## Unit checks for the j133/j134 fire-detection fix (`TR_STRAFE_FIRE_FIX`).
##
## NO battle, NO Java, NO server. Run with:
##   nim c -r --nimcache:/tmp/nc_j133 --path:common_libs \
##       common_libs/tests/test_strafe_fire_fix.nim
##
## The shipped detector classified the enemy energy delta `prev - cur` with the
## single window `0.09 <= drop <= 3.01`.  Two SERVER facts break that window:
##
##   1. `BULLET_HIT_ENERGY_GAIN_FACTOR = 3` (server rules.kt): when an ENEMY
##      bullet hits us, the SHOOTER's energy RISES by `3*power`.  If it fired in
##      the same tick the two cancel and the net delta reads as "no fire" ->
##      the bullet gets NO heat.
##   2. our own bullet damaging the enemy in the same tick adds `damage` to the
##      delta, so it can exceed 3.01 -> REJECTED, no heat for the enemy's shot.
##
## The fix undoes both from the events (`noteEnemyBulletHit` / `noteDamageDealt`)
## and splits any still-too-large delta instead of dropping it.  These checks pin
## the four behaviours plus the OFF-switch parity with the shipped detector.
##
## ── The one-SCAN delay (j134, MEASURED LIVE) ────────────────────────────────
## The correction is NOT applied to the immediately-next reading.  The server
## emits the hit event on turn N but applies the energy change to turn N+1's
## reading (live evidence: `EV hit getTurn=67` -> the `raw=-5.803` gain appears
## in the `getTurn=68` reading).  Because `note*` runs during `go()`, AFTER that
## turn's `endScan`, the tracker keeps a one-slot double buffer so the
## correction lands on the reading that carries the change.  A unit test must
## therefore feed: (1) a scan to rotate the event in, then (2) the reading whose
## raw shows the effect.  `advance` below does exactly that.

import std/[math, os]
import gun_harness/gun_interface
# Private-field access: include (do NOT import) the mover, exactly as
# `measure_strafe_heat_display.nim` does for the display check.
include movements/strafe

var failures = 0
proc check(name: string, ok: bool) =
  if ok: echo "PASS: ", name
  else: echo "FAIL: ", name; inc failures

proc ws(ee: float): WorldState =
  WorldState(
    enemyX: 200.0, enemyY: 200.0, enemyEnergy: ee,
    selfX: 400.0, selfY: 300.0, selfHeading: 0.0, selfSpeed: 6.0,
    arenaWidth: 800.0, arenaHeight: 600.0, tick: 10,
    enemies: @[EnemyInfo(id: 1, x: 200.0, y: 200.0, energy: ee)])

proc freshModule(): StrafeModule =
  var m = initStrafe()
  m.initGrid(800.0, 600.0)
  m.resetRound()
  m

# ── 1. plain fire (unchanged behaviour) ───────────────────────────────────────
block:
  var mm = freshModule()
  mm.detectFires(ws(100.0))
  mm.detectFires(ws(97.95))          # 2.05 drop, in range -> one wave
  check "plain fire creates exactly one wave", mm.bullets.len == 1
  check "plain fire wave power == drop",
        mm.bullets.len == 1 and abs(mm.bullets[0].power - 2.05) < 1e-9

# ── 2. the +3*power bonus masks a fire (the owner's "bullet without heat") ────
block:
  # Enemy at 100 fires 0.35 while an EARLIER 0.45 bullet of its own hits us
  # (+3*0.45 = +1.35).  Net energy = 100 - 0.35 + 1.35 = 101.0 -> raw drop = -1.0.
  var mm = freshModule()
  mm.detectFires(ws(100.0))          # establish prev = 100
  mm.noteEnemyBulletHit(0.45)        # event noted (staged)
  mm.detectFires(ws(100.0))          # rotates the staged correction in
  mm.detectFires(ws(101.0))          # the reading carrying the change
  check "masked fire: WITH fix a wave is created", mm.bullets.len == 1
  check "masked fire: WITH fix the power is recovered",
        mm.bullets.len == 1 and abs(mm.bullets[0].power - 0.35) < 1e-9

# ── 3. our own damage inflates the drop past the cap ─────────────────────────
block:
  # Enemy at 50 fires 2.0 and our bullet hits it for 1.8 -> energy 46.2,
  # raw drop 3.8 > 3.01 (shipped detector rejects it outright).
  var mm = freshModule()
  mm.prevEnergySet(1, 50.0)
  mm.noteDamageDealt(1.8)
  mm.detectFires(ws(50.0))           # rotates the staged correction in
  mm.detectFires(ws(46.2))           # raw 3.8 - 1.8 = 2.0 -> wave
  check "inflated drop: WITH fix a wave is created", mm.bullets.len == 1
  check "inflated drop: WITH fix the power is recovered",
        mm.bullets.len == 1 and abs(mm.bullets[0].power - 2.0) < 1e-9

# ── 4. never silently drop a too-large delta (unobserved contamination) ───────
block:
  var mm = freshModule()
  mm.detectFires(ws(100.0))
  mm.detectFires(ws(93.0))           # 7.0 with no events -> split, not dropped
  check "too-large drop is SPLIT, never dropped", mm.bullets.len == 3
  check "split waves all within the power cap",
        mm.bullets.len == 3 and mm.bullets[0].power <= 3.0 and mm.bullets[1].power <= 3.0
  check "split waves sum back to the drop",
        mm.bullets.len == 3 and abs(mm.bullets[0].power * 3.0 - 7.0) < 1e-9

# ── 5. OFF switch == shipped detector, byte for byte ─────────────────────────
block:
  putEnv("TR_STRAFE_FIRE_FIX", "0")
  loadStrafeEnv()
  # (a) masked fire: shipped detector sees raw = -1.0 -> NO wave.
  var a = freshModule()
  a.detectFires(ws(100.0))
  a.noteEnemyBulletHit(0.45)          # must be a no-op when the fix is off
  a.detectFires(ws(100.0))
  a.detectFires(ws(101.0))
  check "OFF: masked fire is NOT detected (shipped behaviour)", a.bullets.len == 0
  # (b) inflated drop: shipped detector sees 3.8 -> rejected -> NO wave.
  var b = freshModule()
  b.prevEnergySet(1, 50.0)
  b.noteDamageDealt(1.8)
  b.detectFires(ws(50.0))
  b.detectFires(ws(46.2))
  check "OFF: inflated drop is rejected (shipped behaviour)", b.bullets.len == 0
  # (c) in-range drop is still caught exactly once.
  var c = freshModule()
  c.detectFires(ws(100.0))
  c.detectFires(ws(98.0))
  check "OFF: plain fire still caught once",
        c.bullets.len == 1 and abs(c.bullets[0].power - 2.0) < 1e-9
  delEnv("TR_STRAFE_FIRE_FIX")
  loadStrafeEnv()

# ── 6. default is ON ─────────────────────────────────────────────────────────
block:
  delEnv("TR_STRAFE_FIRE_FIX")
  delEnv("TR_FIRE_FIX")
  loadStrafeEnv()
  check "default TR_STRAFE_FIRE_FIX is ON", StrafeFireFix

# ── 7. the global TR_FIRE_FIX also gates STRAFE ──────────────────────────────
block:
  putEnv("TR_FIRE_FIX", "0")
  loadStrafeEnv()
  check "TR_FIRE_FIX=0 disables STRAFE too", not StrafeFireFix
  delEnv("TR_FIRE_FIX")
  loadStrafeEnv()

if failures == 0:
  echo "\nAll STRAFE fire-detection fix checks passed."
else:
  echo "\n", failures, " STRAFE fire-detection fix check(s) FAILED."
  quit(1)