"use strict";
/**
 * Copyright (c) 2023 The xterm.js authors. All rights reserved.
 * @license MIT
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.UNSUPPORTED_TYPE = void 0;
exports.imageType = imageType;
exports.UNSUPPORTED_TYPE = {
    mime: 'unsupported',
    width: 0,
    height: 0
};
function imageType(d) {
    if (d.length < 24) {
        return exports.UNSUPPORTED_TYPE;
    }
    const d32 = new Uint32Array(d.buffer, d.byteOffset, 6);
    // PNG: 89 50 4E 47 0D 0A 1A 0A (8 first bytes == magic number for PNG)
    // + first chunk must be IHDR
    if (d32[0] === 0x474E5089 && d32[1] === 0x0A1A0A0D && d32[3] === 0x52444849) {
        return {
            mime: 'image/png',
            width: d[16] << 24 | d[17] << 16 | d[18] << 8 | d[19],
            height: d[20] << 24 | d[21] << 16 | d[22] << 8 | d[23]
        };
    }
    // JPEG: FF D8 FF
    if (d[0] === 0xFF && d[1] === 0xD8 && d[2] === 0xFF) {
        const [width, height] = jpgSize(d);
        return { mime: 'image/jpeg', width, height };
    }
    // GIF: GIF87a or GIF89a
    if (d32[0] === 0x38464947 && (d[4] === 0x37 || d[4] === 0x39) && d[5] === 0x61) {
        return {
            mime: 'image/gif',
            width: d[7] << 8 | d[6],
            height: d[9] << 8 | d[8]
        };
    }
    return exports.UNSUPPORTED_TYPE;
}
function jpgSize(d) {
    const len = d.length;
    let i = 4;
    let blockLength = d[i] << 8 | d[i + 1];
    while (true) {
        i += blockLength;
        if (i >= len) {
            // exhausted without size info
            return [0, 0];
        }
        if (d[i] !== 0xFF) {
            return [0, 0];
        }
        if (d[i + 1] === 0xC0 || d[i + 1] === 0xC2) {
            if (i + 8 < len) {
                return [
                    d[i + 7] << 8 | d[i + 8],
                    d[i + 5] << 8 | d[i + 6]
                ];
            }
            return [0, 0];
        }
        i += 2;
        blockLength = d[i] << 8 | d[i + 1];
    }
}