/**
 * 系统配置 Prisma 行 -> 共享 DTO 映射（A4-BE-02）。
 *
 * 元数据（标签 / 说明 / 影响面 / 类型 / 上下限 / 是否公开）唯一来源是
 * `SYSTEM_CONFIG_DEFINITIONS`；`system_configs` 只提供当前值与版本。
 * DB 缺行时用定义默认值 + version 1 兜底，不写库。
 */
import {
  type SystemConfig,
  type SystemConfigChange,
  type SystemConfigDefinition,
  type SystemConfigValue,
  systemConfigValueType,
} from '@lingxi/shared';
import type { Prisma } from '@prisma/client';
import type {
  SystemConfig as PrismaSystemConfig,
  SystemConfigVersion as PrismaSystemConfigVersion,
} from '@prisma/client';

/** 从未落库的配置：用 epoch 表示「未更新过」，避免伪造读取时间 */
const NEVER_UPDATED_AT = new Date(0).toISOString();

/** Prisma JsonB 只应存原始值；异常结构回退配置默认值，避免脏数据打穿前端 schema */
export function normalizeConfigValue(
  raw: Prisma.JsonValue | undefined,
  fallback: SystemConfigValue,
): SystemConfigValue {
  if (typeof raw === 'string' || typeof raw === 'number' || typeof raw === 'boolean') {
    return raw;
  }
  return fallback;
}

export function toSystemConfig(
  definition: SystemConfigDefinition,
  row: PrismaSystemConfig | undefined,
  updatedByName?: string | null,
): SystemConfig {
  return {
    key: definition.key,
    group: definition.group,
    label: definition.label,
    description: definition.description,
    impact: definition.impact,
    type: definition.type,
    value: normalizeConfigValue(row?.configValue, definition.defaultValue),
    valueType: systemConfigValueType(definition),
    unit: definition.unit ?? null,
    version: row?.version ?? 1,
    updatedAt: row === undefined ? NEVER_UPDATED_AT : row.updatedAt.toISOString(),
    updatedBy: updatedByName ?? row?.updatedBy ?? null,
    editable: definition.editable,
    isPublic: definition.public,
    min: definition.min ?? null,
    max: definition.max ?? null,
    step: definition.step ?? null,
    maxLength: definition.maxLength ?? null,
  };
}

export function toSystemConfigChange(
  row: PrismaSystemConfigVersion,
  label: string,
  operator: string | null,
): SystemConfigChange {
  return {
    key: row.configKey,
    label,
    version: row.version,
    oldValue: row.oldValue,
    newValue: row.newValue,
    reason: row.reason,
    operator,
    changedAt: row.changedAt.toISOString(),
    result: '已生效',
  };
}