#!/usr/bin/env bash
# Track mutation testing scores over time
set -euo pipefail

# Configuration
HISTORY_FILE="mutation_history.json"
TEMP_FILE="mutants.out/outcomes.json"

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

echo "🧬 Running mutation testing..."
echo ""

# Run mutation tests
if ! cargo mutants --no-shuffle --test-tool nextest --output-json; then
    echo ""
    echo -e "${RED}❌ Mutation testing failed${NC}"
    exit 1
fi

echo ""
echo "📊 Analyzing results..."

# Check if outcomes.json exists
if [ ! -f "$TEMP_FILE" ]; then
    echo -e "${RED}❌ No mutation results found${NC}"
    exit 1
fi

# Extract stats from outcomes.json using jq
TOTAL_MUTANTS=$(jq '[.outcomes[] | select(.scenario != "Baseline")] | length' "$TEMP_FILE")
CAUGHT=$(jq '[.outcomes[] | select(.scenario != "Baseline") | select(.summary == "CaughtMutant")] | length' "$TEMP_FILE")
MISSED=$(jq '[.outcomes[] | select(.scenario != "Baseline") | select(.summary == "MissedMutant")] | length' "$TEMP_FILE")
TIMEOUT=$(jq '[.outcomes[] | select(.scenario != "Baseline") | select(.summary == "Timeout")] | length' "$TEMP_FILE")
UNVIABLE=$(jq '[.outcomes[] | select(.scenario != "Baseline") | select(.summary == "Unviable")] | length' "$TEMP_FILE")

# Calculate viable mutants (total - unviable)
VIABLE=$((TOTAL_MUTANTS - UNVIABLE))

# Calculate mutation score (caught / viable * 100)
if [ "$VIABLE" -eq 0 ]; then
    SCORE=0
else
    SCORE=$(echo "scale=2; $CAUGHT * 100 / $VIABLE" | bc)
fi

# Get current timestamp and git info
TIMESTAMP=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
GIT_COMMIT=$(git rev-parse HEAD 2>/dev/null || echo "unknown")
GIT_BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null || echo "unknown")

# Create history entry
ENTRY=$(cat <<EOF
{
  "timestamp": "$TIMESTAMP",
  "git_commit": "$GIT_COMMIT",
  "git_branch": "$GIT_BRANCH",
  "stats": {
    "total_mutants": $TOTAL_MUTANTS,
    "viable": $VIABLE,
    "caught": $CAUGHT,
    "missed": $MISSED,
    "timeout": $TIMEOUT,
    "unviable": $UNVIABLE,
    "score": $SCORE
  }
}
EOF
)

# Initialize history file if it doesn't exist
if [ ! -f "$HISTORY_FILE" ]; then
    echo "[]" > "$HISTORY_FILE"
fi

# Append entry to history
jq ". += [$ENTRY]" "$HISTORY_FILE" > "${HISTORY_FILE}.tmp"
mv "${HISTORY_FILE}.tmp" "$HISTORY_FILE"

# Display results
echo ""
echo "═══════════════════════════════════════════════════════"
echo "           MUTATION TESTING RESULTS"
echo "═══════════════════════════════════════════════════════"
echo ""
echo "Total mutants:       $TOTAL_MUTANTS"
echo "├─ Viable:           $VIABLE"
echo "├─ Caught:           $CAUGHT ($(echo "scale=1; $CAUGHT * 100 / $VIABLE" | bc)%)"
echo "├─ Missed:           $MISSED"
echo "├─ Timeout:          $TIMEOUT"
echo "└─ Unviable:         $UNVIABLE"
echo ""

# Color the score based on value
if (( $(echo "$SCORE >= 90" | bc -l) )); then
    COLOR=$GREEN
    STATUS="✅ EXCELLENT"
elif (( $(echo "$SCORE >= 80" | bc -l) )); then
    COLOR=$YELLOW
    STATUS="⚠️  GOOD"
else
    COLOR=$RED
    STATUS="❌ NEEDS IMPROVEMENT"
fi

echo -e "${COLOR}Mutation Score: ${SCORE}% ${STATUS}${NC}"
echo ""

# Show previous score if available
PREV_SCORE=$(jq -r '.[-2].stats.score // empty' "$HISTORY_FILE" 2>/dev/null || echo "")
if [ -n "$PREV_SCORE" ]; then
    DIFF=$(echo "scale=2; $SCORE - $PREV_SCORE" | bc)
    if (( $(echo "$DIFF > 0" | bc -l) )); then
        echo -e "${GREEN}⬆ Improved by ${DIFF}% from previous run${NC}"
    elif (( $(echo "$DIFF < 0" | bc -l) )); then
        echo -e "${RED}⬇ Decreased by ${DIFF#-}% from previous run${NC}"
    else
        echo "➡ No change from previous run"
    fi
    echo ""
fi

echo "═══════════════════════════════════════════════════════"
echo ""
echo "📝 Results saved to: $HISTORY_FILE"
echo "🔬 Full report: mutants.out/"
echo ""

# Exit with failure if score is below threshold
THRESHOLD=85
if (( $(echo "$SCORE < $THRESHOLD" | bc -l) )); then
    echo -e "${RED}⚠️  Mutation score ($SCORE%) is below threshold ($THRESHOLD%)${NC}"
    exit 1
fi

echo -e "${GREEN}✅ Mutation testing passed!${NC}"