import { Injectable } from '@nestjs/common';
import { WhatsappConfigRepository } from './repositories/whatsapp-config.repository';

interface WhatsappConfig {
  access_token: string | null;
  phone_number_id: string | null;
  api_version: string;
  webhook_token: string | null;
}

@Injectable()
export class WhatsappConfigService {
  private _cache: { config: WhatsappConfig; expiresAt: number } | null = null;
  private readonly CACHE_TTL_MS = 60_000;

  constructor(private readonly repo: WhatsappConfigRepository) {}

  async getConfig(): Promise<WhatsappConfig> {
    if (this._cache && Date.now() < this._cache.expiresAt) {
      return this._cache.config;
    }
    const row = await this.repo.find();
    const config: WhatsappConfig = {
      access_token: row?.access_token || process.env.META_ACCESS_TOKEN || null,
      phone_number_id: row?.phone_number_id || process.env.META_PHONE_NUMBER_ID || null,
      api_version: row?.api_version || process.env.META_API_VERSION || 'v25.0',
      webhook_token: row?.webhook_token || process.env.META_WEBHOOK_TOKEN || null,
    };
    this._cache = { config, expiresAt: Date.now() + this.CACHE_TTL_MS };
    return config;
  }

  async getPublicConfig() {
    const row = await this.repo.find();
    const effectiveToken = row?.access_token || process.env.META_ACCESS_TOKEN;
    const effectivePhoneId = row?.phone_number_id || process.env.META_PHONE_NUMBER_ID;
    return {
      phone_number_id: effectivePhoneId || null,
      api_version: row?.api_version || process.env.META_API_VERSION || 'v25.0',
      webhook_token: row?.webhook_token || process.env.META_WEBHOOK_TOKEN || null,
      is_configured: !!(effectiveToken && effectivePhoneId),
      has_token: !!effectiveToken,
      token_source: row?.access_token ? 'database' : effectiveToken ? 'env' : null,
      updated_at: row?.updated_at || null,
    };
  }

  async saveConfig(
    dto: { access_token?: string; phone_number_id?: string; api_version?: string; webhook_token?: string },
    userId?: number,
  ) {
    this._cache = null;
    await this.repo.update({
      access_token: dto.access_token || null,
      phone_number_id: dto.phone_number_id || null,
      api_version: dto.api_version || null,
      webhook_token: dto.webhook_token || null,
      updated_by: userId,
    });
    return this.getPublicConfig();
  }

  async validateCredentials(token: string, phoneNumberId: string, apiVersion = 'v25.0') {
    const url = `https://graph.facebook.com/${apiVersion}/${phoneNumberId}?access_token=${token}&fields=display_phone_number,verified_name,quality_rating`;
    try {
      const response = await fetch(url);
      const data = (await response.json()) as any;
      if (!response.ok) {
        return {
          valid: false,
          error: data?.error?.message || 'Credenciais inválidas',
          code: data?.error?.code,
        };
      }
      return {
        valid: true,
        phone_number: data.display_phone_number,
        verified_name: data.verified_name,
        quality_rating: data.quality_rating,
      };
    } catch (err: any) {
      const msg = err?.message || String(err);
      console.error('[WhatsappConfig] validateCredentials falhou:', msg);
      return { valid: false, error: `Erro de conexão com a Meta API: ${msg}` };
    }
  }
}