import type { GenerationCapability, GenerationProvider } from "@/lib/types";

export const USAGE_TIME_ZONE = "Asia/Shanghai";
export const UNASSIGNED_ORGANIZATION_ID = "__unassigned__";

export type UsagePreset = "today" | "7d" | "30d" | "month";

export type UsageDateRange = {
  from: string;
  to: string;
  startDate: string;
  endDate: string;
  label: string;
  dayCount: number;
};

export type UsageCountItem = {
  key: string;
  label: string;
  count: number;
};

export type UsageRecordView = {
  id: string;
  jobId: string;
  ownerId: string;
  accountName: string;
  accountUsername?: string;
  organizationId: string;
  organizationName: string;
  capability: GenerationCapability;
  capabilityLabel: string;
  provider?: GenerationProvider;
  providerLabel: string;
  reqKey?: string;
  createdAt: string;
};

export type PersonalUsageReport = {
  preset: UsagePreset;
  range: UsageDateRange;
  total: number;
  byCapability: UsageCountItem[];
  recent: UsageRecordView[];
};

export type UsageTrendPoint = {
  date: string;
  label: string;
  count: number;
};

export type UsageOrganizationRow = {
  organizationId: string;
  organizationName: string;
  count: number;
  accountCount: number;
  lastUsedAt?: string;
};

export type UsageAccountRow = {
  ownerId: string;
  accountName: string;
  accountUsername?: string;
  organizationId: string;
  organizationName: string;
  count: number;
  lastUsedAt?: string;
};

export type UsageFilterOption = {
  value: string;
  label: string;
};

export type AdminUsageReport = {
  range: UsageDateRange;
  summary: {
    total: number;
    activeAccounts: number;
    activeOrganizations: number;
    averagePerDay: number;
  };
  trend: UsageTrendPoint[];
  byCapability: UsageCountItem[];
  byProvider: UsageCountItem[];
  organizations: UsageOrganizationRow[];
  accounts: UsageAccountRow[];
  recent: UsageRecordView[];
  options: {
    organizations: UsageFilterOption[];
    accounts: UsageFilterOption[];
    capabilities: UsageFilterOption[];
    providers: UsageFilterOption[];
  };
  warnings?: string[];
};

export const USAGE_PRESET_OPTIONS: Array<{ value: UsagePreset; label: string }> = [
  { value: "today", label: "今天" },
  { value: "7d", label: "近 7 天" },
  { value: "30d", label: "近 30 天" },
  { value: "month", label: "本月" }
];

export const CAPABILITY_OPTIONS: Array<{ value: GenerationCapability; label: string }> = [
  { value: "image.generate", label: "图片生成" },
  { value: "video.generate", label: "视频生成" }
];

export function capabilityLabel(capability: GenerationCapability): string {
  return CAPABILITY_OPTIONS.find((item) => item.value === capability)?.label || capability;
}

export function providerLabel(provider?: GenerationProvider): string {
  if (provider === "volcengine-visual") return "即梦图片";
  if (provider === "evolink") return "EvoLink";
  if (provider === "seedance") return "Seedance";
  if (provider === "seedream") return "Seedream 5.0 Pro";
  if (provider === "bailian") return "阿里云百炼";
  if (provider === "mock") return "历史任务";
  return "未知服务商";
}

export function usagePresetRange(preset: UsagePreset, now = new Date()): UsageDateRange {
  const today = dateKeyInChina(now);
  let startDate = today;
  if (preset === "7d") startDate = shiftDateKey(today, -6);
  if (preset === "30d") startDate = shiftDateKey(today, -29);
  if (preset === "month") startDate = `${today.slice(0, 7)}-01`;
  return usageDateRange(startDate, today, USAGE_PRESET_OPTIONS.find((item) => item.value === preset)?.label);
}

export function usageDateRange(startDate: string, endDate: string, label?: string): UsageDateRange {
  if (!isDateKey(startDate) || !isDateKey(endDate)) throw badDateRange("日期格式必须为 YYYY-MM-DD。");
  if (startDate > endDate) throw badDateRange("开始日期不能晚于结束日期。");
  const dayCount = daysBetween(startDate, endDate) + 1;
  if (dayCount > 3660) throw badDateRange("单次查询最多支持 10 年。");
  return {
    from: `${startDate}T00:00:00+08:00`,
    to: `${shiftDateKey(endDate, 1)}T00:00:00+08:00`,
    startDate,
    endDate,
    label: label || (startDate === endDate ? startDate : `${startDate} 至 ${endDate}`),
    dayCount
  };
}

export function usageDateKey(iso: string): string {
  return dateKeyInChina(new Date(iso));
}

export function shiftDateKey(date: string, days: number): string {
  const value = new Date(`${date}T00:00:00Z`);
  value.setUTCDate(value.getUTCDate() + days);
  return value.toISOString().slice(0, 10);
}

function dateKeyInChina(date: Date): string {
  const parts = new Intl.DateTimeFormat("en-CA", {
    timeZone: USAGE_TIME_ZONE,
    year: "numeric",
    month: "2-digit",
    day: "2-digit"
  }).formatToParts(date);
  const values = Object.fromEntries(parts.map((part) => [part.type, part.value]));
  return `${values.year}-${values.month}-${values.day}`;
}

function isDateKey(value: string): boolean {
  if (!/^\d{4}-\d{2}-\d{2}$/.test(value)) return false;
  return new Date(`${value}T00:00:00Z`).toISOString().slice(0, 10) === value;
}

function daysBetween(startDate: string, endDate: string): number {
  return Math.round((Date.parse(`${endDate}T00:00:00Z`) - Date.parse(`${startDate}T00:00:00Z`)) / 86_400_000);
}

function badDateRange(message: string): Error & { status: number } {
  return Object.assign(new Error(message), { status: 400 });
}