#!/usr/bin/env bash
# parse_image_ref.sh

DEFAULT_REGISTRY="registry.tm0.app"
DEFAULT_TAG="latest"

parse_image_ref() {
  local input="$1"

  local image_ref registry repo tag label

  if [[ $input == */* ]]; then
    local prefix="${input%%/*}"
    if [[ "$prefix" == "docker" ]]; then
      input="docker.io/library/${input#*/}"
    elif [[ "$prefix" == "tm0" ]]; then
      input="${DEFAULT_REGISTRY}/${input#*/}"
    fi

    registry="${input%%/*}"
    input=${input#*/}
  else
    registry="$DEFAULT_REGISTRY"
  fi

  if [[ "${input##*/}" == *:* ]]; then
    tag="${input##*:}"
    input="${input%:*}"
  else
    tag="$DEFAULT_TAG"
  fi

  repo="${registry}/${input}"
  repo="${repo#*/}"
  image_ref="${registry}/${repo}:${tag}"

  label="${registry%.*}"
  label="${label##*.}/${repo##*/}"

  echo "$image_ref $repo $tag $label"
}

# -------------------------------------------------------------------
# Test harness
# -------------------------------------------------------------------
test_case() {
  local input="$1"
  local expected="$2"
  local output
  output="$(parse_image_ref "$input")"

  if [[ "$output" == "$expected" ]]; then
    printf "✅ PASS: %-35s => %s\n" "$input" "$output"
  else
    printf "❌ FAIL: %-35s\n" "$input"
    printf "   expected: %s\n" "$expected"
    printf "   got:      %s\n" "$output"
  fi
}

run_tests() {
  echo "Running test cases..."
  echo

  test_case "tm0/nginx" \
    "registry.tm0.app/nginx:latest nginx latest tm0/nginx"

  test_case "tm0/dev/api" \
    "registry.tm0.app/dev/api:latest dev/api latest tm0/api"

  test_case "registry.tm0.app/nginx" \
    "registry.tm0.app/nginx:latest nginx latest tm0/nginx"

  test_case "registry.tm0.app:2525/nginx" \
    "registry.tm0.app:2525/nginx:latest nginx latest tm0/nginx"

  test_case "registry.tm0.app/dev/api" \
    "registry.tm0.app/dev/api:latest dev/api latest tm0/api"

  test_case "a.b.c.registry.tm0.app/dev/api" \
    "a.b.c.registry.tm0.app/dev/api:latest dev/api latest tm0/api"

  test_case "docker/nginx" \
    "docker.io/library/nginx:latest library/nginx latest docker/nginx"

  test_case "docker/nginx:1.25" \
    "docker.io/library/nginx:1.25 library/nginx 1.25 docker/nginx"

  test_case "docker.io/library/nginx:1.25" \
    "docker.io/library/nginx:1.25 library/nginx 1.25 docker/nginx"

  test_case "docker/redis" \
    "docker.io/library/redis:latest library/redis latest docker/redis"

  test_case "custom-registry.io/team/api:2.3.1" \
    "custom-registry.io/team/api:2.3.1 team/api 2.3.1 custom-registry/api"

  test_case "custom-registry.io:2525/team/api:2.3.1" \
    "custom-registry.io:2525/team/api:2.3.1 team/api 2.3.1 custom-registry/api"

  test_case "custom-registry.io:2525/api:2.3.1" \
    "custom-registry.io:2525/api:2.3.1 api 2.3.1 custom-registry/api"

  test_case "custom-registry.io/app" \
    "custom-registry.io/app:latest app latest custom-registry/app"
}

if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
  run_tests
fi