import { BadRequestException, HttpException, HttpStatus, Logger, NotFoundException } from '@nestjs/common';
import { Prisma } from '@prisma/client';
import { Queue, Worker } from 'bullmq';
import IORedis from 'ioredis';
import { createHash, randomUUID } from 'node:crypto';
import { setTimeout as sleep } from 'node:timers/promises';
import { BillingService } from '../billing/billing.service';
import { isIpAllowed } from '../common/ip-allowlist';
import { moneyToNumber } from '../common/money';
import { PhoneRoutingLookupService } from '../dictionaries/phone-routing-lookup.service';
import { PrismaService } from '../prisma/prisma.service';
import { RiskReviewService } from '../risk-review/risk-review.service';
import { PhoneFrequencyService } from '../risk-review/phone-frequency.service';
import type { CreateBatchTaskDto, CreateHttpBatchTaskDto, GatewayInboundAuthDto, GatewayInboundSubmitDto, GatewayInboundSingleSubmitResult, ImportPreviewDto, ConfirmImportDto, SendJob, QueuePriority, RoutedChannel } from './send-chain.contracts';
import { SEND_QUEUE, GATEWAY_SUBMIT_QUEUE, GATEWAY_SUBMIT_STREAM, DEFAULT_SCHEDULED_DISPATCH_STALE_MS, DEFAULT_INBOUND_LONG_MESSAGE_PROCESSING_STALE_SECONDS, GATEWAY_SUBMIT_REQUEUE_IDEMPOTENCY_TTL_SECONDS, BULLMQ_PRIORITY, drainageRejectionReason, statusFromRisk, parseSchedule, parseImportRows, splitImportLine, cellByHeader, normalizeCarrier, normalizeQueuePriority, getPositiveConfigInteger, getNonNegativeConfigInteger, isCarrierCompatible, matchTemplateContent, isNationalChannel, validateInboundApplicationSrcId, composeUpstreamSrcId, positiveInteger, parseOptionalSequenceId, shanghaiDateKey, bullmqConnection, matchesApplicationSecret, octetString, selectChannelCandidate } from './send-chain.helpers';
import type { SendSubmissionCallbacks, SendSubmissionService } from './send-submission.service';

/**
 * R9 scheduledDispatch implementation. Cross-method calls return through the stable SendChainService seam.
 */
export class SendScheduledDispatchService {
  private readonly logger = new Logger('SendChainService');
  private scheduledDispatchScanRunning = false;

  constructor(
    private readonly prisma: PrismaService,
    private readonly billing: BillingService,
    private readonly riskReview: RiskReviewService,
    private readonly phoneFrequency: PhoneFrequencyService,
    private readonly phoneRouting: PhoneRoutingLookupService,
    private readonly facade: SendSubmissionService,
    private readonly callbacks: SendSubmissionCallbacks,
  ) {}

  private releaseMessageReservation(
    message: { tenantId: string; batchTaskId: string; messageId: string; amountCents: number | bigint; billingUnits: number },
    remark: string,
  ) {
    return this.callbacks.releaseMessageReservation(message, remark);
  }

  private recordCmppFailureReceipt(
    message: {
      id: string;
      tenantId?: string | null;
      batchTaskId?: string | null;
      applicationId?: string | null;
      messageId: string;
      phoneNumber: string;
      cmppSubmitSequenceId?: string | null;
      cmppSubmitGroupMessageId?: string | null;
    },
    errorCode: string,
    reason: string,
  ) {
    return this.callbacks.recordCmppFailureReceipt(message, errorCode, reason);
  }


async dispatchDueScheduledTasks(now = new Date()) {
    const staleCutoff = new Date(now.getTime() - positiveInteger(
      process.env.SMS_SCHEDULED_DISPATCH_STALE_MS,
      DEFAULT_SCHEDULED_DISPATCH_STALE_MS,
    ));
    const tasks = await this.prisma.smsBatchTask.findMany({
      where: {
        OR: [
          { status: 'scheduled', scheduledAt: { lte: now } },
          { status: { in: ['scheduled_dispatching', 'scheduled_recovering'] }, updatedAt: { lt: staleCutoff } },
        ],
      },
      orderBy: { scheduledAt: 'asc' },
    });
    const results: Array<{ taskId: string; status: string; enqueued?: number; reason?: string }> = [];
    for (const task of tasks) {
      const candidateStatus = task.status || 'scheduled';
      const claimedStatus = candidateStatus === 'scheduled_dispatching' ? 'scheduled_recovering' : 'scheduled_dispatching';
      const claimed = await this.prisma.smsBatchTask.updateMany({
        where: {
          id: task.id,
          status: candidateStatus,
          ...(candidateStatus === 'scheduled' ? {} : { updatedAt: { lt: staleCutoff } }),
        },
        data: { status: claimedStatus },
      });
      if (claimed.count !== 1) continue;
      let reservationEstablished = false;
      let dispatchPrepared = false;
      try {
        await this.facade.validateSendResources(
          task.tenantId,
          task.applicationId ?? undefined,
          task.templateId ?? undefined,
          { usePersistedTemplateSnapshot: true },
        );
        const messages = await this.prisma.smsMessageRecord.findMany({
          where: { batchTaskId: task.id, status: { in: ['scheduled', 'queued'] } },
          select: { id: true, amountCents: true, billingUnits: true },
          take: 100000,
        });
        const amountCents = messages.reduce((sum, message) => sum + moneyToNumber(message.amountCents), 0);
        const existingReservation = await this.prisma.accountTransaction.findFirst({
          where: { tenantId: task.tenantId, transactionType: 'frozen', relatedType: 'sms_batch_task', relatedId: task.id },
          select: { id: true },
        });
        reservationEstablished = Boolean(existingReservation);
        if (!reservationEstablished) {
          const accountCheck = await this.billing.checkAccount({ tenantId: task.tenantId, amountCents });
          if (!accountCheck.canSend) {
            throw new BadRequestException('定时任务到点时企业账户余额不足');
          }
          if (amountCents > 0) {
            await this.billing.freeze({
              tenantId: task.tenantId,
              amountCents,
              relatedType: 'sms_batch_task',
              relatedId: task.id,
              remark: '定时任务到点冻结',
            });
            reservationEstablished = true;
          }
        }
        dispatchPrepared = true;
        await this.prisma.smsMessageRecord.updateMany({
          where: { batchTaskId: task.id, status: 'scheduled' },
          data: { status: 'queued' },
        });
        const enqueued = await this.facade.enqueueBatchTask(task.id);
        results.push({ taskId: task.id, status: 'queued', enqueued: enqueued.enqueued });
      } catch (error) {
        const reason = error instanceof Error ? error.message : '定时任务到点执行失败';
        if (reservationEstablished || dispatchPrepared) {
          await this.prisma.smsBatchTask.update({
            where: { id: task.id },
            data: { status: claimedStatus, rejectReason: `调度将在超时后恢复：${reason}` },
          });
          results.push({ taskId: task.id, status: 'retrying', reason });
          continue;
        }
        await this.prisma.smsMessageRecord.updateMany({
          where: { batchTaskId: task.id, status: 'scheduled' },
          data: { status: 'rejected', errorMessage: reason },
        });
        await this.prisma.smsBatchTask.update({
          where: { id: task.id },
          data: { status: 'failed', rejectReason: reason },
        });
        results.push({ taskId: task.id, status: 'failed', reason });
      }
    }
    return { dispatched: results.filter((result) => result.status === 'queued').length, results };
  }

async runScheduledDispatchScan() {
    if (this.scheduledDispatchScanRunning) return;
    this.scheduledDispatchScanRunning = true;
    try {
      await this.facade.dispatchDueScheduledTasks();
    } catch (error) {
      this.logger.error(`Scheduled SMS dispatch scan failed: ${error instanceof Error ? error.message : String(error)}`);
    } finally {
      this.scheduledDispatchScanRunning = false;
    }
  }
}