program UsbDriveEraser_SearchForErrors;

{$mode delphi}
{$H+}

uses
  RaspberryPi,
  GlobalConst,
  GlobalTypes,
  Platform,
  Threads,
  Console,
  Framebuffer,
  SysUtils,
  Classes,
  Devices,
  Storage,
  FileSystem,
  Ultibo,

  HTTP,
  WebStatus,

  RemoteShell,
  ShellFilesystem,
  ShellUpdate,

  GPIO;

const
 {Define constants for the states of our switch (On or Off)}
 FORMAT_SWITCH_STATE_OFF = 0;
 FORMAT_SWITCH_STATE_ON  = 1;

var
 UserInput:String;
 WindowHandle:TWindowHandle;
 HTTPListener:THTTPListener;

 CurrentDiskDevice:TDiskDevice;
 CurrentStorageDevice:PStorageDevice;

 FormatSwitchState:LongWord;

function NotifyStorageDevice(Device:PDevice;Data:Pointer;Notification:LongWord):LongWord;
{This function will be called when a storage device event that we have registered for occurs}
var
 Count:Integer;
 DiskDevice:TDiskDevice;
begin
 Result:=ERROR_SUCCESS;

 {Check Device}
 if Device = nil then Exit;

 {Check Notification}
 if (Notification and DEVICE_NOTIFICATION_INSERT) <> 0 then
  begin
   ConsoleWindowWriteLn(WindowHandle,'Storage Device inserted');

   {Get (and Lock) Device}
   Count:=0;
   DiskDevice:=FileSysDriver.GetDeviceByStorage(PStorageDevice(Device),True,FILESYS_LOCK_READ);
   while DiskDevice = nil do
    begin
     {Sleep to allow time for the filesystem to mount the device}
     Sleep(500);

     {Try to get the device again}
     DiskDevice:=FileSysDriver.GetDeviceByStorage(PStorageDevice(Device),True,FILESYS_LOCK_READ);

     Inc(Count);
     if Count >= 5 then Break;
    end;

   try
    if DiskDevice <> nil then
     begin
      ConsoleWindowWriteLn(WindowHandle,'Device Name: ' + DiskDevice.Name);

      {Check for a USB device}
      if Device.DeviceBus = DEVICE_BUS_USB then
       begin
        ConsoleWindowWriteLn(WindowHandle,'USB device detected');

        {Save the details for later}
        CurrentDiskDevice:=DiskDevice;
        CurrentStorageDevice:=PStorageDevice(Device);
       end
      else
       begin
        ConsoleWindowWriteLn(WindowHandle,'Device is not USB');
       end;
     end
    else
     begin
      ConsoleWindowWriteLn(WindowHandle,'Device Name: <Unknown>');
     end;
   finally
    {Unlock Device}
    DiskDevice.ReaderUnlock;
   end;
  end
 else if (Notification and DEVICE_NOTIFICATION_EJECT) <> 0 then
  begin
   ConsoleWindowWriteLn(WindowHandle,'Storage Device ejected');

   {Check Device}
   if PStorageDevice(Device) = CurrentStorageDevice then
    begin
     ConsoleWindowWriteLn(WindowHandle,'Current USB device ejected');

     {Clear the details}
     CurrentDiskDevice:=nil;
     CurrentStorageDevice:=nil;
    end
   else
    begin
     ConsoleWindowWriteLn(WindowHandle,'Other device ejected');
    end;
  end;
end;

function PartitionTypeToFileSysType(PartitionType:Byte):TFileSysType;
{A little function to determine the file system type from the partition id}
begin
 Result:=fsUNKNOWN;

 case PartitionType of
  pidFAT12:Result:=fsFAT12;
  pidFAT16,pidFAT16HUGE,pidFAT16LBA:Result:=fsFAT16;
  pidFAT32,pidFAT32LBA:Result:=fsFAT32;
  pidHPFSNTFS:Result:=fsNTFS51;
 end;
end;

procedure FlashFormattingLED;
{This procedure will toggle the LED GPIO on and off}
begin
 while True do
  GPIOOutputSet(GPIO_PIN_13,GPIO_LEVEL_LOW);
  Sleep(250);
  GPIOOutputSet(GPIO_PIN_13,GPIO_LEVEL_LOW);
  Sleep(250);
 end;

procedure FormatDiskDevice(DiskDevice:TDiskDevice;StorageDevice:PStorageDevice);
{This procedure will format each partition found on the supplied disk device}
var
 Count:Integer;

 Volumes:TList;
 Partitions:TList;
 DiskVolume:TDiskVolume;
 DiskPartition:TDiskPartition;

 FloppyType:TFloppyType;
 FileSysType:TFileSysType;
begin
 ConsoleWindowWriteLn(WindowHandle,'Formatting Disk Device');

 {Start flashing of Formatting-in-Progress LED}
 FlashFormattingLED();

 {Lock Device}
 if FileSysDriver.CheckDevice(DiskDevice,True,FILESYS_LOCK_READ) then
  begin
   try
    ConsoleWindowWriteLn(WindowHandle,'Checking device ' + DiskDevice.Name);

    {Get Partitions}
    Partitions:=FileSysDriver.GetPartitionsByDevice(DiskDevice,False,FILESYS_LOCK_NONE);
    try
     if Partitions.Count > 0 then
      begin
       {Check Partitions}
       for Count:=0 to Partitions.Count - 1 do
        begin
         DiskPartition:=Partitions.Items[Count];
         if FileSysDriver.CheckPartition(DiskPartition,True,FILESYS_LOCK_READ) then
          begin
           try
            ConsoleWindowWriteLn(WindowHandle,'Checking partition ' + DiskPartition.Path);

            {Get Volume}
            DiskVolume:=FileSysDriver.GetVolumeByPartition(DiskPartition,True,FILESYS_LOCK_WRITE);
            if DiskVolume <> nil then
             begin
              try
               ConsoleWindowWriteLn(WindowHandle,'Formatting volume ' + DiskVolume.Name);

               {Get Format Type}
               FileSysType:=DiskVolume.FileSysType;
               if FileSysType = fsUNKNOWN then FileSysType:=PartitionTypeToFileSysType(DiskPartition.PartitionId);
               if FileSysType <> fsUNKNOWN then
                begin
                 {Get Floppy Type}
                 FloppyType:=DiskDevice.FloppyType;

                 {Format Volume}
                 if DiskVolume.FormatVolume(FloppyType,FileSysType) then
                  begin
                   ConsoleWindowWriteLn(WindowHandle,'Format completed ' + DiskVolume.Name);
                  end
                 else
                  begin
                   ConsoleWindowWriteLn(WindowHandle,'Could not format ' + DiskVolume.Name);
                  end;
                end
               else
                begin
                 ConsoleWindowWriteLn(WindowHandle,'Unrecognized type for volume ' + DiskVolume.Name);
                end;
              finally
               {Unlock Volume}
               DiskVolume.WriterUnlock;
              end;
             end
            else
             begin
              ConsoleWindowWriteLn(WindowHandle,'No volume found to format on partition ' + DiskPartition.Path);

              {Illuminate Error LED}
              GPIOOutputSet(GPIO_PIN_26,GPIO_LEVEL_HIGH);
             end;
           finally
            {Unlock Partition}
            DiskPartition.ReaderUnlock;
           end;
          end;
        end;
      end
     else
      begin
       {Get Volumes}
       Volumes:=FileSysDriver.GetVolumesByDevice(DiskDevice,False,FILESYS_LOCK_NONE);
       try
        if Volumes.Count > 0 then
         begin
          {Check Volumes}
          for Count:=0 to Volumes.Count - 1 do
           begin
            DiskVolume:=Volumes.Items[Count];
            if FileSysDriver.CheckVolume(DiskVolume,True,FILESYS_LOCK_WRITE) then
             begin
              try
               ConsoleWindowWriteLn(WindowHandle,'Formatting volume ' + DiskVolume.Name);

               {Get Format Type}
               FileSysType:=DiskVolume.FileSysType;
               if FileSysType = fsUNKNOWN then FileSysType:=fsFAT32;

               {Get Floppy Type}
               FloppyType:=DiskDevice.FloppyType;

               {Format Volume}
               if DiskVolume.FormatVolume(FloppyType,FileSysType) then
                begin
                 ConsoleWindowWriteLn(WindowHandle,'Format completed ' + DiskVolume.Name);
                end
               else
                begin
                 ConsoleWindowWriteLn(WindowHandle,'Could not format ' + DiskVolume.Name);
                end;
              finally
               {Unlock Volume}
               DiskVolume.WriterUnlock;
              end;
             end;
           end;
         end
        else
         begin
          ConsoleWindowWriteLn(WindowHandle,'No volume found to format on device ' + DiskDevice.Name);

          {Illuminate Error LED}
          GPIOOutputSet(GPIO_PIN_26,GPIO_LEVEL_HIGH);
         end;
       finally
        Volumes.Free;
       end;
      end;
    finally
     Partitions.Free;
    end;
   finally
    {Unlock Device}
    DiskDevice.ReaderUnlock;

    {Stop flashing of Formatting-in-Progress LED}
    GPIOOutputSet(GPIO_PIN_13,GPIO_LEVEL_LOW);

    {Illuminate Wipe completion LED}
    GPIOOutputSet(GPIO_PIN_19,GPIO_LEVEL_HIGH);
   end;
  end;
end;

{This is the function called when a GPIO event occurs}
procedure GPIOEventFunction(Data:Pointer;Pin,Trigger:LongWord);
begin
 {Sleep for a few milliseconds to allow the switch to settle}
 Sleep(10);

 {Read the current state of the switch (High or Low)}
 if GPIOInputGet(GPIO_PIN_12) = GPIO_LEVEL_LOW then
  begin
   {If the state is Low the switch is On so update the state variable}
   FormatSwitchState:=FORMAT_SWITCH_STATE_ON;

   {Print a message on the console in green to say the switch is on}
   ConsoleWindowSetForecolor(WindowHandle,COLOR_GREEN);
   ConsoleWindowWriteLn(WindowHandle,'Format switch is ON');

   {Reregister this function to be called when the state changes to High}
   GPIOInputEvent(GPIO_PIN_12,GPIO_TRIGGER_HIGH,INFINITE,@GPIOEventFunction,nil);
  end
 else
  begin
   {The level is High so the switch must be Off, save that to the state variable}
   FormatSwitchState:=FORMAT_SWITCH_STATE_OFF;

   {Print the switch is off message in red}
   ConsoleWindowSetForecolor(WindowHandle,COLOR_RED);
   ConsoleWindowWriteLn(WindowHandle,'Format switch is OFF');

   {And register again for an event when the level changes to Low}
   GPIOInputEvent(GPIO_PIN_12,GPIO_TRIGGER_LOW,INFINITE,@GPIOEventFunction,nil);
  end;
end;

begin
 HTTPListener:=THTTPListener.Create;
 HTTPListener.Active:=True;
 WebStatusRegister(HTTPListener,'','',True);

 {Create a console window at full size}
 WindowHandle:=ConsoleWindowCreate(ConsoleDeviceGetDefault,CONSOLE_POSITION_FULL,True);

 {Output some welcome text on the console window}
 ConsoleWindowWriteLn(WindowHandle,'Disk detection and formatting example');

  {Set GPIO pin 18 (our switch) to Pull Up so the pin will be High when the switch
 is off and Low when the switch is On. Then set the function of pin 18 to be an
 Input so we can read the switch state using the GPIOInputGet() function}
 GPIOPullSelect(GPIO_PIN_18,GPIO_PULL_UP);
 GPIOFunctionSelect(GPIO_PIN_18,GPIO_FUNCTION_IN);

 {Set GPIO pin 5 (System Ready LED) to Pull None and make the function of the pin an Output
 so we can set the level to High or Low to turn the LED On or Off. After setting
 the function we also set the current level to Low so the LED is Off}
 GPIOPullSelect(GPIO_PIN_5,GPIO_PULL_NONE);
 GPIOFunctionSelect(GPIO_PIN_5,GPIO_FUNCTION_OUT);
 GPIOOutputSet(GPIO_PIN_5,GPIO_LEVEL_LOW);

 {Do the same for GPIO pins 6, 13, 19 and 26 (the USB Drive Mounted, Wipe-in-Progress, Wipe Complete and Error LEDs)}
 GPIOPullSelect(GPIO_PIN_6,GPIO_PULL_NONE);
 GPIOFunctionSelect(GPIO_PIN_6,GPIO_FUNCTION_OUT);
 GPIOOutputSet(GPIO_PIN_6,GPIO_LEVEL_LOW);
 GPIOPullSelect(GPIO_PIN_13,GPIO_PULL_NONE);
 GPIOFunctionSelect(GPIO_PIN_13,GPIO_FUNCTION_OUT);
 GPIOOutputSet(GPIO_PIN_13,GPIO_LEVEL_LOW);
 GPIOPullSelect(GPIO_PIN_19,GPIO_PULL_NONE);
 GPIOFunctionSelect(GPIO_PIN_19,GPIO_FUNCTION_OUT);
 GPIOOutputSet(GPIO_PIN_19,GPIO_LEVEL_LOW);
 GPIOPullSelect(GPIO_PIN_26,GPIO_PULL_NONE);
 GPIOFunctionSelect(GPIO_PIN_26,GPIO_FUNCTION_OUT);
 GPIOOutputSet(GPIO_PIN_26,GPIO_LEVEL_LOW);

 {Register for Insert and Eject notifications for Storage Devices}
 StorageDeviceNotification(nil,NotifyStorageDevice,nil,DEVICE_NOTIFICATION_EJECT or DEVICE_NOTIFICATION_INSERT,NOTIFIER_FLAG_WORKER);

 {Loop waiting for a device}
 while True do
  begin
   if (CurrentDiskDevice <> nil) and (CurrentStorageDevice <> nil) then
    begin
     {Prompt the user to format the device, this uses the keyboard but it could be a GPIO input or something else}
     ConsoleWindowWriteLn(WindowHandle,'USB device detected, type FORMAT to proceed');
     ConsoleReadLn(UserInput);
     if UserInput = 'FORMAT' or FormatSwitchState = 1 then
      begin
       {Proceed with format}
       FormatDiskDevice(CurrentDiskDevice,CurrentStorageDevice);
      end;
    end;


   {Sleep on each loop}
   Sleep(500);
  end;

 {Halt the thread}
 ThreadHalt(0);
end.