pre-push

#!/bin/sh
#
# Pre-push hook: checks that a fresh coverage report exists
# when pushing coprocessor changes. Non-blocking (always exits 0).
#

# Preserve Git LFS functionality
command -v git-lfs >/dev/null 2>&1 && git lfs pre-push "$@"

# Get the repo root
REPO_ROOT=$(git rev-parse --show-toplevel)
REPORT_FILE="$REPO_ROOT/coprocessor/fhevm-engine/coverage-report.txt"
COPROCESSOR_DIR="coprocessor/fhevm-engine/"

# Determine the merge base to compare against (what's being pushed)
CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD)
MERGE_BASE=$(git merge-base main HEAD 2>/dev/null || true)
if [ -z "$MERGE_BASE" ]; then
    exit 0
fi

# Get files changed on this branch vs main, filtered to crate subdirectories only
# (ignores root-level config: Makefile, scripts/, Cargo.toml, etc.)
CRATE_CHANGES=$(git diff --name-only "$MERGE_BASE"...HEAD -- "$COPROCESSOR_DIR" 2>/dev/null | \
    while read -r f; do
        # Strip the coprocessor/fhevm-engine/ prefix
        rel=$(echo "$f" | sed "s|^$COPROCESSOR_DIR||")
        # Extract top-level directory name
        crate_name=$(echo "$rel" | cut -d/ -f1)
        # Only include if it's an actual crate (has Cargo.toml)
        if [ -f "$REPO_ROOT/$COPROCESSOR_DIR$crate_name/Cargo.toml" ]; then
            echo "$crate_name"
        fi
    done | sort -u)

if [ -z "$CRATE_CHANGES" ]; then
    # No crate-level changes on this branch — nothing to check
    exit 0
fi

# Get the timestamp of the latest crate-related commit on this branch
LAST_COMMIT_TIME=""
for crate in $CRATE_CHANGES; do
    t=$(git log -1 --format=%ct "$MERGE_BASE"..HEAD -- "$COPROCESSOR_DIR$crate/" 2>/dev/null)
    if [ -n "$t" ] && { [ -z "$LAST_COMMIT_TIME" ] || [ "$t" -gt "$LAST_COMMIT_TIME" ]; }; then
        LAST_COMMIT_TIME="$t"
    fi
done

if [ -z "$LAST_COMMIT_TIME" ]; then
    exit 0
fi

# Check if coverage report exists
if [ ! -f "$REPORT_FILE" ]; then
    echo ""
    echo "WARNING: No coverage report found for coprocessor."
    echo "  Run 'make coverage-changed' in coprocessor/fhevm-engine/ to generate it."
    echo ""
    exit 0
fi

# Check report freshness: compare file mtime vs latest coprocessor commit time
# Handle both macOS (stat -f %m) and Linux (stat -c %Y)
if stat -f %m "$REPORT_FILE" >/dev/null 2>&1; then
    REPORT_TIME=$(stat -f %m "$REPORT_FILE")
else
    REPORT_TIME=$(stat -c %Y "$REPORT_FILE")
fi

if [ "$REPORT_TIME" -lt "$LAST_COMMIT_TIME" ]; then
    echo ""
    echo "WARNING: Coverage report is stale (generated before latest coprocessor commit)."
    echo "  Run 'make coverage' in coprocessor/fhevm-engine/ to regenerate."
    echo ""
    exit 0
fi

# Report is fresh — print summary
TOTAL_LINE=$(grep "^TOTAL" "$REPORT_FILE" 2>/dev/null)
if [ -n "$TOTAL_LINE" ]; then
    echo ""
    echo "Coverage: $TOTAL_LINE"
    echo ""
fi

exit 0