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

separator() {
  printf '\n%s\n' '=================================================='
}

section() {
  separator
  printf '%s\n' "$1"
  printf '%s\n' '--------------------------------------------------'
}

info() {
  printf '[INFO] %s\n' "$1"
}

success() {
  printf '[OK]   %s\n' "$1"
}

warn() {
  printf '[WARN] %s\n' "$1"
}

fail() {
  printf '[ERR]  %s\n' "$1" >&2
}

is_empty_or_null() {
  [ -z "${1:-}" ] || [ "${1:-}" = "null" ]
}

require_value() {
  local name="$1"
  local value="$2"

  info "$name=$value"
  if is_empty_or_null "$value"; then
    fail "$name is required"
    exit 1
  fi
}

require_integer() {
  local name="$1"
  local value="$2"

  if ! [[ "$value" =~ ^[0-9]+$ ]]; then
    fail "$name must be a non-negative integer"
    exit 1
  fi
}

section "參數檢查"
require_value "GITEA_SERVER_URL" "$GITEA_SERVER_URL"
require_value "GITEA_REPOSITORY" "$GITEA_REPOSITORY"
require_value "KEEP_COUNT" "$KEEP_COUNT"
require_integer "KEEP_COUNT" "$KEEP_COUNT"

if is_empty_or_null "${RUNNER_TOKEN:-}"; then
  warn "RUNNER_TOKEN is empty; release API calls will be anonymous"
else
  info "RUNNER_TOKEN=[redacted]"
fi

release_api_url="$GITEA_SERVER_URL/api/v1/repos/$GITEA_REPOSITORY/releases"
auth_header=()

if ! is_empty_or_null "${RUNNER_TOKEN:-}"; then
  auth_header=(-H "Authorization: token $RUNNER_TOKEN")
fi

section "取得成品資訊"
info "GET $release_api_url"

release_json='[]'
page=1

while :; do
  page_url="$release_api_url?page=$page"
  page_json="$(curl -fsS "${auth_header[@]}" "$page_url")"

  if [ "$(jq 'length' <<<"$page_json")" -eq 0 ]; then
    break
  fi

  release_json="$(jq -s 'add' <<<"$release_json"$'\n'"$page_json")"
  page=$((page + 1))
done

release_json="$(jq -e 'sort_by(.created_at) | reverse' <<<"$release_json")"
release_count="$(jq 'length' <<<"$release_json")"

info "RELEASE_COUNT=$release_count"
info "KEEP_COUNT=$KEEP_COUNT"

if [ "$release_count" -le "$KEEP_COUNT" ]; then
  success "沒有需要清理的舊版本成品"
  exit 0
fi

section "刪除舊版本成品"

release_to_delete="$(jq -c ".[$KEEP_COUNT:]" <<<"$release_json")"

while IFS= read -r release_item; do
  [ -z "$release_item" ] && continue

  release_id="$(jq -r '.id' <<<"$release_item")"
  release_tag="$(jq -r '.tag_name' <<<"$release_item")"
  release_name="$(jq -r '.name' <<<"$release_item")"

  if is_empty_or_null "$release_id"; then
    warn "略過沒有 id 的成品: $release_tag ($release_name)"
    continue
  fi

  delete_url="$GITEA_SERVER_URL/api/v1/repos/$GITEA_REPOSITORY/releases/$release_id"
  info "DELETE $release_tag ($release_name)"

  delete_code="$(curl -sS -o /dev/null -w "%{http_code}" -X DELETE "${auth_header[@]}" "$delete_url")"

  if [ "$delete_code" -eq 204 ]; then
    success "成功刪除: $release_tag ($release_name)"
  else
    fail "刪除失敗: $release_tag ($release_name), HTTP $delete_code"
  fi
done < <(jq -c '.[]' <<<"$release_to_delete")

separator