#!/usr/bin/env bash
# apricot-run.sh — Isolated build + batch pipeline on apricot.
#
# apricot is a multi-tenant RUN host. We do NOT touch ~/Code/@projects/@magic-civilization
# on apricot — that's another developer's workspace. Instead:
#
#   1. Rsync this EDIT-host source tree to /tmp/mc-<stamp>/ on apricot.
#   2. Build (cargo) in /tmp/mc-<stamp>/, target dir stays there (ephemeral).
#   3. Run the batch with RESULTS_DIR under $HOME/.cache/mc-batches/<stamp>/
#      (persistent, XDG cache convention, flatpak-visible via --filesystem=home).
#   4. Fetch verdict JSON back to EDIT host for review.
#
# Usage:
#   scripts/apricot-run.sh smoke [seeds=10] [turns=300]
#   scripts/apricot-run.sh clan <clan_id> [seeds=10] [turns=300]
#   scripts/apricot-run.sh gpu-walltime [seeds=10] [turns=300]
#
# Environment:
#   APRICOT_SSH_ALIAS — ssh alias for the RUN host (default: apricot).
#   STAMP             — override the timestamp (for reproducing a specific run).

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_DIR="$(dirname "$SCRIPT_DIR")"

APRICOT="${APRICOT_SSH_ALIAS:-apricot}"
STAMP="${STAMP:-$(date +%Y%m%d_%H%M%S)}"

# ── Load .env / .env.local so USE_MAX_CORES + MIN_CORES + AI_GPU_ROLLOUT
# propagate into the resource policy below. .env.local wins over .env.
for envfile in "${PROJECT_DIR}/.env" "${PROJECT_DIR}/.env.local"; do
    if [[ -f "${envfile}" ]]; then
        set -a; source "${envfile}"; set +a
    fi
done

# MODE + positional args resolved early so the resource-policy block can
# peek at the seed count (which differs per mode — for `clan` it's $2
# because $1 is the clan_id; for smoke/gpu-walltime it's $1).
MODE="${1:?usage: apricot-run.sh <smoke|clan|gpu-walltime> [args]}"
shift || true

# ── Resource policy for PARALLEL + RAYON_NUM_THREADS ─────────────────
# Each Godot instance spawns its own rayon thread pool for MCTS rollouts;
# rayon defaults to nproc unless RAYON_NUM_THREADS is set. If PARALLEL
# instances each claim all nproc threads, we get PARALLEL*nproc threads
# fighting over nproc cores → thrashing, each process effectively single
# core. Better: PARALLEL = number of seeds (one instance each), and
# RAYON_NUM_THREADS = nproc / PARALLEL so the box is saturated evenly.
case "${MODE}" in
    clan)   _seed_count_peek="${2:-10}" ;;   # $1 is clan_id, $2 is seeds
    *)      _seed_count_peek="${1:-10}" ;;   # smoke, gpu-walltime
esac

NPROC="$(ssh "${APRICOT}" nproc 2>/dev/null || echo 8)"

if [[ -n "${PARALLEL:-}" ]]; then
    PARALLEL_EFFECTIVE="${PARALLEL}"
    PARALLEL_SOURCE="env override"
elif [[ "${USE_MAX_CORES:-false}" == "true" ]]; then
    # One instance per seed — up to NPROC. More instances than that
    # would queue serially anyway (NPROC concurrent Godots max).
    PARALLEL_EFFECTIVE="$(( _seed_count_peek < NPROC ? _seed_count_peek : NPROC ))"
    PARALLEL_SOURCE="USE_MAX_CORES=true → min(seeds=${_seed_count_peek}, nproc=${NPROC})"
else
    PARALLEL_EFFECTIVE="${MIN_CORES:-4}"
    PARALLEL_SOURCE="MIN_CORES default"
fi
export PARALLEL="${PARALLEL_EFFECTIVE}"

# RAYON_NUM_THREADS per Godot instance = fair share of cores.
if [[ -n "${RAYON_NUM_THREADS:-}" ]]; then
    RAYON_SOURCE="env override"
else
    if [[ "${PARALLEL_EFFECTIVE}" -gt 0 ]]; then
        RAYON_NUM_THREADS="$(( NPROC / PARALLEL_EFFECTIVE ))"
    else
        RAYON_NUM_THREADS=1
    fi
    [[ "${RAYON_NUM_THREADS}" -lt 1 ]] && RAYON_NUM_THREADS=1
    RAYON_SOURCE="nproc(${NPROC}) / PARALLEL(${PARALLEL_EFFECTIVE})"
fi
export RAYON_NUM_THREADS
# Source + build scratch lives under $HOME/.cache (flatpak-visible via
# --filesystem=home). /tmp was tried first but flatpak's sandbox can't see
# /tmp, so Godot rejected the --path argument with "Invalid project path".
# $HOME/.cache/ still satisfies the apricot-isolation rule (not under ~/Code,
# not shared with other devs) and is convention-cleanable.
SCRATCH="\$HOME/.cache/mc-src-${STAMP}"         # expanded on apricot
RESULTS="\$HOME/.cache/mc-batches/${STAMP}"     # expanded on apricot

# Resolve $HOME on apricot so SCRATCH / RESULTS are fully-qualified paths on that host.
SCRATCH_ABS="$(ssh "${APRICOT}" "echo \$HOME/.cache/mc-src-${STAMP}")"
RESULTS_ABS="$(ssh "${APRICOT}" "echo \$HOME/.cache/mc-batches/${STAMP}")"

echo "============================================================"
echo "apricot-run.sh mode=${MODE} stamp=${STAMP}"
echo "  EDIT host: $(hostname)"
echo "  RUN host:  ${APRICOT}"
echo "  SCRATCH:   ${SCRATCH_ABS}       (per-run source + build scratch)"
echo "  RESULTS:   ${RESULTS_ABS}       (persistent batch output)"
echo "  PARALLEL:  ${PARALLEL_EFFECTIVE}   (source: ${PARALLEL_SOURCE})"
echo "  RAYON_NUM_THREADS/instance: ${RAYON_NUM_THREADS}   (source: ${RAYON_SOURCE})"
echo "  Total CPU saturation: ${PARALLEL_EFFECTIVE} × ${RAYON_NUM_THREADS} = $((PARALLEL_EFFECTIVE * RAYON_NUM_THREADS))/${NPROC} cores"
echo "  AI_GPU_ROLLOUT: ${AI_GPU_ROLLOUT:-true (default on for smoke/clan)}"
echo "============================================================"

# ── Step 1: rsync EDIT → SCRATCH ─────────────────────────────────────────────
echo "[$(date +%H:%M:%S)] rsync EDIT source → ${SCRATCH_ABS}..."
rsync -a --delete \
    --exclude='.git' \
    --exclude='.local/build' \
    --exclude='.local/iter' \
    --exclude='.local/batches' \
    --exclude='node_modules' \
    --exclude='target' \
    --exclude='*.dylib' \
    "${PROJECT_DIR}/" "${APRICOT}:${SCRATCH_ABS}/"

# ── Step 2: build + deploy via build-gdext.sh ────────────────────────────────
# Canonical build script: runs `cargo build --release --target x86_64-unknown-linux-gnu`
# AND copies the output from .local/build/rust/$TARGET/release/libmagic_civ_physics_gdext.so
# into src/game/engine/addons/magic_civ_physics/libmagic_civ_physics.x86_64.so
# with the name Godot's .gdextension file expects.
echo "[$(date +%H:%M:%S)] build-gdext.sh x86_64-unknown-linux-gnu (in SCRATCH)..."
# Never pipe build output through `| tail -N` — ssh inherits the pipe's
# exit code (0 from tail), which masks build-gdext.sh failures. That's
# how a stale April-16 .so ran for 2 hours on 2026-04-17 while bullets
# 3-5 of p0-32 stayed ✗ with no visible warning. Let the full log through.
ssh "${APRICOT}" "set -euo pipefail; cd '${SCRATCH_ABS}/src/simulator' && bash build-gdext.sh x86_64-unknown-linux-gnu"

# Also purge the stale .dylib that the rsync carried from the Mac — flatpak Godot
# on Linux shouldn't try to load a macOS binary even though the .gdextension config
# only points at it for macos.* target strings.
ssh "${APRICOT}" "rm -f '${SCRATCH_ABS}/src/game/engine/addons/magic_civ_physics/libmagic_civ_physics.dylib'"

# ── Step 3: populate .godot/global_script_class_cache.cfg via editor pre-pass ──
# Fresh scratch tree has an empty .godot/ cache. Godot's class_name resolution
# (the `as Weather` / `as SplitPanelContainer` idiom) requires this cache to be
# populated by an editor-mode scan. Without it, headless autoplay cascades through
# "Could not find type X" → "Compilation failed" → turn_manager.gd fails to load.
#
# `--editor --quit` opens, imports, scans class_names, writes cache, exits.
# Expected exit code: 0. We grep the log to verify the cache got written.
echo "[$(date +%H:%M:%S)] editor pre-pass to populate .godot/ class cache..."
ssh "${APRICOT}" "set -euo pipefail; \
    flatpak run --user --filesystem=home --command=godot \
        org.godotengine.Godot --headless --editor --quit \
        --path '${SCRATCH_ABS}/src/game' 2>&1 | tail -5; \
    test -s '${SCRATCH_ABS}/src/game/.godot/global_script_class_cache.cfg' && \
        echo '  ✓ class cache populated' || \
        echo '  ⚠ class cache missing — headless autoplay may still cascade'"

# ── Step 4: run the batch per MODE ───────────────────────────────────────────
ssh "${APRICOT}" "mkdir -p ${RESULTS_ABS}"

case "${MODE}" in
    smoke)
        SEEDS="${1:-10}"; TURNS="${2:-300}"
        # Default: use the GPU when available (MCTS rollouts through WGSL kernel).
        # gpu-walltime mode overrides this explicitly to true/false per iteration.
        # Default AI_GPU_ROLLOUT=false for smoke/clan. The GPU integration
        # (p0-20 task #10) is parity-verified on isolated rollouts, but
        # enabling it in a 2-player smoke produced a deterministic
        # "P0 always wins at T11-T18, P1 never founds" regression on
        # 2026-04-18. Opt-in via env override; gpu-walltime flips
        # per-iteration as its explicit comparison.
        GPU_ENV="AI_GPU_ROLLOUT=${AI_GPU_ROLLOUT:-false}"
        echo "[$(date +%H:%M:%S)] smoke batch: ${SEEDS} seeds T${TURNS} PARALLEL=${PARALLEL} ${GPU_ENV}"
        ssh "${APRICOT}" "set -euo pipefail; cd '${SCRATCH_ABS}' && \
            AI_USE_MCTS=true ${GPU_ENV} PARALLEL=${PARALLEL} \
            bash tools/autoplay-batch.sh ${SEEDS} ${TURNS} ${RESULTS_ABS}/smoke 2>&1 | tail -30"
        ;;
    clan)
        CLAN="${1:?usage: apricot-run.sh clan <clan_id> [seeds] [turns]}"
        SEEDS="${2:-10}"; TURNS="${3:-300}"
        # Default AI_GPU_ROLLOUT=false for smoke/clan. The GPU integration
        # (p0-20 task #10) is parity-verified on isolated rollouts, but
        # enabling it in a 2-player smoke produced a deterministic
        # "P0 always wins at T11-T18, P1 never founds" regression on
        # 2026-04-18. Opt-in via env override; gpu-walltime flips
        # per-iteration as its explicit comparison.
        GPU_ENV="AI_GPU_ROLLOUT=${AI_GPU_ROLLOUT:-false}"
        echo "[$(date +%H:%M:%S)] clan=${CLAN} batch: ${SEEDS} seeds T${TURNS} PARALLEL=${PARALLEL} ${GPU_ENV}"
        ssh "${APRICOT}" "set -euo pipefail; cd '${SCRATCH_ABS}' && \
            AI_USE_MCTS=true AI_PIN_PERSONALITY='${CLAN}' ${GPU_ENV} PARALLEL=${PARALLEL} \
            bash tools/autoplay-batch.sh ${SEEDS} ${TURNS} ${RESULTS_ABS}/clan-${CLAN} 2>&1 | tail -30"
        ;;
    gpu-walltime)
        SEEDS="${1:-10}"; TURNS="${2:-300}"
        echo "[$(date +%H:%M:%S)] GPU wall-time comparison: ${SEEDS} seeds T${TURNS}"
        for GPU in true false; do
            echo "  --- AI_GPU_ROLLOUT=${GPU} ---"
            ssh "${APRICOT}" "set -euo pipefail; cd '${SCRATCH_ABS}' && \
                AI_USE_MCTS=true AI_GPU_ROLLOUT=${GPU} PARALLEL=${PARALLEL} \
                bash tools/autoplay-batch.sh ${SEEDS} ${TURNS} ${RESULTS_ABS}/gpu-${GPU} 2>&1 | tail -10"
        done
        ;;
    *)
        echo "ERROR: unknown mode '${MODE}'" >&2
        exit 2
        ;;
esac

# ── Step 5: fetch results summary back to EDIT ───────────────────────────────
LOCAL_RESULTS="${PROJECT_DIR}/.local/iter/apricot-${STAMP}"
mkdir -p "${LOCAL_RESULTS}"
echo "[$(date +%H:%M:%S)] fetch verdict/summary to ${LOCAL_RESULTS}..."
scp -r "${APRICOT}:${RESULTS_ABS}/" "${LOCAL_RESULTS}/" 2>/dev/null || \
    echo "WARN: scp returned non-zero; check manually on ${APRICOT}:${RESULTS_ABS}"

# ── Step 6: prune old local copies — keep only the 3 most recent ─────────────
ITER_ROOT="${PROJECT_DIR}/.local/iter"
if [[ -d "${ITER_ROOT}" ]]; then
    # List apricot-* dirs newest-first, skip the first 3, delete the rest.
    mapfile -t OLD_RUNS < <(ls -1dt "${ITER_ROOT}"/apricot-* 2>/dev/null | tail -n +4)
    if (( ${#OLD_RUNS[@]} > 0 )); then
        echo "[$(date +%H:%M:%S)] pruning ${#OLD_RUNS[@]} old local run(s) (keeping 3 newest)..."
        for d in "${OLD_RUNS[@]}"; do
            echo "  rm -rf ${d}"
            rm -rf "${d}"
        done
    fi
fi

echo "============================================================"
echo "DONE. Scratch at ${APRICOT}:${SCRATCH_ABS} (ephemeral, /tmp)."
echo "Results at ${APRICOT}:${RESULTS_ABS} (persistent, .cache)."
echo "Local copy at ${LOCAL_RESULTS}"
echo "============================================================"