import { Injectable, BadRequestException, Inject, ConflictException } from "@nestjs/common";
import { Logger } from "nestjs-pino";
import { FreebitOrchestratorService } from "@bff/integrations/freebit/services/freebit-orchestrator.service";
import { WhmcsService } from "@bff/integrations/whmcs/whmcs.service";
import { MappingsService } from "@bff/modules/id-mappings/mappings.service";
import { CacheService } from "@bff/infra/cache/cache.service";
import { getErrorMessage } from "@bff/core/utils/error.util";
import type { SimOrderActivationRequest } from "@customer-portal/domain/sim";
import { randomUUID } from "crypto";

@Injectable()
export class SimOrderActivationService {
  constructor(
    private readonly freebit: FreebitOrchestratorService,
    private readonly whmcs: WhmcsService,
    private readonly mappings: MappingsService,
    private readonly cache: CacheService,
    @Inject(Logger) private readonly logger: Logger
  ) {}

  async activate(
    userId: string,
    req: SimOrderActivationRequest,
    idempotencyKey?: string
  ): Promise<{ success: boolean; invoiceId: number; transactionId?: string }> {
    // Generate idempotency key if not provided
    const idemKey = idempotencyKey || randomUUID();
    const cacheKey = `sim-activation:${userId}:${idemKey}`;

    // Check if already processed
    const existing = await this.cache.get<{
      success: boolean;
      invoiceId: number;
      transactionId?: string;
    }>(cacheKey);
    if (existing) {
      this.logger.log("Returning cached SIM activation result (idempotent)", {
        userId,
        idempotencyKey: idemKey,
        msisdn: req.msisdn,
      });
      return existing;
    }

    // Check if operation is currently processing
    const processingKey = `${cacheKey}:processing`;
    const isProcessing = await this.cache.exists(processingKey);
    if (isProcessing) {
      throw new ConflictException("SIM activation already in progress. Please wait and retry.");
    }

    // Mark as processing (5 minute TTL)
    await this.cache.set(processingKey, true, 300);
    if (req.simType === "eSIM" && (!req.eid || req.eid.length < 15)) {
      throw new BadRequestException("EID is required for eSIM and must be valid");
    }
    if (!req.msisdn || req.msisdn.trim() === "") {
      throw new BadRequestException("Phone number (msisdn) is required for SIM activation");
    }
    if (!/^\d{8}$/.test(req.scheduledAt || "") && req.activationType === "Scheduled") {
      throw new BadRequestException("scheduledAt must be YYYYMMDD when scheduling activation");
    }

    const mapping = await this.mappings.findByUserId(userId);
    if (!mapping?.whmcsClientId) {
      throw new BadRequestException("WHMCS client mapping not found");
    }

    // 1) Create invoice for one-time activation fee only
    const invoice = await this.whmcs.createInvoice({
      clientId: mapping.whmcsClientId,
      description: `SIM Activation Fee (${req.planSku}) for ${req.msisdn}`,
      amount: req.oneTimeAmountJpy,
      currency: "JPY",
      dueDate: new Date(Date.now() + 7 * 24 * 60 * 60 * 1000),
      notes: `SIM activation fee for ${req.msisdn}, plan ${req.planSku}. Monthly billing will start on the 1st of next month.`,
    });

    const paymentResult = await this.whmcs.capturePayment({
      invoiceId: invoice.id,
      amount: req.oneTimeAmountJpy,
      currency: "JPY",
    });

    if (!paymentResult.success) {
      await this.whmcs.updateInvoice({
        invoiceId: invoice.id,
        status: "Cancelled",
        notes: `Payment failed: ${paymentResult.error || "unknown"}`,
      });
      throw new BadRequestException(`Payment failed: ${paymentResult.error || "unknown"}`);
    }

    // 2) Freebit activation
    try {
      if (req.simType === "eSIM") {
        await this.freebit.activateEsimAccountNew({
          account: req.msisdn,
          eid: req.eid!,
          planCode: req.planSku,
          contractLine: "5G",
          shipDate: req.activationType === "Scheduled" ? req.scheduledAt : undefined,
          mnp: req.mnp
            ? {
                reserveNumber: req.mnp.reserveNumber || "",
                reserveExpireDate: req.mnp.reserveExpireDate || "",
              }
            : undefined,
        });
      } else {
        this.logger.warn("Physical SIM activation path is not implemented; skipping Freebit call", {
          account: req.msisdn,
        });
      }

      // 3) Add-ons (voice options) immediately after activation if selected
      if (req.addons && (req.addons.voiceMail || req.addons.callWaiting)) {
        await this.freebit.updateSimFeatures(req.msisdn, {
          voiceMailEnabled: !!req.addons.voiceMail,
          callWaitingEnabled: !!req.addons.callWaiting,
        });
      }

      // 4) Create monthly subscription for recurring billing
      if (req.monthlyAmountJpy > 0) {
        const nextMonth = new Date();
        nextMonth.setMonth(nextMonth.getMonth() + 1);
        nextMonth.setDate(1); // First day of next month
        nextMonth.setHours(0, 0, 0, 0);

        // Create a monthly subscription order using the order service
        const orderService = this.whmcs.getOrderService();
        await orderService.addOrder({
          clientId: mapping.whmcsClientId,
          items: [
            {
              productId: req.planSku, // Use the plan SKU as product ID
              billingCycle: "monthly",
              quantity: 1,
              configOptions: {
                phone_number: req.msisdn,
                activation_date: nextMonth.toISOString().split("T")[0],
              },
              customFields: {
                sim_type: req.simType,
                eid: req.eid || "",
              },
            },
          ],
          paymentMethod: "mailin", // Default payment method
          notes: `Monthly SIM plan billing for ${req.msisdn}, plan ${req.planSku}. Billing starts on the 1st of next month.`,
          noinvoice: false, // Create invoice
          noinvoiceemail: true, // Suppress invoice email for now
          noemail: true, // Suppress order emails
        });

        this.logger.log("Monthly subscription created", {
          account: req.msisdn,
          amount: req.monthlyAmountJpy,
          nextDueDate: nextMonth.toISOString().split("T")[0],
        });
      }

      this.logger.log("SIM activation completed", { account: req.msisdn, invoiceId: invoice.id });

      const result = {
        success: true,
        invoiceId: invoice.id,
        transactionId: paymentResult.transactionId,
      };

      // Cache successful result for 24 hours
      await this.cache.set(cacheKey, result, 86400);

      // Remove processing flag
      await this.cache.del(processingKey);

      return result;
    } catch (err) {
      // Remove processing flag on error
      await this.cache.del(processingKey);

      await this.whmcs.updateInvoice({
        invoiceId: invoice.id,
        notes: `Freebit activation failed after payment: ${getErrorMessage(err)}`,
      });
      throw err;
    }
  }
}