/**
 * 模板字符串解析，如：template = 'hahaha{name}_{id}' ,param = {name: 'hh', id: 1}
 * 解析后为 hahahahh_1
 * @param template 模板字符串
 * @param param   参数占位符
 * @returns 
 */
export function templateResolve(template: string, param: any) {
    return template.replace(/\{\w+\}/g, (word) => {
        const key = word.substring(1, word.length - 1);
        const value = param[key];
        if (value != null || value != undefined) {
            return value;
        }
        return "";
    });
}

// export function textToImg(str: string) {
//     var name, fsize;
//     if (str.length < 2) {
//         name = str;
//         fsize = 60
//     } else {
//         if (str.length == 2) {
//             name = str.substring(0, str.length);
//             fsize = 45
//         } else {
//             if (str.length == 3) {
//                 name = str.substring(0, str.length);
//                 fsize = 30
//             } else {
//                 if (str.length == 4) {
//                     name = str.substring(0, str.length);
//                     fsize = 25
//                 } else {
//                     if (str.length > 4) {
//                         name = str.substring(0, 2);
//                         fsize = 45
//                     }
//                 }
//             }
//         }
//     }
//     var fontSize = 60;
//     var fontWeight = "bold";
//     var canvas: any = document.getElementById("head_canvas_default");
//     var img1 = document.getElementById("head_canvas_default");
//     canvas.width = 120;
//     canvas.height = 120;
//     var context = canvas.getContext("2d");
//     context.fillStyle = getBG();
//     context.fillRect(0, 0, canvas.width, canvas.height);
//     context.fillStyle = "#FFF";
//     context.font = fontWeight + " " + fsize + "px sans-serif";
//     context.textAlign = "center";
//     context.textBaseline = "middle";
//     context.fillText(name, fontSize, fontSize);
//     return canvas.toDataURL("image/png")
// }
// function getBG() {
//     var bgArray = ["#1abc9c", "#2ecc71", "#3498db", "#9b59b6", "#34495e",
//         "#16a085", "#27ae60", "#2980b9", "#8e44ad", "#2c3e50", "#f1c40f",
//         "#e67e22", "#e74c3c", "#eca0f1", "#95a5a6", "#f39c12", "#d35400",
//         "#c0392b", "#bdc3c7", "#7f8c8d"];
//     var color = bgArray[Math.floor(Math.random() * bgArray.length)];
//     return color
// };

export function letterAvatar(name: string, size = 60, color = '') {
    name = name || '';
    size = size || 60;
    var colours = [
        "#1abc9c", "#2ecc71", "#3498db", "#9b59b6", "#34495e", "#16a085", "#27ae60", "#2980b9", "#8e44ad", "#2c3e50",
        "#f1c40f", "#e67e22", "#e74c3c", "#00bcd4", "#95a5a6", "#f39c12", "#d35400", "#c0392b", "#bdc3c7", "#7f8c8d"
    ],
        nameSplit = String(name).split(' '),
        initials, charIndex, colourIndex, canvas, context, dataURI;
    if (nameSplit.length == 1) {
        initials = nameSplit[0] ? nameSplit[0].charAt(0) : '?';
    } else {
        initials = nameSplit[0].charAt(0) + nameSplit[1].charAt(0);
    }
    if (window.devicePixelRatio) {
        size = (size * window.devicePixelRatio);
    }
    initials = initials.toLocaleUpperCase()
    charIndex = (initials == '?' ? 72 : initials.charCodeAt(0)) - 64;
    colourIndex = charIndex % 20;
    canvas = document.createElement('canvas');
    canvas.width = size;
    canvas.height = size;
    context = canvas.getContext("2d") as any;

    context.fillStyle = color ? color : colours[colourIndex - 1];
    context.fillRect(0, 0, canvas.width, canvas.height);
    context.font = Math.round(canvas.width / 2) + "px 'Microsoft Yahei'";
    context.textAlign = "center";
    context.fillStyle = "#FFF";
    context.fillText(initials, size / 2, size / 1.5);
    dataURI = canvas.toDataURL();
    canvas = null;
    return dataURI;
};