#!/usr/bin/env -S /root/.deno/bin/deno run --allow-env --allow-read --allow-sys --allow-run --allow-write

import { printf } from "https://deno.land/std@0.170.0/fmt/printf.ts";
import {brightGreen, brightMagenta} from "https://deno.land/std@0.170.0/fmt/colors.ts";
import { Command } from "https://deno.land/x/cliffy@v0.25.2/command/mod.ts";
import { getLogger } from "https://deno.land/std@0.170.0/log/mod.ts";


class CommandError extends Error{}
class ArgError extends CommandError {}
class NginxError extends CommandError {}

interface DeployedService{
  name: string,
  port?: number,
  unixSocketPath?: string,
}

async function saveService(services: DeployedService[]){
  const content = JSON.stringify(services);
  await Deno.writeTextFile("services.json", content);
}
async function loadService(): Promise<DeployedService[]> {
  try {
    const content = await Deno.readTextFile("services.json");
    return JSON.parse(content);
  } catch (error) {
    if(error instanceof Deno.errors.NotFound){
      return [];
    }
    else{
      throw error;
    }
  }
}

interface NginxConfigOption {
  name: string,
  
  /**
   * port number
   */
  port?: number,
  
  /**
   * unix socket path
   */
  unixSocket?: string,

  /**
   * megabyte unit
   */
  clientMaxBodySize?: number,
  /**
   * proxy pass
   * @default "127.0.0.1"
   */
  proxyPass?: string,
  /**
   * socket IO support
   * @default true
   */
  socketIO?: boolean,
}

function createNginxConfigContent({ port, unixSocket, name, clientMaxBodySize, proxyPass, socketIO }: NginxConfigOption) {
  clientMaxBodySize ??= 20;
  proxyPass ??= "127.0.0.1";
  socketIO ??= true;
  if (!port && !unixSocket) {
    throw new ArgError("Both port and unixSocket cannot be false.");
  }
  if ((!!port) && (!!unixSocket)){
    throw new ArgError("Both port and unixSocket cannot be true.");
  }
  if (!!port && (isNaN(port) || !isFinite(port) )){
    throw new ArgError("Port must be number.");
  }
  if (!!port && (port > 65535 || port < 0)){
    throw new ArgError("Port cannnot be less than 0 or greater than 65535")
  }
  if (!!unixSocket && !unixSocket.startsWith("/")){
    throw new ArgError("unix socket path must be absolute path.")
  }
  const content = `# it created by deploy script.
server {
  server_name ${name}.prelude.duckdns.org;
  
  location /{
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Scheme $scheme;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_set_header X-NginX-Proxy true;
    proxy_pass ${
      port ? `http://${proxyPass}:${port}` : `http://unix:${unixSocket}/`
    };
    proxy_redirect off;
    
    # client body size
    client_max_body_size ${clientMaxBodySize}M;
    
    ${ socketIO ?
    `# Socket.IO Support
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";` : ""
    }
  }
  
  listen 80;
}`;
  return content;
}

function isRunAsRoot() {
  return Deno.uid() == 0;
}

async function NginxCheck() {
  const c = new Deno.Command("nginx",{
    args: ["-t"],
  });
  const status = await c.output();
  return status.success && status.code == 0;
}

async function NginxReload() {
  const c = new Deno.Command("nginx",{
    args: ["-s", "reload"],
  });
  const status = await c.output();
  return status.success && status.code == 0;
}

interface DeployCommandOption{
  port?: number;
  proxy?: string;
  disableSocket?: boolean;
  clientMaxBodySize?: number;
  unixSocket?: string;
}

function checkDomainName(name: string){
  return /^[a-z0-9][a-z0-9_-]{0,61}[a-z0-9]?$/i.test(name);
}

async function deployCommand(deployName: string,
    options?: DeployCommandOption): Promise<void>{
  options ??= {}

  if(!checkDomainName(deployName)){
    throw new ArgError("name invalid")
  }

  if(!isRunAsRoot()){
    getLogger().warning("It's not executed as root")
  }

  const services = await loadService();
  const dir = [...Deno.readDirSync("/etc/nginx/sites-available")]
    
  if (dir.map(x => x.name).includes(deployName)) {
    throw new ArgError("duplicated name: please use other name.")
  }

  const proxyPass = options.proxy;
  const socketIO = !options.disableSocket;
  const content = createNginxConfigContent({
    port: options.port,
    name: deployName,
    unixSocket: options.unixSocket,
    proxyPass: proxyPass,
    socketIO: socketIO,
    clientMaxBodySize: options.clientMaxBodySize
  });
  await Deno.writeTextFile("/etc/nginx/sites-available/"+deployName,content);
  await Deno.symlink("/etc/nginx/sites-available/"+deployName,"/etc/nginx/sites-enabled/"+deployName);
  
  if(services.map(x=>x.name).includes(deployName)){
    const target = services.find(x=>x.name == deployName);
    if(target){
      target.port = options.port;
      target.unixSocketPath = options.unixSocket;
    }
  }
  else {
    services.push({
      name: deployName,
      port: options.port,
      unixSocketPath: options.unixSocket,
    });
  }
  await saveService(services);
  
  if(!await NginxCheck()){
    throw new NginxError("nginx config grammar failed");
  }

  if(!await NginxReload()){
    throw new NginxError("nginx reload failed");
  }
}


if (import.meta.main) {
  const cmd = new Command()
    .name("deployNginx")
    .version("1.0.2")
    .description("CLI")
    .action(()=>{
      console.log("sub command required");
    })
    .command("deploy", "deploy app")
    .option("-p, --port <port:number>","port for app")
    .option("--unixSocket <unixSocket:string>","unix socket path")
    .option("--disableSocket","disable socket io")
    .option("--clientMaxBodySize <clientMaxBodySize:number>","client max body size: MB Unit",{
      default: 20
    })
    .option("--proxy <proxy:string>","proxy pass for app. you can bind unix socket like \"unix:<your unix socket path>\"")
    .arguments("<value:string>")
    .action(async (options, name)=>{
      try {
        await deployCommand(name,{
          port: options.port,
          unixSocket: options.unixSocket,
          clientMaxBodySize: options.clientMaxBodySize,
          disableSocket: options.disableSocket,
          proxy: options.proxy
        });
      }
      catch(e){
        if (e instanceof Error){
          console.log(e.message);
        }
      }
    })
    .command("undeploy","undeploy app")
    .arguments("<value:string>")
    .action(async (_,name)=>{
      const services = await loadService();
      const i = services.findIndex(x=>x.name == name);
      if(i < 0){
        console.log("not deployed");
        Deno.exit(1);
      }
      services.splice(i,1);

      await Deno.remove("/etc/nginx/sites-enabled/"+name);
      await Deno.remove("/etc/nginx/sites-available/"+name);

      await saveService(services);
      if(!await NginxReload()){
        console.log("error! nginx reload failed");
        Deno.exit(1);
      }
      console.log(`success to unload ${name}`);
    })
    .command("list","list deployed service")
    .action(async ()=>{
      const services = await loadService();
      if(!Deno.stdout.isTerminal()){
        for (const service of services) {
          printf("%s %s\n",service.name, (service.port ?? service.unixSocketPath ?? "ERROR").toString());
        }
      }
      else {
        const maxServiceNameLength = services.map(x=>x.name.length).reduce((x,y)=>Math.max(x,y), 0);
        const maxPadLength = Math.max(6,maxServiceNameLength);
        const maxServiceOrNumberLength = services.map(x=> Math.max((x.port ?? 0).toString().length, x.unixSocketPath?.length ?? 0)).reduce((x,y)=>Math.max(x,y), 0);
        const maxPad2Length = Math.max("PORT OR SOCKET PATH".length, maxServiceOrNumberLength);
        const prettyPrint = (name: string, port: string) => {
          printf("%s %s\n",brightGreen(name.padEnd(maxPadLength, " ")), 
            brightMagenta(port.padEnd(maxPad2Length)
            ));
        }

        prettyPrint("NAME","PORT OR SOCKET PATH");
        for (const service of services) {
          prettyPrint(service.name,(service.port ?? service.unixSocketPath ?? "ERROR").toString());
        }
      }
    });
  
  await cmd.parse(Deno.args);
}