<?php
namespace taskman;
use Exception;

//NOTE: this class must not have any dependencies on any packages
class DotnetSupport
{
  const VERSION = "8.0.0";

  static function install()
  {
    $version = self::VERSION;

    $has_dotnet = true;

    $dotnet_curr_ver = "";
    $prev_path = self::addEnvPath();
    try 
    {
      $dotnet_curr_ver = self::shellGet("dotnet --version");
      print("DOTNET CURRENT VERSION: $dotnet_curr_ver\n");
    } 
    catch(\Throwable $th) 
    {
      $has_dotnet = false;
    }
    finally
    {
      self::setEnvPath($prev_path);
    }

    if($has_dotnet && version_compare($dotnet_curr_ver, $version) >= 0)
      return;

    print("DOTNET VERSION MISMATCH: $dotnet_curr_ver < $version\n");

    $install_file_path = self::getInstallerPath();

    $version_parts = explode('.', $version);
    $channel = $version_parts[0].'.'.$version_parts[1];
    if(self::isWin())
      self::shell("powershell -NoProfile -ExecutionPolicy unrestricted Invoke-Expression '\"$install_file_path\" -Channel $channel'");
    else
      self::shell("\"$install_file_path\" --channel $channel");
  }

  static function getInstallerPath() : string 
  {
    if(self::isWin())
      return __DIR__ . "/dotnet-install.ps1";
    else
      return __DIR__ . "/dotnet-install.sh";
  }

  static function getPath() : string
  {
    if(self::isWin())
    {
      $appdata_path = getenv('LOCALAPPDATA');
      return "$appdata_path\\Microsoft\\dotnet\\";
    }
    else
    {
      return getenv("HOME")."/.dotnet/";
    }
  }

  static function addEnvPath(string $path = '') : string
  {
    $prev_path = getenv('PATH');

    if(!$path)
      $path = DotnetSupport::getPath();

    if(self::isWin())
      self::setEnvPath("$path;$prev_path");
    else
      self::setEnvPath("$path:$prev_path");

    return $prev_path;
  }

  static function setEnvPath(string $path)
  {
    putenv("PATH=$path");
  }

  static function isWin() : bool
  {
    return !(DIRECTORY_SEPARATOR == '/');
  }

  static function shellGet(string $cmd, bool $as_string = true)
  {
    exec($cmd, $out, $code);
    if($code !== 0)
      throw new Exception("Error($code) executing shell cmd '$cmd'");
    return $as_string ? implode("", $out) : $out;
  }

  static function shell(string $cmd)
  {
    system($cmd, $ret);
    if($ret != 0)
      throw new Exception("Shell execution error(exit code $ret)");
  }
}