MenuLoop.c

#include <Library/BaseLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiLib.h>
#include <Protocol/SimpleTextInEx.h>
#include <Uefi.h>
#include <stdbool.h>

#include "Errors.h"
#include "FileEditor.h"
#include "FileUtils.h"
#include "MenuLoop.h"
#include "Utils.h"

/**
  Main interaction loop.

  @param[in,out] Notes      Dynamic array containing the notes to be displayed to
                            the user. Updated when the user creates or deletes a file.
  @param[in,out] NotesCount The amount of notes used when displaying the notes to
                            the user and interacting with the array. Updated when
                            the user creates or deletes a file.

  @retval ERROR_UNKNOWN An unknown error was occured.
  @retval other       An error was encountered.
**/
EFI_STATUS
MenuLoop
(
    IN OUT CHAR16 **Notes,
    IN OUT UINTN NotesCount
) {
    EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL *ConInEx;
    EFI_STATUS err;
    UINTN i;
    
    UINTN bufferCount = 1;
    UINTN bufferLen = 0;
    CHAR16* buffer;
    err = gBS->HandleProtocol(
        gST->ConsoleInHandle,
        &gEfiSimpleTextInputExProtocolGuid,
        (void **)&ConInEx
    );
    if(EFI_ERROR(err)) {
        Print(L"Unable to get EfiSimpleTextInputExProtocol %r __LINE__=%d __FILE__=%a\n", err, __LINE__, __FILE__);
        pauseForKey();
        return EFI_UNSUPPORTED;
    }
    err = EFI_SUCCESS;
    buffer = AllocatePool(bufferCount * sizeof(CHAR16));
    if(buffer == NULL) {
        Print(L"Out Of Memory.");
        pauseForKey();
        return EFI_OUT_OF_RESOURCES;
    }
    buffer[0] = L'\0';
    gST->ConOut->ClearScreen(gST->ConOut);
    gST->ConOut->EnableCursor(gST->ConOut, true);
    while(true) {
        EFI_KEY_DATA keyData;
        CHAR16 ch;
        UINTN eventIndex;
        gBS->WaitForEvent(1, &gST->ConIn->WaitForKey, &eventIndex);
        err = ConInEx->ReadKeyStrokeEx(ConInEx, &keyData);
        if(err == EFI_NOT_READY) {err = EFI_SUCCESS; continue;} // normal
        if(EFI_ERROR(err)) {
            Print(L"ReadKeyStrokeEx error %r __LINE__=%d __FILE__=%a\n", err, __LINE__, __FILE__);
            pauseForKey();
            return err;
        }
        ch = keyData.Key.UnicodeChar;
        if (ch == CHAR_BACKSPACE) {
            if (bufferLen > 0) {
                buffer[--bufferLen] = L'\0';
            }
        } else if (ch == CHAR_CARRIAGE_RETURN) {
            Print(L"\n");
            if(StrCmp(buffer, L"exit") == 0) {
                gST->RuntimeServices->ResetSystem(EfiResetShutdown, EFI_SUCCESS, 0, NULL);
            }
            if(StrCmp(buffer, L"reboot") == 0) {
                gST->RuntimeServices->ResetSystem(EfiResetCold, EFI_SUCCESS, 0, NULL);
            }
            if(StrCmp(buffer, L"EfiResetWarm") == 0) {
                gST->RuntimeServices->ResetSystem(EfiResetWarm, EFI_SUCCESS, 0, NULL);
            }
            if(StrCmp(buffer, L"help") == 0) {
                Print(L"exit - Shutdown the system\n");
                Print(L"reboot - Reboot the system\n");
                Print(L"EfiResetWarm - Reboot the system using EfiResetWarm\n");
                Print(L"help - Display this help message\n");
                Print(L"e, edit <file> - Open the text editor\n");
                Print(L"c, create <file> - Create a file\n");
                Print(L"delete <file> - Delete a file\n");
                Print(L"Press any key to go back to the prompt");
                pauseForKey();
                goto crCleanup;
            }
            CHAR16 **split;
            UINTN SplitCount;
            err = SplitString(buffer, SPACE, &split, &SplitCount);
            if(EFI_ERROR(err)) {
                Print(L"SplitString error: %r __LINE__=%d __FILE__=%a\n", err, __LINE__, __FILE__);
                pauseForKey();
                goto crCleanup;
            }
            if(SplitCount == 0) goto crCleanup;
            if(SplitCount < 2) {
                Print(L"Not enough arguments for %s\n", split[0]);
                Print(L"Press any key to go back to the prompt");
                pauseForKey();
                goto crCleanup;
            }
            if(StrCmp(split[0], L"e") == 0 || StrCmp(split[0], L"edit") == 0) {
                UINTN RawFileIndex = StrDecimalToUintn(split[1]);
                if(RawFileIndex == 0 || RawFileIndex > NotesCount) {
                    Print(L"File does not exist"); // StrDecimalToUintn returns 0 when the string is not a string form of a UINTN but 0 is never going to be a file anyway so this handles all cases
                    // i guess if there are enough notes a integer overflow could happen, but on a 64 bit system (this is made for one) there would most likely be fat32 limits before it is even that close to the integer limit
                    Print(L"Press any key to go back to the prompt");
                    pauseForKey();
                    goto crCleanup;
                }
                err = OpenEditor(Notes[RawFileIndex - 1]);
                if(EFI_ERROR(err)) {
                    Print(L"Error in OpenEditor %r", err);
                    pauseForKey();
                }
                err = EFI_SUCCESS; // this is most likely not really needed but it became convention in this repo before i thought about it
                goto crCleanup;
            }
            if(StrCmp(split[0], L"c") == 0 || StrCmp(split[0], L"create") == 0) {
                #define NOTES_DIR_PREFIX_LENGTH 8
                #define TXT_EXTENTION_LENGTH 4
                UINTN FilenameBufferLen = NOTES_DIR_PREFIX_LENGTH + TXT_EXTENTION_LENGTH + StrLen(split[1]);
                CHAR16 *FilenameBuffer = AllocatePool(FilenameBufferLen * sizeof(CHAR16));
                if (FilenameBuffer == NULL) {
                    Print(L"Out Of Memory.");
                    pauseForKey();
                    return EFI_OUT_OF_RESOURCES;
                }
                err = StrCpyS(FilenameBuffer, FilenameBufferLen, L"\\notes\\");
                if(EFI_ERROR(err)) {
                    Print(L"Error in StrCpyS %r __LINE__=%d __FILE__=%a\n", err, __LINE__, __FILE__);
                    pauseForKey();
                    goto crCleanup;
                }
                err = StrCatS(FilenameBuffer, FilenameBufferLen, split[1]);
                if(EFI_ERROR(err)) {
                    Print(L"Error in StrCatS %r __LINE__=%d __FILE__=%a\n", err, __LINE__, __FILE__);
                    pauseForKey();
                    goto crCleanup;
                }
                err = StrCatS(FilenameBuffer, FilenameBufferLen, L".txt");
                if(EFI_ERROR(err)) {
                    Print(L"Error in StrCatS %r __LINE__=%d __FILE__=%a\n", err, __LINE__, __FILE__);
                    pauseForKey();
                    goto crCleanup;
                }
                err = EFI_SUCCESS;
                WriteFile(FilenameBuffer, L"", 1);
                FreePool(FilenameBuffer);
                FilenameBuffer = NULL;
                // Update Notes and NotesCount
                if(NotesCount != 0) {
                    for(i=0; i < NotesCount; i++) {
                        FreePool(Notes[i]);
                    }
                }
                if(Notes != NULL) {
                    FreePool(Notes);
                }
                ListFiles(L"\\notes", &Notes, &NotesCount);
                goto crCleanup;
            }
            if(StrCmp(split[0], L"delete") == 0) {
                UINTN RawFileIndex = StrDecimalToUintn(split[1]);
                if(RawFileIndex == 0 || RawFileIndex > NotesCount) {
                    Print(L"File does not exist"); // StrDecimalToUintn returns 0 when the string is not a string form of a UINTN but 0 is never going to be a file anyway so this handles all cases
                    Print(L"Press any key to go back to the prompt");
                    pauseForKey();
                    goto crCleanup;
                }
                #define NOTES_DIR_PREFIX_LENGTH 8
                #define TXT_EXTENTION_LENGTH 4
                UINTN FilenameBufferLen = NOTES_DIR_PREFIX_LENGTH + TXT_EXTENTION_LENGTH + StrLen(Notes[RawFileIndex - 1]);
                CHAR16 *FilenameBuffer = AllocatePool(FilenameBufferLen * sizeof(CHAR16));
                err = StrCpyS(FilenameBuffer, FilenameBufferLen, L"\\notes\\");
                if(EFI_ERROR(err)) {
                    Print(L"Error in StrCpyS %r __LINE__=%d __FILE__=%a\n", err, __LINE__, __FILE__);
                    pauseForKey();
                    goto crCleanup;
                }
                err = StrCatS(FilenameBuffer, FilenameBufferLen, Notes[RawFileIndex - 1]);
                if(EFI_ERROR(err)) {
                    Print(L"Error in StrCatS %r __LINE__=%d __FILE__=%a\n", err, __LINE__, __FILE__);
                    pauseForKey();
                    goto crCleanup;
                }
                
                err = DeleteFile(FilenameBuffer);
                if(EFI_ERROR(err)) {
                    Print(L"Error in DeleteFile %r __LINE__=%d __FILE__=%a\n", err, __LINE__, __FILE__);
                    pauseForKey();
                    goto crCleanup;
                }
                FreePool(FilenameBuffer);
                // Update Notes and NotesCount
                if(NotesCount != 0) {
                    for(i=0; i < NotesCount; i++) {
                        FreePool(Notes[i]);
                    }
                }
                if(Notes != NULL) {
                    FreePool(Notes);
                }
                ListFiles(L"\\notes", &Notes, &NotesCount);
                goto crCleanup;
            }
            // error case (fall through all commands)
            Print(L"Error: %s is not a command. For a list of commands run 'help'\n", split[0]);
            Print(L"Press any key to go back to the prompt");
            pauseForKey();
            crCleanup:
            // reset buffer to empty
            FreePool(buffer);
            bufferCount = 1;
            bufferLen = 0;
            buffer = AllocatePool(bufferCount * sizeof(CHAR16));
            if(buffer == NULL) {
                Print(L"Out Of Memory.");
                pauseForKey();
                return EFI_OUT_OF_RESOURCES;
            }
            buffer[0] = L'\0';
        } else if (ch == 0 || ch == CHAR_TAB) {
            continue;
        } else {
            // grow buffer if needed (keep room for null terminator)
            if (bufferLen + 2 > bufferCount) {
                buffer = ReallocatePool(
                    (bufferCount * sizeof(CHAR16)),
                    (bufferCount * 2 * sizeof(CHAR16)),
                    buffer
                );
                if(buffer == NULL) {
                    Print(L"Out Of Memory.");
                    pauseForKey();
                    return EFI_OUT_OF_RESOURCES;
                }
                bufferCount *= 2;
            }
            buffer[bufferLen++] = ch;
            buffer[bufferLen] = L'\0';
        }
        gST->ConOut->ClearScreen(gST->ConOut);
	    for (i=0; i < NotesCount; i++) {
            CHAR16 *NoteWithoutExtention = RemoveExtension(Notes[i]);
            if(NoteWithoutExtention == NULL) {
                Print(L"Out Of Memory.");
                pauseForKey();
                return EFI_OUT_OF_RESOURCES;
            }
	    	Print(L"%d: %s\n", (i + 1), NoteWithoutExtention); // i + 1 is here since users might get confused with a zero based index
            FreePool(NoteWithoutExtention);
	    }
        Print(L"> %s", buffer);
    }
    return ERROR_UNKNOWN;
}