#!/bin/bash
# Clones the NetBox repository with git from Github and builds the Dockerfile

echo "▶️ $0 $*"

set -e

if [ "${1}x" == "x" ] || [ "${1}" == "--help" ] || [ "${1}" == "-h" ]; then
  cat <<END_OF_DOCS
Usage: ${0} <branch> [--push|--push-only]
  branch       The branch or tag to build. Required.
  --push       Pushes the built Docker image to the registry.
  --push-only  Only pushes the Docker image to the registry, but does not build it.

You can use the following ENV variables to customize the build:
  SRC_ORG     Which fork of netbox to use (i.e. github.com/\${SRC_ORG}/\${SRC_REPO}).
              Default: 'netbox-community'
  SRC_REPO    The name of the repository to use (i.e. github.com/\${SRC_ORG}/\${SRC_REPO}).
              Default: 'netbox'
  URL         Where to fetch the code from.
              Must be a git repository. Can be private.
              Default: 'https://github.com/\${SRC_ORG}/\${SRC_REPO}.git'
  NETBOX_PATH The path where netbox will be checkout out.
              Must not be outside of the netbox-docker repository (because of Docker)!
              Default: '.netbox'
  SKIP_GIT    If defined, git is not invoked and \${NETBOX_PATH} will not be altered.
              This may be useful, if you are manually managing the NETBOX_PATH.
              Example: 'on'
              Default: undefined
  TAG         The version part of the docker tag.
              Default:
                When <branch>=master:  'latest'
                When <branch>=develop: 'snapshot'
                Else:                  same as <branch>
  DOCKER_REGISTRY
              The Docker repository's registry (i.e. '\${DOCKER_REGISTRY}/\${DOCKER_ORG}/\${DOCKER_REPO}'')
              Used for tagging the image.
              Default: 'docker.io'
  DOCKER_ORG  The Docker repository's organisation (i.e. '\${DOCKER_REGISTRY}/\${DOCKER_ORG}/\${DOCKER_REPO}'')
              Used for tagging the image.
              Default: 'netboxcommunity'
  DOCKER_REPO The Docker repository's name (i.e. '\${DOCKER_REGISTRY}/\${DOCKER_ORG}/\${DOCKER_REPO}'')
              Used for tagging the image.
              Default: 'netbox'
  DOCKER_TAG  The name of the tag which is applied to the image.
              Useful for pushing into another registry than hub.docker.com.
              Default: '\${DOCKER_REGISTRY}/\${DOCKER_ORG}/\${DOCKER_REPO}:\${TAG}'
  DOCKER_SHORT_TAG
              The name of the short tag which is applied to the image.
              This is used to tag all patch releases to their containing version, e.g. v2.5.1 -> v2.5.
              Default: '\${DOCKER_REGISTRY}/\${DOCKER_ORG}/\${DOCKER_REPO}:<MAJOR>.<MINOR>'
  DOCKERFILE  The name of Dockerfile to use.
              Default: 'Dockerfile'
  DOCKER_FROM The base image to use.
              Default: 'debian:11-slim'
  DOCKER_TARGET
              A specific target to build.
              It's currently not possible to pass multiple targets.
              Default: 'main ldap'
  BUILDX_PLATFORMS
              Specifies the platform(s) to build the image for.
              Example: 'linux/amd64,linux/arm64'
              Default: 'linux/amd64'
  BUILDX_BUILDER_NAME
              If defined, the image build will be assigned to the given builder.
              If you specify this variable, make sure that the builder exists.
              If this value is not defined, a new builx builder with the directory name of the
              current directory (i.e. '$(basename "${PWD}")') is created.
              Example: 'clever_lovelace'
              Default: undefined
  BUILDX_REMOVE_BUILDER
              If defined (and only if BUILDX_BUILDER_NAME is undefined),
              then the buildx builder created by this script will be removed after use.
              This is useful if you build NetBox Docker on an automated system that does
              not manage the builders for you.
              Example: 'on'
              Default: undefined
  BUILDX_LOCAL_CACHE
              The directory to use for reading and writign the local buildx cache.
              Default: '.buildx-cache'
  BUILDX_CACHE_FROM_DOCKER_TAG
              The tag used for pulling the remote cache.
              Default: '\${DOCKER_TAG}-cache'
  BUILDX_CACHE_TO_DOCKER_TAG
              The tag used for pushing the remote cache.
              Default: '\${DOCKER_TAG}-cache'
  BUILDX_PULL_REMOTE_CACHE
              If defined, buildx will try pulling a remote cache from the registry.
              Example: 'on'
              Default: undefined
  BUILDX_PUSH_REMOTE_CACHE
              If defined, buildx will be configured to push it's cache the remote registry
              after a successful build.
              Example: 'on'
              Default: undefined
  HTTP_PROXY  The proxy to use for http requests.
              Example: 'http://proxy.domain.tld:3128'
              Default: undefined
  NO_PROXY    Comma-separated list of domain extensions proxy should not be used for.
              Example: '.domain1.tld,.domain2.tld'
              Default: undefined
  DEBUG       If defined, the script does not stop when certain checks are not satisfied.
              Example: 'on'
              Default: undefined
  DRY_RUN     Prints all build statements instead of running them.
              Example: 'on'
              Default: undefined
  GH_ACTION   If defined, special 'echo' statements are enabled that set the
              following environment variables in Github Actions:
              - FINAL_DOCKER_TAG: The final value of the DOCKER_TAG env variable
              Default: undefined

Examples:
  ${0} master
              This will fetch the latest 'master' branch, build a Docker Image and tag it
              'netboxcommunity/netbox:latest'.
  ${0} develop
              This will fetch the latest 'develop' branch, build a Docker Image and tag it
              'netboxcommunity/netbox:snapshot'.
  ${0} v2.6.6
              This will fetch the 'v2.6.6' tag, build a Docker Image and tag it
              'netboxcommunity/netbox:v2.6.6' and 'netboxcommunity/netbox:v2.6'.
  ${0} develop-2.7
              This will fetch the 'develop-2.7' branch, build a Docker Image and tag it
              'netboxcommunity/netbox:develop-2.7'.
  SRC_ORG=cimnine ${0} feature-x
              This will fetch the 'feature-x' branch from https://github.com/cimnine/netbox.git,
              build a Docker Image and tag it 'netboxcommunity/netbox:feature-x'.
  SRC_ORG=cimnine DOCKER_ORG=cimnine ${0} feature-x
              This will fetch the 'feature-x' branch from https://github.com/cimnine/netbox.git,
              build a Docker Image and tag it 'cimnine/netbox:feature-x'.
  PLATFORMS=linux/amd64,linux/arm64 ${0} master
              This will fetch the latest 'master' branch, build a Docker Image and tag it
              'netboxcommunity/netbox:latest'.
              It will produce an ARM64 and an AMD64 version of the image.
  DRY_RUN=on ${0} master
              This will print all the commands that it would run to
              fetch the latest 'master' branch, build a Docker Image and tag it
              'netboxcommunity/netbox:latest'.
END_OF_DOCS

  if [ "${1}x" == "x" ]; then
    exit 1
  else
    exit 0
  fi
fi

source ./build-functions/gh-functions.sh

###
# Enabling dry-run mode
###
if [ -z "${DRY_RUN}" ]; then
  DRY=""
else
  echo "⚠️  DRY_RUN MODE ON  ⚠️"
  DRY="echo >>>> "
fi

gh_echo "::group::⤵️ Fetching the NetBox source code"

###
# Variables for fetching the NetBox source
###
SRC_ORG="${SRC_ORG-netbox-community}"
SRC_REPO="${SRC_REPO-netbox}"
NETBOX_BRANCH="${1}"
URL="${URL-https://github.com/${SRC_ORG}/${SRC_REPO}.git}"
NETBOX_PATH="${NETBOX_PATH-.netbox}"

###
# Fetching the NetBox source
###
if [ "${2}" != "--push-only" ] && [ -z "${SKIP_GIT}" ]; then
  REMOTE_EXISTS=$(git ls-remote --heads --tags "${URL}" "${NETBOX_BRANCH}" | wc -l)
  if [ "${REMOTE_EXISTS}" == "0" ]; then
    echo "❌ Remote branch '${NETBOX_BRANCH}' not found in '${URL}'; Nothing to do"
    gh_echo "::set-output name=skipped::true"
    exit 0
  fi
  echo "🌐 Checking out '${NETBOX_BRANCH}' of NetBox from the url '${URL}' into '${NETBOX_PATH}'"
  if [ ! -d "${NETBOX_PATH}" ]; then
    $DRY git clone -q --depth 10 -b "${NETBOX_BRANCH}" "${URL}" "${NETBOX_PATH}"
  fi

  (
    $DRY cd "${NETBOX_PATH}"
    # shellcheck disable=SC2031
    if [ -n "${HTTP_PROXY}" ]; then
      git config http.proxy "${HTTP_PROXY}"
    fi

    $DRY git remote set-url origin "${URL}"
    $DRY git fetch -qp --depth 10 origin "${NETBOX_BRANCH}"
    $DRY git checkout -qf FETCH_HEAD
    $DRY git prune
  )
  echo "✅  Checked out NetBox"
fi

gh_echo "::endgroup::"
gh_echo "::group::🧮 Calculating Values"

###
# Determining the value for DOCKERFILE
# and checking whether it exists
###
DOCKERFILE="${DOCKERFILE-Dockerfile}"
if [ ! -f "${DOCKERFILE}" ]; then
  echo "🚨  The Dockerfile ${DOCKERFILE} doesn't exist."

  if [ -z "${DEBUG}" ]; then
    exit 1
  else
    echo "⚠️  Would exit here with code '1', but DEBUG is enabled."
  fi
fi

###
# Determining the value for DOCKER_FROM
###
if [ -z "$DOCKER_FROM" ]; then
  DOCKER_FROM="debian:11-slim"
fi

###
# Variables for labelling the docker image
###
BUILD_DATE="$(date -u '+%Y-%m-%dT%H:%M+00:00')"

if [ -d ".git" ]; then
  GIT_REF="$(git rev-parse HEAD)"
fi

# Read the project version from the `VERSION` file and trim it, see https://stackoverflow.com/a/3232433/172132
PROJECT_VERSION="${PROJECT_VERSION-$(sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//' VERSION)}"

# Get the Git information from the netbox directory
if [ -d "${NETBOX_PATH}/.git" ]; then
  NETBOX_GIT_REF=$(
    cd "${NETBOX_PATH}"
    git rev-parse HEAD
  )
  NETBOX_GIT_BRANCH=$(
    cd "${NETBOX_PATH}"
    git rev-parse --abbrev-ref HEAD
  )
  NETBOX_GIT_URL=$(
    cd "${NETBOX_PATH}"
    git remote get-url origin
  )
fi

###
# Variables for tagging the docker image
###
DOCKER_REGISTRY="${DOCKER_REGISTRY-docker.io}"
DOCKER_ORG="${DOCKER_ORG-netboxcommunity}"
DOCKER_REPO="${DOCKER_REPO-netbox}"
case "${NETBOX_BRANCH}" in
master)
  TAG="${TAG-latest}"
  ;;
develop)
  TAG="${TAG-snapshot}"
  ;;
*)
  TAG="${TAG-$NETBOX_BRANCH}"
  ;;
esac

###
# Determine targets to build
###
DEFAULT_DOCKER_TARGETS=("main")
DOCKER_TARGETS=("${DOCKER_TARGET:-"${DEFAULT_DOCKER_TARGETS[@]}"}")
echo "🏭  Building the following targets:" "${DOCKER_TARGETS[@]}"

gh_echo "::endgroup::"

###
# Build each target
###
for DOCKER_TARGET in "${DOCKER_TARGETS[@]}"; do
  gh_echo "::group::🏗 Building the target '${DOCKER_TARGET}'"
  echo "🏗  Building the target '${DOCKER_TARGET}'"

  ###
  # composing the final TARGET_DOCKER_TAG
  ###
  TARGET_DOCKER_TAG="${DOCKER_TAG-${DOCKER_REGISTRY}/${DOCKER_ORG}/${DOCKER_REPO}:${TAG}}"
  if [ "${DOCKER_TARGET}" != "main" ]; then
    TARGET_DOCKER_TAG="${TARGET_DOCKER_TAG}-${DOCKER_TARGET}"
  fi
  TARGET_DOCKER_TAG_PROJECT="${TARGET_DOCKER_TAG}-${PROJECT_VERSION}"

  gh_env "FINAL_DOCKER_TAG=${TARGET_DOCKER_TAG_PROJECT}"
  gh_echo "::set-output name=skipped::false"

  ###
  # composing the final CACHE_FROM_DOCKER_TAG and CACHE_TO_DOCKER_TAG
  ###
  CACHE_FROM_DOCKER_TAG="${BUILDX_CACHE_FROM_DOCKER_TAG-${TARGET_DOCKER_TAG}-cache}"
  CACHE_TO_DOCKER_TAG="${BUILDX_CACHE_TO_DOCKER_TAG-${TARGET_DOCKER_TAG}-cache}"

  ###
  # composing the additional DOCKER_SHORT_TAG,
  # i.e. "v2.6.1" becomes "v2.6",
  # which is only relevant for version tags
  # Also let "latest" follow the highest version
  ###
  if [[ "${TAG}" =~ ^v([0-9]+)\.([0-9]+)\.[0-9]+$ ]]; then
    MAJOR=${BASH_REMATCH[1]}
    MINOR=${BASH_REMATCH[2]}

    TARGET_DOCKER_SHORT_TAG="${DOCKER_SHORT_TAG-${DOCKER_REGISTRY}/${DOCKER_ORG}/${DOCKER_REPO}:v${MAJOR}.${MINOR}}"
    TARGET_DOCKER_LATEST_TAG="${DOCKER_REGISTRY}/${DOCKER_ORG}/${DOCKER_REPO}:latest"

    if [ "${DOCKER_TARGET}" != "main" ]; then
      TARGET_DOCKER_SHORT_TAG="${TARGET_DOCKER_SHORT_TAG}-${DOCKER_TARGET}"
      TARGET_DOCKER_LATEST_TAG="${TARGET_DOCKER_LATEST_TAG}-${DOCKER_TARGET}"
    fi

    TARGET_DOCKER_SHORT_TAG_PROJECT="${TARGET_DOCKER_SHORT_TAG}-${PROJECT_VERSION}"
    TARGET_DOCKER_LATEST_TAG_PROJECT="${TARGET_DOCKER_LATEST_TAG}-${PROJECT_VERSION}"
  fi

  ###
  # If `--push-only` is passed, just push and then quit
  ###
  if [ "${2}" == "--push-only" ]; then
    source ./build-functions/docker-functions.sh
    push_image_to_registry "${TARGET_DOCKER_TAG}"

    if [ -n "${TARGET_DOCKER_SHORT_TAG}" ]; then
      push_image_to_registry "${TARGET_DOCKER_SHORT_TAG}"
      push_image_to_registry "${TARGET_DOCKER_LATEST_TAG}"
    fi
    exit 0
  fi

  ###
  # Checking if the build is necessary,
  # meaning build only if one of those values changed:
  # - Python base image digest (Label: PYTHON_BASE_DIGEST)
  # - netbox git ref (Label: NETBOX_GIT_REF)
  # - netbox-docker git ref (Label: org.label-schema.vcs-ref)
  ###
  # Load information from registry (only for docker.io)
  SHOULD_BUILD="false"
  BUILD_REASON=""
  if [ -z "${GH_ACTION}" ]; then
    # Asuming non Github builds should always proceed
    SHOULD_BUILD="true"
    BUILD_REASON="${BUILD_REASON} interactive"
  elif [ "$DOCKER_REGISTRY" = "docker.io" ]; then
    source ./build-functions/get-public-image-config.sh
    IFS=':' read -ra DOCKER_FROM_SPLIT <<<"${DOCKER_FROM}"
    if ! [[ ${DOCKER_FROM_SPLIT[0]} =~ .*/.* ]]; then
      # Need to use "library/..." for images the have no two part name
      DOCKER_FROM_SPLIT[0]="library/${DOCKER_FROM_SPLIT[0]}"
    fi
    PYTHON_LAST_LAYER=$(get_image_last_layer "${DOCKER_FROM_SPLIT[0]}" "${DOCKER_FROM_SPLIT[1]}")
    mapfile -t IMAGES_LAYERS_OLD < <(get_image_layers "${DOCKER_ORG}"/"${DOCKER_REPO}" "${TAG}")
    NETBOX_GIT_REF_OLD=$(get_image_label NETBOX_GIT_REF "${DOCKER_ORG}"/"${DOCKER_REPO}" "${TAG}")
    GIT_REF_OLD=$(get_image_label org.label-schema.vcs-ref "${DOCKER_ORG}"/"${DOCKER_REPO}" "${TAG}")

    if ! printf '%s\n' "${IMAGES_LAYERS_OLD[@]}" | grep -q -P "^${PYTHON_LAST_LAYER}\$"; then
      SHOULD_BUILD="true"
      BUILD_REASON="${BUILD_REASON} upstream-docker"
    fi
    if [ "${NETBOX_GIT_REF}" != "${NETBOX_GIT_REF_OLD}" ]; then
      SHOULD_BUILD="true"
      BUILD_REASON="${BUILD_REASON} netbox"
    fi
    if [ "${GIT_REF}" != "${GIT_REF_OLD}" ]; then
      SHOULD_BUILD="true"
      BUILD_REASON="${BUILD_REASON} netbox-docker"
    fi
  else
    SHOULD_BUILD="true"
    BUILD_REASON="${BUILD_REASON} no-check"
  fi

  ###
  # Building the docker image
  ###
  if [ "${SHOULD_BUILD}" != "true" ]; then
    echo "⏯  Build skipped because sources didn't change"
    gh_echo "::set-output name=skipped::true"
    continue
  fi

  ###
  # Composing all arguments for `docker build`
  ###
  DOCKER_BUILD_ARGS=(
    --pull
    --target "${DOCKER_TARGET}"
    -f "${DOCKERFILE}"
    -t "${TARGET_DOCKER_TAG}"
    -t "${TARGET_DOCKER_TAG_PROJECT}"
  )
  if [ -n "${TARGET_DOCKER_SHORT_TAG}" ]; then
    DOCKER_BUILD_ARGS+=(-t "${TARGET_DOCKER_SHORT_TAG}")
    DOCKER_BUILD_ARGS+=(-t "${TARGET_DOCKER_SHORT_TAG_PROJECT}")
    DOCKER_BUILD_ARGS+=(-t "${TARGET_DOCKER_LATEST_TAG}")
    DOCKER_BUILD_ARGS+=(-t "${TARGET_DOCKER_LATEST_TAG_PROJECT}")
  fi

  # --label
  DOCKER_BUILD_ARGS+=(
    --label "ORIGINAL_TAG=${TARGET_DOCKER_TAG_PROJECT}"

    --label "org.label-schema.build-date=${BUILD_DATE}"
    --label "org.opencontainers.image.created=${BUILD_DATE}"

    --label "org.label-schema.version=${PROJECT_VERSION}"
    --label "org.opencontainers.image.version=${PROJECT_VERSION}"
  )
  if [ -d ".git" ]; then
    DOCKER_BUILD_ARGS+=(
      --label "org.label-schema.vcs-ref=${GIT_REF}"
      --label "org.opencontainers.image.revision=${GIT_REF}"
    )
  fi
  if [ -d "${NETBOX_PATH}/.git" ]; then
    DOCKER_BUILD_ARGS+=(
      --label "NETBOX_GIT_BRANCH=${NETBOX_GIT_BRANCH}"
      --label "NETBOX_GIT_REF=${NETBOX_GIT_REF}"
      --label "NETBOX_GIT_URL=${NETBOX_GIT_URL}"
    )
  fi
  if [ -n "${BUILD_REASON}" ]; then
    BUILD_REASON=$(sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//' <<<"$BUILD_REASON")
    DOCKER_BUILD_ARGS+=(--label "BUILD_REASON=${BUILD_REASON}")
  fi

  # --build-arg
  DOCKER_BUILD_ARGS+=(--build-arg "NETBOX_PATH=${NETBOX_PATH}")

  if [ -n "${DOCKER_FROM}" ]; then
    DOCKER_BUILD_ARGS+=(--build-arg "FROM=${DOCKER_FROM}")
  fi
  if [ -n "${HTTP_PROXY}" ]; then
    DOCKER_BUILD_ARGS+=(--build-arg "http_proxy=${HTTP_PROXY}")
    DOCKER_BUILD_ARGS+=(--build-arg "https_proxy=${HTTPS_PROXY}")
  fi
  if [ -n "${NO_PROXY}" ]; then
    DOCKER_BUILD_ARGS+=(--build-arg "no_proxy=${NO_PROXY}")
  fi

  # --platform
  DOCKER_BUILD_ARGS+=(--platform "${BUILDX_PLATFORMS-linux/amd64}")

  # --cache-from / --cache-to
  if [ -n "${BUILDX_PULL_REMOTE_CACHE}" ]; then
    echo "📥  Pulling cache from '${CACHE_TO_DOCKER_TAG}' before build"
    DOCKER_BUILD_ARGS+=("--cache-from=type=registry,ref=${CACHE_FROM_DOCKER_TAG},mode=max")
  elif [ -n "${GH_ACTION}" ]; then
    echo "📥  Pulling from GitHub Action cache before build"
  else
    echo "📥  Pulling buildx cache from '${BUILDX_LOCAL_CACHE-.buildx-cache}' before build"
    DOCKER_BUILD_ARGS+=("--cache-from=type=local,src=${BUILDX_LOCAL_CACHE-.buildx-cache},mode=max")
  fi
  if [ -n "${BUILDX_PUSH_REMOTE_CACHE}" ]; then
    echo "📤  Pushing buildx cache to '${CACHE_TO_DOCKER_TAG}' after build"
    DOCKER_BUILD_ARGS+=("--cache-to=type=registry,ref=${CACHE_TO_DOCKER_TAG},mode=max")
  elif [ -n "${GH_ACTION}" ]; then
    echo "📤  Pushing to GitHub Action cache after build"
    DOCKER_BUILD_ARGS+=("--cache-to=type=gha")
  else
    echo "📤  Pushing buildx cache to '${BUILDX_LOCAL_CACHE-.buildx-cache}' after build"
    DOCKER_BUILD_ARGS+=("--cache-to=type=local,dest=${BUILDX_LOCAL_CACHE-.buildx-cache},mode=max")
  fi

  ###
  # Pushing the docker images if `--push` is passed
  ###
  if [ "${2}" == "--push" ]; then
    # output type=docker does not work with pushing
    DOCKER_BUILD_ARGS+=(
      --output=type=image
      --push
    )
  else
    DOCKER_BUILD_ARGS+=(
      --output=type=docker
    )
  fi

  if [ -z "${BUILDX_BUILDER_NAME}" ]; then
    BUILDX_BUILDER_NAME="$(basename "${PWD}")"
    if ! docker buildx ls | grep --quiet --word-regexp "${BUILDX_BUILDER_NAME}"; then
      echo "👷  Creating new Buildx Builder '${BUILDX_BUILDER_NAME}'"
      $DRY docker buildx create --name "${BUILDX_BUILDER_NAME}"
      BUILDX_BUILDER_CREATED="yes"
    fi
  fi

  echo "🐳  Building the Docker image '${TARGET_DOCKER_TAG}' on '${BUILDX_BUILDER_NAME}'."
  echo "    Build reason set to: ${BUILD_REASON}"

  $DRY docker buildx \
    --builder "${BUILDX_BUILDER_NAME}" \
    build \
    "${DOCKER_BUILD_ARGS[@]}" \
    .

  echo "✅  Finished building the Docker images '${TARGET_DOCKER_TAG}'"
  echo "🔎  Inspecting labels on '${TARGET_DOCKER_TAG}'"
  $DRY docker inspect "${TARGET_DOCKER_TAG}" --format "{{json .Config.Labels}}"

  if [ -n "${BUILDX_REMOVE_BUILDER}" ] && [ "${BUILDX_BUILDER_CREATED}" == "yes" ]; then
    echo "👷  Removing Buildx Builder '${BUILDX_BUILDER_NAME}'"
    $DRY docker buildx rm "${BUILDX_BUILDER_NAME}"
  fi
done