merge-from-milestone.yml

name: Merge PRs from Milestone

permissions:
  contents: write
  pull-requests: write
  issues: write

on:
  workflow_dispatch:
    inputs:
      milestone_name:
        description: 'Milestone name to collect closed PRs from'
        required: true
        default: 'v3.8.2'
      target_branch:
        description: 'Target branch to merge the consolidated PR'
        required: true
        default: 'pre-release-v3.8.2'
  schedule:
    - cron: '0 10 * * 0'

env:
  MILESTONE_NAME: ${{ github.event.inputs.milestone_name || 'v3.8.2' }}
  TARGET_BRANCH: ${{ github.event.inputs.target_branch || 'pre-release-v3.8.2' }}
  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
  BOT_TOKEN: ${{ secrets.BOT_TOKEN }}
  LABEL_NAME: cherry-picked

jobs:
  cherry_pick_milestone_prs:
    runs-on: ubuntu-latest
    steps:
      # Step 1: Checkout repository with full history
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          token: ${{ secrets.BOT_TOKEN }}

      # Step 2: Setup Git user configuration for the bot
      - name: Setup Git User for OpenIM-Robot
        run: |
          git config --global user.email "OpenIM-Robot@users.noreply.github.com"
          git config --global user.name "OpenIM-Robot"

      # Step 3: Fetch Milestone ID and filter PR numbers without the 'cherry-picked' label
      - name: Fetch Milestone ID and Filter PR Numbers
        env:
          MILESTONE_NAME: ${{ env.MILESTONE_NAME }}
        run: |
          # Fetch all milestones and find the one with the specified name
          milestones=$(curl -s -H "Authorization: token $BOT_TOKEN" \
            -H "Accept: application/vnd.github+json" \
            "https://api.github.com/repos/${{ github.repository }}/milestones")
          milestone_id=$(echo "$milestones" | grep -B3 "\"title\": \"$MILESTONE_NAME\"" | grep '"number":' | head -n1 | grep -o '[0-9]\+')
          echo "Milestone ID: $milestone_id"

          # Fetch all issues for the milestone and filter out PRs without the 'cherry-picked' label
          issues=$(curl -s -H "Authorization: token $BOT_TOKEN" \
                -H "Accept: application/vnd.github+json" \
                "https://api.github.com/repos/${{ github.repository }}/issues?milestone=$milestone_id&state=closed&per_page=100")

          > pr_numbers.txt

          for pr_number in $(echo "$issues" | jq -r '.[] | select(.pull_request != null) | .number'); do
            labels=$(curl -s -H "Authorization: token $BOT_TOKEN" \
              -H "Accept: application/vnd.github+json" \
              "https://api.github.com/repos/${{ github.repository }}/issues/$pr_number/labels" | jq -r '.[].name')

            # Only include PRs that do not have the 'cherry-picked' label
            if ! echo "$labels" | grep -q "${LABEL_NAME}"; then
              echo "$pr_number" >> pr_numbers.txt
            fi
          done

          echo "Filtered PR numbers:"
          cat pr_numbers.txt

          # Sort PR numbers in ascending order
          sort -n pr_numbers.txt -o pr_numbers.txt

          echo "Sorted PR numbers:"
          cat pr_numbers.txt

      # Step 4: Fetch merge commit SHA for each filtered PR and prepare PR title and body
      - name: Fetch Merge Commits for PRs and Prepare PR Title and Body
        run: |
          > commit_hashes.txt
          > pr_title.txt
          > pr_body.txt

          # Collect PR details and format the title and body for the new PR
          for pr_number in $(cat pr_numbers.txt); do
            pr_details=$(curl -s -H "Authorization: token $BOT_TOKEN" \
              -H "Accept: application/vnd.github+json" \
              "https://api.github.com/repos/${{ github.repository }}/pulls/$pr_number")
            
            pr_title=$(echo "$pr_details" | jq -r '.title')
            merge_commit=$(echo "$pr_details" | jq -r '.merge_commit_sha')
            short_commit_hash=$(echo "$merge_commit" | cut -c 1-7)

            commit_url="https://github.com/${{ github.repository }}/commit/$merge_commit"
            pr_url="https://github.com/${{ github.repository }}/pull/$pr_number"

            # Prepare PR title
            echo "#$pr_number" >> pr_title.txt

            # Prepare PR body
            echo "* **$pr_title**: ([#$pr_number]($pr_url)) ([\`$short_commit_hash\`]($commit_url))" >> pr_body.txt
          done

          # Collect commit hashes and prepare the branch name for cherry-picking
          pr_numbers_in_title=$(paste -sd " " pr_title.txt)
          commit_hashes=$(cat commit_hashes.txt | tr '\n' ' ')
          first_commit_hash=$(head -n 1 commit_hashes.txt)
          cherry_pick_branch="cherry-pick-${first_commit_hash:0:7}"

          echo "COMMIT_HASHES=$commit_hashes" >> $GITHUB_ENV
          echo "CHERRY_PICK_BRANCH=$cherry_pick_branch" >> $GITHUB_ENV

      # Step 5: Cherry-pick commits and push to remote
      - name: Cherry-pick Commits and Push
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          BOT_TOKEN: ${{ secrets.BOT_TOKEN }}
        run: |
          # Fetch and pull the latest changes from the target branch
          git fetch origin
          git checkout $TARGET_BRANCH
          git pull origin $TARGET_BRANCH

          # Create a new branch for cherry-picking
          git checkout -b $CHERRY_PICK_BRANCH

          # Cherry-pick the commits and resolve conflicts by taking the incoming changes
          for commit_hash in $COMMIT_HASHES; do
            echo "Attempting to cherry-pick commit $commit_hash"
            if ! git cherry-pick "$commit_hash" --strategy=recursive -X theirs; then
              if git diff --cached --quiet; then
                echo "Empty commit, continuing..."
                git cherry-pick --continue --allow-empty
              else
                echo "Conflict resolved with incoming content"
                git cherry-pick --continue
              fi
            fi
          done

          # Push the new branch with cherry-picked commits
          git push origin $CHERRY_PICK_BRANCH

      # Step 6: Use curl to create the Pull Request
      - name: Create Pull Request using curl
        run: |
          pr_title="deps: Merge $(cat pr_title.txt | paste -sd " ") PRs into $TARGET_BRANCH"
          pr_body=$(cat pr_body.txt)

          echo "Prepared PR title:"
          echo "$pr_title"
          echo "Prepared PR body:"
          echo "$pr_body"

          # Create the Pull Request using curl
          curl -s -X POST -H "Authorization: token $BOT_TOKEN" \
            -H "Accept: application/vnd.github+json" \
            https://api.github.com/repos/${{ github.repository }}/pulls \
            -d "$(jq -n --arg title "$pr_title" \
              --arg head "$CHERRY_PICK_BRANCH" \
              --arg base "$TARGET_BRANCH" \
              --arg body "$pr_body" \
              '{title: $title, head: $head, base: $base, body: $body}')"

      # Step 7: Label PRs as cherry-picked after success
      - name: Label Successfully Cherry-Picked PRs
        if: ${{ success() }}
        run: |
          for pr_number in $(cat pr_numbers.txt); do
            curl -s -X POST -H "Authorization: token $BOT_TOKEN" \
              -H "Accept: application/vnd.github+json" \
              "https://api.github.com/repos/${{ github.repository }}/issues/$pr_number/labels" \
              -d "$(jq -n --arg label "${LABEL_NAME}" '{labels: [$label]}')"
          done