import { Db, ObjectId, WithId } from 'mongodb';
import { FFBProduction } from 'src/FFB/ffb-production.schema';

export class FFBProductionRepository {
  private readonly collectionName = 'FFB Production';

  constructor(private readonly db: Db) { }

  private get collection() {
    return this.db.collection<FFBProduction & { vector?: number[] }>(this.collectionName);
  }

  async init() {
    const collections = await this.db.listCollections({ name: this.collectionName }).toArray();
    if (collections.length === 0) {
      await this.db.createCollection(this.collectionName);
      console.log(`✅ Created collection: ${this.collectionName}`);
    }
  }
  async create(ffb: FFBProduction & { vector?: number[] }): Promise<FFBProduction & { vector?: number[] }> {
    const result = await this.collection.insertOne({
      ...ffb,
      productionDate: new Date(ffb.productionDate),
      vector: ffb.vector, // optional vector
    });
    return { ...ffb, _id: result.insertedId.toString() };
  }

  async findAll(filter: Record<string, any> = {}): Promise<(FFBProduction & { vector?: number[] })[]> {
    const results = await this.collection.find(filter).toArray();
    return results.map((r: WithId<FFBProduction & { vector?: number[] }>) => ({
      ...r,
      _id: r._id?.toString(),
    }));
  }

  async findById(id: string): Promise<(FFBProduction & { vector?: number[] }) | null> {
    const result = await this.collection.findOne({ _id: new ObjectId(id) as any });
    return result ? { ...result, _id: result._id.toString() } : null;
  }

  async delete(id: string) {
    return this.collection.deleteOne({ _id: new ObjectId(id) as any });
  }

  /** Optional: helper for vector search via aggregation */
  async vectorSearch(vector: number[], k = 5, numCandidates = 50) {
    return this.collection
      .aggregate([
        {
          $vectorSearch: {
            index: 'vector_index',
            queryVector: vector,
            path: 'vector',
            numCandidates,
            limit: k
          }
        },
        {
          $lookup: {
            from: this.collectionName,
            localField: "_id",
            foreignField: "_id",
            as: "doc"
          }
        },
        { $unwind: "$doc" },
        {
          $project: {
            _id: "$doc._id",
            productionDate: "$doc.productionDate",
            site: "$doc.site",
            phase: "$doc.phase",
            block: "$doc.block",
            quantity: "$doc.quantity",
            quantityUom: "$doc.quantityUom",
            weight: "$doc.weight",
            weightUom: "$doc.weightUom",
            // vector: "$doc.vector",
            score: "$_score"
          }
        }
      ])
      .toArray();
  }


}