class Train::Transports::VMware::Connection

def connect
  login_command = "Connect-VIServer #{options[:viserver]} -User #{options[:username]} -Password #{options[:password]} | Out-Null"
  result = run_command_via_connection(login_command)
  if result.exit_status != 0
    message = "Unable to connect to VIServer at #{options[:viserver]}. "
    case result.stderr
    when /Invalid server certificate/
      message += "Certification verification failed. Please use `--insecure` or set `Set-PowerCLIConfiguration -InvalidCertificateAction Ignore` in PowerShell"
    when /incorrect user name or password/
      message += "Incorrect username or password"
    else
      message += result.stderr.gsub(/-Password .*\s/, "-Password REDACTED")
    end
    raise message
  end
end

def detect_powershell_binary
  # Detect Powershell first in case of Windows with Powershell 6/7/Core installed as flush_stdout/stderr doesn't work for pwsh on Windows.
  if find_executable0("powershell")
    :powershell
  elsif find_executable0("pwsh")
    :pwsh
  else
    raise "Cannot find PowerShell binary, is `pwsh` installed?"
  end
end

def flush_stderr(pipe)
  loop do
    @stderr_buffer += pipe.read_nonblock(1)
  end
rescue IO::EAGAINWaitReadable
  # If `flush_stderr` is ran after reading stdout we know that all of
  # stderr is in the pipe. Thus, we can return the buffer once the pipe
  # is unreadable.
  @stderr_buffer
ensure
  @stderr_buffer = ""
end

def flush_stdout(pipe)
  @stdout_buffer += pipe.read_nonblock(1) while @stdout_buffer !~ POWERSHELL_PROMPT_REGEX
  @stdout_buffer
rescue IO::EAGAINWaitReadable
  # We cannot know when the stdout pipe is finished so we keep reading
  retry
ensure
  @stdout_buffer = ""
end

def initialize(options)
  super(options)
  options[:viserver] = options[:viserver] || options[:host]
  options[:username] = options[:username] || options[:user]
  @username = options[:username]
  @viserver = options[:viserver]
  @session = nil
  @stdout_buffer = ""
  @stderr_buffer = ""
  @powershell_binary = detect_powershell_binary
  if @powershell_binary == :powershell
    require "train/transports/local"
    @powershell = Train::Transports::Local::Connection.new(options)
  end
  if options[:insecure] == true
    run_command_via_connection("Set-PowerCLIConfiguration -InvalidCertificateAction Ignore -Scope Session -Confirm:$False")
  end
  @platform_details = {
    release: "vmware-powercli-#{powercli_version}",
  }
  connect
end

def parse_pwsh_output(cmd)
  session.stdin.puts(cmd)
  stdout = flush_stdout(session.stdout)
  # Remove stdin from stdout (including trailing newline)
  stdout.slice!(0, cmd.length + 1)
  # Remove prompt from stdout
  stdout.gsub!(POWERSHELL_PROMPT_REGEX, "")
  # Grab stderr
  stderr = flush_stderr(session.stderr)
  CommandResult.new(
    stdout,
    stderr,
    nil # exit_status is attached in `run_command_via_connection`
  )
end

def platform
  force_platform!("vmware", @platform_details)
end

def powercli_version
  version_command = "[string](Get-Module -Name VMware.PowerCLI -ListAvailable | Select -ExpandProperty Version)"
  result = run_command_via_connection(version_command)
  if result.stdout.empty? || result.exit_status != 0
    raise "Unable to determine PowerCLI Module version, is it installed?"
  end
  result.stdout.chomp
end

def run_command_via_connection(cmd, &_data_handler)
  if @powershell_binary == :pwsh
    result = parse_pwsh_output(cmd)
    # Attach exit status to result
    exit_status = parse_pwsh_output("echo $?").stdout.chomp
    result.exit_status = exit_status == "True" ? 0 : 1
    result
  else
    @powershell.run_command(cmd)
  end
end

def session
  return @session unless @session.nil?
  stdin, stdout, stderr = Open3.popen3("pwsh")
  # Remove leading prompt and intro text
  flush_stdout(stdout)
  @session = OpenStruct.new
  @session.stdin = stdin
  @session.stdout = stdout
  @session.stderr = stderr
  @session
end

def unique_identifier
  uuid_command = "(Get-VMHost | Get-View).hardware.systeminfo.uuid"
  run_command_via_connection(uuid_command).stdout.chomp
end

def uri
  "vmware://#{@username}@#{@viserver}"
end