package mongo

import (
	// "log"
	"context"
	// "fmt"
	// "encoding/base64"

	// "go.mongodb.org/mongo-driver/v2/mongo/options"
	"go.mongodb.org/mongo-driver/v2/bson"

	// "git.gsuntres.com/boxtep/boxtep/core"
)

// Find is used to fetch the first page of data.
func (c *MongoClient) Find(ctx context.Context, database, name string, filter bson.M, limit int64) (bson.M, error) {

	// 1. Prepare to query.
	collection := c.GetCollection(database, name)

	pageSize := max(limit, c.Limit)


	// id := DecodeCursor(nextCursor)

  // filter["_id"] = bson.M{"_id": bson.M{"$gt": id}}
	// opts := options.Find().
	// 				SetLimit(pageSize + 1).
	// 				SetSort(bson.M{"_id": 1})
	// id := DecodeCursor(nextCursor)
	sort := bson.M{"_id": 1}
  // filter["_id"] = bson.M{"_id": bson.M{"$gt": id}}

	pipeline := BuildPaginationPipeline(0, pageSize + 1, filter, sort)

	// 2. Query
	cursor, err := collection.Aggregate(ctx, pipeline)
	if err != nil {
		return nil, err
	}
	defer cursor.Close(ctx)

	// 3. Build results
	var facetResults []bson.M
	if err = cursor.All(ctx, &facetResults); err != nil {
		return nil, err
	}

	root := facetResults[0]

	data := root["data"].(bson.A)

	metadata := root["metadata"].(bson.A)

	var totalValue any
	if len(metadata) != 0 {
		metadataRoot := metadata[0].(bson.M)
		totalValue = metadataRoot["total"]
	}

	var total int64
	switch v := totalValue.(type) {
	case int32:
	  total = int64(v)
	case int64:
	  total = v
	default:
		total = 0
	}

	hasMore := false
	if int64(len(data)) > pageSize {
		hasMore = true
		data = data[:pageSize]
	}

	out := bson.M{
		"data": data,
		"has_more": hasMore,
		"total": total,
	}

	if hasMore {
		// next cursor
		var last bson.M = data[len(data) - 1].(bson.M)
		var nextCursor string
		lastId := last["_id"]

		nextCursor = EncodeCursor(lastId.(bson.ObjectID))

		out["next_cursor"] = nextCursor
	}

	// _data, err := bson.Marshal(out)
	// if err != nil {
	// 	return nil, err
	// }

	// var r bson.M
	// if err := bson.Unmarshal(_data, &r); err != nil {
	// 	return nil, err
	// }

	return out, nil
}

// func (c *MongoClient) FindNext(ctx context.Context, database, name string, filter bson.M, nextCursor string, limit int64) ([]bson.M, error) {
// 	collection := c.GetCollection(database, name)

// 	opts := options.Find().
// 					SetLimit(max(limit, c.Limit)).
// 					SetSort()

// 	cursor, err := collection.Find(ctx, filter)
// 	if err != nil {
// 		return nil, err
// 	}

// 	var results []bson.M
// 	if err = cursor.All(ctx, &results); err != nil {
// 		return nil, err
// 	}

// 	return results, err
// }

// func EncodeCursor()