#!/usr/bin/env bash
set -xeuo pipefail

# Inputs expected from the workflow:
#   GITHUB_REPOSITORY  - owner/repo of the current action repo (provided by Actions)
#   GITHUB_SHA         - commit to clone/check out (provided by Actions, optional)
#   GO_VERSION         - optional, e.g. "1.23.3"; if unset, script will query latest.

main() {
  # 1. Create temp directory
  TMPDIR="$(mktemp -d)"
  echo "Using temp dir: ${TMPDIR}"

  # 2. Clone latest CoreDNS release
  cd "${TMPDIR}"
  COREDNS_REPO_URL="https://github.com/coredns/coredns.git"
  COREDNS_DIR="${TMPDIR}/coredns"

  # get latest tag (annotated or lightweight)
  git clone --depth=1 --filter=blob:none --tags "${COREDNS_REPO_URL}" "${COREDNS_DIR}"
  cd "${COREDNS_DIR}"
  git fetch --tags
  LATEST_TAG="$(git tag --list --sort=-version:refname | head -n 1)"
  git fetch --tags --depth=1 origin "${LATEST_TAG}"
  git checkout "${LATEST_TAG}"

  # 3. Clone the GitHub Action's repo (this repo)
  ACTION_REPO_DIR="${TMPDIR}/action-repo"
  mkdir "${ACTION_REPO_DIR}"
  cp -a . "${ACTION_REPO_DIR}/"

  # 4. cd into the CoreDNS repo
  cd "${COREDNS_DIR}"

  # 5. Update plugin.cfg to include netboxdns plugin
  #    Insert netboxdns after the 'cache' plugin entry as recommended. [web:16][web:29]
  if ! grep -q '^netboxdns:' plugin.cfg; then
    awk '
      /^cache:/ {
        print
        print "netboxdns:github.com/doubleu-labs/coredns-netbox-plugin-dns"
        next
      }
      { print }
    ' plugin.cfg >plugin.cfg.new
    mv plugin.cfg.new plugin.cfg
  fi

  ls -lah

  docker run --rm \
    --user "$(id -u):$(id -g)" \
    -v "$PWD":"/work" \
    -w "/work" \
    golang:latest ls -lah

  # 6. Regenerate plugin source files
  #    CoreDNS uses go generate (via Makefile) to rebuild plugin glue code. [web:20][web:26]
  docker run --rm \
    --user "$(id -u):$(id -g)" \
    -v "$PWD":"/work" \
    -w "/work" \
    golang:latest bash -c make core/plugin/zplugin.go core/dnsserver/zdirectives.go

  # 7. go mod replace plugin path to the cloned action repo
  #    This assumes the plugin lives at github.com/doubleu-labs/coredns-netbox-plugin-dns in your repo. [web:16][web:23]
  #    Adjust relative path if your repo layout differs.
  docker run --rm -it \
    --user "$(id -u):$(id -g)" \
    -v "$PWD":"/work" \
    -w "/work" \
    golang:latest go mod edit -replace=github.com/doubleu-labs/coredns-netbox-plugin-dns="${ACTION_REPO_DIR}"

  # 8. Update Go version to the latest
  #    Install or pick latest Go and set GOTOOLCHAIN, or rely on pre-installed toolchain in the runner. [web:17]
  #    Here we query the latest stable from golang.org and export it for this build.
  if [ -z "${GO_VERSION:-}" ]; then
    GO_VERSION="$(curl -s https://go.dev/VERSION?m=text | head -n1 | sed 's/^go//')" # e.g. "1.23.3"
  fi

  echo "Using Go version: ${GO_VERSION}"

  # If you use setup-go in the workflow, this is optional; otherwise install here.
  # Example (Debian-based runner):
  # sudo rm -rf /usr/local/go
  # curl -sL "https://go.dev/dl/go${GO_VERSION}.linux-amd64.tar.gz" | sudo tar -C /usr/local -xz
  # export PATH="/usr/local/go/bin:${PATH}"

  export GOTOOLCHAIN="go${GO_VERSION}"

  # 9. Compile CoreDNS
  make coredns || make

  # 10. Strip the binary
  STRIP_BIN="${STRIP_BIN:-strip}"
  "${STRIP_BIN}" ./coredns

  # 11. Create a .deb installing /usr/local/bin/coredns
  #     Minimal Debian package using dpkg-deb. [web:17]
  PKG_ROOT="${TMPDIR}/pkg-root"
  mkdir -p "${PKG_ROOT}/DEBIAN" "${PKG_ROOT}/usr/local/bin"

  # Basic metadata; tweak as needed
  PKG_NAME="coredns-netboxdns"
  PKG_VERSION="$(echo "${LATEST_TAG}" | sed 's/^v//')"
  PKG_ARCH="$(dpkg --print-architecture 2>/dev/null || echo amd64)"

  cat >"${PKG_ROOT}/DEBIAN/control" <<EOF
Package: ${PKG_NAME}
Version: ${PKG_VERSION}
Section: net
Priority: optional
Architecture: ${PKG_ARCH}
Maintainer: CI <ci@example.invalid>
Description: CoreDNS with netboxdns plugin
 Custom CoreDNS build with netboxdns plugin compiled in.
EOF

  install -m 0755 ./coredns "${PKG_ROOT}/usr/local/bin/coredns"

  DEB_OUT="${TMPDIR}/${PKG_NAME}_${PKG_VERSION}_${PKG_ARCH}.deb"
  dpkg-deb --build "${PKG_ROOT}" "${DEB_OUT}"

  echo "Built Debian package at: ${DEB_OUT}"
}

main "$@"