name: Label Merged PRs

on:
  pull_request:
    types: [closed]

jobs:
  label-pr:
    if: github.event.pull_request.merged == true
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    
    steps:
      - name: Checkout repository
        uses: actions/checkout@v6
      
      - name: Check if author is in tier list
        id: check-author
        run: |
          USERS=(
            "TyDunn"
            "jpoly1219"
            "bdougie"
            "uinstinct"
            "sestinj"
            "tingwai"
            "tomasz-stefaniak"
            "RomneyDa"
            "Patrick-Erichsen"
          )
          
          PR_AUTHOR="${{ github.event.pull_request.user.login }}"
          SHOULD_LABEL="false"
          
          for user in "${USERS[@]}"; do
            if [[ "$PR_AUTHOR" == "$user" ]]; then
              SHOULD_LABEL="true"
              break
            fi
          done
          
          echo "should_label=$SHOULD_LABEL" >> $GITHUB_OUTPUT
      
      - name: Determine and apply tier label
        if: steps.check-author.outputs.should_label == 'true'
        uses: actions/github-script@v8
        with:
          script: |
            const pr = context.payload.pull_request;
            
            // Check if PR already has a tier label
            const existingLabels = pr.labels.map(l => l.name);
            if (existingLabels.some(label => label.match(/^tier [1-3]$/))) {
              console.log('PR already has a tier label, skipping');
              return;
            }
            
            // Function to extract conventional commit prefix
            function getConventionalPrefix(title) {
              const match = title.match(/^([a-z]+)(\s|$|:)/);
              return match ? match[1] : '';
            }
            
            // Function to determine tier
            function determineTier(pr) {
              const additions = pr.additions;
              const deletions = pr.deletions;
              const changedFiles = pr.changed_files;
              const title = pr.title;
              const body = pr.body || '';
              
              const prefix = getConventionalPrefix(title);
              
              // If no conventional commit prefix, skip
              if (!prefix) {
                console.log('No conventional commit format, skipping');
                return null;
              }
              
              // Tier 4 (unlabeled): fix, test, docs, style, refactor, perf, build, ci, revert, improve
              const tier4Prefixes = ['fix', 'test', 'docs', 'style', 'refactor', 'perf', 'build', 'ci', 'revert', 'chore', 'improve'];
              if (tier4Prefixes.includes(prefix)) {
                console.log('Tier 4 prefix detected, will remain unlabeled');
                return null;
              }
              
              const totalChanges = additions + deletions;
              
              // Tier 1: Major features (1000+ lines changed, or 20+ files, or feat with large scope)
              if (totalChanges > 1000 || changedFiles > 20 || 
                  (prefix === 'feat' && totalChanges > 800) ||
                  title.match(/(major|milestone|launch)/)) {
                return 'tier 1';
              }
              
              // Tier 2: Important features (500+ lines changed, or 10+ files, or standard feat)
              if (totalChanges > 500 || changedFiles > 10 || prefix === 'feat') {
                return 'tier 2';
              }
              
              // Tier 3: Smaller improvements
              return 'tier 3';
            }
            
            const tier = determineTier(pr);
            
            if (tier) {
              console.log(`Assigning ${tier} label to PR #${pr.number}`);
              console.log(`Title: ${pr.title}`);
              console.log(`Changes: +${pr.additions} -${pr.deletions} (${pr.changed_files} files)`);
              
              await github.rest.issues.addLabels({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: pr.number,
                labels: [tier]
              });
              
              console.log(`✓ Label '${tier}' added successfully`);
            }