export const DEVICE_ASSET_STATUS_VALUES = ["active", "maintenance", "disabled", "retired"] as const;
export type DeviceAssetStatus = (typeof DEVICE_ASSET_STATUS_VALUES)[number];

export const MAINTENANCE_TICKET_STATUS_VALUES = ["open", "assigned", "resolved", "closed", "cancelled"] as const;
export type MaintenanceTicketStatus = (typeof MAINTENANCE_TICKET_STATUS_VALUES)[number];

export const MAINTENANCE_TICKET_PRIORITY_VALUES = ["low", "normal", "high", "urgent"] as const;
export type MaintenanceTicketPriority = (typeof MAINTENANCE_TICKET_PRIORITY_VALUES)[number];

export const DEVICE_ASSET_STATUS_LABELS: Record<DeviceAssetStatus, string> = {
  active: "运行中",
  maintenance: "维护中",
  disabled: "停用",
  retired: "已退役",
};

export const MAINTENANCE_TICKET_STATUS_LABELS: Record<MaintenanceTicketStatus, string> = {
  open: "待处理",
  assigned: "已派单",
  resolved: "已解决",
  closed: "已关闭",
  cancelled: "已取消",
};

export const MAINTENANCE_TICKET_PRIORITY_LABELS: Record<MaintenanceTicketPriority, string> = {
  low: "低",
  normal: "普通",
  high: "高",
  urgent: "紧急",
};

export type DeviceAsset = {
  id: string;
  organizationId: string;
  name: string;
  code: string;
  category: string;
  location: string;
  status: DeviceAssetStatus;
  lastInspectedAt?: string;
  notes: string;
  createdAt: string;
  updatedAt: string;
};

export type MaintenanceTicket = {
  id: string;
  organizationId: string;
  deviceId?: string;
  deviceName: string;
  title: string;
  description: string;
  priority: MaintenanceTicketPriority;
  status: MaintenanceTicketStatus;
  assigneeLabel: string;
  resolutionNotes: string;
  resolvedAt?: string;
  createdAt: string;
  updatedAt: string;
};

export type DeviceOperationsData = {
  metrics: {
    activeDevices: number;
    maintenanceDevices: number;
    openTickets: number;
    urgentTickets: number;
  };
  devices: DeviceAsset[];
  tickets: MaintenanceTicket[];
};

export type DeviceAssetInput = {
  name: string;
  code: string;
  category: string;
  location: string;
  status: DeviceAssetStatus;
  lastInspectedAt?: string;
  notes: string;
};

export type MaintenanceTicketInput = {
  deviceId?: string;
  title: string;
  description: string;
  priority: MaintenanceTicketPriority;
  status: MaintenanceTicketStatus;
  assigneeLabel: string;
  resolutionNotes: string;
};

type ValidationSuccess<T> = {
  success: true;
  data: T;
};

type ValidationFailure = {
  success: false;
  reason: string;
};

export type ValidationResult<T> = ValidationSuccess<T> | ValidationFailure;

function isRecord(value: unknown): value is Record<string, unknown> {
  return typeof value === "object" && value !== null && !Array.isArray(value);
}

function readString(source: Record<string, unknown>, key: string): string {
  const value = source[key];
  return typeof value === "string" ? value.trim() : "";
}

function readOptionalString(source: Record<string, unknown>, key: string): string | undefined {
  const value = readString(source, key);
  return value || undefined;
}

function readEnum<T extends string>(value: unknown, values: readonly T[]): T | null {
  return typeof value === "string" ? values.find((item) => item === value) ?? null : null;
}

function validateIsoDate(value: string | undefined, label: string): ValidationResult<string | undefined> {
  if (!value) {
    return { success: true, data: undefined };
  }

  return Number.isNaN(new Date(value).getTime())
    ? { success: false, reason: `${label}无效` }
    : { success: true, data: value };
}

export function validateDeviceAssetInput(value: unknown): ValidationResult<DeviceAssetInput> {
  if (!isRecord(value)) {
    return { success: false, reason: "请求数据格式无效" };
  }

  const name = readString(value, "name");
  const code = readString(value, "code");
  if (!name || !code) {
    return { success: false, reason: "设备名称和编号不能为空" };
  }

  const status = readEnum(value.status, DEVICE_ASSET_STATUS_VALUES);
  if (!status) {
    return { success: false, reason: "设备状态无效" };
  }

  const lastInspectedAt = validateIsoDate(readOptionalString(value, "lastInspectedAt"), "最近巡检时间");
  if (!lastInspectedAt.success) {
    return lastInspectedAt;
  }

  return {
    success: true,
    data: {
      name,
      code,
      category: readString(value, "category"),
      location: readString(value, "location"),
      status,
      lastInspectedAt: lastInspectedAt.data,
      notes: readString(value, "notes"),
    },
  };
}

export function validateMaintenanceTicketInput(value: unknown): ValidationResult<MaintenanceTicketInput> {
  if (!isRecord(value)) {
    return { success: false, reason: "请求数据格式无效" };
  }

  const title = readString(value, "title");
  if (!title) {
    return { success: false, reason: "工单标题不能为空" };
  }

  const priority = readEnum(value.priority, MAINTENANCE_TICKET_PRIORITY_VALUES);
  if (!priority) {
    return { success: false, reason: "工单优先级无效" };
  }

  const status = readEnum(value.status, MAINTENANCE_TICKET_STATUS_VALUES);
  if (!status) {
    return { success: false, reason: "工单状态无效" };
  }

  return {
    success: true,
    data: {
      deviceId: readOptionalString(value, "deviceId"),
      title,
      description: readString(value, "description"),
      priority,
      status,
      assigneeLabel: readString(value, "assigneeLabel"),
      resolutionNotes: readString(value, "resolutionNotes"),
    },
  };
}