//  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 regexp_tokenizer

import (
	"regexp"

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

type RegexpTokenizer struct {
	r *regexp.Regexp
}

func NewRegexpTokenizer(r *regexp.Regexp) *RegexpTokenizer {
	return &RegexpTokenizer{
		r: r,
	}
}

func (rt *RegexpTokenizer) Tokenize(input []byte) analysis.TokenStream {
	matches := rt.r.FindAllIndex(input, -1)
	rv := make(analysis.TokenStream, len(matches))
	for i, match := range matches {
		token := analysis.Token{
			Term:     input[match[0]:match[1]],
			Start:    match[0],
			End:      match[1],
			Position: i + 1,
		}
		rv[i] = &token
	}
	return rv
}