/*
 * Copyright (c) 2016 Alex Yatskov <alex@foosoft.net>
 * Author: Alex Yatskov <alex@foosoft.net>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package jmdict

import (
	"encoding/xml"
	"io"
)

type edictKanji struct {
	// This element will contain a word or short phrase in Japanese
	// which is written using at least one non-kana character (usually kanji,
	// but can be other characters). The valid characters are
	// kanji, kana, related characters such as chouon and kurikaeshi, and
	// in exceptional cases, letters from other alphabets.
	Expression string `xml:"keb"`

	// This is a coded information field related specifically to the
	// orthography of the keb, and will typically indicate some unusual
	// aspect, such as okurigana irregularity.
	Information []string `xml:"ke_inf"`

	// This and the equivalent re_pri field are provided to record
	// information about the relative priority of the entry,  and consist
	// of codes indicating the word appears in various references which
	// can be taken as an indication of the frequency with which the word
	// is used. This field is intended for use either by applications which
	// want to concentrate on entries of  a particular priority, or to
	// generate subset files.
	// The current values in this field are:
	// - news1/2: appears in the "wordfreq" file compiled by Alexandre Girardi
	// from the Mainichi Shimbun. (See the Monash ftp archive for a copy.)
	// Words in the first 12,000 in that file are marked "news1" and words
	// in the second 12,000 are marked "news2".
	// - ichi1/2: appears in the "Ichimango goi bunruishuu", Senmon Kyouiku
	// Publishing, Tokyo, 1998.  (The entries marked "ichi2" were
	// demoted from ichi1 because they were observed to have low
	// frequencies in the WWW and newspapers.)
	// - spec1 and spec2: a small number of words use this marker when they
	// are detected as being common, but are not included in other lists.
	// - gai1/2: common loanwords, based on the wordfreq file.
	// - nfxx: this is an indicator of frequency-of-use ranking in the
	// wordfreq file. "xx" is the number of the set of 500 words in which
	// the entry can be found, with "01" assigned to the first 500, "02"
	// to the second, and so on. (The entries with news1, ichi1, spec1 and
	// gai1 values are marked with a "(P)" in the EDICT and EDICT2
	// files.)
	// The reason both the kanji and reading elements are tagged is because
	// on occasions a priority is only associated with a particular
	// kanji/reading pair.
	Priority []string `xml:"ke_pri"`
}

type edictReading struct {
	// This element content is restricted to kana and related
	// characters such as chouon and kurikaeshi. Kana usage will be
	// consistent between the keb and reb elements; e.g. if the keb
	// contains katakana, so too will the reb.
	Reading string `xml:"reb"`

	// This element, which will usually have a null value, indicates
	// that the reb, while associated with the keb, cannot be regarded
	// as a true reading of the kanji. It is typically used for words
	// such as foreign place names, gairaigo which can be in kanji or
	// katakana, etc.
	NoKanji *string `xml:"re_nokanji"`

	// This element is used to indicate when the reading only applies
	// to a subset of the keb elements in the entry. In its absence, all
	// readings apply to all kanji elements. The contents of this element
	// must exactly match those of one of the keb elements.
	Restrictions []string `xml:"re_restr"`

	// General coded information pertaining to the specific reading.
	// Typically it will be used to indicate some unusual aspect of
	// the reading.
	Information []string `xml:"re_inf"`

	// See the comment on ke_pri above.
	Priority []string `xml:"re_pri"`
}

type edictSource struct {
	Content string `xml:",chardata"`

	// The xml:lang attribute defines the language(s) from which
	// a loanword is drawn.  It will be coded using the three-letter language
	// code from the ISO 639-2 standard. When absent, the value "eng" (i.e.
	// English) is the default value. The bibliographic (B) codes are used.
	Language string `xml:"lang,attr"`

	// The ls_type attribute indicates whether the lsource element
	// fully or partially describes the source word or phrase of the
	// loanword. If absent, it will have the implied value of "full".
	// Otherwise it will contain "part".
	Type string `xml:"ls_type,attr"`

	// The ls_wasei attribute indicates that the Japanese word
	// has been constructed from words in the source language, and
	// not from an actual phrase in that language. Most commonly used to
	// indicate "waseieigo".
	Wasei string `xml:"ls_wasei,attr"`
}

type edictGlossary struct {
	Content string `xml:",chardata"`

	// The xml:lang attribute defines the target language of the
	// gloss. It will be coded using the three-letter language code from
	// the ISO 639 standard. When absent, the value "eng" (i.e. English)
	// is the default value.
	Language string `xml:"lang,attr"`

	// The g_gend attribute defines the gender of the gloss (typically
	// a noun in the target language. When absent, the gender is either
	// not relevant or has yet to be provided.
	Gender string `xml:"g_gend"`
}

type edictSense struct {
	// These elements, if present, indicate that the sense is restricted
	// to the lexeme represented by the keb and/or reb.
	RestrictKanji   []string `xml:"stagk"`
	RestrictReading []string `xml:"stagr"`

	// This element is used to indicate a cross-reference to another
	// entry with a similar or related meaning or sense. The content of
	// this element is typically a keb or reb element in another entry. In some
	// cases a keb will be followed by a reb and/or a sense number to provide
	// a precise target for the cross-reference. Where this happens, a JIS
	// "centre-dot" (0x2126) is placed between the components of the
	// cross-reference.
	References []string `xml:"xref"`

	// This element is used to indicate another entry which is an
	// antonym of the current entry/sense. The content of this element
	// must exactly match that of a keb or reb element in another entry.
	Antonyms []string `xml:"ant"`

	// Part-of-speech information about the entry/sense. Should use
	// appropriate entity codes. In general where there are multiple senses
	// in an entry, the part-of-speech of an earlier sense will apply to
	// later senses unless there is a new part-of-speech indicated.
	PartOfSpeech []string `xml:"pos"`

	// Information about the field of application of the entry/sense.
	// When absent, general application is implied. Entity coding for
	// specific fields of application.
	Field []string `xml:"field"`

	// This element is used for other relevant information about
	// the entry/sense. As with part-of-speech, information will usually
	// apply to several senses.
	Misc []string `xml:"misc"`

	// This element records the information about the source
	// language(s) of a loan-word/gairaigo. If the source language is other
	// than English, the language is indicated by the xml:lang attribute.
	// The element value (if any) is the source word or phrase.
	SourceLanguage []edictSource `xml:"lsource"`

	// For words specifically associated with regional dialects in
	// Japanese, the entity code for that dialect, e.g. ksb for Kansaiben.
	Dialect []string `xml:"dial"`

	// The sense-information elements provided for additional
	// information to be recorded about a sense. Typical usage would
	// be to indicate such things as level of currency of a sense, the
	// regional variations, etc.
	Information []string `xml:"s_inf"`

	// Within each sense will be one or more "glosses", i.e.
	// target-language words or phrases which are equivalents to the
	// Japanese word. This element would normally be present, however it
	// may be omitted in entries which are purely for a cross-reference.
	Glossary []edictGlossary `xml:"gloss"`
}

// Entries consist of kanji elements, reading elements,
// general information and sense elements. Each entry must have at
// least one reading element and one sense element. Others are optional.
type edictEntry struct {
	// A unique numeric sequence number for each entry
	Sequence int `xml:"ent_seq"`

	// The kanji element, or in its absence, the reading element, is
	// the defining component of each entry.
	// The overwhelming majority of entries will have a single kanji
	// element associated with a word in Japanese. Where there are
	// multiple kanji elements within an entry, they will be orthographical
	// variants of the same word, either using variations in okurigana, or
	// alternative and equivalent kanji. Common "mis-spellings" may be
	// included, provided they are associated with appropriate information
	// fields. Synonyms are not included; they may be indicated in the
	// cross-reference field associated with the sense element.
	Kanji []edictKanji `xml:"k_ele"`

	// The reading element typically contains the valid readings
	// of the word(s) in the kanji element using modern kanadzukai.
	// Where there are multiple reading elements, they will typically be
	// alternative readings of the kanji element. In the absence of a
	// kanji element, i.e. in the case of a word or phrase written
	// entirely in kana, these elements will define the entry.
	Reading []edictReading `xml:"r_ele"`

	// The sense element will record the translational equivalent
	// of the Japanese word, plus other related information. Where there
	// are several distinctly different meanings of the word, multiple
	// sense elements will be employed.
	Sense []edictSense `xml:"sense"`
}

func LoadEdict(reader io.Reader) ([]edictEntry, error) {
	var (
		err     error
		entries []edictEntry
	)

	decoder := xml.NewDecoder(reader)

	for {
		token, _ := decoder.Token()
		if token == nil {
			break
		}

		switch startElement := token.(type) {
		case xml.Directive:
			directive := token.(xml.Directive)
			if decoder.Entity, err = parseEntities(&directive); err != nil {
				return nil, err
			}
		case xml.StartElement:
			if startElement.Name.Local == "entry" {
				var entry edictEntry
				if err := decoder.DecodeElement(&entry, &startElement); err != nil {
					return nil, err
				}

				entries = append(entries, entry)
			}
		}
	}

	return entries, nil
}