coverage.yml

name: Code Coverage

on:
  push:
    branches: [main]
    paths:
      - 'server/src/**'
      - 'client/src/**'
      - 'coverage.sh'
      - '.github/workflows/coverage.yml'
  pull_request:
    paths:
      - 'server/src/**'
      - 'client/src/**'
      - 'coverage.sh'
      - '.github/workflows/coverage.yml'

permissions:
  contents: read
  pages: write
  id-token: write
  pull-requests: write

concurrency:
  group: coverage-${{ github.ref }}
  cancel-in-progress: true

jobs:
  coverage:
    name: Generate Coverage Report
    runs-on: ubuntu-latest
    if: github.event_name != 'pull_request' || (github.event.pull_request.user.login != 'gnometranslations' && github.event.pull_request.user.login != 'dependabot[bot]')

    steps:
      - name: Checkout
        uses: actions/checkout@v6

      - name: Install Rust toolchain
        uses: dtolnay/rust-toolchain@stable
        with:
          components: llvm-tools-preview

      - name: Setup Rust cache
        uses: Swatinem/rust-cache@v2

      - name: Install cargo-tarpaulin
        uses: taiki-e/install-action@v2
        with:
          tool: cargo-tarpaulin

      - name: Install grcov for merging coverage
        uses: taiki-e/install-action@v2
        with:
          tool: grcov

      - name: Run coverage script
        run: |
          chmod +x coverage.sh
          ./coverage.sh

      - name: Prepare coverage for deployment
        run: |
          mkdir -p site/coverage
          cp -r coverage/* site/coverage/

          # Extract coverage percentage from the generated JSON file
          CURRENT_COVERAGE=$(jq -r '.message' site/coverage/html/coverage.json | sed 's/%//')
          echo "CURRENT_COVERAGE=$CURRENT_COVERAGE" >> $GITHUB_ENV
          echo "Combined coverage: $CURRENT_COVERAGE%"

      - name: Generate coverage summary for PR comparison
        if: github.event_name == 'pull_request'
        run: |
          echo "PR_COVERAGE=$CURRENT_COVERAGE" >> $GITHUB_ENV
          echo "PR coverage: $CURRENT_COVERAGE%"

      - name: Store coverage percentage for main branch
        if: github.ref == 'refs/heads/main' && github.event_name == 'push'
        run: |
          echo "Main branch coverage: $CURRENT_COVERAGE%"

          # Store in a simple text file artifact for PR comparisons
          mkdir -p coverage-baseline
          echo "$CURRENT_COVERAGE" > coverage-baseline/main-coverage.txt

          # Generate coverage badge
          COVERAGE_INT=$(echo "$CURRENT_COVERAGE" | cut -d. -f1)
          if [ "$COVERAGE_INT" -ge 80 ]; then
            COLOR="brightgreen"
          elif [ "$COVERAGE_INT" -ge 60 ]; then
            COLOR="yellow"
          else
            COLOR="red"
          fi

          # Create badge SVG using shields.io format
          curl -s "https://img.shields.io/badge/coverage-${CURRENT_COVERAGE}%25-${COLOR}" > site/coverage/badge.svg

      - name: Upload baseline coverage
        if: github.ref == 'refs/heads/main' && github.event_name == 'push'
        uses: actions/upload-artifact@v7
        with:
          name: coverage-baseline
          path: coverage-baseline/main-coverage.txt
          retention-days: 90

      - name: Get main branch coverage for comparison
        if: github.event_name == 'pull_request'
        uses: actions/github-script@v9
        with:
          script: |
            // Find the latest successful coverage run on main that has the baseline artifact
            const { data: runs } = await github.rest.actions.listWorkflowRuns({
              owner: context.repo.owner,
              repo: context.repo.repo,
              workflow_id: 'coverage.yml',
              status: 'completed',
              conclusion: 'success',
              branch: 'main',
              per_page: 10
            });

            for (const run of runs.workflow_runs) {
              try {
                const { data: artifacts } = await github.rest.actions.listWorkflowRunArtifacts({
                  owner: context.repo.owner,
                  repo: context.repo.repo,
                  run_id: run.id
                });

                const baselineArtifact = artifacts.artifacts.find(a => a.name === 'coverage-baseline');
                if (baselineArtifact) {
                  core.exportVariable('BASELINE_RUN_ID', run.id.toString());
                  console.log(`Found baseline artifact in run ${run.id}`);
                  return;
                }
              } catch (error) {
                console.log(`Error checking run ${run.id}: ${error.message}`);
              }
            }

            console.log('No baseline artifact found in recent main branch runs');
            core.exportVariable('BASELINE_RUN_ID', '');

      - name: Download baseline artifact
        if: github.event_name == 'pull_request' && env.BASELINE_RUN_ID != ''
        uses: actions/download-artifact@v8
        with:
          name: coverage-baseline
          path: coverage-baseline/
          github-token: ${{ secrets.GITHUB_TOKEN }}
          run-id: ${{ env.BASELINE_RUN_ID }}
        continue-on-error: true

      - name: Set main coverage for comparison
        if: github.event_name == 'pull_request'
        run: |
          if [ -f coverage-baseline/main-coverage.txt ]; then
            MAIN_COVERAGE=$(cat coverage-baseline/main-coverage.txt)
            echo "MAIN_COVERAGE=$MAIN_COVERAGE" >> $GITHUB_ENV
            echo "Using stored main branch coverage: $MAIN_COVERAGE%"
          else
            echo "MAIN_COVERAGE=0.00" >> $GITHUB_ENV
            echo "No baseline coverage found, using 0.00%"
          fi

      - name: Post coverage comment on PR
        if: github.event_name == 'pull_request'
        uses: actions/github-script@v9
        with:
          script: |
            const prCoverage = parseFloat(process.env.PR_COVERAGE || '0.00');
            const mainCoverage = parseFloat(process.env.MAIN_COVERAGE || '0.00');
            const diff = prCoverage - mainCoverage;
            const diffText = diff > 0 ? `+${diff.toFixed(2)}%` : `${diff.toFixed(2)}%`;
            const emoji = diff > 0 ? '📈' : diff < 0 ? '📉' : '➡️';

            const body = `## 📊 Code Coverage Report

            | Metric | Value |
            |--------|-------|
            | **Current PR Coverage** | ${prCoverage.toFixed(2)}% |
            | **Main Branch Coverage** | ${mainCoverage.toFixed(2)}% |
            | **Coverage Change** | ${emoji} ${diffText} |

            ${diff < -1 ? '⚠️ **Warning**: Coverage decreased by more than 1%' : ''}
            ${diff > 1 ? '🎉 **Great**: Coverage increased by more than 1%!' : ''}

            *Coverage report generated by [cargo-tarpaulin](https://github.com/xd009642/tarpaulin)*`;

            // Find existing coverage comment
            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
            });

            const existingComment = comments.find(comment =>
              comment.body.includes('## 📊 Code Coverage Report')
            );

            if (existingComment) {
              // Update existing comment
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: existingComment.id,
                body: body
              });
            } else {
              // Create new comment
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.issue.number,
                body: body
              });
            }

      - name: Upload coverage artifacts
        if: github.ref == 'refs/heads/main' && github.event_name == 'push'
        uses: actions/upload-artifact@v7
        with:
          name: coverage-reports
          path: site/coverage/html/
          retention-days: 30