name: Slack Notify First Responders

on:
  issues:
    types: [labeled]

permissions:
  contents: read

env:
  SEVERITY_LABELS: '["severity:S0", "severity:S1"]'
  REPRODUCIBLE_LABEL: 'state:reproducible'
  REACH_LABELS: '["reach:all users", "reach:many users"]'
  MARKER_REACTION: 'eyes'

jobs:
  notify-slack:
    if: github.repository_owner == 'zed-industries' && github.event.issue.state == 'open'
    runs-on: namespace-profile-2x4-ubuntu-2404
    permissions:
      contents: read
      # For the issue reaction used to dedupe notifications.
      issues: write
    # Serialize per issue so the reaction claim below can't race.
    concurrency:
      group: slack-notify-first-responders-${{ github.event.issue.number }}
      cancel-in-progress: false

    steps:
      - name: Check label combination and claim the notification
        id: check-label
        env:
          GH_TOKEN: ${{ github.token }}
          GH_REPO: ${{ github.repository }}
          LABEL_NAME: ${{ github.event.label.name }}
          ISSUE_NUMBER: ${{ github.event.issue.number }}
        run: |
          set -euo pipefail

          api() {
            curl -sS \
              -H "Authorization: Bearer $GH_TOKEN" \
              -H "Accept: application/vnd.github+json" \
              -H "X-GitHub-Api-Version: 2022-11-28" \
              "$@"
          }

          # Ignore labels outside the trifecta so unrelated later edits don't re-fire.
          TRIGGER_LABELS=$(jq -cn \
            --argjson severity "$SEVERITY_LABELS" \
            --arg repro "$REPRODUCIBLE_LABEL" \
            --argjson reach "$REACH_LABELS" \
            '$severity + [$repro] + $reach')

          if ! echo "$TRIGGER_LABELS" | jq -e --arg l "$LABEL_NAME" 'index($l) != null' > /dev/null; then
            echo "Added label '$LABEL_NAME' is not in the trigger set, skipping"
            echo "should_notify=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          # The webhook's issue.labels snapshot is racy under bulk apply; read live.
          ISSUE_LABELS_JSON=$(api -f "https://api.github.com/repos/$GH_REPO/issues/$ISSUE_NUMBER/labels?per_page=100" | jq '[.[].name]')

          MATCHED_SEVERITY=$(echo "$ISSUE_LABELS_JSON" | jq -r --argjson severity "$SEVERITY_LABELS" 'map(select(. as $x | $severity | index($x) != null)) | first // ""')
          HAS_REPRO=$(echo "$ISSUE_LABELS_JSON" | jq --arg l "$REPRODUCIBLE_LABEL" 'index($l) != null')
          HAS_REACH=$(echo "$ISSUE_LABELS_JSON" | jq --argjson reach "$REACH_LABELS" 'any(.[]; . as $x | $reach | index($x) != null)')

          if [ -z "$MATCHED_SEVERITY" ] || [ "$HAS_REPRO" != "true" ] || [ "$HAS_REACH" != "true" ]; then
            echo "Combination not yet satisfied (severity=$MATCHED_SEVERITY, reproducible=$HAS_REPRO, reach=$HAS_REACH), skipping"
            echo "should_notify=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          # A bulk label apply emits one `labeled` event per label, so several
          # runs reach this point. Creating the reaction is our atomic claim:
          # one run gets 201 and notifies, the rest get 200. It's scoped to our
          # own reaction, so a human's reaction can't suppress it.
          REACTION_PAYLOAD=$(jq -cn --arg content "$MARKER_REACTION" '{content: $content}')
          REACTION_RESPONSE=$(api -w "\n%{http_code}" -X POST \
            "https://api.github.com/repos/$GH_REPO/issues/$ISSUE_NUMBER/reactions" \
            -d "$REACTION_PAYLOAD")
          REACTION_BODY=$(echo "$REACTION_RESPONSE" | sed '$d')
          REACTION_STATUS=$(echo "$REACTION_RESPONSE" | tail -n1)

          if [ "$REACTION_STATUS" = "200" ]; then
            echo "First responders already notified for this issue (reaction present), skipping"
            echo "should_notify=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          if [ "$REACTION_STATUS" != "201" ]; then
            echo "::error::Unexpected status $REACTION_STATUS creating reaction: $REACTION_BODY"
            exit 1
          fi

          REACTION_ID=$(echo "$REACTION_BODY" | jq -r '.id')
          LABELS=$(echo "$ISSUE_LABELS_JSON" | jq -r 'join(", ")')

          echo "Confirmed high-reach $MATCHED_SEVERITY, notifying"
          {
            echo "notify_reason=confirmed $MATCHED_SEVERITY"
            echo "issue_labels=$LABELS"
            echo "reaction_id=$REACTION_ID"
            echo "should_notify=true"
          } >> "$GITHUB_OUTPUT"

      - name: Build Slack message payload
        if: steps.check-label.outputs.should_notify == 'true'
        env:
          ISSUE_TITLE: ${{ github.event.issue.title }}
          ISSUE_URL: ${{ github.event.issue.html_url }}
          LABELED_BY: ${{ github.event.sender.login }}
          NOTIFY_REASON: ${{ steps.check-label.outputs.notify_reason }}
          LABELS: ${{ steps.check-label.outputs.issue_labels }}
        run: |
          jq -n \
            --arg notify_reason "$NOTIFY_REASON" \
            --arg issue_title "$ISSUE_TITLE" \
            --arg issue_url "$ISSUE_URL" \
            --arg labeled_by "$LABELED_BY" \
            --arg labels "$LABELS" \
            '{
              "blocks": [
                {
                  "type": "section",
                  "text": {
                    "type": "mrkdwn",
                    "text": "<!subteam^S096CPUUGLF> New *\($notify_reason)* issue"
                  }
                },
                {
                  "type": "section",
                  "fields": [
                    {
                      "type": "mrkdwn",
                      "text": "*Issue:*\n<\($issue_url)|\($issue_title)>"
                    },
                    {
                      "type": "mrkdwn",
                      "text": "*Labeled by:*\n\($labeled_by)"
                    },
                    {
                      "type": "mrkdwn",
                      "text": "*Labels:*\n\($labels)"
                    }
                  ]
                }
              ]
            }' > payload.json

          echo "Payload built successfully:"
          cat payload.json

      - name: Send Slack notification
        if: steps.check-label.outputs.should_notify == 'true'
        env:
          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_FIRST_RESPONDERS }}
          GH_TOKEN: ${{ github.token }}
          GH_REPO: ${{ github.repository }}
          ISSUE_NUMBER: ${{ github.event.issue.number }}
          REACTION_ID: ${{ steps.check-label.outputs.reaction_id }}
        run: |
          set -uo pipefail

          release_claim() {
            if [ -n "${REACTION_ID:-}" ]; then
              echo "Releasing reaction claim so the notification can be retried"
              curl -sS -X DELETE \
                -H "Authorization: Bearer $GH_TOKEN" \
                -H "Accept: application/vnd.github+json" \
                -H "X-GitHub-Api-Version: 2022-11-28" \
                "https://api.github.com/repos/$GH_REPO/issues/$ISSUE_NUMBER/reactions/$REACTION_ID" || true
            fi
          }

          if [ -z "$SLACK_WEBHOOK_URL" ]; then
            echo "::error::SLACK_WEBHOOK_FIRST_RESPONDERS secret is not set"
            release_claim
            exit 1
          fi

          HTTP_RESPONSE=$(curl -s -w "\n%{http_code}" -X POST "$SLACK_WEBHOOK_URL" \
            -H "Content-Type: application/json" \
            -d @payload.json)

          HTTP_BODY=$(echo "$HTTP_RESPONSE" | sed '$d')
          HTTP_STATUS=$(echo "$HTTP_RESPONSE" | tail -n 1)

          echo "Slack API response status: $HTTP_STATUS"
          echo "Slack API response body: $HTTP_BODY"

          if [ "$HTTP_STATUS" -ne 200 ]; then
            echo "::error::Slack notification failed with status $HTTP_STATUS: $HTTP_BODY"
            release_claim
            exit 1
          fi

          echo "Slack notification sent successfully"