import {
  BadRequestException,
  Injectable,
  NotFoundException,
} from '@nestjs/common';
import { Prisma, SmsAccount } from '@prisma/client';
import { PrismaService } from '../prisma/prisma.service';
import { AuditService } from '../audit/audit.service';
import { ChargeSmsWalletDto, UpdateSmsAccountDto } from './dto/sms-account.dto';

type BalanceLevel = 'healthy' | 'warning' | 'critical' | 'unknown';

@Injectable()
export class SmsService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly audit: AuditService,
  ) {}

  async listTenants() {
    await this.ensureAccountsForAllTenants();

    const rows = await this.prisma.tenant.findMany({
      where: { isActive: true },
      orderBy: [{ product: 'asc' }, { nameFa: 'asc' }],
      include: { smsAccount: true },
    });

    return rows.map((tenant) => {
      const account = tenant.smsAccount!;
      return {
        id: tenant.id,
        product: tenant.product,
        slug: tenant.slug,
        nameFa: tenant.nameFa,
        nameEn: tenant.nameEn,
        domain: tenant.domain,
        avatarUrl: tenant.avatarUrl,
        isActive: tenant.isActive,
        isBlocked: account.isBlocked,
        sms: this.toSummary(account),
      };
    });
  }

  async getLowestBalances(limit = 5) {
    const rows = await this.listTenants();
    return [...rows]
      .sort((a, b) => a.sms.balanceRials - b.sms.balanceRials)
      .slice(0, limit);
  }

  async getAccount(tenantId: string) {
    const tenant = await this.requireTenant(tenantId);
    const account = await this.ensureAccount(tenant.id);
    const ledgers = await this.prisma.smsLedger.findMany({
      where: { smsAccountId: account.id },
      orderBy: { createdAt: 'desc' },
      take: 20,
    });

    return {
      tenant: {
        id: tenant.id,
        product: tenant.product,
        slug: tenant.slug,
        nameFa: tenant.nameFa,
        nameEn: tenant.nameEn,
        domain: tenant.domain,
        avatarUrl: tenant.avatarUrl,
      },
      account: {
        id: account.id,
        balanceRials: account.balanceRials,
        pricePerPartRials: account.pricePerPartRials,
        isBlocked: account.isBlocked,
        alertCriticalRials: account.alertCriticalRials,
        alertWarningRials: account.alertWarningRials,
        gatewayProvider: account.gatewayProvider,
        melipayamakUser: account.melipayamakUser,
        melipayamakPassword: account.melipayamakPassword,
        melipayamakFrom: account.melipayamakFrom,
        panelUsername: account.panelUsername,
        panelPassword: account.panelPassword,
        panelFrom: account.panelFrom,
        extraSettings: (account.extraSettings as Record<string, string>) || {},
        todayMessages: account.todayMessages,
        todayParts: account.todayParts,
        todayCostRials: account.todayCostRials,
        monthMessages: account.monthMessages,
        monthParts: account.monthParts,
        monthCostRials: account.monthCostRials,
      },
      summary: this.toSummary(account),
      ledgers,
      safeNote:
        'این پنل متعلق به سوپرادمین است و فعلاً پنل پیامکی داخل همکار/خانگی را تغییر نمی‌دهد.',
    };
  }

  async updateAccount(tenantId: string, dto: UpdateSmsAccountDto, userId?: string) {
    const account = await this.ensureAccount(tenantId);
    const before = { ...account };

    if (
      dto.alertCriticalRials != null &&
      dto.alertWarningRials != null &&
      dto.alertCriticalRials > dto.alertWarningRials
    ) {
      throw new BadRequestException('آستانه قرمز نباید از آستانه زرد بزرگ‌تر باشد');
    }

    const updated = await this.prisma.smsAccount.update({
      where: { id: account.id },
      data: {
        pricePerPartRials: dto.pricePerPartRials ?? undefined,
        isBlocked: dto.isBlocked ?? undefined,
        alertCriticalRials: dto.alertCriticalRials ?? undefined,
        alertWarningRials: dto.alertWarningRials ?? undefined,
        gatewayProvider: dto.gatewayProvider ?? undefined,
        melipayamakUser: dto.melipayamakUser ?? undefined,
        melipayamakPassword: dto.melipayamakPassword ?? undefined,
        melipayamakFrom: dto.melipayamakFrom ?? undefined,
        panelUsername: dto.panelUsername ?? undefined,
        panelPassword: dto.panelPassword ?? undefined,
        panelFrom: dto.panelFrom ?? undefined,
        extraSettings:
          dto.extraSettings === undefined
            ? undefined
            : (dto.extraSettings as Prisma.InputJsonValue),
      },
    });

    await this.audit.log({
      action: 'sms.account.update',
      entityType: 'sms_account',
      entityId: updated.id,
      tenantId,
      userId,
      before: this.publicAccount(before) as unknown as Prisma.InputJsonValue,
      after: this.publicAccount(updated) as unknown as Prisma.InputJsonValue,
    });

    return this.getAccount(tenantId);
  }

  async chargeWallet(tenantId: string, dto: ChargeSmsWalletDto, userId?: string) {
    if (!dto.amountRials || dto.amountRials === 0) {
      throw new BadRequestException('مبلغ شارژ نامعتبر است');
    }

    const account = await this.ensureAccount(tenantId);
    const nextBalance = account.balanceRials + dto.amountRials;
    if (nextBalance < 0) {
      throw new BadRequestException('موجودی نمی‌تواند منفی شود');
    }

    const type = dto.amountRials > 0 ? 'charge' : 'adjust';

    const [updated] = await this.prisma.$transaction([
      this.prisma.smsAccount.update({
        where: { id: account.id },
        data: { balanceRials: nextBalance },
      }),
      this.prisma.smsLedger.create({
        data: {
          smsAccountId: account.id,
          type,
          amountRials: dto.amountRials,
          note: dto.note || (dto.amountRials > 0 ? 'شارژ کیف پول' : 'اصلاح موجودی'),
          createdById: userId,
        },
      }),
    ]);

    await this.audit.log({
      action: 'sms.wallet.charge',
      entityType: 'sms_account',
      entityId: account.id,
      tenantId,
      userId,
      after: {
        amountRials: dto.amountRials,
        balanceRials: updated.balanceRials,
        note: dto.note || null,
      } as unknown as Prisma.InputJsonValue,
    });

    return this.getAccount(tenantId);
  }

  async setBlocked(tenantId: string, isBlocked: boolean, userId?: string) {
    return this.updateAccount(tenantId, { isBlocked }, userId);
  }

  private async ensureAccountsForAllTenants() {
    const tenants = await this.prisma.tenant.findMany({
      where: { smsAccount: null },
      select: { id: true },
    });
    for (const tenant of tenants) {
      await this.ensureAccount(tenant.id);
    }
  }

  private async ensureAccount(tenantId: string) {
    await this.requireTenant(tenantId);
    const existing = await this.prisma.smsAccount.findUnique({ where: { tenantId } });
    if (existing) return existing;

    // Seed varied demo balances so color cards are visible until real charges exist
    const demoBalances = [250000, 85000, 7500, 150000, 12000, 3000, 500000, 45000];
    const hash = [...tenantId].reduce((sum, ch) => sum + ch.charCodeAt(0), 0);
    const balanceRials = demoBalances[hash % demoBalances.length];

    return this.prisma.smsAccount.create({
      data: {
        tenantId,
        balanceRials,
        pricePerPartRials: 2500,
        alertCriticalRials: 10000,
        alertWarningRials: 100000,
      },
    });
  }

  private toSummary(account: SmsAccount) {
    const level = this.balanceLevel(
      account.balanceRials,
      account.alertCriticalRials,
      account.alertWarningRials,
    );
    return {
      balanceRials: account.balanceRials,
      balanceLabel: this.formatMoney(account.balanceRials),
      balanceLevel: level,
      perPartRials: account.pricePerPartRials,
      todayMessages: account.todayMessages,
      todayParts: account.todayParts,
      todayCostRials: account.todayCostRials,
      monthMessages: account.monthMessages,
      monthParts: account.monthParts,
      monthCostRials: account.monthCostRials,
      isBlocked: account.isBlocked,
      alertCriticalRials: account.alertCriticalRials,
      alertWarningRials: account.alertWarningRials,
    };
  }

  private balanceLevel(
    balanceRials: number,
    critical = 10000,
    warning = 100000,
  ): BalanceLevel {
    if (balanceRials < critical) return 'critical';
    if (balanceRials <= warning) return 'warning';
    return 'healthy';
  }

  private formatMoney(value: number) {
    return `${new Intl.NumberFormat('fa-IR').format(value)} ریال`;
  }

  private publicAccount(account: SmsAccount) {
    return {
      balanceRials: account.balanceRials,
      pricePerPartRials: account.pricePerPartRials,
      isBlocked: account.isBlocked,
      alertCriticalRials: account.alertCriticalRials,
      alertWarningRials: account.alertWarningRials,
      gatewayProvider: account.gatewayProvider,
      melipayamakUser: account.melipayamakUser,
      melipayamakFrom: account.melipayamakFrom,
      panelUsername: account.panelUsername,
      panelFrom: account.panelFrom,
    };
  }

  private async requireTenant(tenantId: string) {
    const tenant = await this.prisma.tenant.findUnique({ where: { id: tenantId } });
    if (!tenant) throw new NotFoundException('نسخه یافت نشد');
    return tenant;
  }
}