/*
 * Copyright (C) 2016-2017  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 Frontend {
    constructor() {
        this.popup = new Popup();
        this.popupTimer = null;
        this.mouseDownLeft = false;
        this.mouseDownMiddle = false;
        this.textSourceLast = null;
        this.pendingLookup = false;
        this.options = null;

        this.primaryTouchIdentifier = null;
        this.contextMenuChecking = false;
        this.contextMenuPrevent = false;
        this.contextMenuPreviousRange = null;
        this.mouseDownPrevent = false;
        this.clickPrevent = false;
        this.scrollPrevent = false;
    }

    async prepare() {
        try {
            this.options = await apiOptionsGet();

            window.addEventListener('message', this.onFrameMessage.bind(this));
            window.addEventListener('mousedown', this.onMouseDown.bind(this));
            window.addEventListener('mousemove', this.onMouseMove.bind(this));
            window.addEventListener('mouseover', this.onMouseOver.bind(this));
            window.addEventListener('mouseup', this.onMouseUp.bind(this));
            window.addEventListener('resize', this.onResize.bind(this));

            if (this.options.scanning.touchInputEnabled) {
                window.addEventListener('click', this.onClick.bind(this));
                window.addEventListener('touchstart', this.onTouchStart.bind(this));
                window.addEventListener('touchend', this.onTouchEnd.bind(this));
                window.addEventListener('touchcancel', this.onTouchCancel.bind(this));
                window.addEventListener('touchmove', this.onTouchMove.bind(this), {passive: false});
                window.addEventListener('contextmenu', this.onContextMenu.bind(this));
            }

            chrome.runtime.onMessage.addListener(this.onBgMessage.bind(this));
        } catch (e) {
            this.onError(e);
        }
    }

    onMouseOver(e) {
        if (e.target === this.popup.container && this.popupTimer) {
            this.popupTimerClear();
        }
    }

    onMouseMove(e) {
        this.popupTimerClear();

        if (!this.options.general.enable) {
            return;
        }

        if (this.mouseDownLeft) {
            return;
        }

        if (this.pendingLookup) {
            return;
        }

        const mouseScan = this.mouseDownMiddle && this.options.scanning.middleMouse;
        const keyScan =
            this.options.scanning.modifier === 'alt' && e.altKey ||
            this.options.scanning.modifier === 'ctrl' && e.ctrlKey ||
            this.options.scanning.modifier === 'shift' && e.shiftKey ||
            this.options.scanning.modifier === 'none';

        if (!keyScan && !mouseScan) {
            return;
        }

        const search = async () => {
            try {
                await this.searchAt({x: e.clientX, y: e.clientY}, 'mouse');
            } catch (e) {
                this.onError(e);
            }
        };

        if (this.options.scanning.modifier === 'none') {
            this.popupTimerSet(search);
        } else {
            search();
        }
    }

    onMouseDown(e) {
        if (this.mouseDownPrevent) {
            this.setMouseDownPrevent(false, false);
            this.setClickPrevent(true);
            e.preventDefault();
            e.stopPropagation();
            return false;
        }

        this.mousePosLast = {x: e.clientX, y: e.clientY};
        this.popupTimerClear();
        this.searchClear();

        if (e.which === 1) {
            this.mouseDownLeft = true;
        } else if (e.which === 2) {
            this.mouseDownMiddle = true;
        }
    }

    onMouseUp(e) {
        if (e.which === 1) {
            this.mouseDownLeft = false;
        } else if (e.which === 2) {
            this.mouseDownMiddle = false;
        }
    }

    onFrameMessage(e) {
        const handlers = {
            popupClose: () => {
                this.searchClear();
            },

            selectionCopy: () => {
                document.execCommand('copy');
            }
        };

        const handler = handlers[e.data];
        if (handler) {
            handler();
        }
    }

    onResize() {
        this.searchClear();
    }

    onClick(e) {
        if (this.clickPrevent) {
            this.setClickPrevent(false);
            e.preventDefault();
            e.stopPropagation();
            return false;
        }
    }

    onTouchStart(e) {
        if (this.primaryTouchIdentifier !== null && this.getIndexOfTouch(e.touches, this.primaryTouchIdentifier) >= 0) {
            return;
        }

        let touch = this.getPrimaryTouch(e.changedTouches);
        if (this.selectionContainsPoint(window.getSelection(), touch.clientX, touch.clientY)) {
            touch = null;
        }

        this.setPrimaryTouch(touch);
    }

    onTouchEnd(e) {
        if (this.primaryTouchIdentifier === null) {
            return;
        }

        if (this.getIndexOfTouch(e.changedTouches, this.primaryTouchIdentifier) < 0) {
            return;
        }

        this.setPrimaryTouch(this.getPrimaryTouch(this.excludeTouches(e.touches, e.changedTouches)));
    }

    onTouchCancel(e) {
        this.onTouchEnd(e);
    }

    onTouchMove(e) {
        if (!this.scrollPrevent || !e.cancelable || this.primaryTouchIdentifier === null) {
            return;
        }

        const touches = e.changedTouches;
        const index = this.getIndexOfTouch(touches, this.primaryTouchIdentifier);
        if (index < 0) {
            return;
        }

        const touch = touches[index];
        this.searchFromTouch(touch.clientX, touch.clientY, 'touchMove');

        e.preventDefault(); // Disable scroll
    }

    onContextMenu(e) {
        if (this.contextMenuPrevent) {
            this.setContextMenuPrevent(false, false);
            e.preventDefault();
            e.stopPropagation();
            return false;
        }
    }

    onAfterSearch(newRange, type, searched, success) {
        if (type === 'mouse') {
            return;
        }

        if (
            !this.contextMenuChecking ||
            (this.contextMenuPreviousRange === null ? newRange === null : this.contextMenuPreviousRange.equals(newRange))) {
            return;
        }

        if (type === 'touchStart' && newRange !== null) {
            this.scrollPrevent = true;
        }

        this.setContextMenuPrevent(true, false);
        this.setMouseDownPrevent(true, false);
        this.contextMenuChecking = false;
    }

    onBgMessage({action, params}, sender, callback) {
        const handlers = {
            optionsSet: options => {
                this.options = options;
                if (!this.options.enable) {
                    this.searchClear();
                }
            },

            popupSetVisible: ({visible}) => {
                this.popup.setVisible(visible);
            }
        };

        const handler = handlers[action];
        if (handler) {
            handler(params);
        }

        callback();
    }

    onError(error) {
        console.log(error);
    }

    popupTimerSet(callback) {
        this.popupTimerClear();
        this.popupTimer = window.setTimeout(callback, this.options.scanning.delay);
    }

    popupTimerClear() {
        if (this.popupTimer) {
            window.clearTimeout(this.popupTimer);
            this.popupTimer = null;
        }
    }

    async searchAt(point, type) {
        if (this.pendingLookup || this.popup.containsPoint(point)) {
            return;
        }

        const textSource = docRangeFromPoint(point);
        let hideResults = !textSource || !textSource.containsPoint(point);
        let searched = false;
        let success = false;

        try {
            if (!hideResults && (!this.textSourceLast || !this.textSourceLast.equals(textSource))) {
                searched = true;
                this.pendingLookup = true;
                const focus = (type === 'mouse');
                hideResults = !await this.searchTerms(textSource, focus) && !await this.searchKanji(textSource, focus);
                success = true;
            }
        } catch (e) {
            if (window.yomichan_orphaned) {
                if (textSource && this.options.scanning.modifier !== 'none') {
                    this.popup.showOrphaned(textSource.getRect(), this.options);
                }
            } else {
                this.onError(e);
            }
        } finally {
            if (hideResults && this.options.scanning.autoHideResults) {
                this.searchClear();
            } else {
                docImposterDestroy();
            }

            this.pendingLookup = false;
            this.onAfterSearch(this.textSourceLast, type, searched, success);
        }
    }

    async searchTerms(textSource, focus) {
        textSource.setEndOffset(this.options.scanning.length);

        const {definitions, length} = await apiTermsFind(textSource.text());
        if (definitions.length === 0) {
            return false;
        }

        textSource.setEndOffset(length);

        const sentence = docSentenceExtract(textSource, this.options.anki.sentenceExt);
        const url = window.location.href;
        this.popup.termsShow(
            textSource.getRect(),
            definitions,
            this.options,
            {sentence, url, focus}
        );

        this.textSourceLast = textSource;
        if (this.options.scanning.selectText) {
            textSource.select();
        }

        return true;
    }

    async searchKanji(textSource, focus) {
        textSource.setEndOffset(1);

        const definitions = await apiKanjiFind(textSource.text());
        if (definitions.length === 0) {
            return false;
        }

        const sentence = docSentenceExtract(textSource, this.options.anki.sentenceExt);
        const url = window.location.href;
        this.popup.kanjiShow(
            textSource.getRect(),
            definitions,
            this.options,
            {sentence, url, focus}
        );

        this.textSourceLast = textSource;
        if (this.options.scanning.selectText) {
            textSource.select();
        }

        return true;
    }

    searchClear() {
        docImposterDestroy();
        this.popup.hide();
        this.popup.clearAutoPlayTimer();

        if (this.options.scanning.selectText && this.textSourceLast) {
            this.textSourceLast.deselect();
        }

        this.textSourceLast = null;
    }

    getPrimaryTouch(touchList) {
        return touchList.length > 0 ? touchList[0] : null;
    }

    getIndexOfTouch(touchList, identifier) {
        for (let i in touchList) {
            let t = touchList[i];
            if (t.identifier === identifier) {
                return i;
            }
        }
        return -1;
    }

    excludeTouches(touchList, excludeTouchList) {
        const result = [];
        for (let r of touchList) {
            if (this.getIndexOfTouch(excludeTouchList, r.identifier) < 0) {
                result.push(r);
            }
        }
        return result;
    }

    setPrimaryTouch(touch) {
        if (touch === null) {
            this.primaryTouchIdentifier = null;
            this.contextMenuPreviousRange = null;
            this.contextMenuChecking = false;
            this.scrollPrevent = false;
            this.setContextMenuPrevent(false, true);
            this.setMouseDownPrevent(false, true);
            this.setClickPrevent(false);
        }
        else {
            this.primaryTouchIdentifier = touch.identifier;
            this.contextMenuPreviousRange = this.textSourceLast ? this.textSourceLast.clone() : null;
            this.contextMenuChecking = true;
            this.scrollPrevent = false;
            this.setContextMenuPrevent(false, false);
            this.setMouseDownPrevent(false, false);
            this.setClickPrevent(false);

            this.searchFromTouch(touch.clientX, touch.clientY, 'touchStart');
        }
    }

    setContextMenuPrevent(value, delay) {
        if (!delay) {
            this.contextMenuPrevent = value;
        }
    }

    setMouseDownPrevent(value, delay) {
        if (!delay) {
            this.mouseDownPrevent = value;
        }
    }

    setClickPrevent(value) {
        this.clickPrevent = value;
    }

    searchFromTouch(x, y, type) {
        this.popupTimerClear();

        if (!this.options.general.enable || this.pendingLookup) {
            return;
        }

        const search = async () => {
            try {
                await this.searchAt({x, y}, type);
            } catch (e) {
                this.onError(e);
            }
        };

        search();
    }

    selectionContainsPoint(selection, x, y) {
        for (let i = 0; i < selection.rangeCount; ++i) {
            const range = selection.getRangeAt(i);
            for (const rect of range.getClientRects()) {
                if (x >= rect.left && x <= rect.right && y >= rect.top && y <= rect.bottom) {
                    return true;
                }
            }
        }
        return false;
    }
}

window.yomichan_frontend = new Frontend();
window.yomichan_frontend.prepare();