/*
 * Copyright (C) 2016  Alex Yatskov <alex@foosoft.net>
 * Author: Alex Yatskov <alex@foosoft.net>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */


class Translator {
    constructor() {
        this.database = null;
        this.deinflector = null;
    }

    async prepare() {
        if (!this.database) {
            this.database = new Database();
            await this.database.prepare();
        }

        if (!this.deinflector) {
            const url = chrome.extension.getURL('/bg/lang/deinflect.json');
            const reasons = await requestJson(url, 'GET');
            this.deinflector = new Deinflector(reasons);
        }
    }

    async findTermsGrouped(text, dictionaries, alphanumeric) {
        const titles = Object.keys(dictionaries);
        const {length, definitions} = await this.findTerms(text, dictionaries, alphanumeric);

        const definitionsGrouped = dictTermsGroup(definitions, dictionaries);
        for (const definition of definitionsGrouped) {
            await this.buildTermFrequencies(definition, titles);
        }

        return {length, definitions: definitionsGrouped};
    }

    async findTermsSplit(text, dictionaries, alphanumeric) {
        const titles = Object.keys(dictionaries);
        const {length, definitions} = await this.findTerms(text, dictionaries, alphanumeric);

        for (const definition of definitions) {
            await this.buildTermFrequencies(definition, titles);
        }

        return {length, definitions};
    }

    async findTerms(text, dictionaries, alphanumeric) {
        if (!alphanumeric && text.length > 0) {
            const c = text[0];
            if (!jpIsKana(c) && !jpIsKanji(c)) {
                return {length: 0, definitions: []};
            }
        }

        const cache = {};
        const titles = Object.keys(dictionaries);
        let deinflections = await this.findTermDeinflections(text, titles, cache);
        const textHiragana = jpKatakanaToHiragana(text);
        if (text !== textHiragana) {
            deinflections = deinflections.concat(await this.findTermDeinflections(textHiragana, titles, cache));
        }

        let definitions = [];
        for (const deinflection of deinflections) {
            for (const definition of deinflection.definitions) {
                const tags = await this.expandTags(definition.tags, definition.dictionary);
                tags.push(dictTagBuildSource(definition.dictionary));

                definitions.push({
                    source: deinflection.source,
                    reasons: deinflection.reasons,
                    score: definition.score,
                    id: definition.id,
                    dictionary: definition.dictionary,
                    expression: definition.expression,
                    reading: definition.reading,
                    glossary: definition.glossary,
                    tags: dictTagsSort(tags)
                });
            }
        }

        definitions = dictTermsUndupe(definitions);
        definitions = dictTermsSort(definitions, dictionaries);

        let length = 0;
        for (const definition of definitions) {
            length = Math.max(length, definition.source.length);
        }

        return {length, definitions};
    }

    async findTermDeinflections(text, titles, cache) {
        const definer = async term => {
            if (cache.hasOwnProperty(term)) {
                return cache[term];
            } else {
                return cache[term] = await this.database.findTerms(term, titles);
            }
        };

        let deinflections = [];
        for (let i = text.length; i > 0; --i) {
            const textSlice = text.slice(0, i);
            deinflections = deinflections.concat(await this.deinflector.deinflect(textSlice, definer));
        }

        return deinflections;
    }

    async findKanji(text, dictionaries) {
        let definitions = [];
        const processed = {};
        const titles = Object.keys(dictionaries);
        for (const c of text) {
            if (!processed[c]) {
                definitions = definitions.concat(await this.database.findKanji(c, titles));
                processed[c] = true;
            }
        }

        for (const definition of definitions) {
            const tags = await this.expandTags(definition.tags, definition.dictionary);
            tags.push(dictTagBuildSource(definition.dictionary));

            definition.tags = dictTagsSort(tags);
            definition.stats = await this.expandStats(definition.stats, definition.dictionary);
            definition.frequencies = await this.database.findKanjiFreq(definition.character, titles);
        }

        return definitions;
    }

    async buildTermFrequencies(definition, titles) {
        definition.frequencies = await this.database.findTermFreq(definition.expression, titles);
        if (definition.frequencies.length === 0) {
            definition.frequencies = await this.database.findTermFreq(definition.reading, titles);
        }
    }

    async expandTags(names, title) {
        const tags = [];
        for (const name of names) {
            const base = name.split(':')[0];
            const meta = await this.database.findTagForTitle(base, title);

            const tag = {name};
            for (const prop in meta || {}) {
                if (prop !== 'name') {
                    tag[prop] = meta[prop];
                }
            }

            tags.push(dictTagSanitize(tag));
        }

        return tags;
    }

    async expandStats(items, title) {
        const stats = {};
        for (const name in items) {
            const base = name.split(':')[0];
            const meta = await this.database.findTagForTitle(base, title);
            const group = stats[meta.category] || [];

            const stat = {name, value: items[name]};
            for (const prop in meta || {}) {
                if (prop !== 'name') {
                    stat[prop] = meta[prop];
                }
            }

            group.push(dictTagSanitize(stat));
        }

        return stats;
    }
}