import { Injectable, NestMiddleware, Logger } from '@nestjs/common';
import { FastifyRequest, FastifyReply } from 'fastify';
import { TenantDatabaseService } from './tenant-database.service';

@Injectable()
export class TenantMiddleware implements NestMiddleware {
  private readonly logger = new Logger(TenantMiddleware.name);

  constructor(private readonly tenantDbService: TenantDatabaseService) {}

  async use(
    req: FastifyRequest['raw'],
    res: FastifyReply['raw'],
    next: () => void,
  ) {
    try {
      // Extract subdomain from hostname
      const host = req.headers.host || '';
      const hostname = host.split(':')[0]; // Remove port if present
      const parts = hostname.split('.');

      this.logger.log(`Host header: ${host}, hostname: ${hostname}, parts: ${JSON.stringify(parts)}`);

      // For local development, accept x-tenant-id header
      let tenantId = req.headers['x-tenant-id'] as string;
      let subdomain: string | null = null;

      this.logger.log(`Host header: ${host}, hostname: ${hostname}, parts: ${JSON.stringify(parts)}, x-tenant-id: ${tenantId}`);

      // If x-tenant-id is explicitly provided, use it directly
      if (tenantId) {
        this.logger.log(`Using explicit x-tenant-id: ${tenantId}`);
        (req as any).tenantId = tenantId;
        next();
        return;
      }

      // Extract subdomain (e.g., "tenant1" from "tenant1.routebox.co")
      // For production domains with 3+ parts, extract first part as subdomain
      if (parts.length >= 3) {
        subdomain = parts[0];
        // Ignore www subdomain
        if (subdomain === 'www') {
          subdomain = null;
        }
      }
      // For development (e.g., tenant1.localhost), also check 2 parts
      else if (parts.length === 2 && parts[1] === 'localhost') {
        subdomain = parts[0];
      }

      this.logger.log(`Extracted subdomain: ${subdomain}`);

      // Get tenant by subdomain if available
      if (subdomain) {
        try {
          const tenant = await this.tenantDbService.getTenantByDomain(subdomain);
          if (tenant) {
            tenantId = tenant.id;
            this.logger.log(
              `Tenant identified: ${tenant.name} (${tenant.id}) from subdomain: ${subdomain}`,
            );
          }
        } catch (error) {
          this.logger.warn(`No tenant found for subdomain: ${subdomain}`, error.message);
          // Fall back to using subdomain as tenantId directly if domain lookup fails
          tenantId = subdomain;
          this.logger.log(`Using subdomain as tenantId fallback: ${tenantId}`);
        }
      }

      if (tenantId) {
        // Attach tenant info to request object
        (req as any).tenantId = tenantId;
        if (subdomain) {
          (req as any).subdomain = subdomain;
        }
      } else {
        this.logger.warn(`No tenant identified from host: ${hostname}`);
      }

      next();
    } catch (error) {
      this.logger.error('Error in tenant middleware', error);
      next();
    }
  }
}