#!/usr/bin/env bash
# derive-gitlab.sh — 从 git origin 远程派生 GitLab 凭据并回填 .env.local
#
# 用法: bash derive-gitlab.sh [.env.local 路径，默认 .env.local]
#
# 派生字段:
#   GITLAB_PROJECT_ID = origin 的 namespace/path（/ 编码成 %2F）
#   GITLAB_API_URL    = <scheme>://<host>/api/v3
#
# 仅当字段值为 TBD(A5 自动补) 或空时回填；用户手填值不动。
# 仅支持 http(s) origin URL；其他协议（ssh / git@）跳过。
# GITLAB_TOKEN 不派生，留给用户手填。
#
# 退出码:
#   0 = 派生完成或主动跳过（origin 不存在 / 协议不支持）
#   2 = .env.local 路径错

set -uo pipefail

ENV_FILE=${1:-.env.local}
[ -f "$ENV_FILE" ] || { echo "derive-gitlab.sh: env file not found: $ENV_FILE" >&2; exit 2; }

URL=$(git remote get-url origin 2>/dev/null || true)
if [ -z "$URL" ]; then
  echo "derive-gitlab.sh: 未配置 origin 远程，GITLAB_* 留给用户手填" >&2
  exit 0
fi

case "$URL" in
  https://*) SCHEME=https ;;
  http://*)  SCHEME=http ;;
  *)
    echo "derive-gitlab.sh: origin 不是 http(s) URL ($URL)，跳过派生" >&2
    exit 0
    ;;
esac

REST=${URL#${SCHEME}://}
HOST=${REST%%/*}
PATH_RAW=${REST#*/}
PATH_RAW=${PATH_RAW%.git}

PROJECT_ID=${PATH_RAW//\//%2F}
API_URL="${SCHEME}://${HOST}/api/v3"

update_field() {
  local key=$1 newval=$2
  local line
  line=$(grep -E "^${key}=" "$ENV_FILE" | head -1)
  if [ -z "$line" ]; then
    echo "  ${key} = (.env.local 中无此行，跳过)" >&2
    return
  fi
  local current=${line#${key}=}
  if [ -z "$current" ] || [ "$current" = "TBD(A5 自动补)" ]; then
    sed -i.bak -E "s|^${key}=.*$|${key}=${newval}|" "$ENV_FILE" && rm -f "${ENV_FILE}.bak"
    echo "  ${key} = ${newval}"
  else
    echo "  ${key} = (保留用户手填: ${current})"
  fi
}

echo "derive-gitlab.sh: 从 origin ($URL) 派生 GitLab 凭据："
update_field GITLAB_PROJECT_ID "$PROJECT_ID"
update_field GITLAB_API_URL "$API_URL"
echo "  GITLAB_TOKEN = (保持占位，请去 GitLab Profile → Account → Private token 手填)"