/**
 * 门户主题 favicon 兜底资产生成器（4 套皮肤各一份）
 * - 输出 templates/themes/<theme>/assets/favicon.svg + favicon.png(128×128)
 * - head.html 在 site.config['favicon'] 未配置时输出 url.asset('favicon.png')（见 fragments/head.html）
 * 图形语言对齐种子 logo-8 系（圆点+书脊），主色取各主题 theme.json 的 primary 参数默认值；
 * 小尺寸下高对比扁平化：无边框、无环形留白。
 * 用法：node theme-favicons.cjs （在 front/ 下执行，依赖 ./node_modules/ws 与系统 Edge）
 */
const fs = require("fs");
const path = require("path");
const { spawn } = require("child_process");
const http = require("http");
const WebSocket = require("ws");

const EDGE = "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe";
const ROOT = path.join(__dirname, "..", "..", "service", "src", "main", "resources", "templates", "themes");
const THEMES = [
    { dir: "default",     primary: "#1a5cb0" },
    { dir: "classic-red", primary: "#b01a2e" },
    { dir: "blue-white",  primary: "#2f6bd8" },
    { dir: "warm-kinder", primary: "#e8722a" },
];

/** #rrggbb -> [r,g,b] */
function rgb(hex) {
    return [1, 3, 5].map(i => parseInt(hex.slice(i, i + 2), 16));
}
function mix(hex, target, t) {
    const c = rgb(hex).map((v, i) => Math.round(v + (target[i] - v) * t));
    return "#" + c.map(v => v.toString(16).padStart(2, "0")).join("");
}
const light = hex => mix(hex, [255, 255, 255], 0.18);
const dark = hex => mix(hex, [0, 0, 0], 0.30);

function faviconSvg(primary) {
    return `<svg xmlns="http://www.w3.org/2000/svg" width="64" height="64" viewBox="0 0 64 64">
  <defs><linearGradient id="bg" x1="0" y1="0" x2="0" y2="1">
    <stop offset="0" stop-color="${light(primary)}"/><stop offset="1" stop-color="${dark(primary)}"/>
  </linearGradient></defs>
  <rect width="64" height="64" fill="url(#bg)"/>
  <circle cx="32" cy="25" r="10" fill="#ffffff"/>
  <path d="M 16 49.3 Q 32 30.7 48 49.3 Z" fill="#ffffff" opacity="0.92"/>
</svg>`;
}

/* ---- CDP 栅格化（Edge headless，128×128 视图内 img 渲染 svg 矢量，天然高清） ---- */
const sleep = ms => new Promise(r => setTimeout(r, ms));
function getJson(port, p) {
    return new Promise((resolve, reject) => {
        http.get({ host: "127.0.0.1", port, path: p }, res => {
            let d = "";
            res.on("data", c => d += c);
            res.on("end", () => { try { resolve(JSON.parse(d)); } catch (e) { reject(e); } });
        }).on("error", reject);
    });
}
async function waitFor(fn, timeout, label) {
    const t0 = Date.now();
    for (;;) {
        try { if (await fn()) return; } catch (e) { /* retry */ }
        if (Date.now() - t0 > timeout) throw new Error("timeout: " + label);
        await sleep(200);
    }
}
async function rasterizeSvg(svgPath, pngPath) {
    const PORT = 9400 + Math.floor(Math.random() * 300);
    const profile = path.join(require("os").tmpdir(), "fav-" + process.pid + "-" + Math.floor(Math.random() * 1e6));
    const htmlPath = path.join(profile, "icon.html");
    fs.mkdirSync(profile, { recursive: true });
    fs.writeFileSync(htmlPath,
        `<html><head><style>html,body{margin:0;padding:0;background:#fff}</style></head>
<body><img src="file:///${svgPath.replace(/\\/g, "/")}" width="128" height="128"></body></html>`);
    const proc = spawn(EDGE, [
        "--headless=new", "--disable-gpu", "--no-sandbox", "--hide-scrollbars",
        `--remote-debugging-port=${PORT}`, `--user-data-dir=${profile}`,
        "--window-size=128,128", "--no-first-run", "--no-default-browser-check", "about:blank",
    ], { stdio: "ignore" });
    try {
        await waitFor(async () => { try { await getJson(PORT, "/json/version"); return true; } catch (e) { return false; } }, 20000, "devtools");
        const pages = await getJson(PORT, "/json");
        const page = pages.find(p => p.type === "page");
        const ws = new WebSocket(page.webSocketDebuggerUrl, { maxPayload: 64 * 1024 * 1024 });
        await new Promise(r => ws.on("open", r));
        const cdp = {
            id: 0,
            pending: new Map(),
            send(method, params = {}) {
                return new Promise((resolve, reject) => {
                    const id = ++this.id;
                    this.pending.set(id, { resolve, reject });
                    ws.send(JSON.stringify({ id, method, params }));
                });
            },
        };
        ws.on("message", m => {
            const msg = JSON.parse(m);
            if (msg.id && cdp.pending.has(msg.id)) {
                const { resolve, reject } = cdp.pending.get(msg.id);
                cdp.pending.delete(msg.id);
                msg.error ? reject(new Error(JSON.stringify(msg.error))) : resolve(msg.result);
            }
        });
        await cdp.send("Page.enable");
        await cdp.send("Emulation.setDeviceMetricsOverride", { width: 128, height: 128, deviceScaleFactor: 1, mobile: false });
        const loaded = new Promise(r => {
            const on = m => { const d = JSON.parse(m); if (d.method === "Page.loadEventFired") { ws.off("message", on); r(); } };
            ws.on("message", on);
        });
        await cdp.send("Page.navigate", { url: "file:///" + htmlPath.replace(/\\/g, "/") });
        await loaded;
        await sleep(500);
        const shot = await cdp.send("Page.captureScreenshot", { format: "png", captureBeyondViewport: false });
        fs.writeFileSync(pngPath, Buffer.from(shot.data, "base64"));
        ws.close();
    } finally {
        proc.kill();
    }
}

(async () => {
    for (const t of THEMES) {
        const dir = path.join(ROOT, t.dir, "assets");
        fs.writeFileSync(path.join(dir, "favicon.svg"), faviconSvg(t.primary));
        await rasterizeSvg(path.join(dir, "favicon.svg"), path.join(dir, "favicon.png"));
        console.log("wrote", t.dir, "favicon.svg + favicon.png");
    }
    console.log("done");
})().catch(e => { console.error(e); process.exit(1); });