//  Copyright (c) 2014 Couchbase, 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, 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 length_filter

import (
	"unicode/utf8"

	"github.com/couchbaselabs/bleve/analysis"
)

type LengthFilter struct {
	min int
	max int
}

func NewLengthFilter(min, max int) *LengthFilter {
	return &LengthFilter{
		min: min,
		max: max,
	}
}

func (f *LengthFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
	rv := make(analysis.TokenStream, 0)

	for _, token := range input {
		wordLen := utf8.RuneCount(token.Term)
		if f.min > 0 && f.min > wordLen {
			continue
		}
		if f.max > 0 && f.max < wordLen {
			continue
		}
		rv = append(rv, token)
	}

	return rv
}