/*
Copyright 2024 New Vector Ltd.
Copyright 2019-2021 The Matrix.org Foundation C.I.C.

SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
Please see LICENSE files in the repository root for full details.
*/

/*
 * Based on...
 * ChromaCheck 1.16
 * author Roel Nieskens, https://pixelambacht.nl
 * MIT license
 */
import { logger } from "matrix-js-sdk/src/logger";

function safariVersionCheck(ua: string): boolean {
    logger.log("Browser is Safari - checking version for COLR support");
    try {
        const safariVersionMatch = ua.match(/Mac OS X ([\d|_]+).*Version\/([\d|.]+).*Safari/);
        if (safariVersionMatch) {
            const macOSVersionStr = safariVersionMatch[1];
            const safariVersionStr = safariVersionMatch[2];
            const macOSVersion = macOSVersionStr.split("_").map((n) => parseInt(n, 10));
            const safariVersion = safariVersionStr.split(".").map((n) => parseInt(n, 10));
            const colrFontSupported =
                macOSVersion[0] >= 10 && macOSVersion[1] >= 14 && safariVersion[0] >= 12 && safariVersion[0] < 17;
            // https://www.colorfonts.wtf/ states Safari supports COLR fonts from this version on but Safari 17 breaks it
            logger.log(
                `COLR support on Safari requires macOS 10.14 and Safari 12-16, ` +
                    `detected Safari ${safariVersionStr} on macOS ${macOSVersionStr}, ` +
                    `COLR supported: ${colrFontSupported}`,
            );
            return colrFontSupported;
        }
    } catch (err) {
        logger.error("Error in Safari COLR version check", err);
    }
    logger.warn("Couldn't determine Safari version to check COLR font support, assuming no.");
    return false;
}

async function isColrFontSupported(): Promise<boolean> {
    logger.log("Checking for COLR support");

    const { userAgent } = navigator;
    // Firefox has supported COLR fonts since version 26
    // but doesn't support the check below without
    // "Extract canvas data" permissions
    // when content blocking is enabled.
    if (userAgent.includes("Firefox")) {
        logger.log("Browser is Firefox - assuming COLR is supported");
        return true;
    }
    // Safari doesn't wait for the font to load (if it doesn't have it in cache)
    // to emit the load event on the image, so there is no way to not make the check
    // reliable. Instead sniff the version.
    // Excluding "Chrome", as it's user agent unhelpfully also contains Safari...
    if (!userAgent.includes("Chrome") && userAgent.includes("Safari")) {
        return safariVersionCheck(userAgent);
    }

    try {
        const canvas = document.createElement("canvas");
        const context = canvas.getContext("2d")!;
        const img = new Image();
        // eslint-disable-next-line
        const fontCOLR =
            "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";
        const svg = `
        <svg xmlns="http://www.w3.org/2000/svg" width="20" height="100" style="background:#fff;fill:#000;">
            <style type="text/css">
                @font-face {
                    font-family: "chromacheck-colr";
                    src: url(data:application/x-font-woff;base64,${fontCOLR}) format("woff");
                }
            </style>
            <text x="0" y="0" font-size="20">
                <tspan font-family="chromacheck-colr" x="0" dy="20">&#xe900;</tspan>
            </text>
        </svg>`;
        canvas.width = 20;
        canvas.height = 100;

        img.src = "data:image/svg+xml;charset=utf-8," + encodeURIComponent(svg);

        logger.log("Waiting for COLR SVG to load");
        await new Promise((resolve) => (img.onload = resolve));
        logger.log("Drawing canvas to detect COLR support");
        context.drawImage(img, 0, 0);
        const colrFontSupported = context.getImageData(10, 10, 1, 1).data[0] === 200;
        logger.log("Canvas check revealed COLR is supported? " + colrFontSupported);
        return colrFontSupported;
    } catch (e) {
        logger.error("Couldn't load COLR font", e);
        return false;
    }
}

let colrFontCheckStarted = false;
export async function fixupColorFonts(): Promise<void> {
    if (colrFontCheckStarted) {
        return;
    }
    colrFontCheckStarted = true;

    if (await isColrFontSupported()) {
        const path = `url('${require("../../res/fonts/Twemoji_Mozilla/TwemojiMozilla-colr.woff2")}')`;
        document.fonts.add(new FontFace("Twemoji", path, {}));
        // For at least Chrome on Windows 10, we have to explictly add extra
        // weights for the emoji to appear in bold messages, etc.
        document.fonts.add(new FontFace("Twemoji", path, { weight: "600" }));
        document.fonts.add(new FontFace("Twemoji", path, { weight: "700" }));
    } else {
        // fall back to SBIX, generated via https://github.com/matrix-org/twemoji-colr/tree/matthew/sbix
        const path = `url('${require("../../res/fonts/Twemoji_Mozilla/TwemojiMozilla-sbix.woff2")}')`;
        document.fonts.add(new FontFace("Twemoji", path, {}));
        document.fonts.add(new FontFace("Twemoji", path, { weight: "600" }));
        document.fonts.add(new FontFace("Twemoji", path, { weight: "700" }));
    }
    // ...and if SBIX is not supported, the browser will fall back to one of the native fonts specified.
}