#!/usr/bin/env bash

set -euo pipefail

source "$(cd "$(dirname "$0")/.." && pwd)/lib/common.sh"

require_cmd awk
require_cmd curl
require_cmd dpkg
require_cmd git
require_cmd gzip

load_build_config

work_root="$(ci_work_root)"
artifacts_dir="$(ci_artifacts_dir)"
metadata_file="$(ci_metadata_file)"
helper_dir="$work_root/hercules-helper-preflight"
hyperion_dir="$work_root/hyperion-preflight"

owner="${GITEA_PACKAGE_OWNER:-${CI_REPO_OWNER:-}}"
username="${GITEA_PACKAGE_USERNAME:-${CI_REPO_OWNER:-}}"
base_url="${GITEA_BASE_URL:-$DEFAULT_GITEA_BASE_URL}"
package_distribution="${DEBIAN_DISTRIBUTION:-$(detect_debian_distribution)}"
package_component="${DEBIAN_COMPONENT:-$DEFAULT_DEBIAN_COMPONENT}"
package_architecture="$(dpkg --print-architecture)"

resolve_helper_template_dir() {
  local template_dir="$1/packagers/debian/hercules-hyperion"

  if [[ -d "$template_dir" ]]; then
    printf '%s\n' "$template_dir"
    return 0
  fi

  template_dir="$(
    find "$1/packagers/debian" -mindepth 1 -maxdepth 1 -type d -name 'hyperion-*' \
      | sort -V \
      | tail -n 1
  )"

  [[ -n "$template_dir" ]] || die "No Hyperion Debian package template directory found under $1/packagers/debian"
  printf '%s\n' "$template_dir"
}

resolve_hyperion_repo_url() {
  printf '%s\n' "${GIT_REPO_HYPERION:-${git_repo_hyperion:-https://github.com/SDL-Hercules-390/hyperion.git}}"
}

resolve_hyperion_repo_branch() {
  printf '%s\n' "${GIT_BRANCH_HYPERION:-${git_branch_hyperion:-}}"
}

resolve_hyperion_repo_commit() {
  printf '%s\n' "${GIT_COMMIT_HYPERION:-${git_commit_hyperion:-}}"
}

clone_repo() {
  local repo_url="$1"
  local repo_dir="$2"
  local repo_branch="${3:-}"

  rm -rf "$repo_dir"

  if [[ -n "$repo_branch" ]]; then
    git clone --branch "$repo_branch" "$repo_url" "$repo_dir"
  else
    git clone "$repo_url" "$repo_dir"
  fi
}

determine_hyperion_version() {
  local repo_dir="$1"

  if [[ -x "$repo_dir/_dynamic_version" ]]; then
    (
      cd "$repo_dir"
      ./_dynamic_version . VERSION \
        | awk '{sub("-modified","", $0); print}' \
        | tr -d '"'
    )
    return 0
  fi

  git -C "$repo_dir" describe --tags --dirty --always 2>/dev/null || echo unknown
}

fetch_package_index() {
  local response_file
  local status_code
  local url
  local suffix

  response_file="$(mktemp)"

  for suffix in Packages Packages.gz; do
    url="$base_url/api/packages/$owner/debian/dists/$package_distribution/$package_component/binary-$package_architecture/$suffix"
    status_code="$(
      curl \
        --silent \
        --show-error \
        --location \
        --output "$response_file" \
        --write-out '%{http_code}' \
        --user "$username:$GITEA_PACKAGE_TOKEN" \
        "$url"
    )"

    case "$status_code" in
      200)
        if [[ "$suffix" == "Packages.gz" ]]; then
          gzip -dc "$response_file"
        else
          cat "$response_file"
        fi
        rm -f "$response_file"
        return 0
        ;;
      404)
        ;;
      *)
        cat "$response_file" >&2
        rm -f "$response_file"
        die "Package index query failed with HTTP $status_code for $url"
        ;;
    esac
  done

  rm -f "$response_file"
  return 1
}

package_exists_in_index() {
  local package_name="$1"
  local package_version="$2"

  awk -v target_package="$package_name" -v target_version="$package_version" '
    BEGIN {
      RS = ""
      FS = "\n"
    }
    {
      found_package = 0
      found_version = 0
      for (i = 1; i <= NF; i++) {
        if ($i == "Package: " target_package) {
          found_package = 1
        }
        if ($i == "Version: " target_version) {
          found_version = 1
        }
      }
      if (found_package && found_version) {
        matched = 1
        exit
      }
    }
    END {
      if (matched) {
        exit 0
      }
      exit 1
    }
  '
}

write_metadata() {
  local skip_build="$1"
  local package_name="$2"
  local package_version="$3"

  mkdir -p "$artifacts_dir"

  cat >"$metadata_file" <<EOF
SKIP_PACKAGE_BUILD=$skip_build
PACKAGE_NAME=$package_name
PACKAGE_VERSION=$package_version
PACKAGE_ARCHITECTURE=$package_architecture
PACKAGE_DISTRIBUTION=$package_distribution
PACKAGE_COMPONENT=$package_component
EOF
}

require_env GITEA_PACKAGE_TOKEN
[[ -n "$owner" ]] || die "Unable to determine Gitea package owner. Set GITEA_PACKAGE_OWNER or CI_REPO_OWNER."
[[ -n "$username" ]] || die "Unable to determine Gitea package username. Set GITEA_PACKAGE_USERNAME or CI_REPO_OWNER."

mkdir -p "$work_root"

log "Cloning helper repo $REPO (branch: $BRANCH) for package preflight"
clone_repo "$REPO" "$helper_dir" "$BRANCH"

template_dir="$(resolve_helper_template_dir "$helper_dir")"
control_file="$template_dir/DEBIAN/control"
[[ -f "$control_file" ]] || die "Package control file not found: $control_file"
package_name="$(awk '/^Package:/ {print $2; exit}' "$control_file")"
[[ -n "$package_name" ]] || die "Unable to determine package name from $control_file"

hyperion_repo_url="$(resolve_hyperion_repo_url)"
hyperion_repo_branch="$(resolve_hyperion_repo_branch)"
hyperion_repo_commit="$(resolve_hyperion_repo_commit)"

log "Cloning Hyperion source repo for version preflight"
clone_repo "$hyperion_repo_url" "$hyperion_dir" "$hyperion_repo_branch"
if [[ -n "$hyperion_repo_commit" ]]; then
  git -C "$hyperion_dir" checkout "$hyperion_repo_commit"
fi

package_version="$(determine_hyperion_version "$hyperion_dir")"
[[ -n "$package_version" ]] || die "Unable to determine package version"

log "Checking Gitea for $package_name/$package_version ($package_distribution/$package_component/$package_architecture)"
package_index_file="$(mktemp)"
have_package_index=false

if fetch_package_index >"$package_index_file"; then
  have_package_index=true
fi

if [[ "$have_package_index" == "true" ]] && package_exists_in_index "$package_name" "$package_version" <"$package_index_file"; then
  rm -f "$package_index_file"
  write_metadata true "$package_name" "$package_version"
  log "Package already exists in registry; build will be skipped"
  exit 0
fi

rm -f "$package_index_file"
write_metadata false "$package_name" "$package_version"
log "Package does not exist in registry; build will continue"