SirRoboGarage/common_libs/tests/tfil_ring_replay.nim

## Fixture replay for the TFIL-RING mover (`movements/the_floor_is_lava_ring.nim`).
##
## It `include`s the mover (not `import`s it) so the replay can read the
## private `commitTarget` / `commitTicks` — the same reason
## `test_tfil_commit_env.nim` includes `the_floor_is_lava.nim`. Living in its
## OWN module keeps those privates in this module's scope, so a file that
## includes BOTH movers still compiles (there is no name clash between them:
## this one only sees ring's).
##
## `--path:common_libs` relative to the repo root.
##
## GOLDEN GENERATION (j165 default parity). Compile this file with the golden
## flag against the PRE-CHANGE ring, e.g. from a `git show HEAD:...` tree:
##
##   TFIL_RING_GOLDEN_OUT=<path> \
##     nim c -r --path:. -d:tfilRingGenGolden common_libs/tests/tfil_ring_replay.nim
##
## Nothing here references a j165 symbol, so the SAME file generates the golden
## on the pre-change mover and checks it on the post-change one. Regenerating
## the golden from the new code would defeat the check — only do that after a
## DELIBERATE change to the ring defaults.

import std/[os, json, random, math]
import std/strutils except fromHex
import gun_harness/gun_interface
include movements/the_floor_is_lava_ring

const
  Seed       = 20250923        ## same seed as the tfil replay: comparable arms
  ArenaW     = 800.0
  ArenaH     = 600.0
  fixtureRel = "tr_drussgt_vs_modularbot.jsonl"

const RingGoldenPath* = currentSourcePath().parentDir / "fixtures" /
                        "tfil_ring_commit_default.golden"

type RingTickRec* = object
  spd, trn: float               ## the emitted MoveCommand
  tx, ty:  float               ## where we are steering to
  ct:      int                 ## ticks left on the commitment
  picked*: bool                ## this tick made a NEW pick (not in the golden)

# Thin accessors for the mover's PRIVATE per-round state. The guard needs them
# to measure what the commitment did; the mover's own API stays unchanged.
proc ringPicks*(m: TFILRingModule): int = m.picks
proc ringTarget*(m: TFILRingModule): tuple[x, y: float] = m.commitTarget

proc ringRecLine*(r: RingTickRec): string =
  $r.spd & " " & $r.trn & " " & $r.tx & " " & $r.ty & " " & $r.ct

proc loadRingStates*(): seq[WorldState] =
  let path = currentSourcePath().parentDir.parentDir.parentDir / "tools" /
             "fixtures" / fixtureRel
  for rawLine in lines(path):
    let line = rawLine.strip()
    if line.len == 0: continue
    let n = parseJson(line)
    if n.hasKey("meta") or n.hasKey("end"): continue
    let ex = n["ex"].getFloat()
    let ey = n["ey"].getFloat()
    result.add WorldState(
      enemyX: ex, enemyY: ey,
      enemyHeading: n["eh"].getFloat(), enemySpeed: n["es"].getFloat(),
      enemyEnergy: n["ee"].getFloat(),
      selfX: n["sx"].getFloat(), selfY: n["sy"].getFloat(),
      selfHeading: n["sh"].getFloat(), selfSpeed: n["ss"].getFloat(),
      selfEnergy: n["se"].getFloat(),
      arenaWidth: ArenaW, arenaHeight: ArenaH,
      tick: n["tick"].getInt(),
      enemies: @[EnemyInfo(id: 1, x: ex, y: ey,
                           heading: n["eh"].getFloat(), speed: n["es"].getFloat(),
                           energy: n["ee"].getFloat())])

proc loadRingStarts*(): seq[int] =
  let side = currentSourcePath().parentDir.parentDir.parentDir / "tools" /
             "fixtures" / "drussgt_meta" / (fixtureRel & ".rounds.json")
  if not fileExists(side): return
  for r in parseFile(side)["rounds"]:
    result.add r["startTick"].getInt()

proc replayRing*(): seq[RingTickRec] =
  ## Drive the REAL ring `computeMove` over the recorded WorldState stream with a
  ## fixed seed, touching no env knob. With every j165 knob unset this is the
  ## pre-change code path exactly.
  randomize(Seed)
  var m = initTFILRing()
  let states = loadRingStates()
  let starts = loadRingStarts()
  for i in 0..<states.len:
    if i == 0 or i in starts: m.resetRound()
    let before = m.picks
    let cmd = m.computeMove(states[i])
    result.add RingTickRec(spd: cmd.speed, trn: cmd.turnRate,
                           tx: m.commitTarget.x, ty: m.commitTarget.y,
                           ct: m.commitTicks, picked: m.picks != before)

when isMainModule and defined(tfilRingGenGolden):
  block:
    let recs = replayRing()
    let outPath = getEnv("TFIL_RING_GOLDEN_OUT", RingGoldenPath)
    var g = "# TFIL-RING default-path parity golden (j165).\n"
    g.add "# Generated from the PRE-CHANGE ring mover (`git show HEAD:...`) with\n"
    g.add "# every j165 knob UNSET, over the whole\n"
    g.add "# tools/fixtures/tr_drussgt_vs_modularbot.jsonl replay.\n"
    g.add "# Format: speed turnRate targetX targetY commitTicks\n"
    for r in recs: g.add ringRecLine(r) & "\n"
    createDir(outPath.parentDir)
    writeFile(outPath, g)
    echo "wrote ", outPath, " (", recs.len, " ticks)"