package segments

/*
#cgo pkg-config: milvus_segcore milvus_common

#include "segcore/collection_c.h"
#include "segcore/segment_c.h"
#include "segcore/segcore_init_c.h"
#include "common/init_c.h"

*/
import "C"

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"io"
	"strconv"

	"go.uber.org/zap"

	"github.com/milvus-io/milvus-proto/go-api/v2/schemapb"
	"github.com/milvus-io/milvus/internal/proto/internalpb"
	"github.com/milvus-io/milvus/internal/querynodev2/segments/metricsutil"
	"github.com/milvus-io/milvus/internal/storage"
	"github.com/milvus-io/milvus/pkg/common"
	"github.com/milvus-io/milvus/pkg/log"
	"github.com/milvus-io/milvus/pkg/mq/msgstream"
	"github.com/milvus-io/milvus/pkg/util/typeutil"
)

func GetPkField(schema *schemapb.CollectionSchema) *schemapb.FieldSchema {
	for _, field := range schema.GetFields() {
		if field.GetIsPrimaryKey() {
			return field
		}
	}
	return nil
}

// TODO: remove this function to proper file
// GetPrimaryKeys would get primary keys by insert messages
func GetPrimaryKeys(msg *msgstream.InsertMsg, schema *schemapb.CollectionSchema) ([]storage.PrimaryKey, error) {
	if msg.IsRowBased() {
		return getPKsFromRowBasedInsertMsg(msg, schema)
	}
	return getPKsFromColumnBasedInsertMsg(msg, schema)
}

func getPKsFromRowBasedInsertMsg(msg *msgstream.InsertMsg, schema *schemapb.CollectionSchema) ([]storage.PrimaryKey, error) {
	offset := 0
	for _, field := range schema.Fields {
		if field.IsPrimaryKey {
			break
		}
		switch field.DataType {
		case schemapb.DataType_Bool:
			offset++
		case schemapb.DataType_Int8:
			offset++
		case schemapb.DataType_Int16:
			offset += 2
		case schemapb.DataType_Int32:
			offset += 4
		case schemapb.DataType_Int64:
			offset += 8
		case schemapb.DataType_Float:
			offset += 4
		case schemapb.DataType_Double:
			offset += 8
		case schemapb.DataType_FloatVector:
			for _, t := range field.TypeParams {
				if t.Key == common.DimKey {
					dim, err := strconv.Atoi(t.Value)
					if err != nil {
						return nil, fmt.Errorf("strconv wrong on get dim, err = %s", err)
					}
					offset += dim * 4
					break
				}
			}
		case schemapb.DataType_BinaryVector:
			for _, t := range field.TypeParams {
				if t.Key == common.DimKey {
					dim, err := strconv.Atoi(t.Value)
					if err != nil {
						return nil, fmt.Errorf("strconv wrong on get dim, err = %s", err)
					}
					offset += dim / 8
					break
				}
			}
		case schemapb.DataType_Float16Vector:
			for _, t := range field.TypeParams {
				if t.Key == common.DimKey {
					dim, err := strconv.Atoi(t.Value)
					if err != nil {
						return nil, fmt.Errorf("strconv wrong on get dim, err = %s", err)
					}
					offset += dim * 2
					break
				}
			}
		case schemapb.DataType_BFloat16Vector:
			for _, t := range field.TypeParams {
				if t.Key == common.DimKey {
					dim, err := strconv.Atoi(t.Value)
					if err != nil {
						return nil, fmt.Errorf("strconv wrong on get dim, err = %s", err)
					}
					offset += dim * 2
					break
				}
			}
		case schemapb.DataType_SparseFloatVector:
			return nil, fmt.Errorf("SparseFloatVector not support in row based message")
		}
	}

	log.Info(strconv.FormatInt(int64(offset), 10))
	blobReaders := make([]io.Reader, len(msg.RowData))
	for i, blob := range msg.RowData {
		blobReaders[i] = bytes.NewReader(blob.GetValue()[offset : offset+8])
	}
	pks := make([]storage.PrimaryKey, len(blobReaders))

	for i, reader := range blobReaders {
		var int64PkValue int64
		err := binary.Read(reader, common.Endian, &int64PkValue)
		if err != nil {
			log.Warn("binary read blob value failed", zap.Error(err))
			return nil, err
		}
		pks[i] = storage.NewInt64PrimaryKey(int64PkValue)
	}

	return pks, nil
}

func getPKsFromColumnBasedInsertMsg(msg *msgstream.InsertMsg, schema *schemapb.CollectionSchema) ([]storage.PrimaryKey, error) {
	primaryFieldSchema, err := typeutil.GetPrimaryFieldSchema(schema)
	if err != nil {
		return nil, err
	}

	primaryFieldData, err := typeutil.GetPrimaryFieldData(msg.GetFieldsData(), primaryFieldSchema)
	if err != nil {
		return nil, err
	}

	pks, err := storage.ParseFieldData2PrimaryKeys(primaryFieldData)
	if err != nil {
		return nil, err
	}

	return pks, nil
}

// mergeRequestCost merge the costs of request, the cost may came from different worker in same channel
// or different channel in same collection, for now we just choose the part with the highest response time
func mergeRequestCost(requestCosts []*internalpb.CostAggregation) *internalpb.CostAggregation {
	var result *internalpb.CostAggregation
	for _, cost := range requestCosts {
		if result == nil || result.ResponseTime < cost.ResponseTime {
			result = cost
		}
	}

	return result
}

func getIndexEngineVersion() (minimal, current int32) {
	cMinimal, cCurrent := C.GetMinimalIndexVersion(), C.GetCurrentIndexVersion()
	return int32(cMinimal), int32(cCurrent)
}

// getSegmentMetricLabel returns the label for segment metrics.
func getSegmentMetricLabel(segment Segment) metricsutil.SegmentLabel {
	return metricsutil.SegmentLabel{
		DatabaseName:  segment.DatabaseName(),
		ResourceGroup: segment.ResourceGroup(),
	}
}