/*
 * 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 Client {
    constructor() {
        this.popup = new Popup();
        this.audio = {};
        this.lastMousePos = null;
        this.lastTextSource = null;
        this.pendingLookup = false;
        this.enabled = false;
        this.options = {};
        this.definitions = null;
        this.sequence = 0;
        this.fgRoot = chrome.extension.getURL('fg');

        chrome.runtime.onMessage.addListener(this.onBgMessage.bind(this));
        window.addEventListener('message', this.onFrameMessage.bind(this));
        window.addEventListener('mousedown', this.onMouseDown.bind(this));
        window.addEventListener('mousemove', this.onMouseMove.bind(this));
        window.addEventListener('keydown', this.onKeyDown.bind(this));
        window.addEventListener('scroll', e => this.hidePopup());
        window.addEventListener('resize', e => this.hidePopup());
    }

    onKeyDown(e) {
        if (this.enabled && this.lastMousePos !== null && (e.keyCode === 16 || e.charCode === 16)) {
            this.searchAt(this.lastMousePos);
        }
    }

    onMouseMove(e) {
        this.lastMousePos = {x: e.clientX, y: e.clientY};
        if (this.enabled && (e.shiftKey || e.which === 2)) {
            this.searchAt(this.lastMousePos);
        }
    }

    onMouseDown(e) {
        this.lastMousePos = {x: e.clientX, y: e.clientY};
        if (this.enabled && (e.shiftKey || e.which === 2)) {
            this.searchAt(this.lastMousePos);
        } else {
            this.hidePopup();
        }
    }

    onBgMessage({action, params}, sender, callback) {
        const method = this['api_' + action];
        if (typeof(method) === 'function') {
            method.call(this, params);
        }

        callback();
    }

    onFrameMessage(e) {
        const {action, params} = e.data, method = this['api_' + action];
        if (typeof(method) === 'function') {
            method.call(this, params);
        }
    }

    searchAt(point) {
        if (this.pendingLookup) {
            return;
        }

        const textSource = Client.textSourceFromPoint(point);
        if (textSource === null || !textSource.containsPoint(point)) {
            this.hidePopup();
            return;
        }

        if (this.lastTextSource !== null && this.lastTextSource.equals(textSource)) {
            return;
        }

        textSource.setEndOffset(this.options.scanLength);

        this.pendingLookup = true;
        bgFindTerm(textSource.text()).then(({definitions, length}) => {
            if (length === 0) {
                this.hidePopup();
            } else {
                textSource.setEndOffset(length);

                const sentence = Client.extractSentence(textSource, this.options.sentenceExtent);
                definitions.forEach(definition => {
                    definition.url = window.location.href;
                    definition.sentence = sentence;
                });

                const sequence = ++this.sequence;
                return bgRenderText({definitions, sequence, root: this.fgRoot, options: this.options}, 'term-list.html').then((content) => {
                    this.definitions = definitions;
                    this.showPopup(textSource, content);
                    return bgCanAddDefinitions(definitions, ['term_kanji', 'term_kana']);
                }).then(states => {
                    if (states !== null) {
                        states.forEach((state, index) => this.popup.sendMessage('setActionState', {index, state, sequence }));
                    }
                });
            }
        }).then(() => this.pendingLookup = false);
    }

    showPopup(textSource, content) {
        this.popup.showNextTo(textSource.getRect(), content);

        if (this.options.selectMatchedText) {
            textSource.select();
        }

        this.lastTextSource = textSource;
    }

    hidePopup() {
        this.popup.hide();

        if (this.options.selectMatchedText && this.lastTextSource !== null) {
            this.lastTextSource.deselect();
        }

        this.lastTextSource = null;
        this.definitions = null;
    }

    api_setOptions(opts) {
        this.options = opts;
    }

    api_setEnabled(enabled) {
        if (!(this.enabled = enabled)) {
            this.hidePopup();
        }
    }

    api_addNote({index, mode}) {
        const state = {[mode]: false};
        bgAddDefinition(this.definitions[index], mode).then(success => {
            if (success) {
                this.popup.sendMessage('setActionState', {index, state, sequence: this.sequence});
            } else {
                alert('Note could not be added');
            }
        });
    }

    api_playAudio(index) {
        const definition = this.definitions[index];

        let url = `https://assets.languagepod101.com/dictionary/japanese/audiomp3.php?kanji=${encodeURIComponent(definition.expression)}`;
        if (definition.reading) {
            url += `&kana=${encodeURIComponent(definition.reading)}`;
        }

        for (const key in this.audio) {
            this.audio[key].pause();
        }

        const audio = this.audio[url] || new Audio(url);
        audio.currentTime = 0;
        audio.play();

        this.audio[url] = audio;
    }

    api_displayKanji(kanji) {
        let defs = [];
        let seq = -1;

        bgFindKanji(kanji).then(definitions => {
            definitions.forEach(definition => definition.url = window.location.href);

            defs = definitions;
            seq = ++this.sequence;

            return bgRenderText({definitions, root: this.fgRoot, options: this.options, sequence: seq}, 'kanji-list.html');
        }).then(content => {
            this.definitions = defs;
            this.popup.setContent(content, defs);

            return bgCanAddDefinitions(defs, ['kanji']);
        }).then(states => {
            if (states !== null) {
                states.forEach((state, index) => this.popup.sendMessage('setActionState', {index, state, sequence: seq}));
            }
        });
    }

    static textSourceFromPoint(point) {
        const element = document.elementFromPoint(point.x, point.y);
        if (element !== null) {
            const names = ['IMG', 'INPUT', 'BUTTON', 'TEXTAREA'];
            if (names.includes(element.nodeName)) {
                return new TextSourceElement(element);
            }
        }

        const range = document.caretRangeFromPoint(point.x, point.y);
        if (range !== null) {
            return new TextSourceRange(range);
        }

        return null;
    }

    static extractSentence(source, extent) {
        const quotesFwd = {'「': '」', '『': '』', "'": "'", '"': '"'};
        const quotesBwd = {'」': '「', '』': '『', "'": "'", '"': '"'};
        const terminators = '…。．.？?！!';

        const sourceLocal = source.clone();
        const position = sourceLocal.setStartOffset(extent);
        sourceLocal.setEndOffset(position + extent);
        const content = sourceLocal.text();

        let quoteStack = [];

        let startPos = 0;
        for (let i = position; i >= startPos; --i) {
            const c = content[i];

            if (quoteStack.length === 0 && (terminators.includes(c) || c in quotesFwd)) {
                startPos = i + 1;
                break;
            }

            if (quoteStack.length > 0 && c === quoteStack[0]) {
                quoteStack.pop();
            } else if (c in quotesBwd) {
                quoteStack = [quotesBwd[c]].concat(quoteStack);
            }
        }

        quoteStack = [];

        let endPos = content.length;
        for (let i = position; i < endPos; ++i) {
            const c = content[i];

            if (quoteStack.length === 0) {
                if (terminators.includes(c)) {
                    endPos = i + 1;
                    break;
                }
                else if (c in quotesBwd) {
                    endPos = i;
                    break;
                }
            }

            if (quoteStack.length > 0 && c === quoteStack[0]) {
                quoteStack.pop();
            } else if (c in quotesFwd) {
                quoteStack = [quotesFwd[c]].concat(quoteStack);
            }
        }

        return content.substring(startPos, endPos).trim();
    }
}

window.yomiClient = new Client();