## Linear gun: predict enemy continues at current velocity and heading.
## Coordinate system: 0° = East, CCW positive (Tank Royale standard).

import std/math
import gun_harness/gun_interface

type LinearGun* = object
  debugGraphics*: bool

proc predict*(g: var LinearGun, state: WorldState, bulletSpeed: float): GunPrediction =
  let dist = hypot(state.enemyX - state.selfX, state.enemyY - state.selfY)
  let ticksToArrive = dist / bulletSpeed
  let headingRad = degToRad(state.enemyHeading)
  var px = state.enemyX + cos(headingRad) * state.enemySpeed * ticksToArrive
  var py = state.enemyY + sin(headingRad) * state.enemySpeed * ticksToArrive
  # Clamp to arena bounds
  px = clamp(px, 0.0, state.arenaWidth)
  py = clamp(py, 0.0, state.arenaHeight)
  GunPrediction(x: px, y: py)

proc onResult*(g: var LinearGun, e: FeedbackEvent) =
  discard  # analytical gun — no learning