email.yml

name: email
on:
    # this workflow is intended to run on merges from a forked repo to main(base-repo). Use pull_request_target
    # this will provide read access to the secrets in main
    pull_request_target:
      types:
        - closed
      
jobs: 
  send_email:
   # run this workflow step only when the PR is merged 
    if:  github.event.pull_request.merged == true 
    runs-on: ubuntu-latest 
    steps:
      - name: print git events
        run:  cat "$GITHUB_EVENT_PATH"                     
      - name: print GitHub context
        env:
          GITHUB_CONTEXT: ${{ toJson(github) }}
        run: echo "$GITHUB_CONTEXT" 
     # This workflow step will parse github env. The parsed env will be used in the email body.
      - name: get commits payload
        id: build-payload
        env:
           PR_LINK: ${{github.event.pull_request._links.html.href}}
        run: |      
              echo "LINK=$(echo $PR_LINK )" >> $GITHUB_ENV   
              echo "AUTHOR=$(echo ${{github.event.pull_request.head.user.login}})" >> $GITHUB_ENV
              echo "COMPARE_URL= $( echo '${{github.event.repository.html_url}}/compare/${{github.event.pull_request.base.sha}}...${{github.event.pull_request.head.sha}}' )" >> $GITHUB_ENV      
              echo "FILES_CHANGED=$(echo '$PR_LINK/files' )" >> $GITHUB_ENV     
  
      - name: checkout
        uses: actions/checkout@v3
        # To get git diff on the files that were changed in the PR checkout with fetch-depth 2.
        with:
          fetch-depth: 0 
      # this step will (1) get the merge log for the merge_commit_sha and save it to the git  actions EN for later use in the email body. 
      # (2) Get the files changed on the merge commit using the git log --name-status command.
      - name: Get merge log
        id: merge-log
        env:
           MERGE_SHA: ${{github.event.pull_request.merge_commit_sha}}
        run: |   
              merge_log=$(git show -s --format=%B $MERGE_SHA )
              echo "$merge_log" 
              echo 'MERGE<<EOF' >> $GITHUB_ENV
              echo "$merge_log" >> $GITHUB_ENV
              echo 'EOF' >> $GITHUB_ENV

              diff=$(git --no-pager diff --merge-base --name-status --diff-filter=ACDMRT ${{github.event.pull_request.base.sha}} ${{github.event.pull_request.head.sha}})
              echo "$diff" 
              echo 'DIFF<<EOF' >> $GITHUB_ENV
              echo "$diff" >> $GITHUB_ENV
              echo 'EOF' >> $GITHUB_ENV                   
      
      - name: Send mail  
        uses: dawidd6/action-send-mail@v3
        with:
           # Required mail server address if not connection_url:
           server_address: ${{ secrets.SMTP_PROVIDER}}
           server_port: 465
           # Optional whether this connection use TLS (default is true if server_port is 465)
           secure: true
           # Optional (recommended): mail server username:
           username:  ${{ secrets.MAIL_USERNAME}} 
           # Optional (recommended) mail server password:
           password: ${{secrets.MAIL_PASSWORD}}
           # Required mail subject:
           subject: "[Chapel Merge] ${{github.event.pull_request.title}}"
           # Required recipients' addresses:
           to: chapel+commits@discoursemail.com
           # Required sender full name (address can be skipped):
           from:  ${{env.AUTHOR}}
           body: |
              
              Branch: ${{github.ref}} 
              Revision: ${{ github.event.pull_request.merge_commit_sha }} 
              Author: ${{ env.AUTHOR}} 
              Link: ${{github.event.pull_request._links.html.href}}              
              Log Message: 
              ${{env.MERGE}} 

              Compare: ${{env.COMPARE_URL}}

              Diff: 
                       ${{env.DIFF}} 
                       ${{github.event.pull_request.diff_url}}
           # Optional priority: 'high', 'normal' (default) or 'low'
           priority: low