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

domain="registry.gitea.faerro.it"
image="$domain/andrea/faerro-kb"
repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
bump="patch"

while [[ $# -gt 0 ]]; do
  case "$1" in
    --major|--minor)
      if [[ "$bump" != "patch" ]]; then
        echo "Choose only one of --major or --minor." >&2
        exit 1
      fi
      bump="${1#--}"
      ;;
    *)
      echo "Usage: $0 [--major | --minor]" >&2
      exit 1
      ;;
  esac
  shift
done

if ! command -v docker >/dev/null 2>&1; then
  echo "Docker is required to build and publish the image." >&2
  exit 1
fi

if ! command -v git >/dev/null 2>&1; then
  echo "Git is required to determine the release version." >&2
  exit 1
fi

if [[ -n "$(git -C "$repo_root" status --porcelain)" ]]; then
  echo "Commit or discard all staged, unstaged, and untracked changes before publishing." >&2
  exit 1
fi

latest_version=""
while IFS= read -r candidate; do
  if [[ "$candidate" =~ ^(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)$ ]]; then
    latest_version="$candidate"
    break
  fi
done < <(git -C "$repo_root" tag --list --sort=-version:refname)

if [[ -z "$latest_version" ]]; then
  echo "At least one MAJOR.MINOR.PATCH Git tag is required to determine the next version." >&2
  exit 1
fi

commits_since_release="$(git -C "$repo_root" rev-list --count "$latest_version..HEAD")"
if [[ "$commits_since_release" -eq 0 ]]; then
  echo "No new commits since Git tag $latest_version; nothing to publish." >&2
  exit 1
fi

IFS=. read -r major minor patch <<< "$latest_version"
case "$bump" in
  major)
    major=$((10#$major + 1))
    minor=0
    patch=0
    ;;
  minor)
    minor=$((10#$minor + 1))
    patch=0
    ;;
  patch)
    patch=$((10#$patch + 1))
    ;;
esac
version="$major.$minor.$patch"

if git -C "$repo_root" show-ref --verify --quiet "refs/tags/$version"; then
  echo "Git tag $version already exists; refusing to move it." >&2
  exit 1
fi

build_context="$(mktemp -d)"
trap 'rm -rf "$build_context"' EXIT
git -C "$repo_root" archive HEAD | tar -x -C "$build_context"
footer_file="$build_context/frontend/index.html"
footer_count="$(grep -c '<footer>' "$footer_file" || true)"
if [[ "$footer_count" -ne 1 ]]; then
  echo "Expected exactly one footer in frontend/index.html." >&2
  exit 1
fi
sed -E -i "/<footer>/ { s/ · v[0-9]+\.[0-9]+\.[0-9]+//; s#</p># · v$version</p>#; }" "$footer_file"
if ! grep -Fq "· v$version</p></footer>" "$footer_file"; then
  echo "Could not update the footer version in the build context." >&2
  exit 1
fi

git -C "$repo_root" tag --annotate "$version" --message "Release $version" HEAD

cd "$repo_root"
docker build --tag "$image:$version" --tag "$image:latest" "$build_context"
registry_username="${GITEA_USERNAME:-${DOCKER_USERNAME:-}}"
registry_token="${GITEA_TOKEN:-${DOCKER_PASSWORD:-}}"
unset GITEA_TOKEN DOCKER_PASSWORD
env_file="$repo_root/.env"
if [[ -f "$env_file" ]]; then
  while IFS= read -r line || [[ -n "$line" ]]; do
    line="${line%$'\r'}"
    if [[ "$line" =~ ^GITEA_USERNAME=(.*)$ ]]; then
      registry_username="${BASH_REMATCH[1]}"
    elif [[ "$line" =~ ^GITEA_TOKEN=(.*)$ ]]; then
      registry_token="${BASH_REMATCH[1]}"
    fi
  done < "$env_file"
fi

if [[ -n "$registry_username" || -n "$registry_token" ]]; then
  if [[ -z "$registry_username" || -z "$registry_token" ]]; then
    echo "Set both GITEA_USERNAME and GITEA_TOKEN in .env to log in automatically." >&2
    exit 1
  fi
  if ! printf '%s' "$registry_token" | docker login --username "$registry_username" --password-stdin "$domain"; then
    unset registry_token
    exit 1
  fi
  unset registry_token
fi
docker push "$image:$version"
docker push "$image:latest"

while IFS= read -r local_image; do
  [[ -z "$local_image" || "$local_image" == "$image:$version" || "$local_image" == "$image:latest" ]] && continue
  docker image rm "$local_image"
done < <(docker image ls --format '{{.Repository}}:{{.Tag}}' "$image")

echo "Published $image:$version and $image:latest"