// Copyright 2016 PingCAP, Inc.
//
// 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,
// See the License for the specific language governing permissions and
// limitations under the License.

package xeval

import (
	"testing"
	"time"

	. "github.com/pingcap/check"
	"github.com/pingcap/tidb/mysql"
	"github.com/pingcap/tidb/util/codec"
	"github.com/pingcap/tidb/util/types"
	"github.com/pingcap/tipb/go-tipb"
)

func TestT(t *testing.T) {
	TestingT(t)
}

var _ = Suite(&testEvalSuite{})

type testEvalSuite struct{}

// TODO: add more tests.
func (s *testEvalSuite) TestEval(c *C) {
	colID := int64(1)
	row := make(map[int64]types.Datum)
	row[colID] = types.NewIntDatum(100)
	xevaluator := &Evaluator{Row: row}
	cases := []struct {
		expr   *tipb.Expr
		result types.Datum
	}{
		// Datums.
		{
			datumExpr(types.NewFloat32Datum(1.1)),
			types.NewFloat32Datum(1.1),
		},
		{
			datumExpr(types.NewFloat64Datum(1.1)),
			types.NewFloat64Datum(1.1),
		},
		{
			datumExpr(types.NewIntDatum(1)),
			types.NewIntDatum(1),
		},
		{
			datumExpr(types.NewUintDatum(1)),
			types.NewUintDatum(1),
		},
		{
			datumExpr(types.NewBytesDatum([]byte("abc"))),
			types.NewBytesDatum([]byte("abc")),
		},
		{
			datumExpr(types.NewStringDatum("abc")),
			types.NewStringDatum("abc"),
		},
		{
			datumExpr(types.Datum{}),
			types.Datum{},
		},
		{
			datumExpr(types.NewDurationDatum(mysql.Duration{Duration: time.Hour})),
			types.NewDurationDatum(mysql.Duration{Duration: time.Hour}),
		},
		{
			datumExpr(types.NewDecimalDatum(mysql.NewDecimalFromFloat(1.1))),
			types.NewDecimalDatum(mysql.NewDecimalFromFloat(1.1)),
		},
		{
			columnExpr(1),
			types.NewIntDatum(100),
		},
		// Comparison operations.
		{
			binaryExpr(types.NewIntDatum(100), types.NewIntDatum(1), tipb.ExprType_LT),
			types.NewIntDatum(0),
		},
		{
			binaryExpr(types.NewIntDatum(1), types.NewIntDatum(100), tipb.ExprType_LT),
			types.NewIntDatum(1),
		},
		{
			binaryExpr(types.NewIntDatum(100), types.Datum{}, tipb.ExprType_LT),
			types.Datum{},
		},
		{
			binaryExpr(types.NewIntDatum(100), types.NewIntDatum(1), tipb.ExprType_LE),
			types.NewIntDatum(0),
		},
		{
			binaryExpr(types.NewIntDatum(1), types.NewIntDatum(1), tipb.ExprType_LE),
			types.NewIntDatum(1),
		},
		{
			binaryExpr(types.NewIntDatum(100), types.Datum{}, tipb.ExprType_LE),
			types.Datum{},
		},
		{
			binaryExpr(types.NewIntDatum(100), types.NewIntDatum(1), tipb.ExprType_EQ),
			types.NewIntDatum(0),
		},
		{
			binaryExpr(types.NewIntDatum(100), types.NewIntDatum(100), tipb.ExprType_EQ),
			types.NewIntDatum(1),
		},
		{
			binaryExpr(types.NewIntDatum(100), types.Datum{}, tipb.ExprType_EQ),
			types.Datum{},
		},
		{
			binaryExpr(types.NewIntDatum(100), types.NewIntDatum(100), tipb.ExprType_NE),
			types.NewIntDatum(0),
		},
		{
			binaryExpr(types.NewIntDatum(100), types.NewIntDatum(1), tipb.ExprType_NE),
			types.NewIntDatum(1),
		},
		{
			binaryExpr(types.NewIntDatum(100), types.Datum{}, tipb.ExprType_NE),
			types.Datum{},
		},
		{
			binaryExpr(types.NewIntDatum(1), types.NewIntDatum(100), tipb.ExprType_GE),
			types.NewIntDatum(0),
		},
		{
			binaryExpr(types.NewIntDatum(100), types.NewIntDatum(100), tipb.ExprType_GE),
			types.NewIntDatum(1),
		},
		{
			binaryExpr(types.NewIntDatum(100), types.Datum{}, tipb.ExprType_GE),
			types.Datum{},
		},
		{
			binaryExpr(types.NewIntDatum(100), types.NewIntDatum(100), tipb.ExprType_GT),
			types.NewIntDatum(0),
		},
		{
			binaryExpr(types.NewIntDatum(100), types.NewIntDatum(1), tipb.ExprType_GT),
			types.NewIntDatum(1),
		},
		{
			binaryExpr(types.NewIntDatum(100), types.Datum{}, tipb.ExprType_GT),
			types.Datum{},
		},
		{
			binaryExpr(types.NewIntDatum(1), types.Datum{}, tipb.ExprType_NullEQ),
			types.NewIntDatum(0),
		},
		{
			binaryExpr(types.Datum{}, types.Datum{}, tipb.ExprType_NullEQ),
			types.NewIntDatum(1),
		},
		// Logic operation.
		{
			binaryExpr(types.NewIntDatum(0), types.NewIntDatum(1), tipb.ExprType_And),
			types.NewIntDatum(0),
		},
		{
			binaryExpr(types.NewIntDatum(1), types.NewIntDatum(1), tipb.ExprType_And),
			types.NewIntDatum(1),
		},
		{
			binaryExpr(types.NewIntDatum(0), types.Datum{}, tipb.ExprType_And),
			types.NewIntDatum(0),
		},
		{
			binaryExpr(types.NewIntDatum(1), types.Datum{}, tipb.ExprType_And),
			types.Datum{},
		},
		{
			binaryExpr(types.NewIntDatum(0), types.NewIntDatum(0), tipb.ExprType_Or),
			types.NewIntDatum(0),
		},
		{
			binaryExpr(types.NewIntDatum(0), types.NewIntDatum(1), tipb.ExprType_Or),
			types.NewIntDatum(1),
		},
		{
			binaryExpr(types.NewIntDatum(0), types.Datum{}, tipb.ExprType_Or),
			types.Datum{},
		},
		{
			binaryExpr(types.NewIntDatum(1), types.Datum{}, tipb.ExprType_Or),
			types.NewIntDatum(1),
		},
		{
			binaryExpr(
				binaryExpr(types.NewIntDatum(1), types.NewIntDatum(1), tipb.ExprType_EQ),
				binaryExpr(types.NewIntDatum(1), types.NewIntDatum(1), tipb.ExprType_EQ),
				tipb.ExprType_And),
			types.NewIntDatum(1),
		},
		{
			notExpr(datumExpr(types.NewIntDatum(1))),
			types.NewIntDatum(0),
		},
		{
			notExpr(datumExpr(types.NewIntDatum(0))),
			types.NewIntDatum(1),
		},
		{
			notExpr(datumExpr(types.Datum{})),
			types.Datum{},
		},
	}
	for _, ca := range cases {
		result, err := xevaluator.Eval(ca.expr)
		c.Assert(err, IsNil)
		c.Assert(result.Kind(), Equals, ca.result.Kind())
		cmp, err := result.CompareDatum(ca.result)
		c.Assert(err, IsNil)
		c.Assert(cmp, Equals, 0)
	}
}

func binaryExpr(left, right interface{}, tp tipb.ExprType) *tipb.Expr {
	expr := new(tipb.Expr)
	expr.Tp = tp.Enum()
	expr.Children = make([]*tipb.Expr, 2)
	switch x := left.(type) {
	case types.Datum:
		expr.Children[0] = datumExpr(x)
	case *tipb.Expr:
		expr.Children[0] = x
	}
	switch x := right.(type) {
	case types.Datum:
		expr.Children[1] = datumExpr(x)
	case *tipb.Expr:
		expr.Children[1] = x
	}
	return expr
}

func datumExpr(d types.Datum) *tipb.Expr {
	expr := new(tipb.Expr)
	switch d.Kind() {
	case types.KindInt64:
		expr.Tp = tipb.ExprType_Int64.Enum()
		expr.Val = codec.EncodeInt(nil, d.GetInt64())
	case types.KindUint64:
		expr.Tp = tipb.ExprType_Uint64.Enum()
		expr.Val = codec.EncodeUint(nil, d.GetUint64())
	case types.KindString:
		expr.Tp = tipb.ExprType_String.Enum()
		expr.Val = d.GetBytes()
	case types.KindBytes:
		expr.Tp = tipb.ExprType_Bytes.Enum()
		expr.Val = d.GetBytes()
	case types.KindFloat32:
		expr.Tp = tipb.ExprType_Float32.Enum()
		expr.Val = codec.EncodeFloat(nil, d.GetFloat64())
	case types.KindFloat64:
		expr.Tp = tipb.ExprType_Float64.Enum()
		expr.Val = codec.EncodeFloat(nil, d.GetFloat64())
	case types.KindMysqlDuration:
		expr.Tp = tipb.ExprType_MysqlDuration.Enum()
		expr.Val = codec.EncodeInt(nil, int64(d.GetMysqlDuration().Duration))
	case types.KindMysqlDecimal:
		expr.Tp = tipb.ExprType_MysqlDecimal.Enum()
		expr.Val = codec.EncodeDecimal(nil, d.GetMysqlDecimal())
	default:
		expr.Tp = tipb.ExprType_Null.Enum()
	}
	return expr
}

func columnExpr(columnID int64) *tipb.Expr {
	expr := new(tipb.Expr)
	expr.Tp = tipb.ExprType_ColumnRef.Enum()
	expr.Val = codec.EncodeInt(nil, columnID)
	return expr
}

func likeExpr(target, pattern string) *tipb.Expr {
	targetExpr := datumExpr(types.NewStringDatum(target))
	patternExpr := datumExpr(types.NewStringDatum(pattern))
	return &tipb.Expr{Tp: tipb.ExprType_Like.Enum(), Children: []*tipb.Expr{targetExpr, patternExpr}}
}

func notExpr(value interface{}) *tipb.Expr {
	expr := new(tipb.Expr)
	expr.Tp = tipb.ExprType_Not.Enum()
	switch x := value.(type) {
	case types.Datum:
		expr.Children = []*tipb.Expr{datumExpr(x)}
	case *tipb.Expr:
		expr.Children = []*tipb.Expr{x}
	}
	return expr
}

func (s *testEvalSuite) TestLike(c *C) {
	cases := []struct {
		expr   *tipb.Expr
		result int64
	}{
		{
			expr:   likeExpr("a", ""),
			result: 0,
		},
		{
			expr:   likeExpr("a", "a"),
			result: 1,
		},
		{
			expr:   likeExpr("a", "b"),
			result: 0,
		},
		{
			expr:   likeExpr("aAb", "AaB"),
			result: 1,
		},
		{
			expr:   likeExpr("a", "%"),
			result: 1,
		},
		{
			expr:   likeExpr("aAD", "%d"),
			result: 1,
		},
		{
			expr:   likeExpr("aAeD", "%e"),
			result: 0,
		},
		{
			expr:   likeExpr("aAb", "Aa%"),
			result: 1,
		},
		{
			expr:   likeExpr("abAb", "Aa%"),
			result: 0,
		},
		{
			expr:   likeExpr("aAcb", "%C%"),
			result: 1,
		},
		{
			expr:   likeExpr("aAb", "%C%"),
			result: 0,
		},
	}
	ev := &Evaluator{}
	for _, ca := range cases {
		res, err := ev.Eval(ca.expr)
		c.Check(err, IsNil)
		c.Check(res.GetInt64(), Equals, ca.result)
	}
}

func (s *testEvalSuite) TestWhereIn(c *C) {
	cases := []struct {
		expr   *tipb.Expr
		result interface{}
	}{
		{
			expr:   inExpr(1, 1, 2),
			result: true,
		},
		{
			expr:   inExpr(1, 1, nil),
			result: true,
		},
		{
			expr:   inExpr(1, 2, nil),
			result: nil,
		},
		{
			expr:   inExpr(nil, 1, nil),
			result: nil,
		},
		{
			expr:   inExpr(2, 1, nil),
			result: nil,
		},
		{
			expr:   inExpr(2),
			result: false,
		},
		{
			expr:   inExpr("abc", "abc", "ab"),
			result: true,
		},
		{
			expr:   inExpr("abc", "aba", "bab"),
			result: false,
		},
	}
	ev := &Evaluator{}
	for _, ca := range cases {
		res, err := ev.Eval(ca.expr)
		c.Check(err, IsNil)
		if ca.result == nil {
			c.Check(res.Kind(), Equals, types.KindNull)
		} else {
			c.Check(res.Kind(), Equals, types.KindInt64)
			if ca.result == true {
				c.Check(res.GetInt64(), Equals, int64(1))
			} else {
				c.Check(res.GetInt64(), Equals, int64(0))
			}
		}
	}
}

func inExpr(target interface{}, list ...interface{}) *tipb.Expr {
	targetDatum := types.NewDatum(target)
	var listDatums []types.Datum
	for _, v := range list {
		listDatums = append(listDatums, types.NewDatum(v))
	}
	types.SortDatums(listDatums)
	targetExpr := datumExpr(targetDatum)
	val, _ := codec.EncodeValue(nil, listDatums...)
	listExpr := &tipb.Expr{Tp: tipb.ExprType_ValueList.Enum(), Val: val}
	return &tipb.Expr{Tp: tipb.ExprType_In.Enum(), Children: []*tipb.Expr{targetExpr, listExpr}}
}