action.yml

# action.yml

name: 'Auto PR: dev to main/master'
description: 'Automates PR creation from dev to main/master, generates descriptions with OpenAI, and adds reviewers.'
author: 'Yuri V'
branding:
  icon: 'git-pull-request'
  color: 'green'
inputs:
  openai_api_key:
    description: 'OpenAI API Key'
    required: true
  openai_model:
    description: 'OpenAI model to use (e.g., gpt-4, gpt-3.5-turbo, etc.) https://platform.openai.com/docs/models'
    required: false
    default: 'gpt-4o-mini'
  github_token:
    description: 'GitHub (PAT) token with repo permissions'
    required: true
  dev_branch:
    description: 'Development branch name'
    required: false
    default: 'dev'
outputs:
  pr_number:
    description: 'The number of the pull request created or updated'
runs:
  using: 'composite'
  steps:
    - name: Checkout repository
      uses: actions/checkout@v4
      with:
        ref: ${{ inputs.dev_branch }}

    - name: Set up Git
      shell: bash
      run: |
        git config --global user.name "github-actions[bot]"
        git config --global user.email "github-actions[bot]@users.noreply.github.com"

    - name: Get the default branch
      id: get_default_branch
      shell: bash
      run: |
        default_branch=$(git remote show origin | grep 'HEAD branch' | awk '{print $NF}')
        echo "branch=${default_branch}" >> $GITHUB_OUTPUT

    - name: Get the diff using custom script
      id: get_diff
      shell: bash
      run: |
        set -e
        branch_from="${{ steps.get_default_branch.outputs.branch }}"
        branch_to="${{ inputs.dev_branch }}"
        echo "Branch from: $branch_from"
        echo "Branch to: $branch_to"

        git fetch --all

        mkdir -p diff
        output_file="diff/${branch_from:-main}-${branch_to}_$(date +'%Y%m%d_%H%M').diff"
        echo "Output file: $output_file"

        {
          echo "Commits between $branch_from and $branch_to:"
          echo "============================================"
          git log origin/"$branch_from"..origin/"$branch_to" || echo "No commits found"
          echo "--------------------------------------------"
          echo "Git diff between $branch_from and $branch_to"
          echo "============================================"
          git diff origin/"$branch_from" origin/"$branch_to" || echo "No differences found"
        } > "$output_file"

        if [ -s "$output_file" ]; then
          echo "diff_output<<EOF" >> $GITHUB_OUTPUT
          cat "$output_file" >> $GITHUB_OUTPUT
          echo "EOF" >> $GITHUB_OUTPUT
        else
          echo "diff_output=No changes detected between $branch_from and $branch_to" >> $GITHUB_OUTPUT
        fi

    - name: Generate release description using OpenAI API
      id: generate_release_notes
      env:
        OPENAI_API_KEY: ${{ inputs.openai_api_key }}
        OPENAI_MODEL: ${{ inputs.openai_model }}
        DIFF_OUTPUT: ${{ steps.get_diff.outputs.diff_output }}
      shell: bash
      run: |
        prompt="**Instructions:**\n\nPlease generate a **Pull Request description** for the provided diff, following these guidelines:\n- Add appropriate emojis to the description.\n- Do **not** include the words \"Title\" and \"Description\" in your output.\n- Format your answer in **Markdown**."

        escaped_prompt=$(echo "$prompt" | jq -Rs .)
        escaped_diff=$(echo "$DIFF_OUTPUT" | jq -Rs .)

        response=$(curl -s -X POST https://api.openai.com/v1/chat/completions \
          -H "Content-Type: application/json" \
          -H "Authorization: Bearer $OPENAI_API_KEY" \
          -d "{
            \"model\": \"${OPENAI_MODEL}\",
            \"messages\": [
              {
                \"role\": \"system\",
                \"content\": ${escaped_prompt}
              },
              {
                \"role\": \"user\",
                \"content\": ${escaped_diff}
              }
            ],
            \"temperature\": 1,
            \"max_tokens\": 2048,
            \"top_p\": 1,
            \"frequency_penalty\": 0,
            \"presence_penalty\": 0
          }")

        # Check for errors in the response
        error_message=$(echo "$response" | jq -r '.error.message // empty')
        if [ -n "$error_message" ]; then
          echo "Error from OpenAI API: $error_message"
          exit 1
        fi

        description=$(echo "$response" | jq -r '.choices[0].message.content')
        echo "description<<EOF" >> $GITHUB_OUTPUT
        echo "$description" >> $GITHUB_OUTPUT
        echo "EOF" >> $GITHUB_OUTPUT

    - name: Set Release Title
      id: set_release_title
      shell: bash
      run: |
        echo "title=Release v$(date +'%Y.%m.%d')" >> $GITHUB_OUTPUT

    - name: Create or Update Pull Request and Add Reviewers
      id: create_pr
      uses: actions/github-script@v6
      env:
        PR_TITLE: ${{ steps.set_release_title.outputs.title }}
        PR_BODY: ${{ toJSON(steps.generate_release_notes.outputs.description) }}
      with:
        github-token: ${{ inputs.github_token }}
        script: |
          const owner = context.repo.owner;
          const repo = context.repo.repo;
          const head = '${{ inputs.dev_branch }}';
          const base = '${{ steps.get_default_branch.outputs.branch }}';
          const title = process.env.PR_TITLE;
          const body = JSON.parse(process.env.PR_BODY);
          
          // Check if there are any commits between base and head
          const { data: comparison } = await github.rest.repos.compareCommits({
            owner,
            repo,
            base,
            head,
          });
          
          if (comparison.commits.length === 0) {
            console.log('No commits between ' + base + ' and ' + head + '. Skipping PR creation.');
            core.setOutput('pr_number', 'none');
            return;
          }
          
          // Check if PR from dev to default branch already exists
          const { data: pulls } = await github.rest.pulls.list({
            owner: owner,
            repo: repo,
            head: `${owner}:${head}`,
            base: base,
            state: 'open',
          });

          let prNumber;
          let prAuthor;
          if (pulls.length > 0) {
            prNumber = pulls[0].number;
            prAuthor = pulls[0].user.login;
            console.log(`Updating existing PR #${prNumber}`);
            await github.rest.pulls.update({
              owner: owner,
              repo: repo,
              pull_number: prNumber,
              title: title,
              body: body,
            });
          } else {
            console.log('Creating new PR');
            const { data: pr } = await github.rest.pulls.create({
              owner: owner,
              repo: repo,
              head: head,
              base: base,
              title: title,
              body: body,
            });
            prNumber = pr.number;
            prAuthor = pr.user.login;
          }

          // Now, add reviewers
          // First, get the list of committers to this PR
          const { data: commits } = await github.rest.pulls.listCommits({
            owner: owner,
            repo: repo,
            pull_number: prNumber,
          });

          const committersSet = new Set();
          for (const commit of commits) {
            if (commit.author && commit.author.login) {
              committersSet.add(commit.author.login);
            }
          }

          // Add the repo owner
          committersSet.add(owner);

          // Remove the PR author from reviewers
          committersSet.delete(prAuthor);

          // Remove the bot user (if present)
          const botUser = 'github-actions[bot]';
          committersSet.delete(botUser);

          // Convert set to array
          const reviewers = Array.from(committersSet);

          console.log(`Adding reviewers: ${reviewers.join(', ')}`);

          if (reviewers.length > 0) {
            // Add reviewers to the PR
            await github.rest.pulls.requestReviewers({
              owner: owner,
              repo: repo,
              pull_number: prNumber,
              reviewers: reviewers,
            });
          } else {
            console.log('No reviewers to add.');
          }

          core.setOutput('pr_number', prNumber);