import { BadRequestException, Injectable, Logger, NotFoundException } from '@nestjs/common';
import { WhatsappTemplateRepository } from './repositories/whatsapp-template.repository';
import { WhatsappConfigService } from './whatsapp-config.service';
import { CreateWhatsappTemplateDto, UpdateWhatsappTemplateDto } from './dto/whatsapp.dto';

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

  constructor(
    private readonly repo: WhatsappTemplateRepository,
    private readonly configService: WhatsappConfigService,
  ) {}

  async getTemplates() {
    const result = await this.repo.listTemplates();
    return result.rows;
  }

  async getTemplateById(id: number) {
    const result = await this.repo.getTemplateById(id);
    return result.rows[0] || null;
  }

  async saveTemplate(dto: CreateWhatsappTemplateDto) {
    const metaName = this.toMetaName(dto.name);
    const result = await this.repo.saveTemplate({
      name: dto.name,
      content: dto.content,
      category: this.normalizeCategory(dto.category),
      areaId: dto.areaId ?? null,
      language: dto.language || 'pt_BR',
      metaTemplateName: metaName,
      headerType: dto.headerType || null,
      headerText: dto.headerText || null,
      footerText: dto.footerText || null,
      buttonsJson: dto.buttons?.length ? JSON.stringify(dto.buttons) : null,
      bodyVariablesJson: dto.bodyVariables?.length ? JSON.stringify(dto.bodyVariables) : null,
    });
    return result.rows[0];
  }

  async updateTemplate(id: number, dto: UpdateWhatsappTemplateDto) {
    const metaName = this.toMetaName(dto.name);
    const result = await this.repo.updateTemplate(id, {
      name: dto.name,
      content: dto.content,
      category: this.normalizeCategory(dto.category),
      areaId: dto.areaId ?? null,
      language: dto.language || 'pt_BR',
      metaTemplateName: metaName,
      headerType: dto.headerType || null,
      headerText: dto.headerText || null,
      footerText: dto.footerText || null,
      buttonsJson: dto.buttons?.length ? JSON.stringify(dto.buttons) : null,
      bodyVariablesJson: dto.bodyVariables?.length ? JSON.stringify(dto.bodyVariables) : null,
    });
    return result.rows[0];
  }

  async submitToMeta(templateId: number) {
    const template = await this.getTemplateById(templateId);
    if (!template) throw new NotFoundException('Template não encontrado');

    const config = await this.configService.getConfig();
    if (!config.access_token || !config.waba_id) {
      throw new BadRequestException(
        'Access Token e WABA ID são obrigatórios para enviar templates. Configure em Admin → Canais → WhatsApp → Configurar.',
      );
    }

    const metaName = template.meta_template_name || this.toMetaName(template.name);
    const components = this.buildComponents(template);

    const payload = {
      name: metaName,
      language: template.language || 'pt_BR',
      category: template.category || 'UTILITY',
      components,
    };

    this.logger.log(`[Meta Templates] Submetendo "${metaName}" para WABA ${config.waba_id}`);

    const response = await fetch(
      `https://graph.facebook.com/${config.api_version}/${config.waba_id}/message_templates`,
      {
        method: 'POST',
        headers: {
          Authorization: `Bearer ${config.access_token}`,
          'Content-Type': 'application/json',
        },
        body: JSON.stringify(payload),
      },
    );

    const data = (await response.json()) as any;

    if (!response.ok) {
      this.logger.error('[Meta Templates] Erro ao submeter:', data?.error);
      throw new BadRequestException(
        data?.error?.message || `Erro ${response.status} ao submeter template à Meta`,
      );
    }

    await this.repo.updateMetaInfo(templateId, {
      metaTemplateId: String(data.id),
      metaTemplateName: metaName,
      metaStatus: data.status || 'PENDING',
    });

    return { success: true, metaId: data.id, metaName, status: data.status || 'PENDING' };
  }

  async syncFromMeta() {
    const config = await this.configService.getConfig();
    if (!config.access_token || !config.waba_id) {
      return { synced: 0, imported: 0, error: 'WhatsApp não configurado com WABA ID' };
    }

    try {
      const response = await fetch(
        `https://graph.facebook.com/${config.api_version}/${config.waba_id}/message_templates?fields=id,name,status,language,category,components&limit=250`,
        { headers: { Authorization: `Bearer ${config.access_token}` } },
      );

      const data = (await response.json()) as any;

      if (!response.ok || !Array.isArray(data?.data)) {
        this.logger.error('[Meta Templates] Erro ao buscar lista:', data?.error);
        return { synced: 0, imported: 0, error: data?.error?.message || 'Erro ao sincronizar' };
      }

      let synced = 0;
      let imported = 0;

      for (const t of data.data) {
        const metaId = String(t.id);
        const updated = await this.repo.updateMetaStatusByName(t.name, t.status, metaId);
        if (updated > 0) {
          synced++;
          continue;
        }

        const parsed = this.parseComponents(t.components || []);
        const wasInserted = await this.repo.importFromMeta({
          metaTemplateId: metaId,
          metaTemplateName: t.name,
          metaStatus: t.status,
          language: t.language || 'pt_BR',
          category: this.normalizeCategory(t.category),
          content: parsed.content,
          headerType: parsed.headerType,
          headerText: parsed.headerText,
          footerText: parsed.footerText,
          buttonsJson: parsed.buttons?.length ? JSON.stringify(parsed.buttons) : null,
        });

        if (wasInserted) {
          imported++;
          this.logger.log(`[Meta Templates] Importado: "${t.name}" (${t.status})`);
        }
      }

      return { synced, imported };
    } catch (err: any) {
      this.logger.error('[Meta Templates] Falha na sincronização:', err?.message);
      return { synced: 0, imported: 0, error: 'Erro de conexão com a Meta' };
    }
  }

  async handleTemplateStatusUpdate(data: {
    event?: string;
    message_template_name?: string;
    message_template_id?: number | string;
    reason?: string;
  }) {
    const status = data.event;
    const name = data.message_template_name;
    const id = String(data.message_template_id || '');

    if (!status || !name) return;

    this.logger.log(`[Meta Templates] Status automático: "${name}" → ${status}`);
    await this.repo.updateMetaStatusByName(name, status, id);
  }

  async deleteTemplate(id: number) {
    const result = await this.repo.deleteTemplate(id);
    const metaName = result.rows[0]?.meta_template_name;

    if (metaName) {
      await this.deleteFromMeta(metaName).catch((err) =>
        this.logger.warn(`[Meta Templates] Falha ao excluir "${metaName}" da Meta:`, err?.message),
      );
    }

    return { success: true };
  }

  private async deleteFromMeta(metaTemplateName: string) {
    const config = await this.configService.getConfig();
    if (!config.access_token || !config.waba_id) return;

    await fetch(
      `https://graph.facebook.com/${config.api_version}/${config.waba_id}/message_templates?name=${encodeURIComponent(metaTemplateName)}`,
      {
        method: 'DELETE',
        headers: { Authorization: `Bearer ${config.access_token}` },
      },
    );
  }

  private buildComponents(template: any): any[] {
    const components: any[] = [];

    if (template.header_type && template.header_text) {
      components.push({
        type: 'HEADER',
        format: template.header_type,
        text: template.header_text,
      });
    }

    const bodyComp: any = { type: 'BODY', text: template.content };
    const vars = Array.isArray(template.body_variables) ? template.body_variables : [];
    if (vars.length > 0) {
      bodyComp.example = { body_text: [vars.map((v: any) => v.example || v.label || `valor${v.index}`)] };
    }
    components.push(bodyComp);

    if (template.footer_text) {
      components.push({ type: 'FOOTER', text: template.footer_text });
    }

    const btns = Array.isArray(template.buttons) ? template.buttons : [];
    if (btns.length > 0) {
      components.push({
        type: 'BUTTONS',
        buttons: btns.map((b: any) => {
          if (b.type === 'QUICK_REPLY') return { type: 'QUICK_REPLY', text: b.text };
          if (b.type === 'URL') return { type: 'URL', text: b.text, url: b.url };
          if (b.type === 'PHONE_NUMBER') return { type: 'PHONE_NUMBER', text: b.text, phone_number: b.phone };
          return b;
        }),
      });
    }

    return components;
  }

  private parseComponents(components: any[]): {
    content: string;
    headerType?: string | null;
    headerText?: string | null;
    footerText?: string | null;
    buttons?: any[];
  } {
    const result: any = { content: '', headerType: null, headerText: null, footerText: null, buttons: [] };
    for (const c of components || []) {
      if (c.type === 'BODY') result.content = c.text || '';
      else if (c.type === 'HEADER') {
        result.headerType = c.format || null;
        result.headerText = c.format === 'TEXT' ? (c.text || null) : null;
      }
      else if (c.type === 'FOOTER') result.footerText = c.text || null;
      else if (c.type === 'BUTTONS') {
        result.buttons = (c.buttons || []).map((b: any) => ({
          type: b.type,
          text: b.text || '',
          url: b.url || '',
          phone: b.phone_number || '',
        }));
      }
    }
    return result;
  }

  private toMetaName(displayName: string): string {
    return String(displayName || '')
      .normalize('NFD')
      .replace(/[̀-ͯ]/g, '')
      .toLowerCase()
      .replace(/[^a-z0-9]+/g, '_')
      .replace(/^_+|_+$/g, '')
      .substring(0, 512) || 'template';
  }

  private normalizeCategory(category?: string): string {
    const normalized = String(category || 'UTILITY').trim().toUpperCase();
    return ['UTILITY', 'MARKETING', 'AUTHENTICATION'].includes(normalized) ? normalized : 'UTILITY';
  }
}