import { Injectable, Logger } from '@nestjs/common';
import { Cron } from '@nestjs/schedule';
import { PrismaService } from '../../prisma/prisma.service';
import { TahesabPersonLinkService } from './person-link.service';

/** ساعت و تاریخ امروز به وقت تهران، برای نوبت یک‌بار در هر ساعت. */
export function tehranSyncSlot(now = new Date()): { hour: number; slot: string } {
  const parts = new Intl.DateTimeFormat('en-GB', {
    timeZone: 'Asia/Tehran',
    year: 'numeric',
    month: '2-digit',
    day: '2-digit',
    hour: '2-digit',
    hourCycle: 'h23',
  }).formatToParts(now);
  const read = (type: Intl.DateTimeFormatPartTypes) =>
    parts.find((part) => part.type === type)?.value ?? '';
  let hour = Number(read('hour'));
  if (!Number.isFinite(hour) || hour === 24) hour = 0;
  const slot = `${read('year')}-${read('month')}-${read('day')}-${String(hour).padStart(2, '0')}`;
  return { hour, slot };
}

@Injectable()
export class TahesabCustomerSyncScheduler {
  private readonly logger = new Logger(TahesabCustomerSyncScheduler.name);
  private busy = false;

  constructor(
    private readonly prisma: PrismaService,
    private readonly links: TahesabPersonLinkService,
  ) {}

  @Cron('* * * * *', { timeZone: 'Asia/Tehran' })
  async tick() {
    if (process.env.NODE_ENV === 'test' || this.busy) return;
    this.busy = true;
    try {
      const { hour, slot } = tehranSyncSlot();
      const connections = await this.prisma.accountingConnection.findMany({
        where: {
          provider: 'tahesab',
          enabled: true,
          customerSyncHours: { has: hour },
        },
        select: { id: true, organizationId: true, label: true, customerSyncLastSlot: true },
      });
      for (const connection of connections) {
        if (connection.customerSyncLastSlot === slot) continue;
        const claimed = await this.prisma.accountingConnection.updateMany({
          where: {
            id: connection.id,
            OR: [
              { customerSyncLastSlot: null },
              { customerSyncLastSlot: { not: slot } },
            ],
          },
          data: { customerSyncLastSlot: slot },
        });
        if (claimed.count !== 1) continue;
        await this.run(connection.organizationId, connection.id, connection.label);
      }
    } catch (err) {
      this.logger.warn(
        `بررسی زمان‌بندی مشتریان ته‌حساب ناموفق بود: ${
          err instanceof Error ? err.message : err
        }`,
      );
    } finally {
      this.busy = false;
    }
  }

  private async run(organizationId: string, connectionId: string, label: string) {
    try {
      const result = await this.links.syncAllCustomers(organizationId, connectionId);
      await this.prisma.accountingConnection.update({
        where: { id: connectionId },
        data: {
          customerSyncLastRunAt: new Date(),
          customerSyncLastSummary: result.summary,
          customerSyncLastError: result.error,
        },
      });
      this.logger.log(`بروزرسانی خودکار «${label}»: ${result.summary}`);
    } catch (err) {
      const message = (err instanceof Error ? err.message : 'همگام‌سازی ناموفق بود').slice(0, 500);
      await this.prisma.accountingConnection.update({
        where: { id: connectionId },
        data: {
          customerSyncLastRunAt: new Date(),
          customerSyncLastSummary: null,
          customerSyncLastError: message,
        },
      });
      this.logger.warn(`بروزرسانی خودکار «${label}» ناموفق بود: ${message}`);
    }
  }
}