package main

import (
	"context"
	"fmt"
	"strconv"

	"github.com/qdrant/go-client/qdrant"
)

const collectionName = "knowledge"

type entry struct {
	ID      int64    `json:"id"`
	Note    string   `json:"note"`
	Repos   []string `json:"repos,omitempty"`
	Host    string   `json:"host,omitempty"`
	Tags    []string `json:"tags,omitempty"`
	User    string   `json:"user,omitempty"`
	Context string   `json:"context,omitempty"`
	Created string   `json:"created"`
}

type searchResult struct {
	Entry entry   `json:",inline"`
	Score float32 `json:"score"`
}

type qdrantStore struct {
	client   *qdrant.Client
	embedder *embedder
}

func newQdrantStore(client *qdrant.Client, embedder *embedder) *qdrantStore {
	return &qdrantStore{client: client, embedder: embedder}
}

func (s *qdrantStore) ensureCollection(ctx context.Context) error {
	exists, err := s.client.CollectionExists(ctx, collectionName)
	if err != nil {
		return fmt.Errorf("check collection exists: %w", err)
	}
	if exists {
		return nil
	}

	err = s.client.CreateCollection(ctx, &qdrant.CreateCollection{
		CollectionName: collectionName,
		VectorsConfig: qdrant.NewVectorsConfig(&qdrant.VectorParams{
			Size:     1536,
			Distance: qdrant.Distance_Cosine,
		}),
	})
	if err != nil {
		return fmt.Errorf("create collection: %w", err)
	}

	return nil
}

func (s *qdrantStore) index(ctx context.Context, id int64, note string) error {
	vec, err := s.embedder.embedText(ctx, note)
	if err != nil {
		return fmt.Errorf("embed text: %w", err)
	}

	payload := map[string]*qdrant.Value{
		"id":      qdrant.NewValueString(strconv.FormatInt(id, 10)),
		"content": qdrant.NewValueString(note),
	}

	_, err = s.client.Upsert(ctx, &qdrant.UpsertPoints{
		CollectionName: collectionName,
		Points: []*qdrant.PointStruct{
			{
				Id:      qdrant.NewIDNum(uint64(id)),
				Vectors: qdrant.NewVectors(vec...),
				Payload: payload,
			},
		},
	})
	if err != nil {
		return fmt.Errorf("upsert point: %w", err)
	}

	return nil
}

func (s *qdrantStore) search(ctx context.Context, query string, limit uint64) ([]searchResult, error) {
	vec, err := s.embedder.embedText(ctx, query)
	if err != nil {
		return nil, fmt.Errorf("embed query: %w", err)
	}

	if limit == 0 {
		limit = 5
	}

	results, err := s.client.Query(ctx, &qdrant.QueryPoints{
		CollectionName: collectionName,
		Query:          qdrant.NewQueryDense(vec),
		Limit:          &limit,
		WithPayload:    qdrant.NewWithPayload(true),
	})
	if err != nil {
		return nil, fmt.Errorf("query points: %w", err)
	}

	var searchResults []searchResult
	for _, pt := range results {
		r := searchResult{
			Score: pt.Score,
		}

		if payload := pt.GetPayload(); payload != nil {
			if v, ok := payload["id"]; ok {
				if n, err := strconv.ParseInt(v.GetStringValue(), 10, 64); err == nil {
					r.Entry.ID = n
				}
			}
		}

		searchResults = append(searchResults, r)
	}

	return searchResults, nil
}