#!/bin/bash
#
# collect-coverage.sh - Generate LCOV coverage report for Qt6 project
#
# Usage: ./collect-coverage.sh [build_dir]
#
# This script:
# 1. Cleans previous coverage data
# 2. Runs tests with coverage enabled
# 3. Collects coverage data using lcov
# 4. Generates HTML report using genhtml
#

set -e

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(dirname "$SCRIPT_DIR")"
BUILD_DIR="${1:-${PROJECT_ROOT}/build-coverage}"
COVERAGE_DIR="${PROJECT_ROOT}/coverage"

echo "=== LCOV Coverage Collection ==="
echo "Project root: ${PROJECT_ROOT}"
echo "Build directory: ${BUILD_DIR}"
echo "Coverage output: ${COVERAGE_DIR}"

# Clean previous coverage data
echo ""
echo "Step 1: Cleaning previous coverage data..."
find "${BUILD_DIR}" -name "*.gcda" -delete 2>/dev/null || true
find "${BUILD_DIR}" -name "*.gcno" -delete 2>/dev/null || true
rm -rf "${COVERAGE_DIR}"
mkdir -p "${COVERAGE_DIR}"

# Configure with coverage enabled (if not already configured)
if [ ! -f "${BUILD_DIR}/CMakeCache.txt" ]; then
    echo ""
    echo "Step 2: Configuring project with coverage enabled..."
    cmake -S "${PROJECT_ROOT}" -B "${BUILD_DIR}" -G Ninja \
        -DCMAKE_BUILD_TYPE=Debug \
        -DENABLE_COVERAGE=ON \
        -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
else
    echo ""
    echo "Step 2: Build directory already configured"
fi

# Build the project
echo ""
echo "Step 3: Building project..."
cmake --build "${BUILD_DIR}" --target all

# Run tests to generate coverage data
echo ""
echo "Step 4: Running tests to generate coverage data..."
ctest --test-dir "${BUILD_DIR}" --output-on-failure

# Collect coverage data
echo ""
echo "Step 5: Collecting coverage data with lcov..."
lcov --directory "${BUILD_DIR}" \
     --capture \
     --output-file "${COVERAGE_DIR}/coverage.info" \
     --ignore-errors mismatch \
     --no-external \
     --rc lcov_branch_coverage=1

# Remove Qt and system libraries from coverage report
echo "Step 6: Filtering coverage data..."
lcov --remove "${COVERAGE_DIR}/coverage.info" \
     '/usr/*' \
     '/opt/*' \
     '*/Qt6/*' \
     '*/qt6-migrated-benchmark/tests/*' \
     --output-file "${COVERAGE_DIR}/coverage.filtered.info" \
     --ignore-errors mismatch \
     --rc lcov_branch_coverage=1

# Generate HTML report
echo ""
echo "Step 7: Generating HTML report with genhtml..."
genhtml "${COVERAGE_DIR}/coverage.filtered.info" \
        --output-directory "${COVERAGE_DIR}/html" \
        --branch-coverage \
        --ignore-errors mismatch \
        --title "Qt6 Migration Benchmark Coverage" \
        --prefix "${PROJECT_ROOT}"

# Generate summary
echo ""
echo "=== Coverage Summary ==="
lcov --list "${COVERAGE_DIR}/coverage.filtered.info" \
     --ignore-errors mismatch \
     --rc lcov_branch_coverage=1

# Copy to expected Jenkins location
cp "${COVERAGE_DIR}/coverage.filtered.info" "${COVERAGE_DIR}/lcov.info"

echo ""
echo "=== Coverage Report Generated ==="
echo "HTML report: ${COVERAGE_DIR}/html/index.html"
echo "LCOV data: ${COVERAGE_DIR}/lcov.info (for Jenkins)"
echo ""
echo "To view the HTML report, open: ${COVERAGE_DIR}/html/index.html"