import {
  BadRequestException,
  Injectable,
  NotFoundException,
} from '@nestjs/common';
import { Prisma, SmsAccount, SmsLedgerType } from '@prisma/client';
import { PrismaService } from '../prisma/prisma.service';
import { AuditService } from '../audit/audit.service';
import { AdminNotifyService } from '../notifications/admin-notify.service';
import { iranYmd } from '../common/iran-time.util';
import {
  ChargeSmsWalletDto,
  SmsTableQueryDto,
  UpdateSmsAccountDto,
  UpdateSmsChargeInfoDto,
} from './dto/sms-account.dto';

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

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

  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.toSummaryQuick(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: this.publicAccount(account),
      chargeInfo: this.chargeInfoOf(account),
      summary: await this.toSummaryFromLogs(account),
      ledgers,
      safeNote:
        'این پنل متعلق به سوپرادمین است و فعلاً پنل پیامکی داخل همکار/خانگی را تغییر نمی‌دهد.',
    };
  }

  async getChargeInfo(tenantId: string) {
    const account = await this.ensureAccount(tenantId);
    return this.chargeInfoOf(account);
  }

  async updateChargeInfo(
    tenantId: string,
    dto: UpdateSmsChargeInfoDto,
    userId?: string,
  ) {
    const account = await this.ensureAccount(tenantId);
    const before = this.chargeInfoOf(account);
    const updated = await this.prisma.smsAccount.update({
      where: { id: account.id },
      data: {
        chargeCard: dto.chargeCard === undefined ? undefined : dto.chargeCard || null,
        chargeIban: dto.chargeIban === undefined ? undefined : dto.chargeIban || null,
        chargeHolder:
          dto.chargeHolder === undefined ? undefined : dto.chargeHolder || null,
        chargeInstruction:
          dto.chargeInstruction === undefined
            ? undefined
            : dto.chargeInstruction || null,
      },
    });

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

    return this.chargeInfoOf(updated);
  }

  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,
    });

    if (before.isBlocked !== updated.isBlocked) {
      const tenant = await this.requireTenant(tenantId);
      this.notify.notifyAdmins(
        updated.isBlocked
          ? `سوپرادمین: ارسال SMS نسخه «${tenant.nameFa}» مسدود شد.`
          : `سوپرادمین: مسدودسازی SMS نسخه «${tenant.nameFa}» برداشته شد.`,
      );
    }

    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: SmsLedgerType = 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,
          balanceAfterRials: nextBalance,
          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,
    });

    const tenant = await this.requireTenant(tenantId);
    const amountLabel = dto.amountRials.toLocaleString('fa-IR');
    this.notify.notifyAdmins(
      `سوپرادمین: کیف پول SMS «${tenant.nameFa}» ${dto.amountRials > 0 ? 'شارژ' : 'اصلاح'} شد (${amountLabel} ریال). موجودی: ${updated.balanceRials.toLocaleString('fa-IR')}`,
    );

    return this.getAccount(tenantId);
  }

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

  async getPeriodReport(tenantId: string, fromDate?: string, toDate?: string) {
    const account = await this.ensureAccount(tenantId);
    const range = this.resolveDateRange(fromDate, toDate, true);

    const logs = await this.prisma.smsSendLog.findMany({
      where: {
        smsAccountId: account.id,
        createdAt: { gte: range.from, lte: range.to },
      },
      select: {
        parts: true,
        totalAmountRials: true,
        provider: true,
      },
    });

    const byProviderMap = new Map<
      string,
      { provider: string; messages: number; parts: number; amount: number }
    >();
    let messages = 0;
    let parts = 0;
    let amount = 0;

    for (const row of logs) {
      messages += 1;
      parts += row.parts;
      amount += row.totalAmountRials;
      const key = row.provider || 'نامشخص';
      const cur = byProviderMap.get(key) || {
        provider: key,
        messages: 0,
        parts: 0,
        amount: 0,
      };
      cur.messages += 1;
      cur.parts += row.parts;
      cur.amount += row.totalAmountRials;
      byProviderMap.set(key, cur);
    }

    return {
      fromDate: iranYmd(range.from),
      toDate: iranYmd(range.to),
      balance: account.balanceRials,
      summary: { messages, parts, amount },
      byProvider: [...byProviderMap.values()].sort((a, b) => b.amount - a.amount),
    };
  }

  async getChargeReport(tenantId: string, fromDate?: string, toDate?: string) {
    const account = await this.ensureAccount(tenantId);
    const range = this.resolveDateRange(fromDate, toDate, false);

    const where: Prisma.SmsLedgerWhereInput = {
      smsAccountId: account.id,
      type: 'charge',
    };
    if (range) {
      where.createdAt = { gte: range.from, lte: range.to };
    }

    const items = await this.prisma.smsLedger.findMany({
      where,
      orderBy: { createdAt: 'desc' },
      take: 200,
    });

    return {
      fromDate: range ? iranYmd(range.from) : null,
      toDate: range ? iranYmd(range.to) : null,
      summary: {
        charges: items.length,
        amount: items.reduce((sum, row) => sum + row.amountRials, 0),
      },
      items: items.map((row) => ({
        id: row.id,
        amount: row.amountRials,
        balanceAfter: row.balanceAfterRials,
        note: row.note,
        createdBy: row.createdById,
        createdAt: row.createdAt,
      })),
    };
  }

  async getLogsTable(tenantId: string, dto: SmsTableQueryDto) {
    const account = await this.ensureAccount(tenantId);
    const page = dto.page || 1;
    const pageSize = dto.pageSize || 20;
    const range = this.resolveDateRange(dto.fromDate, dto.toDate, false);

    const where: Prisma.SmsSendLogWhereInput = {
      smsAccountId: account.id,
    };
    if (range) {
      where.createdAt = { gte: range.from, lte: range.to };
    }
    if (dto.search?.trim()) {
      const q = dto.search.trim();
      where.OR = [
        { receiver: { contains: q } },
        { body: { contains: q } },
        { provider: { contains: q } },
        { source: { contains: q } },
      ];
    }

    const [total, rows] = await this.prisma.$transaction([
      this.prisma.smsSendLog.count({ where }),
      this.prisma.smsSendLog.findMany({
        where,
        orderBy: { createdAt: 'desc' },
        skip: (page - 1) * pageSize,
        take: pageSize,
      }),
    ]);

    return {
      page,
      pageSize,
      total,
      rows: rows.map((row) => ({
        id: row.id,
        receiver: row.receiver,
        body: row.body,
        parts: row.parts,
        pricePerPart: row.pricePerPartRials,
        totalAmount: row.totalAmountRials,
        provider: row.provider,
        source: row.source,
        isAlert: row.isAlert,
        createdAt: row.createdAt,
      })),
    };
  }

  async getLedgerTable(tenantId: string, dto: SmsTableQueryDto) {
    const account = await this.ensureAccount(tenantId);
    const page = dto.page || 1;
    const pageSize = dto.pageSize || 20;
    const range = this.resolveDateRange(dto.fromDate, dto.toDate, false);

    const where: Prisma.SmsLedgerWhereInput = {
      smsAccountId: account.id,
    };
    if (range) {
      where.createdAt = { gte: range.from, lte: range.to };
    }
    if (dto.search?.trim()) {
      where.note = { contains: dto.search.trim() };
    }

    const [total, rows] = await this.prisma.$transaction([
      this.prisma.smsLedger.count({ where }),
      this.prisma.smsLedger.findMany({
        where,
        orderBy: { createdAt: 'desc' },
        skip: (page - 1) * pageSize,
        take: pageSize,
      }),
    ]);

    return {
      page,
      pageSize,
      total,
      rows: rows.map((row) => ({
        id: row.id,
        type: row.type,
        amount: row.amountRials,
        balanceAfter: row.balanceAfterRials,
        pricePerPart: null as number | null,
        parts: row.parts,
        note: row.note,
        createdBy: row.createdById,
        createdAt: row.createdAt,
      })),
    };
  }

  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;

    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 toSummaryQuick(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 async toSummaryFromLogs(account: SmsAccount) {
    const usage = await this.computeUsageStats(account.id);
    const base = this.toSummaryQuick(account);
    return {
      ...base,
      todayMessages: usage.today.messages,
      todayParts: usage.today.parts,
      todayCostRials: usage.today.amount,
      monthMessages: usage.month.messages,
      monthParts: usage.month.parts,
      monthCostRials: usage.month.amount,
    };
  }

  private async computeUsageStats(smsAccountId: string) {
    const todayYmd = iranYmd(new Date());
    const todayStart = new Date(`${todayYmd}T00:00:00+03:30`);
    const monthStartYmd = `${todayYmd.slice(0, 8)}01`;
    const monthStart = new Date(`${monthStartYmd}T00:00:00+03:30`);
    const now = new Date();

    const [todayLogs, monthLogs] = await Promise.all([
      this.prisma.smsSendLog.findMany({
        where: { smsAccountId, createdAt: { gte: todayStart, lte: now } },
        select: { parts: true, totalAmountRials: true },
      }),
      this.prisma.smsSendLog.findMany({
        where: { smsAccountId, createdAt: { gte: monthStart, lte: now } },
        select: { parts: true, totalAmountRials: true },
      }),
    ]);

    const fold = (rows: { parts: number; totalAmountRials: number }[]) => ({
      messages: rows.length,
      parts: rows.reduce((s, r) => s + r.parts, 0),
      amount: rows.reduce((s, r) => s + r.totalAmountRials, 0),
    });

    return { today: fold(todayLogs), month: fold(monthLogs) };
  }

  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 chargeInfoOf(account: SmsAccount) {
    return {
      card: account.chargeCard || '',
      iban: account.chargeIban || '',
      accountHolder: account.chargeHolder || '',
      instruction: account.chargeInstruction || '',
    };
  }

  private publicAccount(account: SmsAccount) {
    return {
      id: account.id,
      balanceRials: account.balanceRials,
      pricePerPartRials: account.pricePerPartRials,
      isBlocked: account.isBlocked,
      alertCriticalRials: account.alertCriticalRials,
      alertWarningRials: account.alertWarningRials,
      chargeCard: account.chargeCard,
      chargeIban: account.chargeIban,
      chargeHolder: account.chargeHolder,
      chargeInstruction: account.chargeInstruction,
    };
  }

  /**
   * @param defaultMonth when true and no dates: from month start to now (always returns a range)
   * @returns null when optional and no dates provided
   */
  private resolveDateRange(
    fromDate: string | undefined,
    toDate: string | undefined,
    defaultMonth: true,
  ): { from: Date; to: Date };
  private resolveDateRange(
    fromDate?: string,
    toDate?: string,
    defaultMonth?: false,
  ): { from: Date; to: Date } | null;
  private resolveDateRange(
    fromDate?: string,
    toDate?: string,
    defaultMonth = false,
  ): { from: Date; to: Date } | null {
    const today = iranYmd(new Date());
    if (!fromDate && !toDate) {
      if (!defaultMonth) return null;
      return {
        from: new Date(`${today.slice(0, 8)}01T00:00:00+03:30`),
        to: new Date(`${today}T23:59:59.999+03:30`),
      };
    }

    const fromYmd = fromDate && /^\d{4}-\d{2}-\d{2}$/.test(fromDate) ? fromDate : today;
    const toYmd = toDate && /^\d{4}-\d{2}-\d{2}$/.test(toDate) ? toDate : today;
    return {
      from: new Date(`${fromYmd}T00:00:00+03:30`),
      to: new Date(`${toYmd}T23:59:59.999+03:30`),
    };
  }

  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;
  }
}