#!/bin/sh
# 12b_servability_gate.sh — permanent 12B servability detection gate.
#
# C-path reality (documented unsupported, NOT silently shippable): Gemma-4-12B
# at the only manifest-allowed Q4_0 grade produces the degenerate high-ID logits
# signature (argmax in the ~236xxx band) — proven with oracle-validated
# independent math (artifacts/2026-08-30-12b-diagnosis/DIAGNOSIS.md). Correct
# 12B serving requires Q8_0 projection support (engine task: "12B serving:
# Q8_0 projection support + config/detection router").
#
# This ctest drives scripts/remediate-12b.sh --verify as the servability
# DETECTOR (sane = argmax < 200000). It asserts the classifier runs and the
# status is reported loudly:
#   - model absent      -> SKIP (exit 0)
#   - classified sane   -> PASS "servable" (future: after Q8_0+router land)
#   - classified as the known degenerate 236xxx signature -> PASS with an
#     explicit UNSUPPORTED notice (documented, not silently shipped)
#   - verifier error    -> FAIL (exit 1)
#
# Usage: 12b_servability_gate.sh [MODEL.gguf]
# (no arg: auto-locate GEM_MODEL_DIR/.state/models gemma-4-12B-it-Q4_0.gguf)
set -eu

root=$(CDPATH='' cd -- "$(dirname -- "$0")/.." && pwd)
model=${1:-}
if [ -z "$model" ]; then
    for d in ${GEM_MODEL_DIR:-} "$root/.state/models"; do
        [ -n "$d" ] || continue
        candidate="$d/gemma-4-12B-it-Q4_0.gguf"
        if [ -r "$candidate" ]; then
            model=$candidate
            break
        fi
    done
fi
if [ -z "$model" ] || [ ! -r "$model" ]; then
    echo "12B servability gate: SKIP (no 12B Q4_0 model present)"
    exit 0
fi

out=$("$root/scripts/remediate-12b.sh" --verify "$model" --prompt Hello 2>/dev/null || true)
parsed=$(printf '%s' "$out" | python3 -c '
import json, sys
try:
    d = json.load(sys.stdin)
    print("sane" if d.get("pass") else "degenerate", d.get("model", {}).get("argmax", "?"))
except Exception:
    print("parse-error ?")
' || echo 'parse-error ?')
status=$(printf '%s' "$parsed" | awk '{print $1}')
argmax=$(printf '%s' "$parsed" | awk '{print $2}')

echo "12B servability gate: model=$model"
case "$status" in
sane)
    echo "PASS: 12B classified SERVABLE (argmax $argmax < 200000)."
    exit 0
    ;;
degenerate)
    echo "UNSUPPORTED (documented): 12B Q4_0 logits fall in the degenerate"
    echo "high-ID band (argmax $argmax). Correct 12B serving requires Q8_0"
    echo "projection support + the config/detection router (engine task)."
    echo "PASS as documented-unsupported (not silently shipped)."
    exit 0
    ;;
*)
    echo "FAIL: servability verifier could not classify $model"
    echo "$out"
    exit 1
    ;;
esac