#!/bin/bash
# Claude Code PostToolUse hook: HARD ERROR on GPU→CPU leaks in hot-path files.
# Reads JSON from stdin (Claude Code hook input), extracts file_path, runs guard.
# Exit 1 = leak detected → Claude Code blocks the edit and must fix immediately.
set -euo pipefail

INPUT=$(cat)
FILE=$(echo "$INPUT" | jq -r '.tool_input.file_path // .tool_input.path // empty' 2>/dev/null)

if [ -z "$FILE" ] || [ ! -f "$FILE" ]; then
    exit 0
fi

# Check Rust and CUDA files
SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"

case "$FILE" in
    *.rs)
        GUARD="$SCRIPT_DIR/gpu-hotpath-guard.sh"
        if [ -x "$GUARD" ]; then
            OUTPUT=$("$GUARD" "$FILE" 2>&1) || {
                echo "⛔ GPU HOT-PATH HARD ERROR in $FILE"
                echo "$OUTPUT"
                echo ""
                echo "CPU usage in GPU hot paths is NOT allowed. Fix the code — do not annotate with // gpu-ok:"
                exit 1
            }
        fi
        ;;
    *.cu|*.cuh)
        GUARD="$SCRIPT_DIR/cuda-kernel-guard.sh"
        if [ -x "$GUARD" ]; then
            OUTPUT=$("$GUARD" "$FILE" 2>&1) || {
                echo "⛔ CUDA KERNEL HARD ERROR in $FILE"
                echo "$OUTPUT"
                echo ""
                echo "CPU/host operations in CUDA kernels are NOT allowed."
                exit 1
            }
        fi
        ;;
    *) exit 0 ;;
esac

exit 0