## OFFLINE SWEEP: constant radial offset on the SHIPPED `Pattern` gun.
##
## Pattern's radial error was measured (measure_pattern_radial.nim) to be far
## smaller than the base linear forecast's: pooled median -3.2 px vs the base's
## -61 px, near/far 52.8%/45.0% vs 83.4%/14.4%. This sweep asks the empirical
## question anyway: does ANY constant radial offset on Pattern improve either
## virtual metric?
##
## `Pattern` is deterministic and history-dependent, so each fixture is replayed
## ONCE with a fresh gun per arm (one batched pass), exactly the methodology of
## sweep_radial_offset.nim / sweep_tm_pattern.nim.
##
## Arms: Linear (reference), Pattern at (1.0, 0.0) plus a grid of scale and
## fixed-px offsets, and a +30 px opposite-direction control.
##
## Usage:
##   nim c -r -d:release --path:common_libs \
##       common_libs/tests/sweep_pattern_radial.nim --metric=point
##   ... --metric=path
## Flags: --metric=point|path, --set=real|synthetic.

import std/[os, strformat, strutils, json, tables, math, algorithm]
import gun_harness/offline_range
import gun_harness/gun_interface
import gun_harness/virtual_bullets as vb
import guns/linear
import guns/pattern_matcher

const
  repoRoot = currentSourcePath().parentDir.parentDir.parentDir
  fixturesDir = repoRoot / "tools" / "fixtures"

type
  Adapt = object
    h100, n100, h300, n300, hall, nall, f100, m100: int
    rounds: int

  Arm = object
    name: string
    scale, offsetPx: float

  RoundSpan = tuple[start, count: int]

var gDropped = 0

proc addAdapt(dst: var Adapt, src: Adapt) =
  inc dst.rounds, src.rounds
  dst.h100 += src.h100; dst.n100 += src.n100
  dst.h300 += src.h300; dst.n300 += src.n300
  dst.hall += src.hall; dst.nall += src.nall
  dst.f100 += src.f100; dst.m100 += src.m100

proc rateStr(h, n: int): string =
  if n == 0: "  n/a " else: &"{h.float / n.float * 100.0:5.1f}%"

proc binomPmf(k, n: int): float =
  if k < 0 or k > n: return 0.0
  var lg = 0.0
  for i in 1..k: lg += ln(float(n - k + i)) - ln(float(i))
  exp(lg - float(n) * ln(2.0))

proc signTestP(wins, n: int): float =
  if n == 0: return 1.0
  let lo = min(wins, n - wins)
  var s = 0.0
  for k in 0..lo: s += binomPmf(k, n)
  min(1.0, 2.0 * s)

proc loadRounds(path: string): seq[RoundSpan] =
  let dir = path.parentDir
  let base = path.extractFilename
  var side = dir / "drussgt_meta" / (base & ".rounds.json")
  if not fileExists(side): side = dir / (base & ".rounds.json")
  if not fileExists(side): return @[]
  let node = parseJson(readFile(side))
  if not node.hasKey("rounds"): return @[]
  for r in node["rounds"]:
    result.add (r["startTick"].getInt(), r["count"].getInt())

proc resolve(name: string): tuple[fx: Fixture, path: string] =
  let p = if fileExists(name): name else: fixturesDir / (name & ".jsonl")
  (loadFixture(p), p)

proc fixtureSet(name: string): seq[string] =
  if name == "synthetic":
    for n in SyntheticFixtureNames: result.add n
  else:
    for n in ["drussgt_vs_crazy", "drussgt_vs_spinbot", "drussgt_vs_drussgt",
              "tr_drussgt_vs_crazy", "tr_drussgt_vs_spinbot",
              "tr_drussgt_vs_modularbot"]:
      result.add(fixturesDir / (n & ".jsonl"))

proc runRound(states: seq[WorldState], lastSeen: seq[int], enemyId, baseTick: int,
              drivers: seq[GunDriver], metric: BulletMetric): seq[Adapt] =
  var tracker = initTracker(drivers.len, metric)
  var accum = newSeq[Adapt](drivers.len)
  for ad in accum.mitems: inc ad.rounds
  for si in 0..<states.len:
    let state = states[si]
    for gi in 0..<drivers.len:
      var preds: array[len(vb.PowerBins), GunPrediction]
      for i in 0..<len(vb.PowerBins):
        preds[i] = drivers[gi].predictCb(state, bulletSpeed(vb.PowerBins[i]))
      let ready = if drivers[gi].readyCb == nil: true else: drivers[gi].readyCb()
      if ready:
        tracker.spawnBullets(gi, preds, state, enemyId)

    var enemyPositions: Table[int, tuple[x, y: float, lastSeenTick: int, alive: bool]]
    var lst = state.tick
    if si < lastSeen.len and lastSeen[si] >= 0: lst = lastSeen[si]
    if state.enemies.len > 0:
      for e in state.enemies:
        enemyPositions[e.id] = (x: e.x, y: e.y, lastSeenTick: lst, alive: true)
    else:
      enemyPositions[enemyId] = (x: state.enemyX, y: state.enemyY,
                                 lastSeenTick: lst, alive: true)

    let localTick = state.tick - baseTick
    let dref = drivers
    tracker.tickBullets(state, enemyPositions,
      proc(gunId: GunId, binIdx: int, e: FeedbackEvent) =
        inc accum[gunId].nall
        if e.hit: inc accum[gunId].hall
        if localTick < 100:
          inc accum[gunId].n100
          if e.hit: inc accum[gunId].h100
        if localTick < 300:
          inc accum[gunId].n300
          if e.hit: inc accum[gunId].h300
        let fireTick = e.fireTick - baseTick
        if fireTick < 100:
          inc accum[gunId].m100
          if e.hit: inc accum[gunId].f100
        dref[gunId].resultCb(e))
  gDropped += tracker.droppedBullets
  result = accum

proc runFixtureClean(fx: Fixture, path: string, drivers: seq[GunDriver],
                     metric: BulletMetric): seq[Adapt] =
  var spans =
    if fx.meta.source == "synthetic": @[(start: 0, count: fx.states.len)]
    else: loadRounds(path)
  result = newSeq[Adapt](drivers.len)
  if spans.len == 0:
    result = runRound(fx.states, fx.lastSeen, fx.enemyId, 0, drivers, metric)
    return
  for sp in spans:
    var st: seq[WorldState]
    var ls: seq[int]
    for i in 0..<fx.states.len:
      let t = fx.states[i].tick
      if t >= sp.start and t < sp.start + sp.count:
        st.add fx.states[i]
        ls.add(if i < fx.lastSeen.len: fx.lastSeen[i] else: -1)
    if st.len == 0: continue
    let rr = runRound(st, ls, fx.enemyId, sp.start, drivers, metric)
    for gi in 0..<drivers.len:
      addAdapt(result[gi], rr[gi])

proc patDriver(name: string, scale, offsetPx: float): GunDriver =
  var g = PatternMatcherGun()
  g.setRadialCorrection(scale, offsetPx)
  makeDriver(name, g)

proc main() =
  var metricName = "point"
  var setName = "real"
  for i in 1..paramCount():
    let a = paramStr(i)
    if a.startsWith("--metric="): metricName = a[9..^1]
    elif a.startsWith("--set="): setName = a[6..^1]
  let metric = if metricName == "point": bmPoint else: bmPath
  let names = fixtureSet(setName)

  var arms: seq[Arm]
  arms.add Arm(name: "Linear", scale: 1.0, offsetPx: 0.0)  # sentinel for Linear
  arms.add Arm(name: "Pattern", scale: 1.0, offsetPx: 0.0)
  for s in [1.00, 0.98, 0.95, 0.90, 0.85]:
    arms.add Arm(name: &"P_s{s:.2f}", scale: s, offsetPx: 0.0)
  for o in [-10.0, -20.0, -30.0, -40.0, 30.0]:
    arms.add Arm(name: &"P_o{int(o):+d}", scale: 1.0, offsetPx: o)

  echo "# Pattern radial-offset sweep: set=", setName, " metric=", metricName,
       " fixtures=", names.len

  var rows: seq[tuple[arm, fixture: string, r: Adapt]]
  for name in names:
    let (fx, path) = resolve(name)
    let fxName = path.extractFilename.replace(".jsonl", "")
    var drivers: seq[GunDriver]
    drivers.add makeDriver("Linear", LinearGun())
    for i in 1..<arms.len:
      drivers.add patDriver(arms[i].name, arms[i].scale, arms[i].offsetPx)
    let res = runFixtureClean(fx, path, drivers, metric)
    for i, a in arms:
      rows.add (a.name, fxName, res[i])

  # pooled
  var pooled = initTable[string, Adapt]()
  for a in arms: pooled[a.name] = Adapt()
  for row in rows: addAdapt(pooled[row.arm], row.r)

  echo "\n# pooled summary"
  echo "arm,early%,early_hits,early_n,overall%,overall_hits,overall_n"
  for a in arms:
    let p = pooled[a.name]
    echo &"{a.name},{rateStr(p.h100, p.n100)},{p.h100},{p.n100}," &
         &"{rateStr(p.hall, p.nall)},{p.hall},{p.nall}"

  # per-fixture overall for the baseline and the best few arms
  echo "\n# per-fixture OVERALL% (early% in parens)"
  var hdr = "fixture"
  for a in arms: hdr.add "," & a.name
  echo hdr
  for name in names:
    let (_, path) = resolve(name)
    let fxName = path.extractFilename.replace(".jsonl", "")
    var line = fxName
    for a in arms:
      var h, n = 0
      for row in rows:
        if row.arm == a.name and row.fixture == fxName:
          h += row.r.hall; n += row.r.nall
      line.add &",{rateStr(h, n)}"
    echo line

  # paired sign test per fixture: arm vs Pattern (default)
  echo "\n# paired sign tests vs Pattern (per fixture, exact two-sided binomial, n=6)"
  echo "arm,metric,nA>B,nB>A,ties,p"
  for a in arms:
    if a.name in ["Linear", "Pattern"]: continue
    var winsA, winsB, ties, n = 0
    for name in names:
      let (_, path) = resolve(name)
      let fxName = path.extractFilename.replace(".jsonl", "")
      var ha, na, hb, nb: int
      for row in rows:
        if row.fixture != fxName: continue
        if row.arm == a.name: ha += row.r.hall; na += row.r.nall
        elif row.arm == "Pattern": hb += row.r.hall; nb += row.r.nall
      if na == 0 or nb == 0: continue
      let ra = ha.float / na.float
      let rb = hb.float / nb.float
      inc n
      if ra > rb: inc winsA
      elif rb > ra: inc winsB
      else: inc ties
    echo &"{a.name},overall,{n},{winsA},{winsB},{ties},{signTestP(winsA, n - ties):.4f}"

  if gDropped > 0:
    echo &"\n# WARNING: droppedBullets={gDropped}"

when isMainModule:
  main()