name: Rollback

# Emergency rollback for production (Hetzner k3s) and preprod (Portainer).
# All images are on Scaleway registry.
#
# Production (k3s):
#   Option A — "previous": kubectl rollout undo (instant, reverts to last ReplicaSet)
#   Option B — "specific-version": kubectl set image to a Scaleway prod-SHA tag
#
# Preprod (Portainer):
#   Re-tags a Scaleway preprod-SHA image back to :preprod, triggers Portainer webhook.
#
# Run from: GitHub Actions → Workflows → Rollback → Run workflow

on:
  workflow_dispatch:
    inputs:
      environment:
        description: 'Target environment'
        required: true
        type: choice
        options:
          - production
          - preprod
      strategy:
        description: 'Rollback strategy ("previous" = kubectl rollout undo, prod only)'
        required: true
        type: choice
        options:
          - previous
          - specific-version
      version_tag:
        description: 'Tag for specific-version (e.g. prod-a1b2c3d or preprod-a1b2c3d)'
        required: false
        type: string
      reason:
        description: 'Reason for rollback (audit trail)'
        required: true
        type: string

env:
  REGISTRY: rg.fr-par.scw.cloud/weworkstudio
  IMAGE_BACKEND: rg.fr-par.scw.cloud/weworkstudio/xpeditis-backend
  IMAGE_FRONTEND: rg.fr-par.scw.cloud/weworkstudio/xpeditis-frontend
  K8S_NAMESPACE: xpeditis-prod

jobs:
  # ──────────────────────────────────────────
  # Validate inputs
  # ──────────────────────────────────────────
  validate:
    name: Validate Inputs
    runs-on: ubuntu-latest

    steps:
      - name: Validate
        run: |
          ENV="${{ github.event.inputs.environment }}"
          STRATEGY="${{ github.event.inputs.strategy }}"
          TAG="${{ github.event.inputs.version_tag }}"

          if [ "$STRATEGY" = "specific-version" ] && [ -z "$TAG" ]; then
            echo "ERROR: version_tag is required for specific-version strategy."
            exit 1
          fi

          if [ "$STRATEGY" = "specific-version" ] && [ "$ENV" = "production" ]; then
            if [[ ! "$TAG" =~ ^prod- ]]; then
              echo "ERROR: Production tag must start with 'prod-' (got: $TAG)"
              exit 1
            fi
          fi

          if [ "$STRATEGY" = "specific-version" ] && [ "$ENV" = "preprod" ]; then
            if [[ ! "$TAG" =~ ^preprod- ]]; then
              echo "ERROR: Preprod tag must start with 'preprod-' (got: $TAG)"
              exit 1
            fi
          fi

          echo "Validation passed."
          echo "  Environment : $ENV"
          echo "  Strategy    : $STRATEGY"
          echo "  Version     : ${TAG:-N/A (previous)}"
          echo "  Reason      : ${{ github.event.inputs.reason }}"

  # ──────────────────────────────────────────
  # PRODUCTION ROLLBACK — k3s via kubectl
  # ──────────────────────────────────────────
  rollback-production:
    name: Rollback Production (k3s)
    runs-on: ubuntu-latest
    needs: validate
    if: github.event.inputs.environment == 'production'
    environment:
      name: production
      url: https://app.xpeditis.com

    steps:
      - name: Configure kubectl
        run: |
          mkdir -p ~/.kube
          echo "${{ secrets.HETZNER_KUBECONFIG }}" | base64 -d > ~/.kube/config
          chmod 600 ~/.kube/config
          kubectl cluster-info

      # ── Strategy A: kubectl rollout undo (fastest)
      - name: Rollback to previous version
        if: github.event.inputs.strategy == 'previous'
        run: |
          echo "Rolling back backend..."
          kubectl rollout undo deployment/xpeditis-backend -n ${{ env.K8S_NAMESPACE }}
          kubectl rollout status deployment/xpeditis-backend -n ${{ env.K8S_NAMESPACE }} --timeout=180s

          echo "Rolling back frontend..."
          kubectl rollout undo deployment/xpeditis-frontend -n ${{ env.K8S_NAMESPACE }}
          kubectl rollout status deployment/xpeditis-frontend -n ${{ env.K8S_NAMESPACE }} --timeout=180s

          kubectl get pods -n ${{ env.K8S_NAMESPACE }}

      # ── Strategy B: kubectl set image to specific Scaleway tag
      - name: Set up Docker Buildx (for image inspect)
        if: github.event.inputs.strategy == 'specific-version'
        uses: docker/setup-buildx-action@v3

      - name: Login to Scaleway Registry
        if: github.event.inputs.strategy == 'specific-version'
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: nologin
          password: ${{ secrets.REGISTRY_TOKEN }}

      - name: Rollback to specific version
        if: github.event.inputs.strategy == 'specific-version'
        run: |
          TAG="${{ github.event.inputs.version_tag }}"
          BACKEND_IMAGE="${{ env.IMAGE_BACKEND }}:${TAG}"
          FRONTEND_IMAGE="${{ env.IMAGE_FRONTEND }}:${TAG}"

          echo "Verifying images exist in Scaleway..."
          docker buildx imagetools inspect "$BACKEND_IMAGE" || \
            { echo "ERROR: Backend image not found: $BACKEND_IMAGE"; exit 1; }
          docker buildx imagetools inspect "$FRONTEND_IMAGE" || \
            { echo "ERROR: Frontend image not found: $FRONTEND_IMAGE"; exit 1; }

          echo "Deploying backend: $BACKEND_IMAGE"
          kubectl set image deployment/xpeditis-backend backend="$BACKEND_IMAGE" -n ${{ env.K8S_NAMESPACE }}
          kubectl rollout status deployment/xpeditis-backend -n ${{ env.K8S_NAMESPACE }} --timeout=180s

          echo "Deploying frontend: $FRONTEND_IMAGE"
          kubectl set image deployment/xpeditis-frontend frontend="$FRONTEND_IMAGE" -n ${{ env.K8S_NAMESPACE }}
          kubectl rollout status deployment/xpeditis-frontend -n ${{ env.K8S_NAMESPACE }} --timeout=180s

          kubectl get pods -n ${{ env.K8S_NAMESPACE }}

      - name: Show rollout history
        if: always()
        run: |
          echo "=== Backend rollout history ==="
          kubectl rollout history deployment/xpeditis-backend -n ${{ env.K8S_NAMESPACE }} || true
          echo "=== Frontend rollout history ==="
          kubectl rollout history deployment/xpeditis-frontend -n ${{ env.K8S_NAMESPACE }} || true

  # ──────────────────────────────────────────
  # PREPROD ROLLBACK — Scaleway re-tag + Portainer
  # ──────────────────────────────────────────
  rollback-preprod:
    name: Rollback Preprod (Portainer)
    runs-on: ubuntu-latest
    needs: validate
    if: github.event.inputs.environment == 'preprod'

    steps:
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Login to Scaleway Registry
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: nologin
          password: ${{ secrets.REGISTRY_TOKEN }}

      - name: Verify target images exist
        run: |
          TAG="${{ github.event.inputs.version_tag }}"
          docker buildx imagetools inspect "${{ env.IMAGE_BACKEND }}:${TAG}" || \
            { echo "ERROR: Backend image not found: $TAG"; exit 1; }
          docker buildx imagetools inspect "${{ env.IMAGE_FRONTEND }}:${TAG}" || \
            { echo "ERROR: Frontend image not found: $TAG"; exit 1; }

      - name: Re-tag target version as preprod
        run: |
          TAG="${{ github.event.inputs.version_tag }}"
          echo "Re-tagging $TAG → preprod..."
          docker buildx imagetools create \
            --tag ${{ env.IMAGE_BACKEND }}:preprod \
            ${{ env.IMAGE_BACKEND }}:${TAG}
          docker buildx imagetools create \
            --tag ${{ env.IMAGE_FRONTEND }}:preprod \
            ${{ env.IMAGE_FRONTEND }}:${TAG}
          echo "Re-tag complete."

      - name: Trigger Backend deployment (Portainer)
        run: |
          curl -sf -X POST -H "Content-Type: application/json" \
            "${{ secrets.PORTAINER_WEBHOOK_BACKEND }}"
          echo "Backend webhook triggered."

      - name: Wait for backend
        run: sleep 20

      - name: Trigger Frontend deployment (Portainer)
        run: |
          curl -sf -X POST -H "Content-Type: application/json" \
            "${{ secrets.PORTAINER_WEBHOOK_FRONTEND }}"
          echo "Frontend webhook triggered."

  # ──────────────────────────────────────────
  # Smoke Tests
  # ──────────────────────────────────────────
  smoke-tests:
    name: Smoke Tests
    runs-on: ubuntu-latest
    needs: [rollback-production, rollback-preprod]
    if: always() && (needs.rollback-production.result == 'success' || needs.rollback-preprod.result == 'success')

    steps:
      - name: Set health check URLs
        id: urls
        run: |
          if [ "${{ github.event.inputs.environment }}" = "production" ]; then
            echo "backend=${{ secrets.PROD_BACKEND_URL }}/api/v1/health" >> $GITHUB_OUTPUT
            echo "frontend=${{ secrets.PROD_FRONTEND_URL }}" >> $GITHUB_OUTPUT
            echo "wait=30" >> $GITHUB_OUTPUT
          else
            echo "backend=${{ secrets.PREPROD_BACKEND_URL }}/api/v1/health" >> $GITHUB_OUTPUT
            echo "frontend=${{ secrets.PREPROD_FRONTEND_URL }}" >> $GITHUB_OUTPUT
            echo "wait=60" >> $GITHUB_OUTPUT
          fi

      - name: Wait for services
        run: sleep ${{ steps.urls.outputs.wait }}

      - name: Health check — Backend
        run: |
          for i in {1..12}; do
            STATUS=$(curl -s -o /dev/null -w "%{http_code}" --max-time 10 \
              "${{ steps.urls.outputs.backend }}" 2>/dev/null || echo "000")
            echo "  Attempt $i: HTTP $STATUS"
            if [ "$STATUS" = "200" ]; then echo "Backend healthy."; exit 0; fi
            sleep 15
          done
          echo "CRITICAL: Backend unhealthy after rollback."
          exit 1

      - name: Health check — Frontend
        run: |
          for i in {1..12}; do
            STATUS=$(curl -s -o /dev/null -w "%{http_code}" --max-time 10 \
              "${{ steps.urls.outputs.frontend }}" 2>/dev/null || echo "000")
            echo "  Attempt $i: HTTP $STATUS"
            if [ "$STATUS" = "200" ]; then echo "Frontend healthy."; exit 0; fi
            sleep 15
          done
          echo "CRITICAL: Frontend unhealthy after rollback."
          exit 1

  # ──────────────────────────────────────────
  # Discord notification
  # ──────────────────────────────────────────
  notify:
    name: Notify Rollback Result
    runs-on: ubuntu-latest
    needs: [rollback-production, rollback-preprod, smoke-tests]
    if: always()

    steps:
      - name: Notify success
        if: needs.smoke-tests.result == 'success'
        run: |
          curl -s -H "Content-Type: application/json" -d '{
            "embeds": [{
              "title": "↩️ Rollback Successful",
              "color": 16776960,
              "fields": [
                {"name": "Environment", "value": "`${{ github.event.inputs.environment }}`", "inline": true},
                {"name": "Strategy", "value": "`${{ github.event.inputs.strategy }}`", "inline": true},
                {"name": "Version", "value": "`${{ github.event.inputs.version_tag || 'previous' }}`", "inline": true},
                {"name": "Triggered by", "value": "${{ github.actor }}", "inline": true},
                {"name": "Reason", "value": "${{ github.event.inputs.reason }}", "inline": false},
                {"name": "Workflow", "value": "[${{ github.workflow }}](${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }})", "inline": false}
              ],
              "footer": {"text": "Xpeditis CI/CD • Rollback"}
            }]
          }' ${{ secrets.DISCORD_WEBHOOK_URL }}

      - name: Notify failure
        if: needs.smoke-tests.result != 'success'
        run: |
          curl -s -H "Content-Type: application/json" -d '{
            "content": "@here ROLLBACK FAILED — MANUAL INTERVENTION REQUIRED",
            "embeds": [{
              "title": "🔴 Rollback Failed",
              "description": "Service may be degraded. Escalate immediately.",
              "color": 15158332,
              "fields": [
                {"name": "Environment", "value": "`${{ github.event.inputs.environment }}`", "inline": true},
                {"name": "Attempted version", "value": "`${{ github.event.inputs.version_tag || 'previous' }}`", "inline": true},
                {"name": "Triggered by", "value": "${{ github.actor }}", "inline": true},
                {"name": "Reason", "value": "${{ github.event.inputs.reason }}", "inline": false},
                {"name": "Workflow", "value": "[${{ github.workflow }}](${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }})", "inline": false}
              ],
              "footer": {"text": "Xpeditis CI/CD • Rollback"}
            }]
          }' ${{ secrets.DISCORD_WEBHOOK_URL }}