name: Deploy (yggdrasil)

on:
  push:
    branches: ["main"]

jobs:
  deploy:
    runs-on: [ mainhost ]
    env:
      SSH_HOST: ${{ secrets.SSH_HOST }}
      SSH_USER: ${{ secrets.SSH_USER }}
      SSH_KEY_PATH: /home/gitea-runner/.ssh/id_ed25519

      SSH_OPTS: >-
        -F /dev/null
        -o IdentitiesOnly=yes
        -o IdentityAgent=none
        -o PreferredAuthentications=publickey
        -o PubkeyAuthentication=yes
        -o PasswordAuthentication=no
        -o NumberOfPasswordPrompts=0
        -o BatchMode=yes
        -o ServerAliveInterval=15
        -o ServerAliveCountMax=3
        -o ConnectTimeout=20
        -o StrictHostKeyChecking=no

      APP_ROOT: /var/www/yggdrasil
      KEEP_N: "5"
      SHARED_DIRS: "uploads:cache"
      HEALTH_URL: "https://yggdrasil.corpintech.net/"
      SERVICE_NAME: "apache2"
      
    steps:
      - name: Checkout (pure git, private repo)
        env:
          GIT_TOKEN: ${{ secrets.GIT_TOKEN }}
        run: |
          set -euo pipefail
          export GIT_TERMINAL_PROMPT=0

          git init -b main
          git remote add origin "${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}.git"

          git -c http.extraHeader="Authorization: token ${GIT_TOKEN}" \
            fetch --no-tags --depth=1 origin "${GITHUB_SHA}"

          git checkout -q "${GITHUB_SHA}"

      - name: SSH smoke test
        run: |
          set -euo pipefail
          ssh $SSH_OPTS -i "$SSH_KEY_PATH" "${SSH_USER}@${SSH_HOST}" true

      - name: Deploy atomically
        run: |
          set -euo pipefail

          REL="$(date -u +%Y%m%d-%H%M%SZ)-${GITHUB_SHA}"
          TAR_LOCAL="release/${REL}.tar.gz"

          mkdir -p release

          IFS=':' read -r -a SHARED_DIR_ARR <<< "${SHARED_DIRS}"

          EXCLUDES=(--exclude-vcs --exclude='./node_modules' --exclude='./release')
          for d in "${SHARED_DIR_ARR[@]}"; do
            EXCLUDES+=( "--exclude=./${d}" )
          done

          tar -czf "${TAR_LOCAL}" "${EXCLUDES[@]}" .

          ssh $SSH_OPTS -i "$SSH_KEY_PATH" "${SSH_USER}@${SSH_HOST}" \
            "set -e;
            install -d -m 2755 '${APP_ROOT}' '${APP_ROOT}/releases' '${APP_ROOT}/shared' '${APP_ROOT}/logs';"

          for d in "${SHARED_DIR_ARR[@]}"; do
            ssh $SSH_OPTS -i "$SSH_KEY_PATH" "${SSH_USER}@${SSH_HOST}" \
              "install -d -m 2755 '${APP_ROOT}/shared/${d}'"
          done

          scp -O $SSH_OPTS -i "$SSH_KEY_PATH" "${TAR_LOCAL}" "${SSH_USER}@${SSH_HOST}:/tmp/${REL}.tar.gz"

          ssh $SSH_OPTS -i "$SSH_KEY_PATH" "${SSH_USER}@${SSH_HOST}" bash -s -- \
            "${APP_ROOT}" \
            "${REL}" \
            "${KEEP_N}" \
            "${SHARED_DIRS}" \
            "${HEALTH_URL}" \
            "${SERVICE_NAME}" \
            "${GITHUB_SHA}" <<'REMOTE'
          set -euo pipefail

          APP_ROOT="$1"
          REL="$2"
          KEEP_N="$3"
          SHARED_DIRS="$4"
          HEALTH_URL="$5"
          SERVICE_NAME="$6"
          GITSHA="$7"

          IFS=':' read -r -a SHARED_DIR_ARR <<< "${SHARED_DIRS}"

          RELEASES="${APP_ROOT}/releases"
          SHARED="${APP_ROOT}/shared"
          CUR="${APP_ROOT}/current"
          NEW="${RELEASES}/${REL}"
          TAR="/tmp/${REL}.tar.gz"

          echo "--> Extracting ${REL}"
          mkdir -p "${NEW}"
          tar -xzf "${TAR}" -C "${NEW}"
          rm -f "${TAR}"

          echo "--> Linking shared dirs"
          for d in "${SHARED_DIR_ARR[@]}"; do
            echo "    ${d}"
            rm -rf "${NEW:?}/${d}"
            ln -s "${SHARED}/${d}" "${NEW}/${d}"
          done

          if [ -f "${SHARED}/.env" ]; then
            ln -sf "${SHARED}/.env" "${NEW}/.env"
          fi

          printf "sha=%s\nbuilt_at=%s\n" "${GITSHA}" "$(date -u +%FT%TZ)" > "${NEW}/RELEASE"

          PREV="$(readlink -f "${CUR}" 2>/dev/null || true)"

          echo "--> Swapping symlink"
          ln -sfn "${NEW}" "${CUR}"

          echo "--> Restarting Apache"
          sudo /usr/bin/systemctl restart "${SERVICE_NAME}"

          if command -v curl >/dev/null 2>&1; then
            echo "--> Health check ${HEALTH_URL}"
            if ! curl -fsS --max-time 10 "${HEALTH_URL}" >/dev/null; then
              echo "Health check failed, rolling back..."
              if [ -n "${PREV}" ] && [ -e "${PREV}" ]; then
                ln -sfn "${PREV}" "${CUR}"
                sudo /usr/bin/systemctl restart "${SERVICE_NAME}"
              fi
              exit 1
            fi
          fi

          echo "--> Cleaning old releases"
          CUR_REAL="$(readlink -f "${CUR}" 2>/dev/null || true)"
          cd "${RELEASES}"

          i=0
          for name in $(ls -1t); do
            path="${RELEASES}/${name}"

            if [ "${path}" = "${CUR_REAL}" ] || [ "${path}" = "${PREV}" ] || [ "${path}" = "${NEW}" ]; then
              continue
            fi

            i=$((i+1))
            if [ "${i}" -gt "${KEEP_N}" ]; then
              rm -rf -- "${path}"
            fi
          done

          echo "--> Deploy complete"
          REMOTE