<?php
namespace ATF;

use Exception;

interface IDevicePool
{
  function get() : array;
}

class ApkInstaller
{
  const ST_IN_PROGRESS = 1;
  const ST_INSTALLED   = 2;

  private string $atf_host;
  private ?string $apk_name;
  private int $max_installs_in_progress;
  private array $installs = array();
  private bool $override_external_files;
  private array $external_files = array();

  function __construct(
    string $atf_host, 
    int $max_installs_in_progress,
    ?string $apk_name, 
    bool $override_external_files, 
    array $external_files
  )
  {
    $this->atf_host = $atf_host;
    $this->max_installs_in_progress = $max_installs_in_progress;
    $this->apk_name = $apk_name;
    $this->override_external_files = $override_external_files;
    $this->external_files = $external_files;
  }

  function isInstalled(string $device)
  {
    return isset($this->installs[$device]) && $this->installs[$device] == self::ST_INSTALLED;
  }

  function forgetInstall(string $device)
  {
    unset($this->installs[$device]);
  }

  function countInstallsInProgress()
  {
    $c = 0;
    foreach($this->installs as $status)
      if($status == self::ST_IN_PROGRESS)
        ++$c;
    return $c;
  }

  function installAsync(string $device, bool $force = false) : Amp\Promise
  {
    return Amp\call(function() use($device, $force) {
    
    while($this->countInstallsInProgress() >= $this->max_installs_in_progress)
      yield Amp\delay(1000);

    if($force)
      unset($this->installs[$device]);

    if(isset($this->installs[$device]))
      return;
    $this->installs[$device] = self::ST_IN_PROGRESS;
    
    try
    {
      yield host_exec_async($this->atf_host, "%{adb}% -s $device shell am force-stop %{package_id}%", DEPLOY_OPT_ERR_OK);
      if($this->apk_name !== null)
      {
        yield host_exec_async($this->atf_host, "%{adb}% -s $device uninstall %{package_id}%", DEPLOY_OPT_ERR_OK, 30);
        yield host_exec_async($this->atf_host, "%{adb}% -s $device install -r %{dir}%/{$this->apk_name}", 0, 300);

        //delete overrides only if there's a new apk file uploaded
        yield del_external_files_async($this->atf_host, $device, $this->external_files);
      }

      if($this->override_external_files)
        yield put_external_files_async($this->atf_host, $device, $this->external_files);

      $this->installs[$device] = self::ST_INSTALLED;
    }
    catch(Exception $e)
    {
      err("Error during install *$device*: " . $e->getMessage());
      unset($this->installs[$device]);
      throw $e;
    }
    });
  }

  function getSize()
  {
    list($status, $lines) = host_exec($this->atf_host, "ls -sd -- %{dir}%/{$this->apk_name}", DEPLOY_OPT_ERR_OK|DEPLOY_OPT_SILENT);
    if($status != 0)
      return 0;
    $items = explode(' ', $lines[0]);
    //ls -s returns size in blocks where each block is 512 bytes long
    return intval($items[0])*512;
  }
}

class AdbDevicePool implements IDevicePool
{
  private string $atf_host;

  function __construct(string $atf_host)
  {
    $this->atf_host = $atf_host;
  }

  function get() : array
  {
    return get_devices($this->atf_host);
  }
}

class FixedDevicePool implements IDevicePool
{
  private array $devices;

  function __construct(array $devices)
  {
    $this->devices = $devices;
  }

  function get() : array
  {
    return $this->devices;
  }
}

class CachedDevices implements IDevicePool
{
  private IDevicePool $provider;
  private ?array $cached = null;
  private int $last_cache_time;
  private int $keep_cache_time;

  function __construct(IDevicePool $provider, int $keep_cache_time)
  {
    $this->provider = $provider;
    $this->keep_cache_time = $keep_cache_time;
  } 

  function get() : array
  {
    if($this->cached === null || (time() - $this->last_cache_time) > $this->keep_cache_time)
    {
      $this->cached = $this->provider->get();
      $this->last_cache_time = time();
    }
    return $this->cached;
  }
}