## Unit tests for EnemyTracker's death invariant: once an enemy is marked dead
## it stays dead, and every alive view excludes it.
##
## This is the invariant that actually matters in production. The earlier
## premise — "BotDeathEvent never reaches the bot, so corpses persist" — was
## MEASURED false (0 dropped BotDeath events, 0 corpse ticks; see
## docs/tracker_death_events.md). The reconciliation feature that used to be
## tested here was retired with it. The event-drop MECHANISM is real and is
## covered separately by test_event_drop_mechanism.nim.
##
## Headless: no Java, no server, no battle.
##   nim c -r common_libs/tests/test_enemy_tracker_death.nim

import std/[tables, algorithm]
import targeting/enemy_tracker

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

proc see(et: var EnemyTracker, id, tick: int) =
  et.update(id, float(id) * 100.0, 0.0, 0.0, 0.0, 100.0, tick)

proc testMarkDeadImmediate() =
  var et: EnemyTracker
  et.see(5, 10)
  check "precondition: a scanned enemy is alive", et.isAlive(5)
  et.markDead(5)
  # Same tick: no intervening update, no reconciliation.
  check "immediate: markDead flips the flag in the same tick", not et.isAlive(5)
  check "immediate: aliveCount drops the dead enemy at once", et.aliveCount == 0
  check "immediate: allAlive drops the dead enemy at once", et.allAlive.len == 0

proc testNoResurrection() =
  var et: EnemyTracker
  et.see(5, 10)
  et.markDead(5)
  # A later scan of the same id (queued/duplicate scan) must not revive it.
  et.update(5, 1.0, 2.0, 3.0, 4.0, 100.0, 11)
  check "no-resurrect: a later update does not revive a dead enemy",
        not et.isAlive(5)
  check "no-resurrect: the dead enemy is not counted alive", et.aliveCount == 0
  check "no-resurrect: allAlive still excludes it", et.allAlive.len == 0

proc testAliveViewsExcludeDead() =
  var et: EnemyTracker
  et.see(1, 10)
  et.see(2, 10)
  et.see(3, 10)
  et.markDead(2)
  check "views: isAlive is false only for the dead id",
        et.isAlive(1) and not et.isAlive(2) and et.isAlive(3)
  check "views: aliveCount counts only the living", et.aliveCount == 2
  var ids: seq[int]
  for s in et.allAlive(): ids.add s.id
  ids.sort()
  check "views: allAlive returns exactly the living ids", ids == @[1, 3]

proc testMarkDeadUnknownIsNoop() =
  var et: EnemyTracker
  et.see(1, 10)
  et.markDead(99)
  check "noop: markDead on an unknown id creates nothing",
        et.enemies.len == 1 and not et.isAlive(99) and et.aliveCount == 1

proc testDoubleMarkDead() =
  var et: EnemyTracker
  et.see(7, 10)
  et.markDead(7)
  et.markDead(7)
  check "idempotent: marking the same enemy dead twice is harmless",
        not et.isAlive(7) and et.aliveCount == 0

proc testResetRoundClears() =
  var et: EnemyTracker
  et.see(1, 10)
  et.see(2, 10)
  et.markDead(2)
  et.resetRound()
  check "resetRound: clears every tracked enemy (alive and dead)",
        et.enemies.len == 0 and et.aliveCount == 0 and not et.isAlive(1) and
        not et.isAlive(2)

testMarkDeadImmediate()
testNoResurrection()
testAliveViewsExcludeDead()
testMarkDeadUnknownIsNoop()
testDoubleMarkDead()
testResetRoundClears()

if failures > 0:
  echo "\n", failures, " check(s) FAILED"
  quit(1)
echo "\nAll enemy-tracker death checks passed."