import { DownProxy } from "../../base/AllAnalysis.js";
import { writeFileSync, mkdirSync } from "fs";
import { downloadProxy } from "../cloudflarePagesDownProxy/worker/cloudflarePagesDownloadPorxy.js";
import { onExtendsBundlerOptions, onGenerated } from "../../base/eventManager.js";
import { ProxyOptions } from "vite";
import { path } from "vuepress/utils";

const outputPath = process.env.VERCEL_URL? '/vercel/output' : "./.vercel/output";
console.log("vercel out path is",outputPath);
/**
 * 生成一个字符串的hashcode
 * */
function hashCode(string: string): number {
    let hash = 0, i, chr;
    if (string.length === 0) return hash;
    for (i = 0; i < string.length; i++) {
        chr = string.charCodeAt(i);
        hash = ((hash << 5) - hash) + chr;
        hash |= 0; // Convert to 32bit integer
    }
    return hash;
}

const proxyConfig: { [path: string]: string } = {}


async function vercelReleaseConfigurationFile(destPath: string) {
    mkdirSync(path.join(outputPath, "functions/api/verceldown.func"), { recursive: true });
    writeFileSync(path.join(outputPath, "functions/api/verceldown.func/.vc-config.json"), JSON.stringify({
        "runtime": "edge",
        "deploymentTarget": "v8-worker",
        "entrypoint": "verceldown.js"
    }));
    writeFileSync(path.join(outputPath, "functions/api/verceldown.func/verceldown.js"), `${downloadProxy.toString()}\nconst proxyConfig = ${JSON.stringify(proxyConfig)}\nexport default (req)=>downloadProxy(req,proxyConfig);export const config = { runtime: 'edge' };`);
}

/**
 * 如果被引用了就注册生成配置文件的事件
 * */
onGenerated(async (app) => vercelReleaseConfigurationFile(app.dir.dest()));
/**
 * 配置dev代理和vercel一样工作
 * */
onExtendsBundlerOptions(async (options, app) => {
    if (app.options.bundler.name === '@vuepress/bundler-vite') {
        const proxy: Record<string, string | ProxyOptions> = {};
        for (const proxyConfigKey in proxyConfig) {
            const proxyConfigValue = proxyConfig[proxyConfigKey];
            proxy[proxyConfigKey] = {
                target: new URL(proxyConfigValue).toString(),
                changeOrigin: true,
                rewrite: () => "",
                followRedirects: true,
            };
        }
        options.viteOptions ??= {};
        options.viteOptions.server ??= {};
        options.viteOptions.server.proxy = { ...options.viteOptions.server.proxy, ...proxy };
    }
});

async function vercelDownProxyInner(sourceUrl: string, fileName: string, contentType?: string): Promise<string> {
    const downProxyPath = `/api/verceldown/${hashCode(sourceUrl)}/${encodeURIComponent(fileName)}`;
    proxyConfig[downProxyPath] = sourceUrl;
    return downProxyPath;
}


/**
 * 使用vercel的下载代理
 * */
export function vercelDownProxy(): DownProxy {
    return (sourceUrl, fileName, contentType) => vercelDownProxyInner(sourceUrl, fileName, contentType);
}