/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/
import * as browser from '../../../base/browser/browser.js';
import { Emitter } from '../../../base/common/event.js';
import { Disposable } from '../../../base/common/lifecycle.js';
import { CharWidthRequest, readCharWidths } from './charWidthReader.js';
import { EditorFontLigatures } from '../../common/config/editorOptions.js';
import { FontInfo } from '../../common/config/fontInfo.js';
class FontMeasurementsImpl extends Disposable {
    constructor() {
        super();
        this._onDidChange = this._register(new Emitter());
        this.onDidChange = this._onDidChange.event;
        this._cache = new FontMeasurementsCache();
        this._evictUntrustedReadingsTimeout = -1;
    }
    dispose() {
        if (this._evictUntrustedReadingsTimeout !== -1) {
            window.clearTimeout(this._evictUntrustedReadingsTimeout);
            this._evictUntrustedReadingsTimeout = -1;
        }
        super.dispose();
    }
    /**
     * Clear all cached font information and trigger a change event.
     */
    clearAllFontInfos() {
        this._cache = new FontMeasurementsCache();
        this._onDidChange.fire();
    }
    _writeToCache(item, value) {
        this._cache.put(item, value);
        if (!value.isTrusted && this._evictUntrustedReadingsTimeout === -1) {
            // Try reading again after some time
            this._evictUntrustedReadingsTimeout = window.setTimeout(() => {
                this._evictUntrustedReadingsTimeout = -1;
                this._evictUntrustedReadings();
            }, 5000);
        }
    }
    _evictUntrustedReadings() {
        const values = this._cache.getValues();
        let somethingRemoved = false;
        for (const item of values) {
            if (!item.isTrusted) {
                somethingRemoved = true;
                this._cache.remove(item);
            }
        }
        if (somethingRemoved) {
            this._onDidChange.fire();
        }
    }
    /**
     * Read font information.
     */
    readFontInfo(bareFontInfo) {
        if (!this._cache.has(bareFontInfo)) {
            let readConfig = this._actualReadFontInfo(bareFontInfo);
            if (readConfig.typicalHalfwidthCharacterWidth <= 2 || readConfig.typicalFullwidthCharacterWidth <= 2 || readConfig.spaceWidth <= 2 || readConfig.maxDigitWidth <= 2) {
                // Hey, it's Bug 14341 ... we couldn't read
                readConfig = new FontInfo({
                    zoomLevel: browser.getZoomLevel(),
                    pixelRatio: browser.getPixelRatio(),
                    fontFamily: readConfig.fontFamily,
                    fontWeight: readConfig.fontWeight,
                    fontSize: readConfig.fontSize,
                    fontFeatureSettings: readConfig.fontFeatureSettings,
                    lineHeight: readConfig.lineHeight,
                    letterSpacing: readConfig.letterSpacing,
                    isMonospace: readConfig.isMonospace,
                    typicalHalfwidthCharacterWidth: Math.max(readConfig.typicalHalfwidthCharacterWidth, 5),
                    typicalFullwidthCharacterWidth: Math.max(readConfig.typicalFullwidthCharacterWidth, 5),
                    canUseHalfwidthRightwardsArrow: readConfig.canUseHalfwidthRightwardsArrow,
                    spaceWidth: Math.max(readConfig.spaceWidth, 5),
                    middotWidth: Math.max(readConfig.middotWidth, 5),
                    wsmiddotWidth: Math.max(readConfig.wsmiddotWidth, 5),
                    maxDigitWidth: Math.max(readConfig.maxDigitWidth, 5),
                }, false);
            }
            this._writeToCache(bareFontInfo, readConfig);
        }
        return this._cache.get(bareFontInfo);
    }
    _createRequest(chr, type, all, monospace) {
        const result = new CharWidthRequest(chr, type);
        all.push(result);
        if (monospace) {
            monospace.push(result);
        }
        return result;
    }
    _actualReadFontInfo(bareFontInfo) {
        const all = [];
        const monospace = [];
        const typicalHalfwidthCharacter = this._createRequest('n', 0 /* Regular */, all, monospace);
        const typicalFullwidthCharacter = this._createRequest('\uff4d', 0 /* Regular */, all, null);
        const space = this._createRequest(' ', 0 /* Regular */, all, monospace);
        const digit0 = this._createRequest('0', 0 /* Regular */, all, monospace);
        const digit1 = this._createRequest('1', 0 /* Regular */, all, monospace);
        const digit2 = this._createRequest('2', 0 /* Regular */, all, monospace);
        const digit3 = this._createRequest('3', 0 /* Regular */, all, monospace);
        const digit4 = this._createRequest('4', 0 /* Regular */, all, monospace);
        const digit5 = this._createRequest('5', 0 /* Regular */, all, monospace);
        const digit6 = this._createRequest('6', 0 /* Regular */, all, monospace);
        const digit7 = this._createRequest('7', 0 /* Regular */, all, monospace);
        const digit8 = this._createRequest('8', 0 /* Regular */, all, monospace);
        const digit9 = this._createRequest('9', 0 /* Regular */, all, monospace);
        // monospace test: used for whitespace rendering
        const rightwardsArrow = this._createRequest('→', 0 /* Regular */, all, monospace);
        const halfwidthRightwardsArrow = this._createRequest('￫', 0 /* Regular */, all, null);
        // U+00B7 - MIDDLE DOT
        const middot = this._createRequest('·', 0 /* Regular */, all, monospace);
        // U+2E31 - WORD SEPARATOR MIDDLE DOT
        const wsmiddotWidth = this._createRequest(String.fromCharCode(0x2E31), 0 /* Regular */, all, null);
        // monospace test: some characters
        const monospaceTestChars = '|/-_ilm%';
        for (let i = 0, len = monospaceTestChars.length; i < len; i++) {
            this._createRequest(monospaceTestChars.charAt(i), 0 /* Regular */, all, monospace);
            this._createRequest(monospaceTestChars.charAt(i), 1 /* Italic */, all, monospace);
            this._createRequest(monospaceTestChars.charAt(i), 2 /* Bold */, all, monospace);
        }
        readCharWidths(bareFontInfo, all);
        const maxDigitWidth = Math.max(digit0.width, digit1.width, digit2.width, digit3.width, digit4.width, digit5.width, digit6.width, digit7.width, digit8.width, digit9.width);
        let isMonospace = (bareFontInfo.fontFeatureSettings === EditorFontLigatures.OFF);
        const referenceWidth = monospace[0].width;
        for (let i = 1, len = monospace.length; isMonospace && i < len; i++) {
            const diff = referenceWidth - monospace[i].width;
            if (diff < -0.001 || diff > 0.001) {
                isMonospace = false;
                break;
            }
        }
        let canUseHalfwidthRightwardsArrow = true;
        if (isMonospace && halfwidthRightwardsArrow.width !== referenceWidth) {
            // using a halfwidth rightwards arrow would break monospace...
            canUseHalfwidthRightwardsArrow = false;
        }
        if (halfwidthRightwardsArrow.width > rightwardsArrow.width) {
            // using a halfwidth rightwards arrow would paint a larger arrow than a regular rightwards arrow
            canUseHalfwidthRightwardsArrow = false;
        }
        // let's trust the zoom level only 2s after it was changed.
        const canTrustBrowserZoomLevel = (browser.getTimeSinceLastZoomLevelChanged() > 2000);
        return new FontInfo({
            zoomLevel: browser.getZoomLevel(),
            pixelRatio: browser.getPixelRatio(),
            fontFamily: bareFontInfo.fontFamily,
            fontWeight: bareFontInfo.fontWeight,
            fontSize: bareFontInfo.fontSize,
            fontFeatureSettings: bareFontInfo.fontFeatureSettings,
            lineHeight: bareFontInfo.lineHeight,
            letterSpacing: bareFontInfo.letterSpacing,
            isMonospace: isMonospace,
            typicalHalfwidthCharacterWidth: typicalHalfwidthCharacter.width,
            typicalFullwidthCharacterWidth: typicalFullwidthCharacter.width,
            canUseHalfwidthRightwardsArrow: canUseHalfwidthRightwardsArrow,
            spaceWidth: space.width,
            middotWidth: middot.width,
            wsmiddotWidth: wsmiddotWidth.width,
            maxDigitWidth: maxDigitWidth
        }, canTrustBrowserZoomLevel);
    }
}
class FontMeasurementsCache {
    constructor() {
        this._keys = Object.create(null);
        this._values = Object.create(null);
    }
    has(item) {
        const itemId = item.getId();
        return !!this._values[itemId];
    }
    get(item) {
        const itemId = item.getId();
        return this._values[itemId];
    }
    put(item, value) {
        const itemId = item.getId();
        this._keys[itemId] = item;
        this._values[itemId] = value;
    }
    remove(item) {
        const itemId = item.getId();
        delete this._keys[itemId];
        delete this._values[itemId];
    }
    getValues() {
        return Object.keys(this._keys).map(id => this._values[id]);
    }
}
export const FontMeasurements = new FontMeasurementsImpl();
