name: Neuron Soul CI

on:
  push:
    branches:
      - main
  pull_request:
    branches:
      - main
  workflow_dispatch:

# Serialize all activity on the single GCE runner.
# With build+deploy in the same workflow, a new push queues a single
# workflow instance — not two competing ones — so the deploy job is
# never orphaned by a cancellation race.
concurrency:
  group: neuron-runner
  cancel-in-progress: false

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Free disk space
        run: |
          df -h /
          docker system prune -af --volumes 2>/dev/null || true
          df -h /

      - name: Checkout
        uses: actions/checkout@v4

      - name: Install build dependencies
        run: |
          apt-get update -qq
          apt-get install -y gcc libcurl4-openssl-dev apt-transport-https ca-certificates
          echo "deb [trusted=yes] https://packages.cloud.google.com/apt cloud-sdk main" \
            > /etc/apt/sources.list.d/google-cloud-sdk.list
          apt-get update -qq && apt-get install -y google-cloud-cli

      - name: Download El runtime from Artifact Registry
        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

          rm -rf /opt/el/runtime
          mkdir -p /opt/el/runtime

          # Get latest version of each runtime package (elc/elb not needed — we compile
          # dist/soul.c directly; running elb on Linux OOM-kills the runner, and we
          # always use the repo's pre-built soul.c anyway).
          get_latest() {
            gcloud artifacts versions list \
              --repository=foundation-prod \
              --location=us-central1 \
              --project=neuron-785695 \
              --package="$1" \
              --sort-by="~createTime" \
              --limit=1 \
              --format="value(name)" 2>/dev/null | awk -F/ '{print $NF}'
          }

          RC_VER=$(get_latest el-runtime-c)
          RH_VER=$(get_latest el-runtime-h)

          echo "Downloading runtime@${RC_VER}"

          gcloud artifacts generic download \
            --repository=foundation-prod --location=us-central1 --project=neuron-785695 \
            --package=el-runtime-c --version="${RC_VER}" \
            --destination=/opt/el/runtime/

          gcloud artifacts generic download \
            --repository=foundation-prod --location=us-central1 --project=neuron-785695 \
            --package=el-runtime-h --version="${RH_VER}" \
            --destination=/opt/el/runtime/

          mv /opt/el/runtime/el_runtime.c* /opt/el/runtime/el_runtime.c 2>/dev/null || true
          mv /opt/el/runtime/el_runtime.h* /opt/el/runtime/el_runtime.h 2>/dev/null || true
          echo "El runtime ready: $(ls /opt/el/runtime/)"

      - name: Build neuron soul binary
        run: |
          RUNTIME=/opt/el/runtime

          # Compile the self-contained translation unit directly from dist/soul.c.
          # dist/soul.c is the authoritative combined unit maintained in the repo —
          # regenerated on macOS by running elb (which succeeds on arm64/macOS ld but
          # fails on Linux due to duplicate strong symbols). We skip the elb step here
          # entirely: elb on Linux would OOM the runner (elc uses 24GB+ virtual memory
          # on a 16GB host) and we always restore from the repo's soul.c anyway.
          mkdir -p dist
          cc -O2 -DHAVE_CURL \
            -I$RUNTIME \
            dist/soul.c \
            $RUNTIME/el_runtime.c \
            -lssl -lcrypto -lcurl -lpthread -lm \
            -o dist/neuron

          # Strip debug symbols and non-essential symbol table entries.
          # -s removes the symbol table + relocation info (max size reduction).
          # Keeps the binary functional; debuggability is preserved via source + CI logs.
          strip -s dist/neuron
          ls -lh dist/neuron

      - name: Smoke test
        run: |
          file dist/neuron
          timeout 3 dist/neuron --help 2>&1 || true
          echo "smoke test complete"

      - name: Publish neuron binary
        if: github.event_name == 'push'
        env:
          GCP_SA_KEY: ${{ secrets.GCP_SA_KEY }}
        run: |
          VERSION="${GITHUB_SHA:0:8}"

          gcloud artifacts generic upload \
            --repository=foundation-prod \
            --location=us-central1 \
            --project=neuron-785695 \
            --package=neuron-soul \
            --version="${VERSION}" \
            --source=dist/neuron

          echo "Published neuron-soul@${VERSION}"
          rm -f /tmp/gcp-key.json

  deploy:
    runs-on: ubuntu-latest
    needs: build
    # Only deploy on push to main, not on PRs or manual workflow_dispatch without intent.
    if: github.event_name == 'push' && github.ref == 'refs/heads/main'

    env:
      USE_GKE_GCLOUD_AUTH_PLUGIN: "True"

    steps:
      - name: Free disk space
        run: |
          df -h /
          docker system prune -af --volumes 2>/dev/null || true
          rm -rf /tmp/.act-* /tmp/act-* 2>/dev/null || true
          df -h /

      - name: Checkout
        uses: actions/checkout@v4

      - name: Install dependencies
        run: |
          apt-get update -qq
          apt-get install -y --no-install-recommends \
            ca-certificates curl apt-transport-https kubectl
          echo "deb [trusted=yes] https://packages.cloud.google.com/apt cloud-sdk main" \
            > /etc/apt/sources.list.d/google-cloud-sdk.list
          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: |
          # GITEA_SHA is set by the Gitea runner; fall back to GITHUB_SHA for
          # compatibility with older Forgejo/Gitea versions.
          RAW_SHA="${GITEA_SHA:-${GITHUB_SHA:-}}"
          SHA="${RAW_SHA:0:8}"
          if [ -z "$SHA" ]; then
            # Last resort: read from git directly
            SHA=$(git rev-parse --short=8 HEAD 2>/dev/null || echo "unknown")
          fi
          IMAGE="us-central1-docker.pkg.dev/neuron-785695/neuron-api/neuron-soul:${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}"

          if [ "${GREEN_REPLICAS}" -eq 0 ] && [ "${BLUE_REPLICAS}" -gt 0 ]; then
            SLOT="green"
          elif [ "${BLUE_REPLICAS}" -eq 0 ] && [ "${GREEN_REPLICAS}" -gt 0 ]; then
            SLOT="blue"
          else
            # Fresh cluster or both idle — deploy to blue first
            SLOT="blue"
          fi

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

      - name: Prepare build artifacts
        run: |
          # Pre-download soul binary and El SDK so the Dockerfile can COPY them
          # from the build context instead of authenticating inside the build.
          mkdir -p build-artifacts

          # ── soul binary ────────────────────────────────────────────────────────
          # The build job (same workflow run) just published this version.
          SOUL_VER=$(gcloud artifacts versions list \
            --repository=foundation-prod \
            --location=us-central1 \
            --project=neuron-785695 \
            --package=neuron-soul \
            --sort-by="~createTime" \
            --limit=1 \
            --format="value(name)" 2>/dev/null | awk -F/ '{print $NF}')
          echo "Downloading neuron-soul@${SOUL_VER}"
          gcloud artifacts generic download \
            --repository=foundation-prod \
            --location=us-central1 \
            --project=neuron-785695 \
            --package=neuron-soul \
            --version="${SOUL_VER}" \
            --destination=build-artifacts/
          mv build-artifacts/neuron* build-artifacts/neuron 2>/dev/null || true
          chmod +x build-artifacts/neuron

          # ── El SDK (for engram source compilation inside the Docker build) ────
          ELC_VER=$(gcloud artifacts versions list \
            --repository=foundation-prod --location=us-central1 --project=neuron-785695 \
            --package=el-elc --sort-by="~createTime" --limit=1 \
            --format="value(name)" 2>/dev/null | awk -F/ '{print $NF}')
          gcloud artifacts generic download \
            --repository=foundation-prod --location=us-central1 --project=neuron-785695 \
            --package=el-elc --version="${ELC_VER}" --destination=build-artifacts/
          mv build-artifacts/elc* build-artifacts/elc 2>/dev/null || true
          chmod +x build-artifacts/elc

          RC_VER=$(gcloud artifacts versions list \
            --repository=foundation-prod --location=us-central1 --project=neuron-785695 \
            --package=el-runtime-c --sort-by="~createTime" --limit=1 \
            --format="value(name)" 2>/dev/null | awk -F/ '{print $NF}')
          gcloud artifacts generic download \
            --repository=foundation-prod --location=us-central1 --project=neuron-785695 \
            --package=el-runtime-c --version="${RC_VER}" --destination=build-artifacts/
          mv build-artifacts/el_runtime.c* build-artifacts/el_runtime.c 2>/dev/null || true

          RH_VER=$(gcloud artifacts versions list \
            --repository=foundation-prod --location=us-central1 --project=neuron-785695 \
            --package=el-runtime-h --sort-by="~createTime" --limit=1 \
            --format="value(name)" 2>/dev/null | awk -F/ '{print $NF}')
          gcloud artifacts generic download \
            --repository=foundation-prod --location=us-central1 --project=neuron-785695 \
            --package=el-runtime-h --version="${RH_VER}" --destination=build-artifacts/
          mv build-artifacts/el_runtime.h* build-artifacts/el_runtime.h 2>/dev/null || true

          echo "Build artifacts ready:"
          ls -lh build-artifacts/

      - 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
        run: |
          IMAGE="${{ steps.vars.outputs.image }}"

          echo "Building ${IMAGE}..."
          docker build \
            --tag "${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: Update infrastructure manifests
        if: success()
        env:
          INFRA_GIT_TOKEN: ${{ secrets.INFRA_GIT_TOKEN }}
        run: |
          SLOT="${{ steps.vars.outputs.slot }}"
          if [ "$SLOT" = "blue" ]; then IDLE="green"; else IDLE="blue"; fi

          git clone "http://${INFRA_GIT_TOKEN}@34.31.145.131/neuron-technologies/infrastructure.git" \
            --depth=1 --branch=main /tmp/infra-update

          cd /tmp/infra-update

          DEPLOY_DIR="platform/k8s/neuron-mcp"
          sed -i "s/^  replicas: .*/  replicas: 1/" "${DEPLOY_DIR}/deployment-${SLOT}.yaml"
          sed -i "s/^  replicas: .*/  replicas: 0/" "${DEPLOY_DIR}/deployment-${IDLE}.yaml"
          echo "  deployment-${SLOT}.yaml: replicas set to 1"
          echo "  deployment-${IDLE}.yaml: replicas set to 0"

          git config user.email "ci@neurontechnologies.ai"
          git config user.name "Neuron CI"
          git add "${DEPLOY_DIR}/deployment-blue.yaml" "${DEPLOY_DIR}/deployment-green.yaml"
          git diff --staged --quiet && { echo "No manifest changes needed"; exit 0; }
          git commit -m "ci: neuron-mcp replica sync after blue-green swap to ${SLOT}"
          git push origin main
          echo "Infrastructure manifests updated: ${SLOT}=1, ${IDLE}=0"

      - 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=8m

          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