/*
Copyright 2018 The KubeSphere Authors.
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 mysql

import (
	"strings"

	"github.com/gocraft/dbr"
)

const (
	placeholder = "?"
)

type EqCondition struct {
	dbr.Builder
	Column string
	Value  interface{}
}

// Copy From vendor/github.com/gocraft/dbr/condition.go:36
func buildCmp(d dbr.Dialect, buf dbr.Buffer, pred string, column string, value interface{}) error {
	buf.WriteString(d.QuoteIdent(column))
	buf.WriteString(" ")
	buf.WriteString(pred)
	buf.WriteString(" ")
	buf.WriteString(placeholder)

	buf.WriteValue(value)
	return nil
}

// And creates AND from a list of conditions
func And(cond ...dbr.Builder) dbr.Builder {
	return dbr.And(cond...)
}

// Or creates OR from a list of conditions
func Or(cond ...dbr.Builder) dbr.Builder {
	return dbr.Or(cond...)
}

func escape(str string) string {
	return strings.Map(func(r rune) rune {
		switch r {
		case '%', '\'', '^', '[', ']', '!', '_':
			return ' '
		}
		return r
	}, str)
}

func Like(column string, value string) dbr.Builder {
	value = "%" + strings.TrimSpace(escape(value)) + "%"
	return dbr.BuildFunc(func(d dbr.Dialect, buf dbr.Buffer) error {
		return buildCmp(d, buf, "LIKE", column, value)
	})
}

// Eq is `=`.
// When value is nil, it will be translated to `IS NULL`.
// When value is a slice, it will be translated to `IN`.
// Otherwise it will be translated to `=`.
func Eq(column string, value interface{}) dbr.Builder {
	return &EqCondition{
		Builder: dbr.Eq(column, value),
		Column:  column,
		Value:   value,
	}
}

// Neq is `!=`.
// When value is nil, it will be translated to `IS NOT NULL`.
// When value is a slice, it will be translated to `NOT IN`.
// Otherwise it will be translated to `!=`.
func Neq(column string, value interface{}) dbr.Builder {
	return dbr.Neq(column, value)
}

// Gt is `>`.
func Gt(column string, value interface{}) dbr.Builder {
	return dbr.Gt(column, value)
}

// Gte is '>='.
func Gte(column string, value interface{}) dbr.Builder {
	return dbr.Gte(column, value)
}

// Lt is '<'.
func Lt(column string, value interface{}) dbr.Builder {
	return dbr.Lt(column, value)
}

// Lte is `<=`.
func Lte(column string, value interface{}) dbr.Builder {
	return dbr.Lte(column, value)
}
