## OFFLINE — j150. WHERE DOES THE LAVA PICKER LOSE ITS TILES?
##
## The owner's report: "the bot chooses only between a poor number of tiles while
## there are a lot of them available but not considered". This ruler drives the
## REAL `TFILModule.computeMove` (with `TR_TFIL_DIAG=1`) over recorded
## DrussGT fixtures and reads the per-pick loss histogram the mover counts:
##
##   reachable hull -> CoolestLevels(=2) distinct-lava filter
##                  -> pathMaxHeat <= PathDangerThreshold  -> draw set -> CHOSEN
##
## No battle, no Java, no server, no behaviour change: every knob it moves is
## default-off or default-identical.
##
## Run:
##   nim c -r --path:common_libs --nimcache:/tmp/nc_j150 \
##       common_libs/tests/measure_tfil_picker_loss.nim [fixture.jsonl ...]

import std/[os, strformat, math, algorithm, json, sets, sequtils]
import std/strutils except fromHex   # `fromHex` would clash with color.fromHex
import gun_harness/offline_range
# Private-field access: include (do NOT import) the shipped mover.
include movements/the_floor_is_lava

proc loadRoundStarts(fixturePath: string): HashSet[int] =
  result = initHashSet[int]()
  let side = currentSourcePath().parentDir.parentDir.parentDir /
             "tools" / "fixtures" / "drussgt_meta" /
             (extractFilename(fixturePath) & ".rounds.json")
  if not fileExists(side): return
  let root = parseFile(side)
  if not root.hasKey("rounds"): return
  for r in root["rounds"]:
    if r.hasKey("startTick"): result.incl r["startTick"].getInt()

proc replay(path: string, threshold: float): TfilLossStats =
  putEnv("TR_TFIL_DIAG", "1")
  putEnv("TR_TFIL_DANGER_THRESHOLD", $threshold)
  loadTfilCommitEnv()
  TfilLoss = TfilLossStats()
  let fx = loadFixture(path)
  let starts = loadRoundStarts(path)
  var m = initTFIL()
  for si in 0..<fx.states.len:
    if si == 0 or si in starts: m.resetRound()
    discard m.computeMove(fx.states[si])
  result = TfilLoss

proc mean(x: seq[float]): float =
  if x.len == 0: return 0.0
  var s = 0.0
  for v in x: s += v
  s / x.len.float

proc pctStr(x: float): string = &"{100.0 * x:.1f}%"

proc f2(x: float): string = &"{x:.2f}"

const SafeBuckets = ["0", "1", "2-3", "4-7", "8-15", "16-31", "32-63", "64+"]

proc heatTally(x: seq[float]): seq[(float, int)] =
  ## distinct heat values -> how many rejected tiles carried it, most common
  ## first. Lava is a sum of quantised terms, so this shows the real steps.
  var counts: seq[(float, int)]
  for v in x:
    var i = 0
    while i < counts.len and counts[i][0] != v: inc i
    if i < counts.len: inc counts[i][1]
    else: counts.add (v, 1)
  result = counts
  result.sort(proc (a, b: (float, int)): int = cmp(b[1], a[1]))

proc report(path: string) =
  let s = replay(path, 10.0)
  echo &"\n\u2550\u2550\u2550 {path}"
  if s.picks == 0:
    echo "  no picks"; return
  let n = s.picks.float
  echo &"  picks = {s.picks} (replayed ticks, one recorded battle, seed fixed)"
  echo &"  stage                                   mean tiles"
  echo &"  1 reachable-hull tiles                 {s.sReach.float/n:>12.2f}"
  echo &"  2 .. after CoolestLevels=2 filter      {s.sCool.float/n:>12.2f}"
  echo &"  3 .. after path heat filter (pre-prom) {s.sSafe.float/n:>12.2f}"
  echo &"  4 .. draw set (what it chooses among)  {s.sCand.float/n:>12.2f}"
  echo &"  LOST at the 2-levels filter            {(1.0 - s.sCool.float/s.sReach.float)*100:>11.1f}%"
  echo &"  LOST at the heat filter                {(1.0 - s.sSafe.float/max(1.0,s.sCool.float))*100:>11.1f}%"
  echo &"  LOST at blocked-tile / no-rev          {(1.0 - s.sCand.float/max(1.0,s.sSafe.float))*100:>11.1f}%"
  echo &"  picks with an EMPTY safe set (<2 at stage 3) = {s.emptySafe} ({pctStr(s.emptySafe.float/n)})"
  echo "  safe-set size distribution (stage 3):"
  for i in 0..<SafeBuckets.len:
    if s.safeHist[i] > 0:
      echo &"    {SafeBuckets[i].alignLeft(6)} {s.safeHist[i]:>7}  ({pctStr(s.safeHist[i].float/n)})"

  # heat of the tiles the filter dropped
  echo &"  heat of the {s.rejectedHeat.len} REJECTED tiles (mean {f2(mean(s.rejectedHeat))}), most common first:"
  for (v, c) in heatTally(s.rejectedHeat)[0 ..< min(8, s.rejectedHeat.len)]:
    echo &"    heat {f2(v):>7}  {c:>7}  ({pctStr(c.float/s.rejectedHeat.len.float)})"
  echo &"  heat of ADMITTED tiles mean {f2(mean(s.admittedHeat))} (n={s.admittedHeat.len}); " &
       &"of CHOSEN mean {f2(mean(s.chosenHeat))} (n={s.chosenHeat.len})"

  # \u2550\u2550 threshold sweep
  echo "  threshold  mean draw set  % empty safe  newly admitted (n, mean heat)  mean heat chosen"
  var baseAdmitted = replay(path, 10.0).admittedHeat.len
  for thr in [10.0, 14.0, 18.0]:
    let a = replay(path, thr)
    let newly = a.admittedHeat.filterIt(it > 10.0)
    let newTxt = $newly.len & ", " & f2(mean(newly))
    echo &"  {thr:>9.0f}  {a.sCand.float / a.picks.float:>13.2f}  " &
         &"{pctStr(a.emptySafe.float / a.picks.float):>12}  {newTxt:>30}  {f2(mean(a.chosenHeat)):>16}"
  echo &"  (admitted at threshold 10: {baseAdmitted} tiles)"

# ── driver ───────────────────────────────────────────────────────────────────
let args = commandLineParams()
let fixtures = if args.len > 0: args
               else: @[currentSourcePath().parentDir.parentDir.parentDir /
                       "tools" / "fixtures" / "tr_drussgt_vs_modularbot.jsonl"]
for f in fixtures:
  if fileExists(f): report(f)
  else: echo "skip (missing): ", f