name: Build & Deploy (Nix)

on:
  push:
    branches:
      - main

jobs:
  build-and-deploy:
    runs-on: ubuntu-latest

    strategy:
      fail-fast: false
      matrix:
        service: [backend, discord-gateway, proxy]

    steps:
      - name: Check out repository
        run: |
          git clone https://git.imrnes.team/MythEclipse/GMW.git .
          git checkout ${{ github.sha }}

      - name: Build & Deploy ${{ matrix.service }}
        env:
          VPS_HOST: ${{ secrets.VPS_HOST }}
          VPS_USER: ${{ secrets.VPS_USER }}
          VPS_SSH_KEY: ${{ secrets.VPS_SSH_KEY }}
          # Declarative env: source of truth = Gitea secrets, CI writes the
          # service env files on the VPS. Update env by editing the secret,
          # never by SSH-ing into the VPS by hand.
          BACKEND_ENV: ${{ secrets.BACKEND_ENV }}
          GATEWAY_ENV: ${{ secrets.GATEWAY_ENV }}
        run: |
          set -eu

          # --- Install Nix & Build ---
          curl -fsSL https://install.determinate.systems/nix \
            | sh -s -- install linux --no-confirm --init none 2>&1

          mkdir -p /etc/nix
          echo "experimental-features = nix-command flakes" >> /etc/nix/nix.conf

          . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh

          SERVICE="${{ matrix.service }}"
          echo "=== Building: $SERVICE ==="
          nix build ".#$SERVICE" --impure --option sandbox false 2>&1

          STORE_PATH=$(readlink result)
          echo "=== Store path: $STORE_PATH"

          # --- Deploy ---
          NIX_BIN="/nix/var/nix/profiles/default/bin"
          PROFILE="/nix/var/nix/profiles/gmw-$SERVICE"

          key_file=$(mktemp /tmp/deploy-key.XXXXXX)
          printf '%s\n' "$VPS_SSH_KEY" > "$key_file"
          chmod 600 "$key_file"

          export NIX_SSHOPTS="-i $key_file -o StrictHostKeyChecking=no"
          nix copy --to "ssh://${VPS_USER}@${VPS_HOST}" "$STORE_PATH" 2>&1

          # --- Deploy env (declarative, from Gitea secrets) ---
          ENV_TARGET=""
          ENV_VALUE=""
          case "$SERVICE" in
            backend)         ENV_TARGET="/etc/gmw/backend.env"; ENV_VALUE="$BACKEND_ENV" ;;
            discord-gateway) ENV_TARGET="/etc/gmw/discord-gateway.env"; ENV_VALUE="$GATEWAY_ENV" ;;
            proxy)           ;;  # nginx proxy has no env file
          esac

          if [ -n "$ENV_VALUE" ] && [ -n "$ENV_TARGET" ]; then
            echo "=== Deploying env: $ENV_TARGET ==="
            printf '%s\n' "$ENV_VALUE" | ssh -i "$key_file" -o StrictHostKeyChecking=no \
              "${VPS_USER}@${VPS_HOST}" "
              set -eu
              mkdir -p /etc/gmw
              cat > $ENV_TARGET
              chown gmw:gmw $ENV_TARGET
              chmod 600 $ENV_TARGET
              echo \"env file lines: \$(grep -c '=' $ENV_TARGET)\"
            "
          else
            echo "=== No env secret for $SERVICE — skipping env deploy ==="
          fi

          ssh -i "$key_file" -o StrictHostKeyChecking=no \
            "${VPS_USER}@${VPS_HOST}" "
            if [ -d $PROFILE ] && [ ! -L $PROFILE ]; then
              rm -rf $PROFILE
            fi
            export PATH=\$PATH:$NIX_BIN
            nix-env --profile $PROFILE --set $STORE_PATH
            systemctl daemon-reload
            systemctl restart gmw-$SERVICE
            sleep 3
            systemctl status gmw-$SERVICE --no-pager 2>&1 | head -12
          " 2>&1