// Copyright 2015 The Xorm Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package xorm

import (
	"errors"
	"fmt"
	"reflect"
	"sort"
	"strconv"
	"strings"
	"time"

	"github.com/go-xorm/core"
)

// str2PK convert string value to primary key value according to tp
func str2PK(s string, tp reflect.Type) (interface{}, error) {
	var err error
	var result interface{}
	switch tp.Kind() {
	case reflect.Int:
		result, err = strconv.Atoi(s)
		if err != nil {
			return nil, errors.New("convert " + s + " as int: " + err.Error())
		}
	case reflect.Int8:
		x, err := strconv.Atoi(s)
		if err != nil {
			return nil, errors.New("convert " + s + " as int16: " + err.Error())
		}
		result = int8(x)
	case reflect.Int16:
		x, err := strconv.Atoi(s)
		if err != nil {
			return nil, errors.New("convert " + s + " as int16: " + err.Error())
		}
		result = int16(x)
	case reflect.Int32:
		x, err := strconv.Atoi(s)
		if err != nil {
			return nil, errors.New("convert " + s + " as int32: " + err.Error())
		}
		result = int32(x)
	case reflect.Int64:
		result, err = strconv.ParseInt(s, 10, 64)
		if err != nil {
			return nil, errors.New("convert " + s + " as int64: " + err.Error())
		}
	case reflect.Uint:
		x, err := strconv.ParseUint(s, 10, 64)
		if err != nil {
			return nil, errors.New("convert " + s + " as uint: " + err.Error())
		}
		result = uint(x)
	case reflect.Uint8:
		x, err := strconv.ParseUint(s, 10, 64)
		if err != nil {
			return nil, errors.New("convert " + s + " as uint8: " + err.Error())
		}
		result = uint8(x)
	case reflect.Uint16:
		x, err := strconv.ParseUint(s, 10, 64)
		if err != nil {
			return nil, errors.New("convert " + s + " as uint16: " + err.Error())
		}
		result = uint16(x)
	case reflect.Uint32:
		x, err := strconv.ParseUint(s, 10, 64)
		if err != nil {
			return nil, errors.New("convert " + s + " as uint32: " + err.Error())
		}
		result = uint32(x)
	case reflect.Uint64:
		result, err = strconv.ParseUint(s, 10, 64)
		if err != nil {
			return nil, errors.New("convert " + s + " as uint64: " + err.Error())
		}
	case reflect.String:
		result = s
	default:
		panic("unsupported convert type")
	}
	result = reflect.ValueOf(result).Convert(tp).Interface()
	return result, nil
}

func splitTag(tag string) (tags []string) {
	tag = strings.TrimSpace(tag)
	var hasQuote = false
	var lastIdx = 0
	for i, t := range tag {
		if t == '\'' {
			hasQuote = !hasQuote
		} else if t == ' ' {
			if lastIdx < i && !hasQuote {
				tags = append(tags, strings.TrimSpace(tag[lastIdx:i]))
				lastIdx = i + 1
			}
		}
	}
	if lastIdx < len(tag) {
		tags = append(tags, strings.TrimSpace(tag[lastIdx:]))
	}
	return
}

type zeroable interface {
	IsZero() bool
}

func isZero(k interface{}) bool {
	switch k.(type) {
	case int:
		return k.(int) == 0
	case int8:
		return k.(int8) == 0
	case int16:
		return k.(int16) == 0
	case int32:
		return k.(int32) == 0
	case int64:
		return k.(int64) == 0
	case uint:
		return k.(uint) == 0
	case uint8:
		return k.(uint8) == 0
	case uint16:
		return k.(uint16) == 0
	case uint32:
		return k.(uint32) == 0
	case uint64:
		return k.(uint64) == 0
	case float32:
		return k.(float32) == 0
	case float64:
		return k.(float64) == 0
	case bool:
		return k.(bool) == false
	case string:
		return k.(string) == ""
	case zeroable:
		return k.(zeroable).IsZero()
	}
	return false
}

func isStructZero(v reflect.Value) bool {
	if !v.IsValid() {
		return true
	}

	for i := 0; i < v.NumField(); i++ {
		field := v.Field(i)
		switch field.Kind() {
		case reflect.Ptr:
			field = field.Elem()
			fallthrough
		case reflect.Struct:
			if !isStructZero(field) {
				return false
			}
		default:
			if field.CanInterface() && !isZero(field.Interface()) {
				return false
			}
		}
	}
	return true
}

func int64ToIntValue(id int64, tp reflect.Type) reflect.Value {
	var v interface{}
	switch tp.Kind() {
	case reflect.Int16:
		v = int16(id)
	case reflect.Int32:
		v = int32(id)
	case reflect.Int:
		v = int(id)
	case reflect.Int64:
		v = id
	case reflect.Uint16:
		v = uint16(id)
	case reflect.Uint32:
		v = uint32(id)
	case reflect.Uint64:
		v = uint64(id)
	case reflect.Uint:
		v = uint(id)
	}
	return reflect.ValueOf(v).Convert(tp)
}

func int64ToInt(id int64, tp reflect.Type) interface{} {
	return int64ToIntValue(id, tp).Interface()
}

func isPKZero(pk core.PK) bool {
	for _, k := range pk {
		if isZero(k) {
			return true
		}
	}
	return false
}

func indexNoCase(s, sep string) int {
	return strings.Index(strings.ToLower(s), strings.ToLower(sep))
}

func splitNoCase(s, sep string) []string {
	idx := indexNoCase(s, sep)
	if idx < 0 {
		return []string{s}
	}
	return strings.Split(s, s[idx:idx+len(sep)])
}

func splitNNoCase(s, sep string, n int) []string {
	idx := indexNoCase(s, sep)
	if idx < 0 {
		return []string{s}
	}
	return strings.SplitN(s, s[idx:idx+len(sep)], n)
}

func makeArray(elem string, count int) []string {
	res := make([]string, count)
	for i := 0; i < count; i++ {
		res[i] = elem
	}
	return res
}

func rValue(bean interface{}) reflect.Value {
	return reflect.Indirect(reflect.ValueOf(bean))
}

func rType(bean interface{}) reflect.Type {
	sliceValue := reflect.Indirect(reflect.ValueOf(bean))
	//return reflect.TypeOf(sliceValue.Interface())
	return sliceValue.Type()
}

func structName(v reflect.Type) string {
	for v.Kind() == reflect.Ptr {
		v = v.Elem()
	}
	return v.Name()
}

func col2NewCols(columns ...string) []string {
	newColumns := make([]string, 0, len(columns))
	for _, col := range columns {
		col = strings.Replace(col, "`", "", -1)
		col = strings.Replace(col, `"`, "", -1)
		ccols := strings.Split(col, ",")
		for _, c := range ccols {
			newColumns = append(newColumns, strings.TrimSpace(c))
		}
	}
	return newColumns
}

func sliceEq(left, right []string) bool {
	if len(left) != len(right) {
		return false
	}
	sort.Sort(sort.StringSlice(left))
	sort.Sort(sort.StringSlice(right))
	for i := 0; i < len(left); i++ {
		if left[i] != right[i] {
			return false
		}
	}
	return true
}

func reflect2value(rawValue *reflect.Value) (str string, err error) {
	aa := reflect.TypeOf((*rawValue).Interface())
	vv := reflect.ValueOf((*rawValue).Interface())
	switch aa.Kind() {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		str = strconv.FormatInt(vv.Int(), 10)
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		str = strconv.FormatUint(vv.Uint(), 10)
	case reflect.Float32, reflect.Float64:
		str = strconv.FormatFloat(vv.Float(), 'f', -1, 64)
	case reflect.String:
		str = vv.String()
	case reflect.Array, reflect.Slice:
		switch aa.Elem().Kind() {
		case reflect.Uint8:
			data := rawValue.Interface().([]byte)
			str = string(data)
		default:
			err = fmt.Errorf("Unsupported struct type %v", vv.Type().Name())
		}
	// time type
	case reflect.Struct:
		if aa.ConvertibleTo(core.TimeType) {
			str = vv.Convert(core.TimeType).Interface().(time.Time).Format(time.RFC3339Nano)
		} else {
			err = fmt.Errorf("Unsupported struct type %v", vv.Type().Name())
		}
	case reflect.Bool:
		str = strconv.FormatBool(vv.Bool())
	case reflect.Complex128, reflect.Complex64:
		str = fmt.Sprintf("%v", vv.Complex())
	/* TODO: unsupported types below
	   case reflect.Map:
	   case reflect.Ptr:
	   case reflect.Uintptr:
	   case reflect.UnsafePointer:
	   case reflect.Chan, reflect.Func, reflect.Interface:
	*/
	default:
		err = fmt.Errorf("Unsupported struct type %v", vv.Type().Name())
	}
	return
}

func value2Bytes(rawValue *reflect.Value) (data []byte, err error) {
	var str string
	str, err = reflect2value(rawValue)
	if err != nil {
		return
	}
	data = []byte(str)
	return
}

func value2String(rawValue *reflect.Value) (data string, err error) {
	data, err = reflect2value(rawValue)
	if err != nil {
		return
	}
	return
}

func rows2Strings(rows *core.Rows) (resultsSlice []map[string]string, err error) {
	fields, err := rows.Columns()
	if err != nil {
		return nil, err
	}
	for rows.Next() {
		result, err := row2mapStr(rows, fields)
		if err != nil {
			return nil, err
		}
		resultsSlice = append(resultsSlice, result)
	}

	return resultsSlice, nil
}

func rows2maps(rows *core.Rows) (resultsSlice []map[string][]byte, err error) {
	fields, err := rows.Columns()
	if err != nil {
		return nil, err
	}
	for rows.Next() {
		result, err := row2map(rows, fields)
		if err != nil {
			return nil, err
		}
		resultsSlice = append(resultsSlice, result)
	}

	return resultsSlice, nil
}

func row2map(rows *core.Rows, fields []string) (resultsMap map[string][]byte, err error) {
	result := make(map[string][]byte)
	scanResultContainers := make([]interface{}, len(fields))
	for i := 0; i < len(fields); i++ {
		var scanResultContainer interface{}
		scanResultContainers[i] = &scanResultContainer
	}
	if err := rows.Scan(scanResultContainers...); err != nil {
		return nil, err
	}

	for ii, key := range fields {
		rawValue := reflect.Indirect(reflect.ValueOf(scanResultContainers[ii]))
		//if row is null then ignore
		if rawValue.Interface() == nil {
			//fmt.Println("ignore ...", key, rawValue)
			continue
		}

		if data, err := value2Bytes(&rawValue); err == nil {
			result[key] = data
		} else {
			return nil, err // !nashtsai! REVIEW, should return err or just error log?
		}
	}
	return result, nil
}

func row2mapStr(rows *core.Rows, fields []string) (resultsMap map[string]string, err error) {
	result := make(map[string]string)
	scanResultContainers := make([]interface{}, len(fields))
	for i := 0; i < len(fields); i++ {
		var scanResultContainer interface{}
		scanResultContainers[i] = &scanResultContainer
	}
	if err := rows.Scan(scanResultContainers...); err != nil {
		return nil, err
	}

	for ii, key := range fields {
		rawValue := reflect.Indirect(reflect.ValueOf(scanResultContainers[ii]))
		//if row is null then ignore
		if rawValue.Interface() == nil {
			//fmt.Println("ignore ...", key, rawValue)
			continue
		}

		if data, err := value2String(&rawValue); err == nil {
			result[key] = data
		} else {
			return nil, err // !nashtsai! REVIEW, should return err or just error log?
		}
	}
	return result, nil
}

func txQuery2(tx *core.Tx, sqlStr string, params ...interface{}) (resultsSlice []map[string]string, err error) {
	rows, err := tx.Query(sqlStr, params...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	return rows2Strings(rows)
}

func query2(db *core.DB, sqlStr string, params ...interface{}) (resultsSlice []map[string]string, err error) {
	s, err := db.Prepare(sqlStr)
	if err != nil {
		return nil, err
	}
	defer s.Close()
	rows, err := s.Query(params...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	return rows2Strings(rows)
}

func setColumnInt(bean interface{}, col *core.Column, t int64) {
	v, err := col.ValueOf(bean)
	if err != nil {
		return
	}
	if v.CanSet() {
		switch v.Type().Kind() {
		case reflect.Int, reflect.Int64, reflect.Int32:
			v.SetInt(t)
		case reflect.Uint, reflect.Uint64, reflect.Uint32:
			v.SetUint(uint64(t))
		}
	}
}

func setColumnTime(bean interface{}, col *core.Column, t time.Time) {
	v, err := col.ValueOf(bean)
	if err != nil {
		return
	}
	if v.CanSet() {
		switch v.Type().Kind() {
		case reflect.Struct:
			v.Set(reflect.ValueOf(t).Convert(v.Type()))
		case reflect.Int, reflect.Int64, reflect.Int32:
			v.SetInt(t.Unix())
		case reflect.Uint, reflect.Uint64, reflect.Uint32:
			v.SetUint(uint64(t.Unix()))
		}
	}
}

func genCols(table *core.Table, session *Session, bean interface{}, useCol bool, includeQuote bool) ([]string, []interface{}, error) {
	colNames := make([]string, 0, len(table.ColumnsSeq()))
	args := make([]interface{}, 0, len(table.ColumnsSeq()))

	for _, col := range table.Columns() {
		if useCol && !col.IsVersion && !col.IsCreated && !col.IsUpdated {
			if _, ok := getFlagForColumn(session.Statement.columnMap, col); !ok {
				continue
			}
		}
		if col.MapType == core.ONLYFROMDB {
			continue
		}

		fieldValuePtr, err := col.ValueOf(bean)
		if err != nil {
			return nil, nil, err
		}
		fieldValue := *fieldValuePtr

		if col.IsAutoIncrement {
			switch fieldValue.Type().Kind() {
			case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int, reflect.Int64:
				if fieldValue.Int() == 0 {
					continue
				}
			case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint, reflect.Uint64:
				if fieldValue.Uint() == 0 {
					continue
				}
			case reflect.String:
				if len(fieldValue.String()) == 0 {
					continue
				}
			}
		}

		if col.IsDeleted {
			continue
		}

		if session.Statement.ColumnStr != "" {
			if _, ok := getFlagForColumn(session.Statement.columnMap, col); !ok {
				continue
			}
		}
		if session.Statement.OmitStr != "" {
			if _, ok := getFlagForColumn(session.Statement.columnMap, col); ok {
				continue
			}
		}

		// !evalphobia! set fieldValue as nil when column is nullable and zero-value
		if _, ok := getFlagForColumn(session.Statement.nullableMap, col); ok {
			if col.Nullable && isZero(fieldValue.Interface()) {
				var nilValue *int
				fieldValue = reflect.ValueOf(nilValue)
			}
		}

		if (col.IsCreated || col.IsUpdated) && session.Statement.UseAutoTime /*&& isZero(fieldValue.Interface())*/ {
			// if time is non-empty, then set to auto time
			val, t := session.Engine.NowTime2(col.SQLType.Name)
			args = append(args, val)

			var colName = col.Name
			session.afterClosures = append(session.afterClosures, func(bean interface{}) {
				col := table.GetColumn(colName)
				setColumnTime(bean, col, t)
			})
		} else if col.IsVersion && session.Statement.checkVersion {
			args = append(args, 1)
		} else {
			arg, err := session.value2Interface(col, fieldValue)
			if err != nil {
				return colNames, args, err
			}
			args = append(args, arg)
		}

		if includeQuote {
			colNames = append(colNames, session.Engine.Quote(col.Name)+" = ?")
		} else {
			colNames = append(colNames, col.Name)
		}
	}
	return colNames, args, nil
}

func indexName(tableName, idxName string) string {
	return fmt.Sprintf("IDX_%v_%v", tableName, idxName)
}

func getFlagForColumn(m map[string]bool, col *core.Column) (val bool, has bool) {

	if len(m) == 0 {
		return false, false
	}

	n := len(col.Name)

	for mk := range m {
		if len(mk) != n {
			continue
		}
		if strings.EqualFold(mk, col.Name) {
			return m[mk], true
		}
	}

	return false, false
}