//  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 web

import (
	"regexp"
	"strings"

	"github.com/blevesearch/bleve/analysis"
	"github.com/blevesearch/bleve/analysis/tokenizer/exception"
	"github.com/blevesearch/bleve/analysis/tokenizer/unicode"
	"github.com/blevesearch/bleve/registry"
)

const Name = "web"

var email = `(?:[a-z0-9!#$%&'*+/=?^_` + "`" + `{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_` + "`" + `{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])`
var url = `(?i)\b((?:[a-z][\w-]+:(?:/{1,3}|[a-z0-9%])|www\d{0,3}[.]|[a-z0-9.\-]+[.][a-z]{2,4}/)(?:[^\s()<>]+|\(([^\s()<>]+|(\([^\s()<>]+\)))*\))+(?:\(([^\s()<>]+|(\([^\s()<>]+\)))*\)|[^\s` + "`" + `!()\[\]{};:'".,<>?«»“”‘’]))`
var twitterHandle = `@([a-zA-Z0-9_]){1,15}`
var twitterHashtag = `#([a-zA-Z0-9_])+`
var exceptions = []string{email, url, twitterHandle, twitterHashtag}

var exceptionsRegexp = regexp.MustCompile(strings.Join(exceptions, "|"))

func TokenizerConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.Tokenizer, error) {
	remainingTokenizer, err := cache.TokenizerNamed(unicode.Name)
	if err != nil {
		return nil, err
	}
	return exception.NewExceptionsTokenizer(exceptionsRegexp, remainingTokenizer), nil
}

func init() {
	registry.RegisterTokenizer(Name, TokenizerConstructor)
}