import { BadRequestException } from '@nestjs/common';
import { randomUUID } from 'node:crypto';
import type { CreateSmsApplicationDto } from './sms-config.contracts';

/** Pure normalization and report-value helpers shared by the R3 domain services. */
export const APPLICATION_QUEUE_PRIORITIES = ['normal', 'priority'] as const;
export type ApplicationQueuePriority = (typeof APPLICATION_QUEUE_PRIORITIES)[number];
export const APPLICATION_INTERFACE_TYPES = ['cmpp20'] as const;
export type ApplicationInterfaceType = (typeof APPLICATION_INTERFACE_TYPES)[number];
export const DEFAULT_DOWNSTREAM_HEARTBEAT_TIMEOUT_MS = 90_000;
export const APPLICATION_DISABLE_GRACE_MS = 72 * 60 * 60 * 1_000;
export const DEFAULT_APPLICATION_DISABLE_SCAN_INTERVAL_MS = 60_000;
export const UNRESOLVED_DOWNSTREAM_STATUSES = ['pending', 'awaiting_ack', 'failed', 'manual_requeueing'] as const;

export interface TemplateVariableInput {
  name: string;
  example?: string;
  required?: boolean;
}

export function normalizeApplicationPassword(value: string | undefined) {
  const password = value?.trim() || generateApplicationPassword();
  if (password.length !== 16) {
    throw new BadRequestException('passwordCipher must be 16 characters');
  }
  return password;
}

export function generateApplicationPassword() {
  return randomUUID().replace(/-/g, '').slice(0, 16);
}

export function estimateBillingUnits(content: string) {
  const length = [...content].length;
  if (length <= 70) {
    return 1;
  }
  return Math.ceil(length / 67);
}

export function inferTemplateVariables(content: string): TemplateVariableInput[] {
  const matches = content.match(/\$\{[a-zA-Z0-9_]+\}/g) ?? [];
  return [...new Set(matches)].map((match) => ({ name: match.slice(2, -1), required: true }));
}

export function validateAndNormalizeTemplateVariables(
  content: string,
  supplied?: Array<{ name: string; example?: string; required?: boolean }>,
): TemplateVariableInput[] {
  const names: string[] = [];
  let cursor = 0;
  while (true) {
    const start = content.indexOf('${', cursor);
    if (start < 0) break;
    const end = content.indexOf('}', start + 2);
    if (end < 0) throw new BadRequestException('模板变量未闭合');
    const name = content.slice(start + 2, end);
    if (!/^[A-Za-z0-9]{1,32}$/.test(name)) {
      throw new BadRequestException('模板变量名仅允许英文字母和数字，长度1至32位');
    }
    if (names.includes(name)) throw new BadRequestException(`模板变量 ${name} 重复`);
    names.push(name);
    cursor = end + 1;
  }
  if (!supplied) return names.map((name) => ({ name, required: true }));
  const suppliedNames = supplied.map((item) => item.name);
  if (suppliedNames.some((name) => typeof name !== 'string' || !/^[A-Za-z0-9]{1,32}$/.test(name))) {
    throw new BadRequestException('变量配置中包含非法变量名');
  }
  if (new Set(suppliedNames).size !== suppliedNames.length) throw new BadRequestException('变量配置中包含重复变量');
  if (suppliedNames.length !== names.length || suppliedNames.some((name) => !names.includes(name))) {
    throw new BadRequestException('变量配置必须与模板正文中的占位符完全一致');
  }
  return supplied.map((item) => ({ ...item, name: item.name.trim() }));
}

export function normalizeSmsSignature(name: string) {
  const innerName = name
    .trim()
    .replace(/^[【[]+|[】\]]+$/g, '')
    .trim();
  return innerName ? `【${innerName}】` : '';
}

export function validateCompleteSmsSignature(name: string) {
  const value = name;
  if (/[\p{White_Space}\p{Cc}\p{Default_Ignorable_Code_Point}]/u.test(value)) {
    throw new BadRequestException('短信签名不能包含空格、换行或不可见字符');
  }
  const match = value.match(/^【([^【】]+)】$/);
  if (!match) {
    throw new BadRequestException('短信签名必须包含完整中文黑括号，例如：【某某科技】');
  }
  return value;
}

export function startOfToday() {
  const date = new Date();
  date.setHours(0, 0, 0, 0);
  return date;
}

export function normalizeApplicationQueuePriority(value?: string): ApplicationQueuePriority {
  const queuePriority = value ?? 'normal';
  if (!APPLICATION_QUEUE_PRIORITIES.includes(queuePriority as ApplicationQueuePriority)) {
    throw new BadRequestException('queuePriority must be normal or priority');
  }
  return queuePriority as ApplicationQueuePriority;
}

export function normalizeApplicationInterfaceType(value?: string): ApplicationInterfaceType {
  const interfaceType = value ?? 'cmpp20';
  if (!APPLICATION_INTERFACE_TYPES.includes(interfaceType as ApplicationInterfaceType)) {
    throw new BadRequestException('interfaceType only supports cmpp20; HTTP interface is not available yet');
  }
  return interfaceType as ApplicationInterfaceType;
}

export function normalizeCmppAccessNumberConfig(
  data: Pick<
    CreateSmsApplicationDto,
    'cmppApplicationExtension' | 'cmppAccessNumberFillEnabled' | 'cmppAccessNumberFillPrefix'
  >,
  current?: {
    cmppApplicationExtension?: string | null;
    cmppAccessNumberFillEnabled?: boolean | null;
    cmppAccessNumberFillPrefix?: string | null;
  },
) {
  const applicationExtension =
    (data.cmppApplicationExtension === undefined
      ? current?.cmppApplicationExtension
      : data.cmppApplicationExtension
    )?.trim() || null;
  const fillEnabled = data.cmppAccessNumberFillEnabled ?? current?.cmppAccessNumberFillEnabled ?? false;
  const configuredPrefix =
    (data.cmppAccessNumberFillPrefix === undefined
      ? current?.cmppAccessNumberFillPrefix
      : data.cmppAccessNumberFillPrefix
    )?.trim() || null;

  if (applicationExtension && !/^\d+$/.test(applicationExtension)) {
    throw new BadRequestException('cmppApplicationExtension must contain digits only');
  }
  if (applicationExtension && applicationExtension.length > 21) {
    throw new BadRequestException('cmppApplicationExtension must not exceed 21 digits');
  }
  if (fillEnabled && !applicationExtension) {
    throw new BadRequestException('cmppApplicationExtension is required when access number filling is enabled');
  }
  if (fillEnabled && !configuredPrefix) {
    throw new BadRequestException('cmppAccessNumberFillPrefix is required when access number filling is enabled');
  }
  if (configuredPrefix && !/^\d+$/.test(configuredPrefix)) {
    throw new BadRequestException('cmppAccessNumberFillPrefix must contain digits only');
  }

  const fillPrefix = fillEnabled ? configuredPrefix : null;
  const clientSrcId = applicationExtension ? `${fillPrefix ?? ''}${applicationExtension}` : null;
  if (clientSrcId && clientSrcId.length > 21) {
    throw new BadRequestException('client CMPP Src_Id must not exceed 21 digits');
  }
  return { applicationExtension, fillEnabled, fillPrefix, clientSrcId };
}

export function getPositiveInteger(value: number | undefined, fallback: number, fieldName: string) {
  if (value === undefined || value === null) {
    return fallback;
  }
  const normalized = Number(value);
  if (!Number.isInteger(normalized) || normalized <= 0) {
    throw new BadRequestException(`${fieldName} must be a positive integer`);
  }
  return normalized;
}

export function normalizeApplicationCmppStatus(connections: Array<{ status: string }>, applicationStatus: string) {
  if (!['active', 'disabling'].includes(applicationStatus)) {
    return 'inactive';
  }
  if (connections.some((connection) => connection.status === 'connected')) {
    return 'connected';
  }
  if (
    connections.some((connection) => ['auth_failed', 'heartbeat_timeout', 'reconnecting'].includes(connection.status))
  ) {
    return 'degraded';
  }
  return 'disconnected';
}

export function getPositiveIntegerEnv(name: string, fallback: number) {
  const value = Number(process.env[name] ?? fallback);
  return Number.isInteger(value) && value > 0 ? value : fallback;
}

export function parseGatewayDate(value?: string) {
  if (!value) return undefined;
  const parsed = new Date(value);
  return Number.isNaN(parsed.getTime()) ? undefined : parsed;
}

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

export function reportValueParts(value: unknown) {
  if (isRecord(value) && typeof value.fileObjectId === 'string') {
    return {
      fieldValue: typeof value.fileName === 'string' ? value.fileName : undefined,
      fileObjectId: value.fileObjectId,
    };
  }
  return { fieldValue: value === undefined || value === null ? undefined : String(value), fileObjectId: undefined };
}

export function hasReportValue(value: unknown) {
  if (isRecord(value)) {
    return Boolean(value.fileObjectId || value.fieldValue || value.value);
  }
  return value !== undefined && value !== null && String(value).trim().length > 0;
}