import { Injectable, Inject } from "@nestjs/common";
import { Logger } from "nestjs-pino";
import { ConfigService } from "@nestjs/config";
import { EmailService } from "@bff/infra/email/email.service";
import { getErrorMessage } from "@bff/core/utils/error.util";
import type { SimNotificationContext } from "../interfaces/sim-base.interface";

@Injectable()
export class SimNotificationService {
  constructor(
    @Inject(Logger) private readonly logger: Logger,
    private readonly email: EmailService,
    private readonly configService: ConfigService
  ) {}

  /**
   * Send notification for SIM actions
   */
  async notifySimAction(
    action: string,
    status: "SUCCESS" | "ERROR",
    context: SimNotificationContext
  ): Promise<void> {
    const subject = `[SIM ACTION] ${action} - ${status}`;
    const toAddress = this.configService.get<string>("SIM_ALERT_EMAIL_TO");
    const fromAddress = this.configService.get<string>("SIM_ALERT_EMAIL_FROM");

    if (!toAddress || !fromAddress) {
      this.logger.debug("SIM action notification skipped: email config missing", {
        action,
        status,
      });
      return;
    }

    const publicContext = this.redactSensitiveFields(context);

    try {
      const lines: string[] = [
        `Action: ${action}`,
        `Result: ${status}`,
        `Timestamp: ${new Date().toISOString()}`,
        "",
        "Context:",
        JSON.stringify(publicContext, null, 2),
      ];
      await this.email.sendEmail({
        to: toAddress,
        from: fromAddress,
        subject,
        text: lines.join("\n"),
      });
    } catch (err) {
      this.logger.warn("Failed to send SIM action notification email", {
        action,
        status,
        error: getErrorMessage(err),
      });
    }
  }

  /**
   * Redact sensitive information from notification context
   */
  private redactSensitiveFields(context: Record<string, unknown>): Record<string, unknown> {
    const sanitized: Record<string, unknown> = {};
    for (const [key, value] of Object.entries(context)) {
      if (typeof key === "string" && key.toLowerCase().includes("password")) {
        sanitized[key] = "[REDACTED]";
        continue;
      }

      if (typeof value === "string" && value.length > 200) {
        sanitized[key] = `${value.substring(0, 200)}…`;
        continue;
      }

      sanitized[key] = value;
    }
    return sanitized;
  }

  /**
   * Convert technical errors to user-friendly messages for SIM operations
   */
  getUserFriendlySimError(technicalError: string): string {
    if (!technicalError) {
      return "SIM operation failed. Please try again or contact support.";
    }

    const errorLower = technicalError.toLowerCase();

    // Freebit API errors
    if (errorLower.includes("api error: ng") || errorLower.includes("account not found")) {
      return "SIM account not found. Please contact support to verify your SIM configuration.";
    }

    if (errorLower.includes("authentication failed") || errorLower.includes("auth")) {
      return "SIM service is temporarily unavailable. Please try again later.";
    }

    if (errorLower.includes("timeout") || errorLower.includes("network")) {
      return "SIM service request timed out. Please try again.";
    }

    // WHMCS errors
    if (errorLower.includes("invalid permissions") || errorLower.includes("not allowed")) {
      return "SIM service is temporarily unavailable. Please contact support for assistance.";
    }

    // Generic errors
    if (errorLower.includes("failed") || errorLower.includes("error")) {
      return "SIM operation failed. Please try again or contact support.";
    }

    // Default fallback
    return "SIM operation failed. Please try again or contact support.";
  }
}