import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { CatalogItemEntity } from '../entities/catalog-item.entity';
import { ClassificationTagEntity } from '../entities/classification-tag.entity';

export type ClassificationResult = {
  publisher?: string;
  format?: string[];
  territory?: string[];
  topics?: string[];
};

@Injectable()
export class ClassifierService {
  constructor(
    @InjectRepository(ClassificationTagEntity)
    private readonly tags: Repository<ClassificationTagEntity>,
  ) {}

  async classify(item: CatalogItemEntity): Promise<ClassificationResult> {
    const res: ClassificationResult = {
      publisher: item.publisher || undefined,
      format: this.splitFormats(item.format),
    };

    const text = `${item.title || ''} ${item.description || ''}`.toLowerCase();

    const territory: string[] = [];
    const topics: string[] = [];

    if (text.includes('madrid')) territory.push('Madrid');
    if (text.includes('andaluc')) territory.push('Andalucía');
    if (text.includes('catalu')) territory.push('Cataluña');

    if (text.includes('subvenc')) topics.push('Subvenciones');
    if (text.includes('licit')) topics.push('Licitaciones');
    if (text.includes('contrat')) topics.push('Contratación');
    if (text.includes('presupuesto')) topics.push('Presupuestos');

    res.territory = territory.length ? territory : undefined;
    res.topics = topics.length ? topics : undefined;

    return res;
  }

  async applyTags(item: CatalogItemEntity, classification: ClassificationResult) {
    await this.tags.delete({ itemId: item.id });
    const next: ClassificationTagEntity[] = [];

    if (classification.publisher) {
      next.push(this.tags.create({ itemId: item.id, type: 'publisher', value: classification.publisher }));
    }

    for (const format of classification.format || []) {
      next.push(this.tags.create({ itemId: item.id, type: 'format', value: format }));
    }

    for (const topic of classification.topics || []) {
      next.push(this.tags.create({ itemId: item.id, type: 'topic', value: topic }));
    }

    for (const territory of classification.territory || []) {
      next.push(this.tags.create({ itemId: item.id, type: 'territory', value: territory }));
    }

    if (next.length) await this.tags.save(next);
  }

  private splitFormats(value?: string): string[] {
    if (!value) return [];
    return value
      .split(',')
      .map((v) => v.trim())
      .filter(Boolean);
  }
}