package extractors

import (
	"context"

	dbwrapper "git.ksdemosapps.com/kylesoda/go-migrate/internal/app/db-wrapper"
	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
	"github.com/google/uuid"
)

type GenericExtractor struct {
	db dbwrapper.DbWrapper
}

func NewExtractor(db dbwrapper.DbWrapper) GenericExtractor {
	return GenericExtractor{db: db}
}

func sendBatch(ctx context.Context, chBatchesOut chan<- models.Batch, batch models.Batch) error {
	select {
	case chBatchesOut <- batch:
		return nil
	case <-ctx.Done():
		return ctx.Err()
	}
}

func flush(
	ctx context.Context,
	partition *models.Partition,
	batchSize int,
	batchRows []models.UnknownRowValues,
	chBatchesOut chan<- models.Batch,
) error {
	if len(batchRows) == 0 {
		return nil
	}

	batch := models.Batch{Id: uuid.New(), PartitionId: partition.Id, Rows: batchRows}
	batchRows = make([]models.UnknownRowValues, 0, batchSize)
	return sendBatch(ctx, chBatchesOut, batch)
}