#!/usr/bin/env bash
# ===========================================================
# config_diff_check.sh — 对比渲染 .env 与服务器当前 .env
# ===========================================================
# 用法: scripts/config_diff_check.sh <rendered_file> <current_file>
#
# 输出:
#   + ADDED   渲染文件有、当前文件没有（新增配置）
#   - REMOVED 当前文件有、渲染文件没有（将被删除）
#   ~ CHANGED 两边都有但值不同（将被覆盖）
#
# 敏感值脱敏：KEY/SECRET/PASSWORD/TOKEN/URL 类变量只显示前4字符+***
# 退出码: 始终返回 0（仅告警，不阻塞部署）
# ===========================================================
set -u

RENDERED_FILE="${1:-}"
CURRENT_FILE="${2:-}"

if [ -z "$RENDERED_FILE" ] || [ -z "$CURRENT_FILE" ]; then
  echo "ERROR: 用法: $0 <rendered_file> <current_file>" >&2
  exit 0
fi

if [ ! -f "$RENDERED_FILE" ]; then
  echo "ERROR: 渲染文件不存在: $RENDERED_FILE" >&2
  exit 0
fi

# 判断是否为敏感变量（键名包含以下关键词）
is_sensitive() {
  local key="$1"
  case "$key" in
    *KEY*|*SECRET*|*PASSWORD*|*TOKEN*|*URL*|*BROKER*|*BACKEND*) return 0 ;;
    *) return 1 ;;
  esac
}

# 脱敏：敏感值只显示前4字符+***
mask_value() {
  local key="$1"
  local value="$2"
  if is_sensitive "$key"; then
    if [ ${#value} -le 4 ]; then
      echo "****"
    else
      echo "${value:0:4}***"
    fi
  else
    echo "$value"
  fi
}

# 解析文件为 KEY=VALUE（忽略注释和空行）
parse_env() {
  local file="$1"
  grep -vE '^\s*#|^\s*$' "$file" 2>/dev/null | while IFS= read -r line; do
    # 只取第一个 = 之前的部分作为 key
    key="${line%%=*}"
    value="${line#*=}"
    # 跳过无效行
    if [ -n "$key" ] && [ "$key" != "$line" ]; then
      echo "${key}=${value}"
    fi
  done
}

echo "=========================================="
echo "  配置 Diff 检查（检测配置漂移）"
echo "=========================================="
echo "渲染文件: $RENDERED_FILE"
echo "当前文件: $CURRENT_FILE"
echo ""

# 解析两个文件
if [ ! -f "$CURRENT_FILE" ] || [ ! -s "$CURRENT_FILE" ]; then
  # 服务器 .env 不存在或为空（首次部署）
  echo "⚠️  服务器 .env 不存在或为空（可能是首次部署）"
  echo "   所有配置项将标记为 ADDED"
  echo ""

  added=0
  while IFS='=' read -r key value; do
    [ -z "$key" ] && continue
    masked=$(mask_value "$key" "$value")
    echo "  + ADDED  ${key}=${masked}"
    added=$((added + 1))
  done < <(parse_env "$RENDERED_FILE")

  echo ""
  echo "=========================================="
  echo "  汇总: 新增 ${added} 项 | 删除 0 项 | 变更 0 项 | 无变化 0 项"
  echo "=========================================="
  exit 0
fi

# 用临时文件存储解析结果
tmp_rendered=$(mktemp)
tmp_current=$(mktemp)
trap "rm -f $tmp_rendered $tmp_current" EXIT

parse_env "$RENDERED_FILE" | sort > "$tmp_rendered"
parse_env "$CURRENT_FILE" | sort > "$tmp_current"

added=0
removed=0
changed=0
unchanged=0

echo "--- 新增配置（渲染文件有、当前文件无）---"
# 找 ADDED：渲染文件有但当前文件没有的 key
while IFS='=' read -r key value; do
  [ -z "$key" ] && continue
  current_line=$(grep -m1 "^${key}=" "$tmp_current" 2>/dev/null || true)
  if [ -z "$current_line" ]; then
    masked=$(mask_value "$key" "$value")
    echo "  + ADDED  ${key}=${masked}"
    added=$((added + 1))
  fi
done < "$tmp_rendered"

if [ "$added" -eq 0 ]; then
  echo "  (无)"
fi

echo ""
echo "--- 删除配置（当前文件有、渲染文件无）---"
# 找 REMOVED：当前文件有但渲染文件没有的 key
while IFS='=' read -r key value; do
  [ -z "$key" ] && continue
  rendered_line=$(grep -m1 "^${key}=" "$tmp_rendered" 2>/dev/null || true)
  if [ -z "$rendered_line" ]; then
    masked=$(mask_value "$key" "$value")
    echo "  - REMOVED  ${key}=${masked}"
    removed=$((removed + 1))
  fi
done < "$tmp_current"

if [ "$removed" -eq 0 ]; then
  echo "  (无)"
fi

echo ""
echo "--- 变更配置（两边都有但值不同）---"
# 找 CHANGED：两边都有但值不同
while IFS='=' read -r key value; do
  [ -z "$key" ] && continue
  current_line=$(grep -m1 "^${key}=" "$tmp_current" 2>/dev/null || true)
  if [ -n "$current_line" ]; then
    current_value="${current_line#*=}"
    if [ "$value" != "$current_value" ]; then
      masked_new=$(mask_value "$key" "$value")
      masked_old=$(mask_value "$key" "$current_value")
      echo "  ~ CHANGED  ${key}: ${masked_old} → ${masked_new}"
      changed=$((changed + 1))
    else
      unchanged=$((unchanged + 1))
    fi
  fi
done < "$tmp_rendered"

if [ "$changed" -eq 0 ]; then
  echo "  (无)"
fi

echo ""
echo "=========================================="
echo "  汇总: 新增 ${added} 项 | 删除 ${removed} 项 | 变更 ${changed} 项 | 无变化 ${unchanged} 项"
echo "=========================================="

if [ "$added" -gt 0 ] || [ "$removed" -gt 0 ] || [ "$changed" -gt 0 ]; then
  echo "⚠️  检测到配置漂移，请确认以上变更是否符合预期"
else
  echo "✅ 配置无漂移，与服务器当前配置一致"
fi

exit 0