name: Deploy Soul to GKE

# Triggers on push to main — after the soul binary is built and published
# by ci.yaml, this workflow builds the Docker image and blue-green deploys
# to the neuron-prod namespace on GKE.
#
# This workflow runs AFTER ci.yaml has published the neuron-soul generic
# artifact to Artifact Registry. The Docker build downloads that binary.

on:
  push:
    branches:
      - main
  workflow_dispatch:
    inputs:
      slot:
        description: "Target blue-green slot (blue or green)"
        required: false
        default: "green"

jobs:
  deploy:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Install dependencies
        run: |
          apt-get update -qq
          apt-get install -y --no-install-recommends \
            ca-certificates curl gnupg apt-transport-https kubectl
          echo "deb [signed-by=/usr/share/keyrings/cloud.google.gpg] https://packages.cloud.google.com/apt cloud-sdk main" \
            > /etc/apt/sources.list.d/google-cloud-sdk.list
          curl -fsSL https://packages.cloud.google.com/apt/doc/apt-key.gpg \
            | gpg --dearmor -o /usr/share/keyrings/cloud.google.gpg
          apt-get update -qq && apt-get install -y google-cloud-cli google-cloud-cli-gke-gcloud-auth-plugin

      - name: Authenticate to GCP
        env:
          GCP_SA_KEY: ${{ secrets.GCP_SA_KEY }}
        run: |
          echo "${GCP_SA_KEY}" > /tmp/gcp-key.json
          gcloud auth activate-service-account --key-file=/tmp/gcp-key.json
          gcloud config set project neuron-785695
          gcloud auth configure-docker us-central1-docker.pkg.dev --quiet

      - name: Get GKE credentials
        run: |
          gcloud container clusters get-credentials neuron-platform \
            --region=us-central1 \
            --project=neuron-785695

      - name: Determine image tag and slot
        id: vars
        run: |
          SHA="${GITEA_SHA:0:8}"
          IMAGE="us-central1-docker.pkg.dev/neuron-785695/neuron-api/neuron-soul:${SHA}"
          echo "sha=${SHA}" >> "$GITEA_OUTPUT"
          echo "image=${IMAGE}" >> "$GITEA_OUTPUT"

          # Determine which slot is currently idle (0 replicas = idle slot)
          # If both are at 0 (fresh deploy), default to blue
          BLUE_REPLICAS=$(kubectl get deployment/neuron-mcp-blue \
            -n neuron-prod \
            -o jsonpath='{.spec.replicas}' 2>/dev/null || echo "0")
          GREEN_REPLICAS=$(kubectl get deployment/neuron-mcp-green \
            -n neuron-prod \
            -o jsonpath='{.spec.replicas}' 2>/dev/null || echo "0")

          echo "  Blue replicas: ${BLUE_REPLICAS}"
          echo "  Green replicas: ${GREEN_REPLICAS}"

          # Use workflow_dispatch override if provided, otherwise pick the idle slot
          if [ "${{ github.event.inputs.slot }}" != "" ]; then
            SLOT="${{ github.event.inputs.slot }}"
          elif [ "${GREEN_REPLICAS}" -eq 0 ] && [ "${BLUE_REPLICAS}" -gt 0 ]; then
            SLOT="green"
          elif [ "${BLUE_REPLICAS}" -eq 0 ] && [ "${GREEN_REPLICAS}" -gt 0 ]; then
            SLOT="blue"
          else
            # Fresh cluster — deploy to blue first
            SLOT="blue"
          fi

          echo "slot=${SLOT}" >> "$GITEA_OUTPUT"
          echo "  Deploying to slot: ${SLOT}"

      - name: Clone engram source for Docker build context
        run: |
          # The Dockerfile builds engram from source (no published AR package).
          # Clone the engram repo into ./engram/ so it's available in the build context.
          git clone http://34.31.145.131/neuron-technologies/engram.git \
            --depth=1 --branch=main \
            engram
          echo "Engram source ready at ./engram/src/server.el"

      - name: Build and push Docker image
        env:
          GCP_SA_KEY: ${{ secrets.GCP_SA_KEY }}
        run: |
          IMAGE="${{ steps.vars.outputs.image }}"
          SHA="${{ steps.vars.outputs.sha }}"

          echo "Building ${IMAGE}..."
          docker build \
            --build-arg SOUL_VERSION="${SHA}" \
            --secret id=gcp_sa_key,env=GCP_SA_KEY \
            --tag "${IMAGE}" \
            --tag "us-central1-docker.pkg.dev/neuron-785695/neuron-api/neuron-soul:latest" \
            .

          echo "Pushing ${IMAGE}..."
          docker push "${IMAGE}"
          docker push "us-central1-docker.pkg.dev/neuron-785695/neuron-api/neuron-soul:latest"

      - name: Blue-green deploy to GKE
        run: |
          chmod +x scripts/blue-green-deploy.sh
          scripts/blue-green-deploy.sh \
            --image "${{ steps.vars.outputs.image }}" \
            --slot "${{ steps.vars.outputs.slot }}"

      - name: Verify deployment
        run: |
          SLOT="${{ steps.vars.outputs.slot }}"
          echo "Verifying neuron-mcp-${SLOT} is healthy..."
          kubectl rollout status deployment/"neuron-mcp-${SLOT}" \
            --namespace=neuron-prod \
            --timeout=3m

          echo "Active service endpoints:"
          kubectl get endpoints neuron-mcp -n neuron-prod

          echo "Pod status:"
          kubectl get pods -n neuron-prod -l app=neuron-mcp

      - name: Cleanup
        if: always()
        run: rm -f /tmp/gcp-key.json