# The docs.github.com project has two repositories: github/docs (public) and github/docs-internal (private)
#
# This GitHub Actions workflow keeps the `main` branch of those two repos in sync.
#
# For more details, see https://github.com/repo-sync/repo-sync#how-it-works

name: Repo Sync

# **What it does**:
#  - close-invalid-repo-sync: Close repo sync pull requests not created by Octomerger or a Hubber.
#  - repo-sync: Syncs docs and docs-internal.
# **Why we have it**:
#  - close-invalid-repo-sync: Another form of spam prevention for the open-source repository.
#  - repo-sync: To keep the open-source repository up-to-date, while still having an internal
#    repository for sensitive work.
# **Who does it impact**: Open-source.

on:
  workflow_dispatch:
  schedule:
    - cron: '10,25,40,55 * * * *' # every 15 minutes

jobs:
  close-invalid-repo-sync:
    name: Close invalid Repo Sync PRs
    runs-on: ubuntu-latest
    steps:
      - name: Find pull request
        if: ${{ github.repository == 'github/docs' }}
        uses: juliangruber/find-pull-request-action@db875662766249c049b2dcd85293892d61cb0b51
        id: find-pull-request
        with:
          github-token: ${{ secrets.DOCS_BOT_SPAM_VISION }}
          branch: repo-sync
          base: main
          state: open

      - name: Close pull request if unwanted
        if: ${{ github.repository == 'github/docs' && steps.find-pull-request.outputs.number }}
        uses: actions/github-script@2b34a689ec86a68d8ab9478298f91d5401337b7d
        with:
          github-token: ${{ secrets.DOCS_BOT_SPAM_VISION }}
          script: |
            const { owner, repo } = context.repo

            const { data: pr } = await github.pulls.get({
              owner,
              repo,
              pull_number: parseInt(${{ steps.find-pull-request.outputs.number }})
            })

            const prCreator = pr.user.login

            // If the PR creator is the expected account, stop now
            if (prCreator === 'Octomerger') {
              return
            }

            try {
              await github.teams.getMembershipForUserInOrg({
                org: 'github',
                team_slug: 'employees',
                username: prCreator
              })

              // If the PR creator is a GitHub employee, stop now
              return
            } catch (err) {
              // An error will be thrown if the user is not a GitHub employee.
              // That said, we still want to proceed anyway!
            }

            // Close the PR and add the invalid label
            await github.issues.update({
              owner,
              repo,
              issue_number: pr.number,
              labels: ['invalid'],
              state: 'closed'
            })

            // Comment on the PR
            await github.issues.createComment({
              owner,
              repo,
              issue_number: pr.number,
              body: "Please leave this `repo-sync` branch to the robots!\n\nI'm going to close this pull request now, but feel free to open a new issue or ask any questions in [discussions](https://github.com/github/docs/discussions)!"
            })

  repo-sync:
    needs: close-invalid-repo-sync
    if: github.repository == 'github/docs-internal' || github.repository == 'github/docs'
    name: Repo Sync
    runs-on: ubuntu-latest
    steps:
      - name: Check out repo
        uses: actions/checkout@5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f

      - name: Sync repo to branch
        uses: repo-sync/github-sync@3832fe8e2be32372e1b3970bbae8e7079edeec88
        env:
          GITHUB_TOKEN: ${{ secrets.OCTOMERGER_PAT_WITH_REPO_AND_WORKFLOW_SCOPE }}
        with:
          source_repo: ${{ secrets.SOURCE_REPO }} # https://${access_token}@github.com/github/the-other-repo.git
          source_branch: main
          destination_branch: repo-sync
          github_token: ${{ secrets.OCTOMERGER_PAT_WITH_REPO_AND_WORKFLOW_SCOPE }}

      - name: Create pull request
        id: create-pull
        uses: repo-sync/pull-request@33777245b1aace1a58c87a29c90321aa7a74bd7d
        env:
          GITHUB_TOKEN: ${{ secrets.OCTOMERGER_PAT_WITH_REPO_AND_WORKFLOW_SCOPE }}
        with:
          source_branch: repo-sync
          destination_branch: main
          pr_title: 'repo sync'
          pr_body: "This is an automated pull request to sync changes between the public and private repos.\n\n:robot: This pull request should be merged (not squashed) to preserve continuity across repos, so please let a bot do the merging!"
          pr_label: autoupdate,automated-reposync-pr
          github_token: ${{ secrets.OCTOMERGER_PAT_WITH_REPO_AND_WORKFLOW_SCOPE }}

      - name: Find pull request
        uses: juliangruber/find-pull-request-action@db875662766249c049b2dcd85293892d61cb0b51
        id: find-pull-request
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          branch: repo-sync
          base: main
          author: Octomerger
          state: open

      - name: Approve pull request
        if: ${{ steps.find-pull-request.outputs.number }}
        uses: juliangruber/approve-pull-request-action@c530832d4d346c597332e20e03605aa94fa150a8
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          number: ${{ steps.find-pull-request.outputs.number }}

      # There are cases where the branch becomes out-of-date in between the time this workflow began and when the pull request is created/updated
      - name: Update branch
        if: ${{ steps.find-pull-request.outputs.number }}
        uses: actions/github-script@2b34a689ec86a68d8ab9478298f91d5401337b7d
        with:
          github-token: ${{ secrets.OCTOMERGER_PAT_WITH_REPO_AND_WORKFLOW_SCOPE }}
          script: |
            const mainHeadSha = await github.git.getRef({
              ...context.repo,
              ref: 'heads/main'
            })
            console.log(`heads/main sha: ${mainHeadSha.data.object.sha}`)

            const pull = await github.pulls.get({
              ...context.repo,
              pull_number: parseInt(${{ steps.find-pull-request.outputs.number }})
            })
            console.log(`Pull request base sha: ${pull.data.base.sha}`)

            if (mainHeadSha.data.object.sha !== pull.data.base.sha || pull.data.mergeable_state === 'behind') {
              try {
                const updateBranch = await github.pulls.updateBranch({
                  ...context.repo,
                  pull_number: parseInt(${{ steps.find-pull-request.outputs.number }})
                })
                console.log(updateBranch.data.message)
              } catch (error) {
                // When the head branch is modified an error with status 422 is thrown
                // We should retry one more time to update the branch
                if (error.status === 422) {
                  try {
                    const updateBranch = await github.pulls.updateBranch({
                      ...context.repo,
                      pull_number: parseInt(${{ steps.find-pull-request.outputs.number }})
                    })
                    console.log(updateBranch.data.message)
                  } catch (error) {
                    // Only retry once. We'll rely on the update branch workflow to update 
                    // this PR in the case of a second failure.
                    console.log(`Retried updating the branch, but an error occurred: ${error}`)
                  }
                } else {
                  // A failed branch update shouldn't fail this worklow. 
                  console.log(`An error occurred when updating the branch: ${error}`)
                }
              }
            } else {
              console.log(`Branch is already up-to-date`)
            }

      - name: Enable GitHub auto-merge
        if: ${{ steps.find-pull-request.outputs.number }}
        uses: actions/github-script@2b34a689ec86a68d8ab9478298f91d5401337b7d
        with:
          github-token: ${{ secrets.OCTOMERGER_PAT_WITH_REPO_AND_WORKFLOW_SCOPE }}
          script: |
            const pull = await github.pulls.get({
              ...context.repo,
              pull_number: parseInt(${{ steps.find-pull-request.outputs.number }})
            })

            const pullNodeId = pull.data.node_id
            console.log(`Pull request GraphQL Node ID: ${pullNodeId}`)

            const mutation = `mutation ($id: ID!) {
              enablePullRequestAutoMerge(input: {
                pullRequestId: $id,
                mergeMethod: MERGE
              }) {
                clientMutationId
              }
            }`
            const variables = {
              id: pullNodeId
            }

            const graph = await github.graphql(mutation, variables)
            console.log('GraphQL mutation result:\n' + JSON.stringify(graph))

            if (graph.errors && graph.errors.length > 0) {
              console.error('ERROR! Failed to enable auto-merge:\n - ' + graph.errors.map(error => error.message).join('\n - '))
            } else {
              console.log('Auto-merge enabled!')
            }

      - name: Send Slack notification if workflow fails
        uses: someimportantcompany/github-actions-slack-message@0b470c14b39da4260ed9e3f9a4f1298a74ccdefd
        if: failure()
        with:
          channel: ${{ secrets.DOCS_ALERTS_SLACK_CHANNEL_ID }}
          bot-token: ${{ secrets.SLACK_DOCS_BOT_TOKEN }}
          color: failure
          text: The last repo-sync run for ${{github.repository}} failed. See https://github.com/${{github.repository}}/actions?query=workflow%3A%22Repo+Sync%22