name: accept-pull-request

on:
  issue_comment:
    types:
      - created

concurrency: accept-pull-request-${{ github.ref }}

jobs:
  accept-pull-request:
    env:
      GITHUB_CONTEXT: ${{ toJson(github) }}    
      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      OWNER: ${{ github.repository_owner }}
      REPO: ${{ github.event.repository.name }}
      PR_NUMBER: ${{ github.event.issue.number }}
      COMMENT_USER_LOGIN: ${{ github.event.comment.user.login }}
    name: accept-pull-request
    runs-on: ubuntu-latest
    if: ${{ github.event.issue.pull_request && startsWith(github.event.comment.body, '/accept') }}
    steps:

      - name: Init all internal env vars       
        run: |
            pr_detail_file="pr_detail.json"
            gh api repos/"${OWNER}"/"${REPO}"/pulls/"${PR_NUMBER}" > "${pr_detail_file}"
            jq . "${pr_detail_file}"
            HEAD_REPO_FULL_NAME=$(jq -rc .head.repo.full_name ${pr_detail_file})
            BASE_REPO_FULL_NAME=$(jq -rc .base.repo.full_name ${pr_detail_file})
            if [ "${HEAD_REPO_FULL_NAME}" = "${BASE_REPO_FULL_NAME}" ] ; then
                HEAD_TYPE=origin
            else
                HEAD_TYPE=fork
            fi        
            echo "HEAD_REPO_FULL_NAME=${HEAD_REPO_FULL_NAME}" | tee -a "${GITHUB_ENV}"
            echo "BASE_REPO_FULL_NAME=${BASE_REPO_FULL_NAME}" | tee -a "${GITHUB_ENV}"
            echo "HEAD_TYPE=${HEAD_TYPE}" | tee -a "${GITHUB_ENV}"
            echo "HEAD_REF=$(jq -rc .head.ref ${pr_detail_file})" | tee -a "${GITHUB_ENV}"
            echo "BASE_REF=$(jq -rc .base.ref ${pr_detail_file})" | tee -a "${GITHUB_ENV}"
            echo "PR_STATE=$(jq -rc .state ${pr_detail_file})" | tee -a "${GITHUB_ENV}"
            echo "PR_DRAFT=$(jq -rc .draft ${pr_detail_file})" | tee -a "${GITHUB_ENV}"
            echo "PR_MERGEABLE=$(jq -rc .mergeable ${pr_detail_file})" | tee -a "${GITHUB_ENV}"
            echo "REMAINING_COMMITS_FILE=remaining_commits.txt" | tee -a "${GITHUB_ENV}"           
            echo "NEW_COMMITS_FILE=new_commits.txt" | tee -a "${GITHUB_ENV}"

      - name: Checkout repository
        uses: actions/checkout@v3
        with:
          ref: ${{ env.BASE_REF }}
          fetch-depth: 0

      - name: Notify user
        run: |
            order="${{ github.event.comment.body }}"
            comment="🕗 [${order}](${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID}) is running, please wait for completion."
            gh pr comment "${PR_NUMBER}" --body "${comment}"

      - name: Check comment user permission
        run: |
            comment_user_permission=$(gh api repos/"${OWNER}"/"${REPO}"/collaborators/"${COMMENT_USER_LOGIN}"/permission -q .permission)
            if [ "${comment_user_permission}" = "admin" ] ; then
                echo "  - ✅ You have the ${comment_user_permission} permission then you are allowed to accept pull request n°${PR_NUMBER}"
            else
                comment="❌ Sorry \`${COMMENT_USER_LOGIN}\`, you are not allowed to accept this pull request because you do not have admin permission (actual permission=${comment_user_permission})."
                echo "  - ${comment}"
                gh pr comment "${PR_NUMBER}" --body "${comment}"
                exit 1
            fi

      - name: Check if pull request state is open
        run: |
            if [ "${{ env.PR_STATE }}" = "open" ] ; then
                echo "  - ✅ Pull request is ${{ env.PR_STATE }}."
            else
                comment="❌ Can not accept this pull request because it is not open (actual state=${{ env.PR_STATE }})."
                echo "  - ${comment}"
                gh pr comment "${PR_NUMBER}" --body "${comment}"
                exit 1         
            fi

      - name: Check if pull request is ready
        run: |
            if [ "${{ env.PR_DRAFT }}" = "false" ] ; then
                echo "  - ✅ Pull request draft state is ${{ env.PR_DRAFT }}."
            else
                comment="❌ Can not accept this pull request because it is still in draft."
                echo "  - ${comment}"
                gh pr comment "${PR_NUMBER}" --body "${comment}"
                exit 1         
            fi

      - name: Check if pull request is mergeable
        run: |
            if [ "${{ env.PR_MERGEABLE }}" = "true" ] ; then
                echo "  - ✅ Pull request mergeable state is ${{ env.PR_MERGEABLE }}."
            else
                comment="❌ Pull request is not mergeable, please check unresolved discussions and pull request messages."
                echo "  - ${comment}"
                gh pr comment "${PR_NUMBER}" --body "${comment}"
                exit 1         
            fi

      - name: Check if pull request checks are successful
        if: ${{ !contains(github.event.comment.body, '--force') }}
        run: |
            gh pr checks "${PR_NUMBER}" --watch --interval 30 && exit_code=0 || exit_code=$?
            if [ "${exit_code}" -eq 0 ] ; then
                echo "  - ✅ Pull request checks are successful."
            else
                comment="❌ Some checks are still failing, please fix them before trying to /accept this pull request."
                echo "  - ${comment}"
                gh pr comment "${PR_NUMBER}" --body "${comment}"
                exit 1
            fi            

      - name: Add remote source branch
        run: |
            if [ "${{ env.HEAD_TYPE }}" = "fork" ] ; then
                git remote add fork https://github.com/${{ env.HEAD_REPO_FULL_NAME}}
                git remote --verbose
                git fetch --all
            fi
            echo "  - ✅ Source branch is from ${{ env.HEAD_TYPE }} repo"

      - name: Check if source branch is rebased from target branch 
        run: |
            git log --oneline --cherry ${{ env.HEAD_TYPE }}/${{ env.HEAD_REF }}...origin/${{ env.BASE_REF }} > "${{ env.REMAINING_COMMITS_FILE }}" && exit_code=0 || exit_code=1
            if [ ${exit_code} -eq 1 ] ; then
                comment="❌ Rebase check fails. Please refer to ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID} logs."
                echo "  - ${comment}"
                gh pr comment "${PR_NUMBER}" --body "${comment}"
                exit 1
            fi
            diff_count=$(grep -c ^+ ${{ env.REMAINING_COMMITS_FILE }} || true)
            if [ ${diff_count} -eq 0 ] ; then
                echo "  - ✅ ${{ env.HEAD_REPO_FULL_NAME}}/${{ env.HEAD_REF }} is already rebased from ${{ env.BASE_REPO_FULL_NAME}}/${{ env.BASE_REF }}."
            else
                comment="❌ You have to rebase your \`${{ env.HEAD_REPO_FULL_NAME}}/${{ env.HEAD_REF }}\` branch first because there are new commits pending on target \`${{ env.BASE_REPO_FULL_NAME}}/${{ env.BASE_REF }}\` branch:<br>$(echo ; sed "s/+/-/g" ${{ env.REMAINING_COMMITS_FILE }})"
                echo "  - ${comment}"
                gh pr comment "${PR_NUMBER}" --body "${comment}"
                exit 1
            fi

      - name: Get new commits list
        run: |
            git log --oneline --cherry origin/${{ env.BASE_REF }}...${{ env.HEAD_TYPE }}/${{ env.HEAD_REF }} | tee ${{ env.NEW_COMMITS_FILE }}

      - name: Merge fast forward head ref to base ref 
        run: |
            git config --local user.email "action@github.com"
            git config --local user.name "GitHub Action"
            git merge ${{ env.HEAD_TYPE }}/${{ env.HEAD_REF }} --ff-only && exit_code=0 || exit_code=1
            if [ ${exit_code} -eq 0 ] ; then
                echo "  - ✅ Merge fast forward succeeds."
            else
                comment="❌ Merge fast forward fails. Please refer to ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID} logs."
                echo "  - ${comment}"
                gh pr comment "${PR_NUMBER}" --body "${comment}"
                exit 1         
            fi
            git push && exit_code=0 || exit_code=1
            if [ ${exit_code} -eq 0 ] ; then
                echo "  - ✅ Push merge fast forward succeeds."
            else
                comment="❌ Push merge fast forward fails. Please refer to ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID} logs."
                echo "  - ${comment}"
                gh pr comment "${PR_NUMBER}" --body "${comment}"
                exit 1         
            fi

      - name: Close pull request
        run: |
            if [[ "${{ github.event.comment.body }}" =~ "--force" ]] ; then
                comment="✅ Pull request accepted without waiting for checks and closed by \`${COMMENT_USER_LOGIN}\` with fast forward merge."          
            else
                comment="✅ Pull request accepted and closed by \`${COMMENT_USER_LOGIN}\` with fast forward merge."
            fi
            gh pr close "${PR_NUMBER}" --delete-branch --comment "${comment}.<br><br>\# List of commits merged from \`${{ env.HEAD_REPO_FULL_NAME}}/${{ env.HEAD_REF }}\` branch into \`${{ env.BASE_REPO_FULL_NAME}}/${{ env.BASE_REF }}\` branch:<br>$(echo ; sed "s/+/-/g" ${{ env.NEW_COMMITS_FILE }})" && exit_code=0 || exit_code=1
            if [ ${exit_code} -eq 0 ] ; then
                echo "  - ${comment}"     
            else
                comment="❌ A problem occured when closing pull request and/or deleting branch."
                echo "  - ${comment}"
                #gh pr comment "${PR_NUMBER}" --body "${comment} Please refer to ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID} logs."
                #exit 1       
            fi