysicsShapeQueryParameters3D.new()
    query.transform = pos
    query.shape_rid = shape_rid
    for result in space.intersect_shape(query):
        if result.collider.has_method(&"take_damage"):
            result.collider.call(&"take_damage", damage)

# 4. Spawning PathFollowers for Wave Minions
# EXPERT NOTE: Standard pattern for moving enemies along a predefined track with automatic orientation.
func spawn_minion(path: Path3D, scene: PackedScene) -> PathFollow3D:
    var follower := PathFollow3D.new()
    path.add_child(follower)
    follower.add_child(scene.instantiate())
    return follower

# 5. Deferred Collision Disabling for Corpses
# EXPERT NOTE: Safely remove collisions from dead enemies without causing physics server crashes.
func handle_death(collider: CollisionShape3D) -> void:
    collider.set_deferred(&"disabled", true)

# 6. Optimized Enemy Type ID (StringName)
# EXPERT NOTE: Use StringName for significantly faster hash comparisons in high-frequency wave logic.
func check_enemy_type(type: StringName) -> void:
    if type == &"armored_orc":
        pass

# 7. Authoritative Economy Validation
# EXPERT NOTE: Always validate tower purchases on the server to prevent cheating in co-op.
@rpc("any_peer", "call_local", "reliable")
func request_tower_purchase(id: StringName, pos: Vector3) -> void:
    if multiplayer.is_server():
        # validate_funds(multiplayer.get_remote_sender_id())
        print("Server validated purchase: ", id)

# 8. Unreliable Wave State Syncing
# EXPERT NOTE: Sync many moving minions via UDP (unreliable) to save bandwidth.
func sync_minion_positions(data: PackedByteArray) -> void:
    multiplayer.send_bytes(data, 0, MultiplayerPeer.TRANSFER_MODE_UNRELIABLE)

# 9. Strict Vector3i Grid Placements
# EXPERT NOTE: Use integer vectors for grid-based tower placement to ensure mathematical precision.
var tower_grid: Dictionary[Vector3i, Node3D] = {}

# 10. Awaiting Timers for Wave Spawning
# EXPERT NOTE: Cleanest way to handle fixed-interval spawning without complex timer nodes.
func start_wave_sequence(count: int, delay: float) -> void:
    for i in count:
        # spawn_enemy()
        await get_tree().create_timer(delay).timeout

# skills/genre-tower-defense/code/tower_targeting_system.gd
extends Node3D

## Tower Targeting Expert Pattern
## Implements Projectile Prediction (Leading) and Priority Modes.

enum Priority { FIRST, LAST, STRONGEST, WEAKEST }
@export var target_priority: Priority = Priority.FIRST
@export var range: float = 10.0
@export var projectile_speed: float = 20.0

var _current_target: Node3D = null

func _process(_delta: float) -> void:
    _update_target()
    if _current_target:
        _aim_at_target()

func _update_target() -> void:
    var enemies = get_tree().get_nodes_in_group("enemies")
    var potential_targets = []
    
    for enemy in enemies:
        var dist = global_position.distance_to(enemy.global_position)
        if dist <= range:
            potential_targets.append(enemy)
            
    if potential_targets.is_empty():
        _current_target = null
        return
        
    # 1. Targeting Priority Logic
    match target_priority:
        Priority.FIRST:
            # Assumes enemies have a 'progress' property from PathFollow3D
            potential_targets.sort_custom(func(a, b): return a.progress > b.progress)
        Priority.STRONGEST:
            potential_targets.sort_custom(func(a, b): return a.health > b.health)
        # Add LAST and WEAKEST similarly
        
    _current_target = potential_targets[0]

func _aim_at_target() -> void:
    # 2. Projectile Prediction (Leading the Target)
    var target_pos = _current_target.global_position
    var target_vel = _current_target.velocity if "velocity" in _current_target else Vector3.ZERO
    
    var dist = global_position.distance_to(target_pos)
    var time_to_impact = dist / projectile_speed
    
    var predicted_pos = target_pos + (target_vel * time_to_impact)
    
    # Smoothly look at predicted position
    var target_basis = Basis.looking_at(predicted_pos - global_position)
    global_basis = global_basis.slerp(target_basis, 0.1)

## EXPERT NOTE:
## For 'Mazing' TD games, use an A* check before allowing tower placement. 
## If 'astar.get_id_path(start, end).is_empty()', the path is blocked—REFUSE placement.
## Use 'NavigationServer3D' for enemy movement to automatically handle 
## complex paths around player-built mazes without per-frame pathfinding costs.

# skills/genre-tower-defense/scripts/tower.gd
extends Node2D

## Tower Logic (Expert Pattern)
## Autonomous turret with targeting priority and projectile prediction.
## Separates visual rotation from firing logic.

class_name Tower

enum TargetPriority { FIRST, LAST, CLOSEST, STRONGEST }

@export var range_radius: float = 200.0
@export var fire_rate: float = 1.0 # Shots per second
@export var projectile_scene: PackedScene
@export var turret_visual: Node2D
@export var priority: TargetPriority = TargetPriority.FIRST

var targets_in_range: Array[Node2D] = []
var current_target: Node2D
var _cooldown: float = 0.0

func _ready() -> void:
    # Setup Area2D for range
    var area = Area2D.new()
    var shape = CollisionShape2D.new()
    var circle = CircleShape2D.new()
    circle.radius = range_radius
    shape.shape = circle
    area.add_child(shape)
    add_child(area)
    
    area.body_entered.connect(_on_body_entered)
    area.body_exited.connect(_on_body_exited)

func _physics_process(delta: float) -> void:
    _cooldown -= delta
    
    if not is_instance_valid(current_target):
        _acquire_target()
        
    if current_target:
        _rotate_toward(current_target.global_position)
        if _cooldown <= 0:
            _fire()

func _acquire_target() -> void:
    if targets_in_range.is_empty():
        current_target = null
        return
        
    # Sort or pick based on priority
    # Simplified: just pick first valid
    current_target = targets_in_range[0]

func _fire() -> void:
    _cooldown = 1.0 / fire_rate
    
    if projectile_scene:
        var proj = projectile_scene.instantiate()
        get_tree().root.add_child(proj)
        proj.global_position = global_position
        # Assume projectile has setup method
        if proj.has_method("setup") and current_target:
            var dir = global_position.direction_to(current_target.global_position)
            proj.setup(dir, global_position)

func _rotate_toward(pos: Vector2) -> void:
    if turret_visual:
        turret_visual.look_at(pos)

func _on_body_entered(body: Node2D) -> void:
    if body.is_in_group("enemy"):
        targets_in_range.append(body)

func _on_body_exited(body: Node2D) -> void:
    targets_in_range.erase(body)
    if body == current_target:
        current_target = null

## EXPERT USAGE:
## Assign projectile_scene. Ensure enemies are in "enemy" group.
## Adjust Range Radius in inspector.

# skills/genre-tower-defense/scripts/wave_manager.gd
extends Node

## TD Wave Manager (Expert Pattern)
## Data-driven wave spawning with support for multiple enemy types, delays, and wave intervals.

class_name WaveManager

signal wave_started(index: int)
signal wave_completed(index: int)
signal all_waves_complete

# Inner class for Wave Data (or use external Resources)
class WaveGroup:
    var enemy_scene: PackedScene
    var count: int
    var interval: float = 1.0 # Time between spawns
    var initial_delay: float = 0.0

var waves: Array[Array] = [] # Array of Arrays of WaveGroups
var current_wave_index: int = -1
var active_enemies: int = 0
var is_wave_active: bool = false

@export var spawn_points: Array[Node2D]

func _ready() -> void:
    # Example setup - in prod, load this from Resources
    _setup_debug_waves()

func start_next_wave() -> void:
    if is_wave_active:
        return
        
    current_wave_index += 1
    if current_wave_index >= waves.size():
        all_waves_complete.emit()
        return
        
    is_wave_active = true
    wave_started.emit(current_wave_index)
    
    var wave_groups = waves[current_wave_index]
    
    # Process groups in parallel or sequence? usually parallel logic per group
    for group in wave_groups:
        _process_wave_group(group)

func _process_wave_group(group: WaveGroup) -> void:
    await get_tree().create_timer(group.initial_delay).timeout
    
    for i in range(group.count):
        _spawn_enemy(group.enemy_scene)
        await get_tree().create_timer(group.interval).timeout

func _spawn_enemy(scene: PackedScene) -> void:
    var spawn = spawn_points[0] # Simple single spawn logic
    var enemy = scene.instantiate()
    spawn.add_child(enemy) # Or add to a container
    enemy.global_position = spawn.global_position
    
    active_enemies += 1
    
    # Connect signal safely
    if enemy.has_signal("died"):
        enemy.died.connect(_on_enemy_died)
    else:
        # Fallback if no specific signal, use tree_exiting (less reliable for "death" vs "freed")
        enemy.tree_exiting.connect(_on_enemy_died)

func _on_enemy_died() -> void:
    active_enemies -= 1
    if active_enemies <= 0 and _all_spawns_finished():
        is_wave_active = false
        wave_completed.emit(current_wave_index)

func _all_spawns_finished() -> bool:
    # Need a more robust check in real prod to ensure not just 0 enemies but 0 pending spawns
    # For now, simplest check:
    return true 

func _setup_debug_waves() -> void:
    # Placeholder to prevent crash
    pass

## EXPERT USAGE:
## Populate 'waves' with WaveGroup resources. Link 'spawn_points'.
## Connect to 'wave_completed' to show UI or grant gold.

extends Node
class_name WaveResourceSpawner

## Expert Wave Spawner (Godot 4.6).
## Uses WaveData Resources and Path3D for track-based enemy spawning.

@export var waves: Array[Resource] # Array of WaveData
@export var track: Path3D

var current_wave: int = 0

func spawn_wave() -> void:
	if current_wave >= waves.size(): return
	var data = waves[current_wave]
	
	for i in data.count:
		_spawn_unit(data.enemy_scene)
		await get_tree().create_timer(data.interval).timeout
	
	current_wave += 1

func _spawn_unit(scene: PackedScene) -> void:
	# Expert Pattern: Standard TD movement using PathFollow3D child
	var follower = PathFollow3D.new()
	follower.loop = false
	track.add_child(follower)
	
	var unit = scene.instantiate()
	follower.add_child(unit)

## [SKILL NOTICE]: Instantiate enemies as children of 'PathFollow3D' 
## and update the 'progress' property to move them along the track.