name: "Weekly Reference Implementation Sync"

on:
  schedule:
    # Every Monday at 10:00 UTC (5:00 AM EST / 6:00 AM EDT)
    - cron: '0 10 * * 1'
  workflow_dispatch:

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

env: 
  # Used for `gh` CLI operations to create/close/comment issues. Must be a PAT with repo permissions because the default
  GH_AW_AGENT_TOKEN: ${{ secrets.GH_AW_AGENT_TOKEN }}
  GH_TOKEN: ${{ secrets.GH_AW_AGENT_TOKEN }}

jobs:

  check-and-sync:
    name: "Check reference implementation & trigger Copilot merge"
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2

      - name: Check for reference implementation changes
        id: check
        run: |
          LAST_MERGE=$(cat .lastmerge)
          echo "Last merged commit: $LAST_MERGE"

          git clone --quiet https://github.com/github/copilot-sdk.git /tmp/reference-impl
          cd /tmp/reference-impl

          REFERENCE_IMPL_HEAD=$(git rev-parse HEAD)
          echo "Reference implementation HEAD: $REFERENCE_IMPL_HEAD"

          echo "last_merge=$LAST_MERGE" >> "$GITHUB_OUTPUT"

          if [ "$LAST_MERGE" = "$REFERENCE_IMPL_HEAD" ]; then
            echo "No new reference implementation changes since last merge."
            echo "has_changes=false" >> "$GITHUB_OUTPUT"
          else
            COMMIT_COUNT=$(git rev-list --count "$LAST_MERGE".."$REFERENCE_IMPL_HEAD")
            echo "Found $COMMIT_COUNT new reference implementation commits."
            echo "has_changes=true" >> "$GITHUB_OUTPUT"
            echo "commit_count=$COMMIT_COUNT" >> "$GITHUB_OUTPUT"
            echo "reference_impl_head=$REFERENCE_IMPL_HEAD" >> "$GITHUB_OUTPUT"

            # Generate a short summary of changes
            SUMMARY=$(git log --oneline "$LAST_MERGE".."$REFERENCE_IMPL_HEAD" | head -20)
            {
              echo "summary<<EOF"
              echo "$SUMMARY"
              echo "EOF"
            } >> "$GITHUB_OUTPUT"
          fi

      - name: Close previous reference-impl-sync issues
        if: steps.check.outputs.has_changes == 'true'
        run: |
          # Find all open issues with the reference-impl-sync label
          OPEN_ISSUES=$(gh issue list \
            --repo "${{ github.repository }}" \
            --label "reference-impl-sync" \
            --state open \
            --json number \
            --jq '.[].number')

          for ISSUE_NUM in $OPEN_ISSUES; do
            echo "Closing superseded issue #${ISSUE_NUM}"
            gh issue comment "$ISSUE_NUM" \
              --repo "${{ github.repository }}" \
              --body "Superseded by a newer reference implementation sync issue. Closing this one."
            gh issue close "$ISSUE_NUM" \
              --repo "${{ github.repository }}" \
              --reason "not planned"
          done

      - name: Close stale reference-impl-sync issues (no changes)
        if: steps.check.outputs.has_changes == 'false'
        run: |
          OPEN_ISSUES=$(gh issue list \
            --repo "${{ github.repository }}" \
            --label "reference-impl-sync" \
            --state open \
            --json number \
            --jq '.[].number')

          for ISSUE_NUM in $OPEN_ISSUES; do
            echo "Closing stale issue #${ISSUE_NUM} — reference implementation is up to date"
            gh issue comment "$ISSUE_NUM" \
              --repo "${{ github.repository }}" \
              --body "No new reference implementation changes detected. The Java SDK is up to date. Closing."
            gh issue close "$ISSUE_NUM" \
              --repo "${{ github.repository }}" \
              --reason "completed"
          done

      - name: Create issue and assign to Copilot
        id: create-issue
        if: steps.check.outputs.has_changes == 'true'
        env:
          SUMMARY: ${{ steps.check.outputs.summary }}
        run: |
          COMMIT_COUNT="${{ steps.check.outputs.commit_count }}"
          LAST_MERGE="${{ steps.check.outputs.last_merge }}"
          REFERENCE_IMPL_HEAD="${{ steps.check.outputs.reference_impl_head }}"
          DATE=$(date -u +"%Y-%m-%d")
          REPO="${{ github.repository }}"

          BODY="## Automated Reference Implementation Sync

          There are **${COMMIT_COUNT}** new commits in the [official Copilot SDK](https://github.com/github/copilot-sdk) since the last merge.

          - **Last merged commit:** [\`${LAST_MERGE}\`](https://github.com/github/copilot-sdk/commit/${LAST_MERGE})
          - **Reference implementation HEAD:** [\`${REFERENCE_IMPL_HEAD}\`](https://github.com/github/copilot-sdk/commit/${REFERENCE_IMPL_HEAD})

          ### Recent reference implementation commits

          \`\`\`
          ${SUMMARY}
          \`\`\`

          ### Instructions

          Follow the [agentic-merge-reference-impl](.github/prompts/agentic-merge-reference-impl.prompt.md) prompt to port these changes to the Java SDK."

          # Create the issue and assign to Copilot coding agent
          ISSUE_URL=$(gh issue create \
            --repo "$REPO" \
            --title "Reference implementation sync: ${COMMIT_COUNT} new commits (${DATE})" \
            --body "$BODY" \
            --label "reference-impl-sync" \
            --assignee "copilot-swe-agent")

          echo "issue_url=$ISSUE_URL" >> "$GITHUB_OUTPUT"
          echo "✅ Issue created and assigned to Copilot coding agent: $ISSUE_URL"

      - name: Summary
        if: always()
        env:
          SUMMARY: ${{ steps.check.outputs.summary }}
        run: |
          HAS_CHANGES="${{ steps.check.outputs.has_changes }}"
          COMMIT_COUNT="${{ steps.check.outputs.commit_count }}"
          LAST_MERGE="${{ steps.check.outputs.last_merge }}"
          REFERENCE_IMPL_HEAD="${{ steps.check.outputs.reference_impl_head }}"
          ISSUE_URL="${{ steps.create-issue.outputs.issue_url }}"

          {
            echo "## Weekly Reference Implementation Sync"
            echo ""
            if [ "$HAS_CHANGES" = "true" ]; then
              echo "### ✅ New reference implementation changes detected"
              echo ""
              echo "| | |"
              echo "|---|---|"
              echo "| **New commits** | ${COMMIT_COUNT} |"
              echo "| **Last merged** | \`${LAST_MERGE:0:12}\` |"
              echo "| **Reference implementation HEAD** | \`${REFERENCE_IMPL_HEAD:0:12}\` |"
              echo ""
              echo "An issue has been created and assigned to the Copilot coding agent: "
              echo "  -> ${ISSUE_URL}"
              echo ""
              echo "### Recent reference implementation commits"
              echo ""
              echo '```'
              echo "$SUMMARY"
              echo '```'
            else
              echo "### ⏭️ No changes"
              echo ""
              echo "The Java SDK is already up to date with the reference implementation Copilot SDK."
              echo ""
              echo "**Last merged commit:** \`${LAST_MERGE:0:12}\`"
            fi
          } >> "$GITHUB_STEP_SUMMARY"