name: Auto-merge Speakeasy PR

# Called as a follow-up job after Speakeasy Generate (mode: pr). Merges the
# regen PR opened/updated in the same workflow run so sdk_publish.yaml can run.
# Prefer branch_name from Generate logs; fall back to run_started_at heuristics.
# Uses GH_DOCS_SYNC GitHub App token (not a PAT) so merges trigger downstream push.

on:
  workflow_call:
    inputs:
      run_started_at:
        description: ISO timestamp when the parent Generate workflow run started
        required: true
        type: string
      branch_name:
        description: Speakeasy regen branch from the parent Generate run (optional)
        required: false
        type: string
        default: ""
    secrets:
      GH_DOCS_SYNC_APP_ID:
        required: true
      GH_DOCS_SYNC_APP_PRIVATE_KEY:
        required: true

permissions:
  contents: write
  pull-requests: write

concurrency:
  group: auto-merge-speakeasy
  cancel-in-progress: false

jobs:
  auto-merge:
    runs-on: ubuntu-latest
    steps:
      - name: Generate GitHub App token
        id: app-token
        # actions/create-github-app-token@v3.2.0 (immutable SHA)
        uses: actions/create-github-app-token@bcd2ba49218906704ab6c1aa796996da409d3eb1
        with:
          app-id: ${{ secrets.GH_DOCS_SYNC_APP_ID }}
          private-key: ${{ secrets.GH_DOCS_SYNC_APP_PRIVATE_KEY }}

      - name: Resolve Speakeasy regen PR
        id: pr
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token }}
        run: |
          set -euo pipefail

          REPO="${{ github.repository }}"
          RUN_STARTED="${{ inputs.run_started_at }}"
          BRANCH="${{ inputs.branch_name }}"

          PR_JSON=$(gh pr list \
            --repo "$REPO" \
            --state open \
            --search "head:speakeasy-sdk-regen-" \
            --limit 500 \
            --json number,updatedAt,title,labels,author,headRefName)

          PR_NUM=""
          if [ -n "$BRANCH" ]; then
            CANDIDATE=$(echo "$PR_JSON" | jq -r --arg branch "$BRANCH" \
              '[.[] | select(.headRefName == $branch)] | .[0] // empty')
            if [ -n "$CANDIDATE" ] && echo "$CANDIDATE" | jq -e '
              (.headRefName | startswith("speakeasy-sdk-regen-"))
              and (.title | contains("🐝 Update SDK"))
              and ([.labels[].name] | any(. == "patch" or . == "minor" or . == "major"))
              and (.author.is_bot == true)
            ' > /dev/null; then
              PR_NUM=$(echo "$CANDIDATE" | jq -r '.number')
              echo "Resolved Speakeasy regen PR #$PR_NUM from branch $BRANCH"
            else
              echo "::warning::branch_name=$BRANCH did not match a valid open regen PR — falling back to run_started_at"
            fi
          fi

          if [ -z "$PR_NUM" ]; then
            PR_NUM=$(echo "$PR_JSON" | jq -r --arg started "$RUN_STARTED" '
              [.[]
                | select(.headRefName | startswith("speakeasy-sdk-regen-"))
                | select(.title | contains("🐝 Update SDK"))
                | select([.labels[].name] | any(. == "patch" or . == "minor" or . == "major"))
                | select(.author.is_bot == true)
                | select(.updatedAt >= $started)
              ] | sort_by(.updatedAt) | last | .number // empty')
          fi

          if [ -z "$PR_NUM" ]; then
            echo "No Speakeasy regen PR for this Generate run — skipping auto-merge"
            echo "::notice title=auto-merge-skipped::No qualifying Speakeasy regen PR to merge"
            {
              echo "## Auto-merge skipped"
              echo "No qualifying \`speakeasy-sdk-regen-*\` PR was found."
              echo "- branch_name input: \`${BRANCH:-<empty>}\`"
              echo "- run_started_at: \`$RUN_STARTED\`"
            } >> "$GITHUB_STEP_SUMMARY"
            echo "pr_num=" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          echo "pr_num=$PR_NUM" >> "$GITHUB_OUTPUT"
          echo "$PR_JSON" > /tmp/speakeasy_pr_json.json

      - name: Close superseded Speakeasy PRs
        if: steps.pr.outputs.pr_num != ''
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token }}
        run: |
          set -euo pipefail

          CURRENT_PR="${{ steps.pr.outputs.pr_num }}"
          PR_JSON=$(cat /tmp/speakeasy_pr_json.json)

          PRIOR_JSON=$(echo "$PR_JSON" | jq -r --arg current_pr "$CURRENT_PR" \
            '[.[].number | select(tostring != $current_pr)] | .[]')

          if [ -z "$PRIOR_JSON" ]; then
            echo "No superseded Speakeasy PRs to close"
            exit 0
          fi

          mapfile -t PRIOR <<< "$PRIOR_JSON"

          echo "Closing ${#PRIOR[@]} superseded Speakeasy PR(s)"
          for N in "${PRIOR[@]}"; do
            gh pr close "$N" --repo "${{ github.repository }}" --delete-branch \
              --comment "Superseded by newer Speakeasy SDK generation PR #${CURRENT_PR}" \
              || echo "::warning::Failed to close PR #$N (continuing)"
            sleep 1
          done

      - name: Auto-merge Speakeasy PR
        if: steps.pr.outputs.pr_num != ''
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token }}
        run: |
          set -euo pipefail

          PR_NUM="${{ steps.pr.outputs.pr_num }}"
          REPO="${{ github.repository }}"

          wait_for_checks() {
            local pr=$1
            local timeout=600
            local interval=15
            local elapsed=0

            echo "Waiting for PR #$pr checks (timeout ${timeout}s)..."
            while [ "$elapsed" -lt "$timeout" ]; do
              TOTAL=$(gh pr view "$pr" --repo "$REPO" --json statusCheckRollup --jq \
                '.statusCheckRollup | length')
              PENDING=$(gh pr view "$pr" --repo "$REPO" --json statusCheckRollup --jq \
                '[.statusCheckRollup[]? | select(.status != "COMPLETED")] | length')
              FAILED=$(gh pr view "$pr" --repo "$REPO" --json statusCheckRollup --jq \
                '[.statusCheckRollup[]? | select(.status == "COMPLETED") | select(.conclusion != "SUCCESS" and .conclusion != "SKIPPED" and .conclusion != "NEUTRAL")] | length')

              if [ "$TOTAL" -eq 0 ]; then
                # GITHUB_TOKEN-authored regen PRs get no pull_request checks at all,
                # so TOTAL stays 0 forever. Wait a short grace window in case checks
                # are merely slow to register, then proceed rather than time out.
                if [ "$elapsed" -ge 60 ]; then
                  echo "No checks registered after ${elapsed}s — proceeding (checkless PR)"
                  return 0
                fi
                echo "Checks not yet registered — waiting ${interval}s..."
                sleep "$interval"
                elapsed=$((elapsed + interval))
                continue
              fi

              if [ "$PENDING" -eq 0 ]; then
                if [ "$FAILED" -gt 0 ]; then
                  echo "::error::PR #$pr has failing checks — refusing direct merge"
                  gh pr checks "$pr" --repo "$REPO" || true
                  exit 1
                fi
                echo "All checks completed"
                return 0
              fi

              echo "Checks pending ($PENDING) — waiting ${interval}s..."
              sleep "$interval"
              elapsed=$((elapsed + interval))
            done

            echo "::error::Timed out waiting for PR #$pr checks"
            exit 1
          }

          STATE=$(gh pr view "$PR_NUM" --repo "$REPO" --json state --jq .state)
          if [ "$STATE" != "OPEN" ]; then
            echo "PR #$PR_NUM is $STATE — skipping merge"
            exit 0
          fi

          MERGE_METHOD=""
          # Prefer GitHub auto-merge when required checks exist; otherwise
          # squash-merge directly after checks pass (sdk-release-prs.yaml pattern).
          AUTO_MERGE_NOOP_PATTERN='is in clean status|protected branch rules|Branch does not have required protected branch rules'
          if gh pr merge "$PR_NUM" --repo "$REPO" --squash --auto --delete-branch 2> /tmp/gh-merge.err; then
            MERGE_METHOD="auto-merge queued"
            echo "Auto-merge enabled for Speakeasy PR #$PR_NUM"
          elif grep -qiE "$AUTO_MERGE_NOOP_PATTERN" /tmp/gh-merge.err; then
            echo "Auto-merge not applicable — waiting for checks, then merging PR #$PR_NUM directly"
            cat /tmp/gh-merge.err >&2
            wait_for_checks "$PR_NUM"
            gh pr merge "$PR_NUM" --repo "$REPO" --squash --delete-branch
            MERGE_METHOD="direct squash (checks passed)"
          else
            echo "::error::Failed to enable auto-merge on Speakeasy PR #$PR_NUM"
            cat /tmp/gh-merge.err >&2
            exit 1
          fi

          echo "::notice title=auto-merge-pr::Merged Speakeasy PR #$PR_NUM ($MERGE_METHOD)"
          {
            echo "## Auto-merge complete"
            echo "- PR: #$PR_NUM"
            echo "- Method: $MERGE_METHOD"
            echo "- Token: GH_DOCS_SYNC GitHub App"
          } >> "$GITHUB_STEP_SUMMARY"