/*
Copyright © 2020 Marvin

Licensed 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 diff

import (
	"log"
	"strconv"

	"github.com/pingcap/parser/model"
	"github.com/pingcap/enterprise-toolkit/tichecker/pkg/dbutil"
	"go.uber.org/zap"
)

// RowData is the struct of rows selected from mysql/tidb
type RowData struct {
	Data   map[string]*dbutil.ColumnData
	Source int
}

// RowDatas is a heap of MergeItems.
type RowDatas struct {
	Rows         []RowData
	OrderKeyCols []*model.ColumnInfo
}

func (r RowDatas) Len() int { return len(r.Rows) }
func (r RowDatas) Less(i, j int) bool {
	for _, col := range r.OrderKeyCols {
		col1, ok := r.Rows[i].Data[col.Name.O]
		if !ok {
			log.Fatal("data don't have column", zap.String("column", col.Name.O), zap.Reflect("data", r.Rows[i].Data))
		}
		col2, ok := r.Rows[j].Data[col.Name.O]
		if !ok {
			log.Fatal("data don't have column", zap.String("column", col.Name.O), zap.Reflect("data", r.Rows[j].Data))
		}

		if col1.IsNull {
			if col2.IsNull {
				continue
			}

			return true
		}
		if col2.IsNull {
			return false
		}

		strData1 := string(col1.Data)
		strData2 := string(col2.Data)

		if needQuotes(col.FieldType) {
			if strData1 == strData2 {
				continue
			}
			if strData1 > strData2 {
				return false
			}
			return true
		}

		num1, err1 := strconv.ParseFloat(strData1, 64)
		if err1 != nil {
			log.Fatal("convert string to float failed", zap.String("column", col.Name.O), zap.String("data", strData1), zap.Error(err1))
		}
		num2, err2 := strconv.ParseFloat(strData2, 64)
		if err2 != nil {
			log.Fatal("convert string to float failed", zap.String("column", col.Name.O), zap.String("data", strData2), zap.Error(err2))
		}

		if num1 == num2 {
			continue
		}
		if num1 > num2 {
			return false
		}
		return true

	}

	return false
}
func (r RowDatas) Swap(i, j int) { r.Rows[i], r.Rows[j] = r.Rows[j], r.Rows[i] }

// Push implements heap.Interface's Push function
func (r *RowDatas) Push(x interface{}) {
	r.Rows = append(r.Rows, x.(RowData))
}

// Pop implements heap.Interface's Pop function
func (r *RowDatas) Pop() interface{} {
	if len(r.Rows) == 0 {
		return nil
	}
	old := r.Rows
	n := len(old)
	x := old[n-1]
	r.Rows = old[0 : n-1]
	return x
}