// Licensed to the LF AI & Data foundation under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package json

import (
	"encoding/json"
	"fmt"
	"strconv"

	"github.com/cockroachdb/errors"
	"github.com/samber/lo"

	"github.com/milvus-io/milvus-proto/go-api/v2/schemapb"
	"github.com/milvus-io/milvus/pkg/util/merr"
	"github.com/milvus-io/milvus/pkg/util/typeutil"
)

type RowParser interface {
	Parse(raw any) (Row, error)
}

type rowParser struct {
	id2Dim       map[int64]int
	id2Field     map[int64]*schemapb.FieldSchema
	name2FieldID map[string]int64
	pkField      *schemapb.FieldSchema
	dynamicField *schemapb.FieldSchema
}

func NewRowParser(schema *schemapb.CollectionSchema) (RowParser, error) {
	id2Field := lo.KeyBy(schema.GetFields(), func(field *schemapb.FieldSchema) int64 {
		return field.GetFieldID()
	})

	id2Dim := make(map[int64]int)
	for id, field := range id2Field {
		if typeutil.IsVectorType(field.GetDataType()) && !typeutil.IsSparseFloatVectorType(field.GetDataType()) {
			dim, err := typeutil.GetDim(field)
			if err != nil {
				return nil, err
			}
			id2Dim[id] = int(dim)
		}
	}

	pkField, err := typeutil.GetPrimaryFieldSchema(schema)
	if err != nil {
		return nil, err
	}

	name2FieldID := lo.SliceToMap(schema.GetFields(),
		func(field *schemapb.FieldSchema) (string, int64) {
			return field.GetName(), field.GetFieldID()
		})

	if pkField.GetAutoID() {
		delete(name2FieldID, pkField.GetName())
	}

	dynamicField := typeutil.GetDynamicField(schema)
	if dynamicField != nil {
		delete(name2FieldID, dynamicField.GetName())
	}
	return &rowParser{
		id2Dim:       id2Dim,
		id2Field:     id2Field,
		name2FieldID: name2FieldID,
		pkField:      pkField,
		dynamicField: dynamicField,
	}, nil
}

func (r *rowParser) wrapTypeError(v any, fieldID int64) error {
	field := r.id2Field[fieldID]
	return merr.WrapErrImportFailed(fmt.Sprintf("expected type '%s' for field '%s', got type '%T' with value '%v'",
		field.GetDataType().String(), field.GetName(), v, v))
}

func (r *rowParser) wrapDimError(actualDim int, fieldID int64) error {
	field := r.id2Field[fieldID]
	return merr.WrapErrImportFailed(fmt.Sprintf("expected dim '%d' for field '%s' with type '%s', got dim '%d'",
		r.id2Dim[fieldID], field.GetName(), field.GetDataType().String(), actualDim))
}

func (r *rowParser) wrapArrayValueTypeError(v any, eleType schemapb.DataType) error {
	return merr.WrapErrImportFailed(fmt.Sprintf("expected element type '%s' in array field, got type '%T' with value '%v'",
		eleType.String(), v, v))
}

func (r *rowParser) Parse(raw any) (Row, error) {
	stringMap, ok := raw.(map[string]any)
	if !ok {
		return nil, merr.WrapErrImportFailed("invalid JSON format, each row should be a key-value map")
	}
	if _, ok = stringMap[r.pkField.GetName()]; ok && r.pkField.GetAutoID() {
		return nil, merr.WrapErrImportFailed(
			fmt.Sprintf("the primary key '%s' is auto-generated, no need to provide", r.pkField.GetName()))
	}
	dynamicValues := make(map[string]any)
	row := make(Row)
	for key, value := range stringMap {
		if fieldID, ok := r.name2FieldID[key]; ok {
			data, err := r.parseEntity(fieldID, value)
			if err != nil {
				return nil, err
			}
			row[fieldID] = data
		} else if r.dynamicField != nil {
			// has dynamic field, put redundant pair to dynamicValues
			dynamicValues[key] = value
		} else {
			return nil, merr.WrapErrImportFailed(fmt.Sprintf("the field '%s' is not defined in schema", key))
		}
	}
	for fieldName, fieldID := range r.name2FieldID {
		if _, ok = row[fieldID]; !ok {
			return nil, merr.WrapErrImportFailed(fmt.Sprintf("value of field '%s' is missed", fieldName))
		}
	}
	if r.dynamicField == nil {
		return row, nil
	}
	// combine the redundant pairs into dynamic field(if it has)
	err := r.combineDynamicRow(dynamicValues, row)
	if err != nil {
		return nil, err
	}
	return row, err
}

func (r *rowParser) combineDynamicRow(dynamicValues map[string]any, row Row) error {
	// Combine the dynamic field value
	// valid inputs:
	// case 1: {"id": 1, "vector": [], "x": 8, "$meta": "{\"y\": 8}"} ==>> {"id": 1, "vector": [], "$meta": "{\"y\": 8, \"x\": 8}"}
	// case 2: {"id": 1, "vector": [], "x": 8, "$meta": {}} ==>> {"id": 1, "vector": [], "$meta": {\"x\": 8}}
	// case 3: {"id": 1, "vector": [], "$meta": "{\"x\": 8}"}
	// case 4: {"id": 1, "vector": [], "$meta": {"x": 8}}
	// case 5: {"id": 1, "vector": [], "$meta": {}}
	// case 6: {"id": 1, "vector": [], "x": 8} ==>> {"id": 1, "vector": [], "$meta": "{\"x\": 8}"}
	// case 7: {"id": 1, "vector": []}
	// invalid inputs:
	// case 8: {"id": 1, "vector": [], "x": 6, "$meta": {"x": 8}} ==>> duplicated key is not allowed
	// case 9: {"id": 1, "vector": [], "x": 6, "$meta": "{\"x\": 8}"} ==>> duplicated key is not allowed
	dynamicFieldID := r.dynamicField.GetFieldID()
	if len(dynamicValues) == 0 {
		// case 7
		row[dynamicFieldID] = []byte("{}")
		return nil
	}

	if obj, ok := dynamicValues[r.dynamicField.GetName()]; ok {
		var mp map[string]interface{}
		switch value := obj.(type) {
		case string:
			// case 1, 3
			err := json.Unmarshal([]byte(value), &mp)
			if err != nil {
				return merr.WrapErrImportFailed("illegal value for dynamic field, not a JSON format string")
			}
		case map[string]interface{}:
			// case 2, 4, 5
			mp = value
		default:
			// invalid input
			return merr.WrapErrImportFailed("illegal value for dynamic field, not a JSON object")
		}
		delete(dynamicValues, r.dynamicField.GetName())
		for k, v := range mp {
			if _, ok = dynamicValues[k]; ok {
				// case 8, 9
				return merr.WrapErrImportFailed(fmt.Sprintf("duplicated key is not allowed, key=%s", k))
			}
			dynamicValues[k] = v
		}
	}
	data, err := r.parseEntity(dynamicFieldID, dynamicValues)
	if err != nil {
		return err
	}
	row[dynamicFieldID] = data

	return nil
}

func (r *rowParser) parseEntity(fieldID int64, obj any) (any, error) {
	switch r.id2Field[fieldID].GetDataType() {
	case schemapb.DataType_Bool:
		b, ok := obj.(bool)
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		return b, nil
	case schemapb.DataType_Int8:
		value, ok := obj.(json.Number)
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		num, err := strconv.ParseInt(value.String(), 0, 8)
		if err != nil {
			return nil, err
		}
		return int8(num), nil
	case schemapb.DataType_Int16:
		value, ok := obj.(json.Number)
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		num, err := strconv.ParseInt(value.String(), 0, 16)
		if err != nil {
			return nil, err
		}
		return int16(num), nil
	case schemapb.DataType_Int32:
		value, ok := obj.(json.Number)
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		num, err := strconv.ParseInt(value.String(), 0, 32)
		if err != nil {
			return nil, err
		}
		return int32(num), nil
	case schemapb.DataType_Int64:
		value, ok := obj.(json.Number)
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		num, err := strconv.ParseInt(value.String(), 0, 64)
		if err != nil {
			return nil, err
		}
		return num, nil
	case schemapb.DataType_Float:
		value, ok := obj.(json.Number)
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		num, err := strconv.ParseFloat(value.String(), 32)
		if err != nil {
			return nil, err
		}
		return float32(num), nil
	case schemapb.DataType_Double:
		value, ok := obj.(json.Number)
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		num, err := strconv.ParseFloat(value.String(), 64)
		if err != nil {
			return nil, err
		}
		return num, nil
	case schemapb.DataType_BinaryVector:
		arr, ok := obj.([]interface{})
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		if len(arr) != r.id2Dim[fieldID]/8 {
			return nil, r.wrapDimError(len(arr)*8, fieldID)
		}
		vec := make([]byte, len(arr))
		for i := 0; i < len(arr); i++ {
			value, ok := arr[i].(json.Number)
			if !ok {
				return nil, r.wrapTypeError(arr[i], fieldID)
			}
			num, err := strconv.ParseUint(value.String(), 0, 8)
			if err != nil {
				return nil, err
			}
			vec[i] = byte(num)
		}
		return vec, nil
	case schemapb.DataType_FloatVector:
		arr, ok := obj.([]interface{})
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		if len(arr) != r.id2Dim[fieldID] {
			return nil, r.wrapDimError(len(arr), fieldID)
		}
		vec := make([]float32, len(arr))
		for i := 0; i < len(arr); i++ {
			value, ok := arr[i].(json.Number)
			if !ok {
				return nil, r.wrapTypeError(arr[i], fieldID)
			}
			num, err := strconv.ParseFloat(value.String(), 32)
			if err != nil {
				return nil, err
			}
			vec[i] = float32(num)
		}
		return vec, nil
	case schemapb.DataType_Float16Vector:
		// parse float string to Float16 bytes
		arr, ok := obj.([]interface{})
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		if len(arr) != r.id2Dim[fieldID] {
			return nil, r.wrapDimError(len(arr), fieldID)
		}
		vec := make([]byte, len(arr)*2)
		for i := 0; i < len(arr); i++ {
			value, ok := arr[i].(json.Number)
			if !ok {
				return nil, r.wrapTypeError(arr[i], fieldID)
			}
			num, err := strconv.ParseFloat(value.String(), 32)
			if err != nil {
				return nil, err
			}
			copy(vec[i*2:], typeutil.Float32ToFloat16Bytes(float32(num)))
		}
		return vec, nil
	case schemapb.DataType_BFloat16Vector:
		// parse float string to BFloat16 bytes
		arr, ok := obj.([]interface{})
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		if len(arr) != r.id2Dim[fieldID] {
			return nil, r.wrapDimError(len(arr), fieldID)
		}
		vec := make([]byte, len(arr)*2)
		for i := 0; i < len(arr); i++ {
			value, ok := arr[i].(json.Number)
			if !ok {
				return nil, r.wrapTypeError(arr[i], fieldID)
			}
			num, err := strconv.ParseFloat(value.String(), 32)
			if err != nil {
				return nil, err
			}
			copy(vec[i*2:], typeutil.Float32ToBFloat16Bytes(float32(num)))
		}
		return vec, nil
	case schemapb.DataType_SparseFloatVector:
		arr, ok := obj.(map[string]interface{})
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		vec, err := typeutil.CreateSparseFloatRowFromMap(arr)
		if err != nil {
			return nil, err
		}
		return vec, nil
	case schemapb.DataType_String, schemapb.DataType_VarChar:
		value, ok := obj.(string)
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		return value, nil
	case schemapb.DataType_JSON:
		// for JSON data, we accept two kinds input: string and map[string]interface
		// user can write JSON content as {"FieldJSON": "{\"x\": 8}"} or {"FieldJSON": {"x": 8}}
		if value, ok := obj.(string); ok {
			var dummy interface{}
			err := json.Unmarshal([]byte(value), &dummy)
			if err != nil {
				return nil, err
			}
			return []byte(value), nil
		} else if mp, ok := obj.(map[string]interface{}); ok {
			bs, err := json.Marshal(mp)
			if err != nil {
				return nil, err
			}
			return bs, nil
		} else {
			return nil, r.wrapTypeError(obj, fieldID)
		}
	case schemapb.DataType_Array:
		arr, ok := obj.([]interface{})
		if !ok {
			return nil, r.wrapTypeError(obj, fieldID)
		}
		scalarFieldData, err := r.arrayToFieldData(arr, r.id2Field[fieldID].GetElementType())
		if err != nil {
			return nil, err
		}
		return scalarFieldData, nil
	default:
		return nil, merr.WrapErrImportFailed(fmt.Sprintf("parse json failed, unsupport data type: %s",
			r.id2Field[fieldID].GetDataType().String()))
	}
}

func (r *rowParser) arrayToFieldData(arr []interface{}, eleType schemapb.DataType) (*schemapb.ScalarField, error) {
	switch eleType {
	case schemapb.DataType_Bool:
		values := make([]bool, 0)
		for i := 0; i < len(arr); i++ {
			value, ok := arr[i].(bool)
			if !ok {
				return nil, r.wrapArrayValueTypeError(arr, eleType)
			}
			values = append(values, value)
		}
		return &schemapb.ScalarField{
			Data: &schemapb.ScalarField_BoolData{
				BoolData: &schemapb.BoolArray{
					Data: values,
				},
			},
		}, nil
	case schemapb.DataType_Int8, schemapb.DataType_Int16, schemapb.DataType_Int32:
		values := make([]int32, 0)
		for i := 0; i < len(arr); i++ {
			value, ok := arr[i].(json.Number)
			if !ok {
				return nil, r.wrapArrayValueTypeError(arr, eleType)
			}
			num, err := strconv.ParseInt(value.String(), 0, 32)
			if err != nil {
				return nil, err
			}
			values = append(values, int32(num))
		}
		return &schemapb.ScalarField{
			Data: &schemapb.ScalarField_IntData{
				IntData: &schemapb.IntArray{
					Data: values,
				},
			},
		}, nil
	case schemapb.DataType_Int64:
		values := make([]int64, 0)
		for i := 0; i < len(arr); i++ {
			value, ok := arr[i].(json.Number)
			if !ok {
				return nil, r.wrapArrayValueTypeError(arr, eleType)
			}
			num, err := strconv.ParseInt(value.String(), 0, 64)
			if err != nil {
				return nil, err
			}
			values = append(values, num)
		}
		return &schemapb.ScalarField{
			Data: &schemapb.ScalarField_LongData{
				LongData: &schemapb.LongArray{
					Data: values,
				},
			},
		}, nil
	case schemapb.DataType_Float:
		values := make([]float32, 0)
		for i := 0; i < len(arr); i++ {
			value, ok := arr[i].(json.Number)
			if !ok {
				return nil, r.wrapArrayValueTypeError(arr, eleType)
			}
			num, err := strconv.ParseFloat(value.String(), 32)
			if err != nil {
				return nil, err
			}
			values = append(values, float32(num))
		}
		return &schemapb.ScalarField{
			Data: &schemapb.ScalarField_FloatData{
				FloatData: &schemapb.FloatArray{
					Data: values,
				},
			},
		}, nil
	case schemapb.DataType_Double:
		values := make([]float64, 0)
		for i := 0; i < len(arr); i++ {
			value, ok := arr[i].(json.Number)
			if !ok {
				return nil, r.wrapArrayValueTypeError(arr, eleType)
			}
			num, err := strconv.ParseFloat(value.String(), 64)
			if err != nil {
				return nil, err
			}
			values = append(values, num)
		}
		return &schemapb.ScalarField{
			Data: &schemapb.ScalarField_DoubleData{
				DoubleData: &schemapb.DoubleArray{
					Data: values,
				},
			},
		}, nil
	case schemapb.DataType_VarChar, schemapb.DataType_String:
		values := make([]string, 0)
		for i := 0; i < len(arr); i++ {
			value, ok := arr[i].(string)
			if !ok {
				return nil, r.wrapArrayValueTypeError(arr, eleType)
			}
			values = append(values, value)
		}
		return &schemapb.ScalarField{
			Data: &schemapb.ScalarField_StringData{
				StringData: &schemapb.StringArray{
					Data: values,
				},
			},
		}, nil
	default:
		return nil, errors.New(fmt.Sprintf("unsupported array data type '%s'", eleType.String()))
	}
}
