## Default-parity + registration guard for the BitBrain gun (id 16).
##
## No Java, no battle, no network build. Covers:
##   * the rack table carries BITBRAIN at id 16 and it defaults to `off`;
##   * the shipped rack still admits exactly Pattern;
##   * TR_RACK_BITBRAIN=both is what admits it, and the spawn gate honours it;
##   * `initBitBrainGun()` is LAZY (no network) and does NOT touch the global
##     RNG, so the default path cannot perturb the selector's random draws;
##   * the mode parser defaults to `perRound`.
##
## Run: nim c -r common_libs/tests/test_bitbrain_registration.nim

import std/[random, os, math]
import gun_harness/virtual_bullets
import gun_harness/selector
import guns/bitbrain_gun

const BitBrainId = 16
const PatternId  = 5

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

proc clearRackEnv() =
  for name in RackGunNames: delEnv("TR_RACK_" & name)

proc testTable() =
  check "rack: BITBRAIN is registered at id 16", RackGunNames[BitBrainId] == "BITBRAIN"
  check "rack: BITBRAIN defaults to `off`", DefaultRackMembership[BitBrainId] == rmOff
  var onlyPattern = true
  for i in 0..<RackGunNames.len:
    let want = if i == PatternId: rmBoth else: rmOff
    if DefaultRackMembership[i] != want: onlyPattern = false
  check "rack: the shipped default is still the onlyPattern rack", onlyPattern
  check "rack: the default rack admits only Pattern (1v1)",
        admittedGuns(17, rm1v1, DefaultRackMembership) == @[PatternId]
  check "gate: BitBrain is NOT spawned under the default rack",
        not vBulletAdmitted(BitBrainId, rm1v1, DefaultRackMembership, true)

proc testEnvOverride() =
  clearRackEnv()
  putEnv("TR_RACK_BITBRAIN", "both")
  let m = loadRackMembership()
  check "env: TR_RACK_BITBRAIN=both admits BitBrain",
        m[BitBrainId] == rmBoth and
        vBulletAdmitted(BitBrainId, rm1v1, m, true)
  check "env: admitting BitBrain leaves Pattern as the only other member",
        admittedGuns(17, rm1v1, m) == @[PatternId, BitBrainId]
  clearRackEnv()

proc testLazyAndRngClean() =
  delEnv("TR_BITBRAIN_MEM")
  var g = initBitBrainGun()
  check "lazy: constructing the gun does NOT build the network (0 bytes)",
        g.networkBytes == 0
  check "default: unset TR_BITBRAIN_MEM is perRound",
        g.memMode == bmPerRound
  check "parse: retained/decay/unknown", 
        parseMemMode("retained") == bmRetained and
        parseMemMode("decay") == bmDecay and
        parseMemMode("banana") == bmPerRound
  # Global RNG parity: constructing the gun must not consume global randomness.
  randomize(1234)
  let a = rand(1_000_000)
  randomize(1234)
  var g2 = initBitBrainGun()
  discard g2
  let b = rand(1_000_000)
  check "parity: initBitBrainGun() does not perturb the global RNG", a == b

proc testGeometry() =
  check "geometry: class 0 centre is the low edge + half a bin",
        abs(bbCenterDeg(0, 32, 40.0) - (-40.0 + 0.5 * 80.0 / 32.0)) < 1e-9
  check "geometry: bbClassOf round-trips the centre",
        bbClassOf(degToRad(bbCenterDeg(17, 32, 40.0)), 32, 40.0) == 17

testTable()
testEnvOverride()
testLazyAndRngClean()
testGeometry()

if failures > 0:
  echo "\n", failures, " check(s) FAILED"
  quit(1)
echo "\nAll BitBrain registration checks passed."