#! /usr/bin/env sh

set -e

cleanup() {
  if [ "${CLEAN_EXIT}" = false ]; then
    echo "something went wrong"
    echo "continue with the pipeline"
    exit 0
  fi
}

trap cleanup EXIT
CLEAN_EXIT=false

if [ -z "${BASE}" ]; then
  echo "the environment variable BASE is not set"
  exit 1
fi

if [ -z "${TARGET}" ]; then
  echo "the environment variable TARGET is not set"
  exit 1
fi

if [ -z "${BASE_REGISTRY_USERNAME}" && -n "${REGISTRY_USERNAME}" ]; then
  BASE_REPO_USERNAME="${REPO_USERNAME}"
fi

if [ -z "${BASE_REGISTRY_PASSWORD}" && -n "${REGISTRY_PASSWORD}" ]; then
  BASE_REPO_PASSWORD="${REPO_PASSWORD}"
fi

if [ -z "${TARGET_REGISTRY_USERNAME}" && -n "${REGISTRY_USERNAME}" ]; then
  TARGET_REPO_USERNAME="${REPO_USERNAME}"
fi

if [ -z "${TARGET_REGISTRY_PASSWORD}" && -n "${REGISTRY_PASSWORD}" ]; then
  BASE_REPO_PASSWORD="${REPO_PASSWORD}"
fi

if [ -z "${REGISTRY_API}" ]; then
  REGISTRY_API = 'docker'
fi

if [ -z "${BASE_REGISTRY_API}" ]; then
  BASE_REGISTRY_API = '${REGISTRY_API}'
fi

if [ -z "${TARGET_REGISTRY_API}" ]; then
  TARGET_REGISTRY_API = '${REGISTRY_API}'
fi

if [ -z "${REGISTRY_URL}" ]; then
  REGISTRY_URL="https://hub.docker.com/v2"
  # repositories
fi

if [ -z "${BASE_REPO_URL}" ]; then
  BASE_REGISTRY_URL="${REPO_URL}"
fi

if [ -z "${TARGET_REPO_URL}" ]; then
  TARGET_REGISTRY_URL="${REPO_URL}"
fi

# remove trailing /
BASE_REGISTRY_URL="${BASE_REGISTRY_URL%/}"
TARGET_REGISTRY_URL="${TARGET_REGISTRY_URL%/}"

# add "library/" if its a "official" docker image (no username is provided)
echo "${BASE}" | grep -q "/" || BASE="library/${BASE}"
echo "${TARGET}" | grep -q "/" || TARGET="library/${TARGET}" 

# if no tag is given default to latest
echo "${BASE}" | grep -q ":" || BASE="${BASE}:latest"
echo "${TARGET}" | grep -q ":" || TARGET="${TARGET}:latest" 

# split repo into user reponame and tag
IFS='/:'
read -ra parts <<< "${BASE_REPO}"
BASE_REPO_USER="${parts[0]}"
BASE_REPO_NAME="${parts[1]}"
BASE_REPO_TAG="${parts[2]}"

read -ra parts <<< "${TARGET_REPO}"
TARGET_REPO_USER="${parts[0]}"
TARGET_REPO_NAME="${parts[1]}"
TARGET_REPO_TAG="${parts[2]}"

if [ -n "${BASE_REGISTRY_USERNAME}" && -n "${BASE_REGISTRY_PASSWORD}" \ ]

# make a shared login header if REGISTRY_API REGISTRY_USERNAME and REGISTRY_PASSWORD are the same for BASE and TARGET
if [ "${BASE_REGISTRY_API}" == "${TARGET_REGISTRY_API}" \
    && "${BASE_REGISTRY_USERNAME}" == "${TARGET_REGISTRY_USERNAME}" \
    && "${BASE_REGISTRY_PASSWORD}" == "${TARGET_REGISTRY_PASSWORD}" \
    && "${BASE_REGISTRY_URL}" == "${TARGET_REGISTRY_URL}" \
    && -n "${BASE_REGISTRY_USERNAME}" \
    && -n "${BASE_REGISTRY_PASSWORD}" \
    ]; then
  if [ "${BASE_REGISTRY_API}" == "docker" ]; then
    TOKEN=$(curl -s -H "Content-Type: application/json" -X POST -d "{\"username\": \"${BASE_REGISTRY_USERNAME}\", \"password\": \"${BASE_REGISTRY_PASSWORD}\"}" ${BASE_REGISTRY_URL}/users/login/ | jq -r .token) 
    BASE_HEADER="Authorization: JWT ${TOKEN}"
    TARGET_HEADER="Authorization: JWT ${TOKEN}"
  elif [ "${BASE_REGISTRY_API}" == "gitea" ]; then
    BASE_HEADER="Authorization: token ${BASE_REGISTRY_PASSWORD}"
    TARGET_HEADER="Authorization: token ${TARGET_REGISTRY_PASSWORD}"
  fi
fi

if [ "${BASE_REGISTRY_API}" == "docker" ]; then
  BASE_URL="${BASE_REPO_URL}/${BASE_REPO_USER}/${BASE_REPO_NAME}/tags/${BASE_REPO_TAG}"
elif [ "${BASE_REGISTRY_API}" == "gitea" ]; then
  
fi

# build the url to the repo
BASE_URL="${BASE_REPO_URL}/${BASE_REPO}/tags/${BASE_TAG}"
TARGET_URL="${TARGET_REPO_URL}/${TARGET_REPO}/tags/${TARGET_TAG}"

# login if credentias are passed
HEADER=""
if [ -n "${DOCKER_USERNAME}" ] && [ -n "${DOCKER_PASSWORD}" ]; then
  TOKEN=$(curl -s -H "Content-Type: application/json" -X POST -d '{"username": "'"${DOCKER_USERNAME}"'", "password": "'"${DOCKER_PASSWORD}"'"}' https://hub.docker.com/v2/users/login/ | jq -r .token) 
  HEADER="Authorization: JWT ${TOKEN}"
fi

# curl -X 'GET' -H 'accept: application/json' 'https://git.narvas.tech/api/v1/packages/[USER]/container/[REPO]/dev?access_token=[TOKEN]'

# compare the update time of the BASE and TARGET images
BASE_DATE=$(curl -s -H "${HEADER}" "${BASE_URL}" | jq -r .last_updated | sed 's/T/ /' | sed 's/\..*//' ) 
TARGET_DATE=$(curl -s -H "${HEADER}" "${TARGET_URL}" | jq -r .last_updated | sed 's/T/ /' | sed 's/\..*//' )

BASE_TIMESTAMP=$(date -d "${BASE_DATE}" +%s)
TARGET_TIMESTAMP=$(date -d "${TARGET_DATE}" +%s)

CLEAN_EXIT=true

if [ "$BASE_TIMESTAMP" -le "$TARGET_TIMESTAMP" ]; then
  echo "no update needed"
  exit 1
fi

echo "$TARGET needs updating"
exit 0