extends RefCounted
class_name EnemyShip

const THRUST        := 0.19
const DRAG          := 0.988
const MAX_SPEED     := 4.8
const TRAIL_LEN     := 16
const ATTACK_RANGE  := 600.0
const FIRE_INTERVAL := 90
const RESPAWN_MIN   := 4.0
const RESPAWN_MAX   := 8.0
const SEP_RADIUS    := 110.0  # anti-clump separation distance
const ORBIT_RADIUS  := 180.0  # circle-strafe orbit distance

# Three attack roles that prevent enemies from all rushing from the same angle.
enum Role { AGGRO, CIRCLE, FLANK }

var x: float; var y: float
var vx: float = 0.0; var vy: float = 0.0
var heading: float = 0.0
var trail: Array = []
var dead: bool = false
var respawn_timer: float = 0.0
var fire_timer: int = 0
var enemy_index: int = 0   # 0=red, 1=cyan (colour variant)
var role_id: int = 0       # sequential id, persists across respawns
var role: int = Role.AGGRO
var orbit_offset: float = 0.0

var patrol_timer: int = 0
var patrol_target: Vector2 = Vector2.ZERO

var stats: ShipStats = null
var current_shields: int = 0
var invuln_timer: int = 0

func apply_stats(s: ShipStats) -> void:
	stats = s
	current_shields = s.shield_charges

# Hull offsets ×2, rendered as 3×3 rects
const HULL_PIXELS := [
	[6, 0, "nose"],
	[4, -2, "mid"],  [4, 2, "mid"],
	[2, 0, "dim"],
	[0, -4, "accent"],[0, 4, "accent"],
	[0, 0, "bright"],
	[-2,-2, "dim"],  [-2, 2, "dim"],
	[-4,-4, "shadow"],[-4, 4, "shadow"],
	[-4, 0, "edge"],
]

var palette: Dictionary

func init(px: float, py: float, idx: int, rid: int = 0) -> void:
	x = px; y = py
	enemy_index = idx
	role_id = rid
	role = rid % 3
	# Each role_id starts at a different point on the orbit so enemies spread out
	orbit_offset = float(rid) * (TAU / 3.0)
	dead = false
	respawn_timer = 0.0
	# Stagger fire timers so enemies don't all shoot at the same frame
	fire_timer = FIRE_INTERVAL + rid * 17
	patrol_target = Vector2(px + randf_range(-250.0, 250.0), py + randf_range(-250.0, 250.0))
	patrol_timer = randi_range(60, 180)
	invuln_timer = 60
	if stats: current_shields = stats.shield_charges
	if idx == 0:
		palette = {
			"nose": Color("#ff8888"), "bright": Color("#ff4444"), "mid": Color("#cc2222"),
			"dim": Color("#882222"), "accent": Color("#ffaaaa"), "edge": Color("#441111"),
			"shadow": Color("#220000"), "trail": Color(1.0, 0.2, 0.2, 0.25),
			"thrustHot": Color("#ffcc44"), "thrustCool": Color(1.0, 0.4, 0.0, 0.5)
		}
	else:
		palette = {
			"nose": Color("#88ffff"), "bright": Color("#44ccff"), "mid": Color("#2288cc"),
			"dim": Color("#224488"), "accent": Color("#aaccff"), "edge": Color("#112244"),
			"shadow": Color("#001122"), "trail": Color(0.2, 0.8, 1.0, 0.25),
			"thrustHot": Color("#aaffcc"), "thrustCool": Color(0.2, 0.8, 1.0, 0.5)
		}

# enemies array is passed in so each enemy can compute separation from allies.
func update(players: Array, black_holes: Array, enemies: Array, world_w: float, world_h: float, delta: float) -> Bullet:
	if dead:
		respawn_timer -= delta
		return null
	if invuln_timer > 0:
		invuln_timer -= 1

	var eff_thrust: float = THRUST    * (stats.speed_mult    if stats else 1.0)
	var eff_max:    float = MAX_SPEED * (stats.speed_mult    if stats else 1.0)
	var eff_turn:   float = 0.1      * (stats.turn_mult     if stats else 1.0)
	var eff_interval: int = max(10, int(float(FIRE_INTERVAL) / (stats.fire_rate_mult if stats else 1.0)))

	# Find nearest living player
	var nearest_player = null
	var nearest_dist := INF
	for p in players:
		if p.dead: continue
		var dx: float = float(p.x) - x
		var dy: float = float(p.y) - y
		var d: float = sqrt(dx*dx + dy*dy)
		if d < nearest_dist:
			nearest_dist = d
			nearest_player = p

	# Black-hole avoidance — steer away when too close to pull radius
	var avoid_vx := 0.0; var avoid_vy := 0.0
	for bh in black_holes:
		var dx: float = x - float(bh.x)
		var dy: float = y - float(bh.y)
		var d: float = sqrt(dx*dx + dy*dy)
		if d < bh.pull_radius * 1.3 and d > 0.01:
			avoid_vx += (dx / d) * 3.0
			avoid_vy += (dy / d) * 3.0

	# Separation force — push away from nearby allies to prevent clumping
	var sep_vx := 0.0; var sep_vy := 0.0
	for en in enemies:
		var oe: EnemyShip = en
		if oe == self or oe.dead: continue
		var dx: float = x - oe.x
		var dy: float = y - oe.y
		var d: float = sqrt(dx*dx + dy*dy)
		if d < SEP_RADIUS and d > 0.01:
			var strength: float = (SEP_RADIUS - d) / SEP_RADIUS
			sep_vx += (dx / d) * strength * 2.0
			sep_vy += (dy / d) * strength * 2.0

	# Role-based movement
	if nearest_player != null and nearest_dist < ATTACK_RANGE:
		var pdx: float = float(nearest_player.x) - x
		var pdy: float = float(nearest_player.y) - y
		_move_attack(pdx, pdy, eff_thrust, eff_turn)
	else:
		_move_patrol(eff_thrust, eff_turn, world_w, world_h)

	vx += (avoid_vx + sep_vx) * 0.05
	vy += (avoid_vy + sep_vy) * 0.05

	vx *= DRAG; vy *= DRAG
	var spd := sqrt(vx*vx + vy*vy)
	if spd > eff_max:
		vx = vx / spd * eff_max
		vy = vy / spd * eff_max

	trail.push_front(Vector2(x, y))
	if trail.size() > TRAIL_LEN: trail.pop_back()

	x += vx; y += vy
	if x < 0: x += world_w
	elif x > world_w: x -= world_w
	if y < 0: y += world_h
	elif y > world_h: y -= world_h

	fire_timer -= 1
	if fire_timer <= 0 and nearest_player != null and nearest_dist < ATTACK_RANGE:
		fire_timer = eff_interval
		# Aim toward player with distance-based spread:
		# accurate at close range (~0.08 rad), less so at max range (~0.32 rad).
		var fdx: float = float(nearest_player.x) - x
		var fdy: float = float(nearest_player.y) - y
		var spread: float = lerp(0.08, 0.32, clamp(nearest_dist / ATTACK_RANGE, 0.0, 1.0))
		var fire_angle: float = atan2(fdy, fdx) + randf_range(-spread, spread)
		var b := Bullet.new()
		b.init(x + cos(fire_angle)*8.0, y + sin(fire_angle)*8.0, fire_angle, "enemy")
		if stats:
			b.vx *= stats.bullet_speed_mult
			b.vy *= stats.bullet_speed_mult
			b.effective_hit_radius = Bullet.HIT_RADIUS * stats.damage_mult
		return b
	return null

# Role.AGGRO: rush straight at player.
# Role.CIRCLE: maintain orbit around player at ORBIT_RADIUS.
# Role.FLANK: approach from a perpendicular angle left or right.
func _move_attack(pdx: float, pdy: float, eff_thrust: float, eff_turn: float) -> void:
	match role:
		Role.AGGRO:
			var ta := atan2(pdy, pdx)
			var ad := fmod(ta - heading + PI * 3.0, TAU) - PI
			heading += clamp(ad, -eff_turn, eff_turn)
			vx += cos(heading) * eff_thrust
			vy += sin(heading) * eff_thrust

		Role.CIRCLE:
			orbit_offset += 0.012
			# Target = player position + point on orbit circle
			var player_x: float = x + pdx
			var player_y: float = y + pdy
			var orbit_x: float = player_x + cos(orbit_offset) * ORBIT_RADIUS
			var orbit_y: float = player_y + sin(orbit_offset) * ORBIT_RADIUS
			var tdx: float = orbit_x - x
			var tdy: float = orbit_y - y
			var ta: float = atan2(tdy, tdx)
			var ad: float = fmod(ta - heading + PI * 3.0, TAU) - PI
			heading += clamp(ad, -eff_turn * 1.2, eff_turn * 1.2)
			vx += cos(heading) * eff_thrust
			vy += sin(heading) * eff_thrust

		Role.FLANK:
			# Approach from +90° or −90° relative to the direct line to player
			var direct: float = atan2(pdy, pdx)
			var flank_side: float = PI * 0.5 if (role_id % 2 == 0) else -PI * 0.5
			var player_x: float = x + pdx
			var player_y: float = y + pdy
			var flank_x: float = player_x + cos(direct + flank_side) * 80.0
			var flank_y: float = player_y + sin(direct + flank_side) * 80.0
			var tdx: float = flank_x - x
			var tdy: float = flank_y - y
			var ta: float = atan2(tdy, tdx)
			var ad: float = fmod(ta - heading + PI * 3.0, TAU) - PI
			heading += clamp(ad, -eff_turn, eff_turn)
			vx += cos(heading) * eff_thrust
			vy += sin(heading) * eff_thrust

func _move_patrol(eff_thrust: float, eff_turn: float, world_w: float, world_h: float) -> void:
	patrol_timer -= 1
	var to_target := Vector2(patrol_target.x - x, patrol_target.y - y)
	# Pick a new target when close enough or timer expires → spreads enemies across map
	if patrol_timer <= 0 or to_target.length() < 40.0:
		patrol_target = Vector2(
			randf_range(world_w * 0.1, world_w * 0.9),
			randf_range(world_h * 0.1, world_h * 0.9))
		patrol_timer = randi_range(120, 300)
	var angle: float = atan2(to_target.y, to_target.x)
	var ad: float = fmod(angle - heading + PI * 3.0, TAU) - PI
	heading += clamp(ad, -eff_turn * 0.8, eff_turn * 0.8)
	vx += cos(heading) * eff_thrust * 0.6
	vy += sin(heading) * eff_thrust * 0.6

func draw(canvas: CanvasItem) -> void:
	if dead: return
	var cos_h := cos(heading); var sin_h := sin(heading)
	for i in trail.size():
		var t_alpha := (1.0 - float(i) / float(TRAIL_LEN)) * 0.5
		var tc := Color(palette["trail"].r, palette["trail"].g, palette["trail"].b, t_alpha)
		canvas.draw_rect(Rect2(trail[i].x - 1, trail[i].y - 1, 2, 2), tc)
	for px_data in HULL_PIXELS:
		var lx: float = px_data[0]
		var ly: float = px_data[1]
		var col: Color = palette.get(px_data[2], Color.WHITE)
		var rx := x + lx * cos_h - ly * sin_h
		var ry := y + lx * sin_h + ly * cos_h
		canvas.draw_rect(Rect2(rx - 1, ry - 1, 3, 3), col)