import { Injectable, Logger } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';

export interface PolimedPatient {
  id: string;
  fullName: string;
  birthDate: string;
  phone: string;
  cardNumber: string;
}

export interface PolimedAppointment {
  id: string;
  patientId: string;
  patientFullName: string;
  doctorFullName: string;
  specialty: string;
  scheduledFor: string;
  status: 'scheduled' | 'completed' | 'cancelled' | 'no_show';
}

export type PolimedVisitEventType =
  | 'arrived'
  | 'service_started'
  | 'service_ended'
  | 'left_without_service';

@Injectable()
export class PolimedClient {
  private readonly logger = new Logger(PolimedClient.name);
  private readonly baseUrl: string;

  constructor(config: ConfigService) {
    this.baseUrl = config.getOrThrow<string>('POLIMED_BASE_URL');
  }

  async searchPatients(query: string, limit = 20): Promise<PolimedPatient[]> {
    const url = new URL('/patients/search', this.baseUrl);
    url.searchParams.set('q', query);
    url.searchParams.set('limit', String(limit));
    return this.fetchJson(url);
  }

  async getAppointments(date?: string): Promise<PolimedAppointment[]> {
    const url = new URL('/appointments', this.baseUrl);
    if (date) url.searchParams.set('date', date);
    return this.fetchJson(url);
  }

  async getAppointment(id: string): Promise<PolimedAppointment> {
    const url = new URL(`/appointments/${id}`, this.baseUrl);
    return this.fetchJson(url);
  }

  async pushVisitEvent(
    appointmentId: string,
    event: { type: PolimedVisitEventType; occurredAt: string; source?: string },
  ): Promise<void> {
    const url = new URL(`/visits/${appointmentId}/events`, this.baseUrl);
    const res = await fetch(url, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ ...event, source: event.source ?? 'reception-video' }),
    });
    if (!res.ok) {
      this.logger.warn(`pushVisitEvent failed: ${res.status} ${url}`);
      throw new Error(`Polimed event failed: ${res.status}`);
    }
  }

  private async fetchJson<T>(url: URL): Promise<T> {
    const res = await fetch(url);
    if (!res.ok) {
      throw new Error(`Polimed ${url.pathname} failed: ${res.status}`);
    }
    return (await res.json()) as T;
  }
}