/*
 * Copyright (C) 2020-2021  Yomichan Authors
 *
 * 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 <https://www.gnu.org/licenses/>.
 */

/* global
 * AnkiUtil
 * TemplateRendererProxy
 */

class AnkiNoteBuilder {
    constructor() {
        this._markerPattern = AnkiUtil.cloneFieldMarkerPattern(true);
        this._templateRenderer = new TemplateRendererProxy();
        this._batchedRequests = [];
        this._batchedRequestsQueued = false;
    }

    async createNote({
        dictionaryEntry,
        mode,
        context,
        template,
        deckName,
        modelName,
        fields,
        tags=[],
        injectedMedia=null,
        checkForDuplicates=true,
        duplicateScope='collection',
        resultOutputMode='split',
        glossaryLayoutMode='default',
        compactTags=false,
        errors=null
    }) {
        let duplicateScopeDeckName = null;
        let duplicateScopeCheckChildren = false;
        if (duplicateScope === 'deck-root') {
            duplicateScope = 'deck';
            duplicateScopeDeckName = AnkiUtil.getRootDeckName(deckName);
            duplicateScopeCheckChildren = true;
        }

        const commonData = this._createData(dictionaryEntry, mode, context, resultOutputMode, glossaryLayoutMode, compactTags, injectedMedia);
        const formattedFieldValuePromises = [];
        for (const [, fieldValue] of fields) {
            const formattedFieldValuePromise = this._formatField(fieldValue, commonData, template, errors);
            formattedFieldValuePromises.push(formattedFieldValuePromise);
        }

        const formattedFieldValues = await Promise.all(formattedFieldValuePromises);
        const noteFields = {};
        for (let i = 0, ii = fields.length; i < ii; ++i) {
            const fieldName = fields[i][0];
            const formattedFieldValue = formattedFieldValues[i];
            noteFields[fieldName] = formattedFieldValue;
        }

        return {
            fields: noteFields,
            tags,
            deckName,
            modelName,
            options: {
                allowDuplicate: !checkForDuplicates,
                duplicateScope,
                duplicateScopeOptions: {
                    deckName: duplicateScopeDeckName,
                    checkChildren: duplicateScopeCheckChildren
                }
            }
        };
    }

    async getRenderingData({
        dictionaryEntry,
        mode,
        context,
        resultOutputMode='split',
        glossaryLayoutMode='default',
        compactTags=false,
        injectedMedia=null,
        marker=null
    }) {
        const commonData = this._createData(dictionaryEntry, mode, context, resultOutputMode, glossaryLayoutMode, compactTags, injectedMedia);
        return await this._templateRenderer.getModifiedData({marker, commonData}, 'ankiNote');
    }

    // Private

    _createData(dictionaryEntry, mode, context, resultOutputMode, glossaryLayoutMode, compactTags, injectedMedia) {
        return {
            dictionaryEntry,
            mode,
            context,
            resultOutputMode,
            glossaryLayoutMode,
            compactTags,
            injectedMedia
        };
    }

    async _formatField(field, commonData, template, errors=null) {
        return await this._stringReplaceAsync(field, this._markerPattern, async (g0, marker) => {
            try {
                return await this._renderTemplateBatched(template, commonData, marker);
            } catch (e) {
                if (Array.isArray(errors)) {
                    const error = new Error(`Template render error for {${marker}}`);
                    error.data = {error: e};
                    errors.push(error);
                }
                return `{${marker}-render-error}`;
            }
        });
    }

    async _stringReplaceAsync(str, regex, replacer) {
        let match;
        let index = 0;
        const parts = [];
        while ((match = regex.exec(str)) !== null) {
            parts.push(str.substring(index, match.index), replacer(...match, match.index, str));
            index = regex.lastIndex;
        }
        if (parts.length === 0) {
            return str;
        }
        parts.push(str.substring(index));
        return (await Promise.all(parts)).join('');
    }

    async _renderTemplate(template, marker, commonData) {
        return await this._templateRenderer.render(template, {marker, commonData}, 'ankiNote');
    }

    _getBatchedTemplateGroup(template) {
        for (const item of this._batchedRequests) {
            if (item.template === template) {
                return item;
            }
        }

        const result = {template, commonDataRequestsMap: new Map()};
        this._batchedRequests.push(result);
        return result;
    }

    _renderTemplateBatched(template, commonData, marker) {
        const {promise, resolve, reject} = deferPromise();
        const {commonDataRequestsMap} = this._getBatchedTemplateGroup(template);
        let requests = commonDataRequestsMap.get(commonData);
        if (typeof requests === 'undefined') {
            requests = [];
            commonDataRequestsMap.set(commonData, requests);
        }
        requests.push({resolve, reject, marker});
        this._runBatchedRequestsDelayed();
        return promise;
    }

    _runBatchedRequestsDelayed() {
        if (this._batchedRequestsQueued) { return; }
        this._batchedRequestsQueued = true;
        Promise.resolve().then(() => {
            this._batchedRequestsQueued = false;
            this._runBatchedRequests();
        });
    }

    _runBatchedRequests() {
        if (this._batchedRequests.length === 0) { return; }

        const allRequests = [];
        const items = [];
        for (const {template, commonDataRequestsMap} of this._batchedRequests) {
            const templateItems = [];
            for (const [commonData, requests] of commonDataRequestsMap.entries()) {
                const datas = [];
                for (const {marker} of requests) {
                    datas.push(marker);
                }
                allRequests.push(...requests);
                templateItems.push({type: 'ankiNote', commonData, datas});
            }
            items.push({template, templateItems});
        }

        this._batchedRequests.length = 0;

        this._resolveBatchedRequests(items, allRequests);
    }

    async _resolveBatchedRequests(items, requests) {
        let responses;
        try {
            responses = await this._templateRenderer.renderMulti(items);
        } catch (e) {
            for (const {reject} of requests) {
                reject(e);
            }
            return;
        }

        for (let i = 0, ii = requests.length; i < ii; ++i) {
            const request = requests[i];
            try {
                const response = responses[i];
                const {error} = response;
                if (typeof error !== 'undefined') {
                    throw deserializeError(error);
                } else {
                    request.resolve(response.result);
                }
            } catch (e) {
                request.reject(e);
            }
        }
    }
}