package indexparamcheck

/*
#cgo pkg-config: milvus_core

#include <stdlib.h>	// free
#include "segcore/vector_index_c.h"
*/
import "C"

import (
	"math"
	"unsafe"

	"google.golang.org/protobuf/proto"

	"github.com/milvus-io/milvus-proto/go-api/v3/commonpb"
	"github.com/milvus-io/milvus-proto/go-api/v3/schemapb"
	_ "github.com/milvus-io/milvus/internal/util/cgo"
	"github.com/milvus-io/milvus/internal/util/vecindexmgr"
	"github.com/milvus-io/milvus/pkg/v3/common"
	"github.com/milvus-io/milvus/pkg/v3/proto/indexcgopb"
	"github.com/milvus-io/milvus/pkg/v3/util/merr"
	"github.com/milvus-io/milvus/pkg/v3/util/paramtable"
	"github.com/milvus-io/milvus/pkg/v3/util/typeutil"
)

type vecIndexChecker struct {
	baseChecker
}

// HandleCStatus deals with the error returned from CGO
func HandleCStatus(status *C.CStatus) error {
	if status.error_code == 0 {
		return nil
	}
	errorMsg := C.GoString(status.error_msg)
	defer C.free(unsafe.Pointer(status.error_msg))

	// The sole caller validates USER-SUPPLIED index params via knowhere, which
	// reports bad params as ConfigInvalid (2006). At this boundary that is the
	// established ParameterInvalid wire contract (code 1100, message suffix
	// "invalid parameter") that SDK/e2e error handling is built on. Any other
	// code is an internal C++ failure and classifies via the shared segcore
	// table (system blame, original code preserved in the message).
	const knowhereConfigInvalid = 2006
	if int32(status.error_code) == knowhereConfigInvalid {
		return merr.WrapErrParameterInvalidMsg("%s", errorMsg)
	}
	return merr.SegcoreError(int32(status.error_code), errorMsg)
}

func (c vecIndexChecker) StaticCheck(dataType schemapb.DataType, elementType schemapb.DataType, params map[string]string) error {
	if typeutil.IsDenseFloatVectorType(dataType) {
		if !CheckStrByValues(params, Metric, FloatVectorMetrics) {
			return merr.WrapErrParameterInvalidMsg("metric type %s not found or not supported, supported: %v", params[Metric], FloatVectorMetrics)
		}
	} else if typeutil.IsSparseFloatVectorType(dataType) {
		if !CheckStrByValues(params, Metric, SparseMetrics) {
			return merr.WrapErrParameterInvalidMsg("metric type not found or not supported, supported: %v", SparseMetrics)
		}
		// Validate inverted_index_algo if provided. This check is done in Go because
		// the C++ knowhere library no longer validates this parameter (removed in knowhere fd532fb).
		if algo, ok := params[SparseInvertedIndexAlgo]; ok {
			validAlgo := false
			for _, a := range SparseInvertedIndexAlgos {
				if a == algo {
					validAlgo = true
					break
				}
			}
			if !validAlgo {
				return merr.WrapErrParameterInvalidMsg("sparse inverted index algo %s not found or not supported, supported: %v", algo, SparseInvertedIndexAlgos)
			}
		}
	} else if typeutil.IsBinaryVectorType(dataType) {
		if !CheckStrByValues(params, Metric, BinaryVectorMetrics) {
			return merr.WrapErrParameterInvalidMsg("metric type %s not found or not supported, supported: %v", params[Metric], BinaryVectorMetrics)
		}
	} else if typeutil.IsIntVectorType(dataType) {
		if !CheckStrByValues(params, Metric, IntVectorMetrics) {
			return merr.WrapErrParameterInvalidMsg("metric type %s not found or not supported, supported: %v", params[Metric], IntVectorMetrics)
		}
	} else if typeutil.IsArrayOfVectorType(dataType) {
		if err := ValidateArrayOfVectorMetricType(elementType, params[Metric]); err != nil {
			return err
		}
	}

	indexType, exist := params[common.IndexTypeKey]

	if !exist {
		return merr.WrapErrParameterInvalidMsg("no indexType is specified")
	}

	if !vecindexmgr.GetVecIndexMgrInstance().IsVecIndex(indexType) {
		return merr.WrapErrParameterInvalidMsg("indexType %s is not supported", indexType)
	}

	protoIndexParams := &indexcgopb.IndexParams{
		Params: make([]*commonpb.KeyValuePair, 0),
	}

	for key, value := range params {
		protoIndexParams.Params = append(protoIndexParams.Params, &commonpb.KeyValuePair{Key: key, Value: value})
	}

	indexParamsBlob, err := proto.Marshal(protoIndexParams)
	if err != nil {
		return merr.WrapErrParameterInvalidMsg("failed to marshal index params: %s", err)
	}

	var status C.CStatus

	cIndexType := C.CString(indexType)
	cDataType := uint32(dataType)
	cElementType := uint32(elementType)
	status = C.ValidateIndexParams(cIndexType, cDataType, cElementType, (*C.uint8_t)(unsafe.Pointer(&indexParamsBlob[0])), (C.uint64_t)(len(indexParamsBlob)))
	C.free(unsafe.Pointer(cIndexType))

	return HandleCStatus(&status)
}

func (c vecIndexChecker) CheckTrain(dataType schemapb.DataType, elementType schemapb.DataType, params map[string]string) error {
	if err := c.StaticCheck(dataType, elementType, params); err != nil {
		return err
	}

	if typeutil.IsFixDimVectorType(dataType) || (typeutil.IsArrayOfVectorType(dataType) && typeutil.IsFixDimVectorType(elementType)) {
		if !CheckIntByRange(params, DIM, 1, math.MaxInt) {
			return merr.WrapErrParameterInvalidMsg("failed to check vector dimension, should be larger than 0 and smaller than math.MaxInt")
		}
	}

	return c.baseChecker.CheckTrain(dataType, elementType, params)
}

func (c vecIndexChecker) CheckValidDataType(indexType IndexType, field *schemapb.FieldSchema) error {
	if !typeutil.IsVectorType(field.GetDataType()) {
		return merr.WrapErrParameterInvalidMsg("index %s only supports vector data type", indexType)
	}
	if !vecindexmgr.GetVecIndexMgrInstance().IsDataTypeSupport(indexType, field.GetDataType(), field.GetElementType()) {
		return merr.WrapErrParameterInvalidMsg("index %s do not support data type: %s", indexType, schemapb.DataType_name[int32(field.GetDataType())])
	}
	return nil
}

func (c vecIndexChecker) SetDefaultMetricTypeIfNotExist(dType schemapb.DataType, params map[string]string) {
	paramtable.SetDefaultMetricTypeIfNotExist(dType, params)
}

func newVecIndexChecker() IndexChecker {
	return &vecIndexChecker{}
}
