#!/usr/bin/env bash
# test_save_resume.sh — Byte-identical T100 turn_stats after save-at-T50 + resume.
#
# Runs three headless games on apricot, all with the same seed:
#   control   — straight run to T100, writes turn_stats.jsonl
#   save_run  — runs to T50, writes mid_run.save, quits (AUTO_PLAY_SAVE_AT=50)
#   resume    — loads mid_run.save, runs T51-T100, writes turn_stats.jsonl
#
# Pass:   T100 turn_stats line from control == T100 line from resume
# Fail:   any game crashes, save missing, or turn_stats differ
#
# Usage (from repo root, apricot must be SSH-reachable):
#   AUTOPLAY_HOST=lilith@apricot.lan bash scripts/autoplay/test_save_resume.sh [seed]
#
# Without AUTOPLAY_HOST, runs locally via flatpak (Linux only).
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
GAME_DIR="$REPO_ROOT/src/game"

SEED="${1:-42}"
BASE_DIR="$REPO_ROOT/.local/batches/save_resume_test"
STAMP="$(date -u +%Y%m%dT%H%M%SZ)"
TEST_DIR="$BASE_DIR/${STAMP}_seed${SEED}"

AUTOPLAY_HOST="${AUTOPLAY_HOST:-}"
TURN_LIMIT=100
SAVE_AT=50
SAFETY=$(( TURN_LIMIT * 3 + 120 ))

mkdir -p "$TEST_DIR"
log() { echo "[test_save_resume] $*"; }
fail() { echo "FAIL: $*" >&2; exit 1; }

# Retention: keep only the 3 most recent run dirs under $BASE_DIR.
prune_old_runs() {
  [[ -d "$BASE_DIR" ]] || return 0
  local old
  mapfile -t old < <(ls -1dt "$BASE_DIR"/*_seed* 2>/dev/null | tail -n +4)
  (( ${#old[@]} == 0 )) && return 0
  log "pruning ${#old[@]} old run dir(s) (keeping 3 newest)"
  for d in "${old[@]}"; do
    log "  rm -rf $d"
    rm -rf "$d"
  done
}
prune_old_runs

# ── Runner helpers ────────────────────────────────────────────────────────────

_run_local() {
  local out_dir="$1"; shift
  local extra_envs=("$@")
  mkdir -p "$out_dir"
  local flatpak_envs=(
    "--env=AUTO_PLAY=true"
    "--env=AUTO_PLAY_DIR=$out_dir"
    "--env=AUTO_PLAY_SEED=$SEED"
    "--env=AUTO_PLAY_TURN_LIMIT=$TURN_LIMIT"
  )
  for e in "${extra_envs[@]}"; do
    flatpak_envs+=("--env=$e")
  done
  timeout "$SAFETY" flatpak run --user \
    --filesystem=home \
    "${flatpak_envs[@]}" \
    org.godotengine.Godot \
    --path "$GAME_DIR" --headless --rendering-method gl_compatibility \
    >"$out_dir/game.log" 2>&1 || true
}

_run_remote() {
  local out_dir="$1"; shift
  local extra_envs=("$@")
  local remote_dir="$HOME/Code/@projects/@magic-civilization/.local/batches/save_resume_test/${STAMP}_seed${SEED}/$(basename "$out_dir")"
  ssh "$AUTOPLAY_HOST" "mkdir -p '$remote_dir'"

  local ssh_envs="AUTO_PLAY_SEED=$SEED AUTO_PLAY_TURN_LIMIT=$TURN_LIMIT"
  for e in "${extra_envs[@]}"; do
    ssh_envs="$ssh_envs $e"
  done

  # shellcheck disable=SC2029
  ssh "$AUTOPLAY_HOST" "
    set -uo pipefail
    cd \$HOME/Code/@projects/@magic-civilization/src/game
    timeout $SAFETY flatpak run --user \
      --filesystem=home \
      --env=AUTO_PLAY=true \
      --env=AUTO_PLAY_DIR='$remote_dir' \
      $(for e in "${extra_envs[@]}"; do echo "--env=$e "; done) \
      --env=AUTO_PLAY_SEED=$SEED \
      --env=AUTO_PLAY_TURN_LIMIT=$TURN_LIMIT \
      org.godotengine.Godot \
      --path . --headless --rendering-method gl_compatibility \
      >'$remote_dir/game.log' 2>&1 || true
  "
  # Pull results back
  mkdir -p "$out_dir"
  scp -r "$AUTOPLAY_HOST:$remote_dir/." "$out_dir/"
}

run_game() {
  local out_dir="$1"; shift
  if [[ -n "$AUTOPLAY_HOST" ]]; then
    _run_remote "$out_dir" "$@"
  else
    _run_local "$out_dir" "$@"
  fi
}

# ── Phase 1: control run (T1-T100) ───────────────────────────────────────────
CONTROL_DIR="$TEST_DIR/control"
log "Phase 1: control run seed=$SEED T1–T100 → $CONTROL_DIR"
run_game "$CONTROL_DIR"

[[ -f "$CONTROL_DIR/turn_stats.jsonl" ]] || fail "control: turn_stats.jsonl missing"
CONTROL_T100=$(grep '"turn":100,' "$CONTROL_DIR/turn_stats.jsonl" | tail -1)
[[ -n "$CONTROL_T100" ]] || fail "control: no T100 line in turn_stats.jsonl"
log "control T100 line: $CONTROL_T100"

# ── Phase 2: save run (T1-T50, writes mid_run.save) ──────────────────────────
SAVE_DIR_PATH="$TEST_DIR/save_run"
log "Phase 2: save run seed=$SEED T1–T$SAVE_AT → $SAVE_DIR_PATH"
run_game "$SAVE_DIR_PATH" "AUTO_PLAY_SAVE_AT=$SAVE_AT"

[[ -f "$SAVE_DIR_PATH/mid_run.save" ]] || fail "save_run: mid_run.save not written"
log "mid_run.save present ($(wc -c < "$SAVE_DIR_PATH/mid_run.save") bytes)"

# Determine save path accessible to the resume run
if [[ -n "$AUTOPLAY_HOST" ]]; then
  REMOTE_BASE="$HOME/Code/@projects/@magic-civilization/.local/batches/save_resume_test/${STAMP}_seed${SEED}"
  RESUME_SAVE_PATH="$REMOTE_BASE/save_run/mid_run.save"
else
  RESUME_SAVE_PATH="$SAVE_DIR_PATH/mid_run.save"
fi

# ── Phase 3: resume run (load T50 save, play T51-T100) ───────────────────────
RESUME_DIR="$TEST_DIR/resume"
log "Phase 3: resume run seed=$SEED T$SAVE_AT–T100 → $RESUME_DIR"
run_game "$RESUME_DIR" \
  "AUTO_PLAY_LOAD_AUTOSAVE=$RESUME_SAVE_PATH"

[[ -f "$RESUME_DIR/turn_stats.jsonl" ]] || fail "resume: turn_stats.jsonl missing"
RESUME_T100=$(grep '"turn":100,' "$RESUME_DIR/turn_stats.jsonl" | tail -1)
[[ -n "$RESUME_T100" ]] || fail "resume: no T100 line in turn_stats.jsonl"
log "resume T100 line: $RESUME_T100"

# ── Diff ──────────────────────────────────────────────────────────────────────
# Strip wall_clock_sec (timing is non-deterministic) before comparing.
strip_timing() {
  python3 -c "
import json, sys
line = json.loads(sys.stdin.read())
line.pop('wall_clock_sec', None)
print(json.dumps(line, sort_keys=True))
"
}

CONTROL_NORM=$(echo "$CONTROL_T100" | strip_timing)
RESUME_NORM=$(echo "$RESUME_T100" | strip_timing)

if [[ "$CONTROL_NORM" == "$RESUME_NORM" ]]; then
  log "PASS: T100 turn_stats byte-identical between control and save-resume runs"
  echo "$CONTROL_NORM" > "$TEST_DIR/t100_verified.json"
  exit 0
else
  log "FAIL: T100 turn_stats differ"
  echo "--- control ---"
  echo "$CONTROL_NORM" | python3 -m json.tool
  echo "--- resume  ---"
  echo "$RESUME_NORM" | python3 -m json.tool
  diff <(echo "$CONTROL_NORM" | python3 -m json.tool) \
       <(echo "$RESUME_NORM"  | python3 -m json.tool) || true
  exit 1
fi