/** @file
  Main file for Help shell level 3 function.

  Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved. <BR>
  Copyright (c) 2014, ARM Limited. All rights reserved. <BR>
  (C) Copyright 2015 Hewlett-Packard Development Company, L.P.<BR>

  This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include "UefiShellLevel3CommandsLib.h"

#include <Library/ShellLib.h>
#include <Library/HandleParsingLib.h>

#include <Protocol/ShellDynamicCommand.h>

/**
   function to insert string items into a list in the correct alphabetical place

   the resultant list is a double NULL terminated list of NULL terminated strings.

   upon successful return the memory must be caller freed (unless passed back in 
   via a loop where it will get reallocated).

   @param[in,out] DestList    double pointer to the list. may be NULL.
   @param[in,out] DestSize    pointer to the size of list. may be 0, if DestList is NULL.
   @param[in]     Item        the item to insert.

   @retval EFI_SUCCESS        the operation was successful.
**/
EFI_STATUS
LexicalInsertIntoList(
  IN OUT   CHAR16 **DestList, 
  IN OUT   UINTN  *DestSize,
  IN CONST CHAR16 *Item
  )
{
  CHAR16                              *NewList;
  INTN                                LexicalMatchValue;
  CHAR16                              *LexicalSpot;
  UINTN                               SizeOfAddedNameInBytes;

  //
  // If there are none, then just return with success
  //
  if (Item == NULL || *Item == CHAR_NULL || StrLen(Item)==0) {
    return (EFI_SUCCESS);
  }

  NewList = *DestList;

  SizeOfAddedNameInBytes = StrSize(Item);
  NewList = ReallocatePool(*DestSize, (*DestSize) + SizeOfAddedNameInBytes, NewList);
  (*DestSize) = (*DestSize) + SizeOfAddedNameInBytes;

  //
  // Find the correct spot in the list
  //
  for (LexicalSpot = NewList
    ; LexicalSpot != NULL && LexicalSpot < NewList + (*DestSize)
    ; LexicalSpot += StrLen(LexicalSpot) + 1
    ) {
    //
    // Get Lexical Comparison Value between PrevCommand and Command list entry
    //
    LexicalMatchValue = gUnicodeCollation->StriColl (
                                              gUnicodeCollation,
                                              (CHAR16 *)LexicalSpot,
                                              (CHAR16 *)Item
                                              );
    //
    // The new item goes before this one.
    //
    if (LexicalMatchValue > 0 || StrLen(LexicalSpot) == 0) {
      if (StrLen(LexicalSpot) != 0) {
        //
        // Move this and all other items out of the way
        //
        CopyMem(
          LexicalSpot + (SizeOfAddedNameInBytes/sizeof(CHAR16)),
          LexicalSpot,
          (*DestSize) - SizeOfAddedNameInBytes - ((LexicalSpot - NewList) * sizeof(CHAR16))
          );
      }

      //
      // Stick this one in place
      //
      StrCpyS(LexicalSpot, SizeOfAddedNameInBytes/sizeof(CHAR16), Item);
      break;
    }
  }

  *DestList = NewList;
  return (EFI_SUCCESS);
}

/**
   function to add each command name from the linked list to the string list.

   the resultant list is a double NULL terminated list of NULL terminated strings.

   @param[in,out] DestList    double pointer to the list. may be NULL.
   @param[in,out] DestSize    pointer to the size of list. may be 0, if DestList is NULL.
   @param[in]     SourceList  the double linked list of commands.

   @retval EFI_SUCCESS        the operation was successful.
**/
EFI_STATUS
CopyListOfCommandNames(
  IN OUT   CHAR16       **DestList, 
  IN OUT   UINTN        *DestSize,
  IN CONST COMMAND_LIST *SourceList
  )
{
  CONST COMMAND_LIST  *Node;

  for ( Node = (COMMAND_LIST*)GetFirstNode(&SourceList->Link)
      ; SourceList != NULL && !IsListEmpty(&SourceList->Link) && !IsNull(&SourceList->Link, &Node->Link)
      ; Node = (COMMAND_LIST*)GetNextNode(&SourceList->Link, &Node->Link)
    ) {
    LexicalInsertIntoList(DestList, DestSize, Node->CommandString);
  }
  return (EFI_SUCCESS);
}

/**
   function to add each dynamic command name to the string list.

   the resultant list is a double NULL terminated list of NULL terminated strings.

   @param[in,out] DestList    double pointer to the list. may be NULL.
   @param[in,out] DestSize    pointer to the size of list. may be 0, if DestList is NULL.

   @retval EFI_SUCCESS        the operation was successful.
   @return an error from HandleProtocol
**/
STATIC
EFI_STATUS
CopyListOfCommandNamesWithDynamic(
  IN OUT  CHAR16** DestList, 
  IN OUT  UINTN    *DestSize
  )
{
  EFI_HANDLE                          *CommandHandleList;
  CONST EFI_HANDLE                    *NextCommand;
  EFI_SHELL_DYNAMIC_COMMAND_PROTOCOL  *DynamicCommand;
  EFI_STATUS                          Status;

  CommandHandleList = GetHandleListByProtocol(&gEfiShellDynamicCommandProtocolGuid);

  //
  // If there are none, then just return with success
  //
  if (CommandHandleList == NULL) {
    return (EFI_SUCCESS);
  }

  Status = EFI_SUCCESS;

  //
  // Append those to the list.
  //
  for (NextCommand = CommandHandleList ; *NextCommand != NULL && !EFI_ERROR(Status) ; NextCommand++) {
    Status = gBS->HandleProtocol(
      *NextCommand,
      &gEfiShellDynamicCommandProtocolGuid,
      (VOID **)&DynamicCommand
      );

    if (EFI_ERROR(Status)) {
      continue;
    }

    Status = LexicalInsertIntoList(DestList, DestSize, DynamicCommand->CommandName);
  }

  SHELL_FREE_NON_NULL(CommandHandleList);
  return (Status);
}


/**
  Attempt to print help from a dynamically added command.

  @param[in]  CommandToGetHelpOn  The unicode name of the command that help is
                                  requested on.
  @param[in]  SectionToGetHelpOn  Pointer to the section specifier(s).
  @param[in]  PrintCommandText    Print the command followed by the help content
                                  or just help.

  @retval EFI_SUCCESS             The help was displayed
  @retval EFI_NOT_FOUND           The command name could not be found
  @retval EFI_DEVICE_ERROR        The help data format was incorrect.
**/
EFI_STATUS
PrintDynamicCommandHelp(
  IN CONST CHAR16  *CommandToGetHelpOn,
  IN CONST CHAR16  *SectionToGetHelpOn,
  IN BOOLEAN       PrintCommandText
 )
{
  EFI_STATUS                          Status;
  BOOLEAN                             Found;
  EFI_HANDLE                          *CommandHandleList;
  EFI_HANDLE                          *NextCommand;
  EFI_SHELL_DYNAMIC_COMMAND_PROTOCOL  *DynamicCommand;

  Status = EFI_NOT_FOUND;
  Found = FALSE;
  CommandHandleList = NULL;

  CommandHandleList = GetHandleListByProtocol(&gEfiShellDynamicCommandProtocolGuid);

  if (CommandHandleList == NULL) {
    //
    // not found or out of resources
    //
    return Status;
  }

  for (NextCommand = CommandHandleList; *NextCommand != NULL; NextCommand++) {
    Status = gBS->HandleProtocol(
      *NextCommand,
      &gEfiShellDynamicCommandProtocolGuid,
      (VOID **)&DynamicCommand
      );

    if (EFI_ERROR(Status)) {
      continue;
    }

    //
    // Check execution break flag when printing multiple command help information.
    //
    if (ShellGetExecutionBreakFlag ()) {
      break;
    }

    if ((gUnicodeCollation->MetaiMatch (gUnicodeCollation, (CHAR16 *)DynamicCommand->CommandName, (CHAR16*)CommandToGetHelpOn)) ||
      (gEfiShellProtocol->GetAlias (CommandToGetHelpOn, NULL) != NULL && (gUnicodeCollation->MetaiMatch (gUnicodeCollation, (CHAR16 *)DynamicCommand->CommandName, (CHAR16*)(gEfiShellProtocol->GetAlias(CommandToGetHelpOn, NULL)))))) {
      // Print as Shell Help if in ManPage format.
      Status = ShellPrintHelp (DynamicCommand->CommandName, SectionToGetHelpOn,
                              PrintCommandText);
      if (Status == EFI_DEVICE_ERROR) {
        ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_HELP_INV),
                        gShellLevel3HiiHandle, DynamicCommand->CommandName);
      } else if (EFI_ERROR(Status)) {
        ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_HELP_NF),
                        gShellLevel3HiiHandle, DynamicCommand->CommandName);
      } else {
        Found = TRUE;
      }
    }
  }

  SHELL_FREE_NON_NULL(CommandHandleList);

  return (Found ? EFI_SUCCESS : Status);

}

STATIC CONST SHELL_PARAM_ITEM ParamList[] = {
  {L"-usage", TypeFlag},
  {L"-section", TypeMaxValue},
  {L"-verbose", TypeFlag},
  {L"-v", TypeFlag},
  {NULL, TypeMax}
  };

/**
  Function for 'help' command.

  @param[in] ImageHandle  Handle to the Image (NULL if Internal).
  @param[in] SystemTable  Pointer to the System Table (NULL if Internal).
**/
SHELL_STATUS
EFIAPI
ShellCommandRunHelp (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS          Status;
  LIST_ENTRY          *Package;
  CHAR16              *ProblemParam;
  SHELL_STATUS        ShellStatus;
  CHAR16              *SortedCommandList;
  CONST CHAR16        *CurrentCommand;
  CHAR16              *CommandToGetHelpOn;
  CHAR16              *SectionToGetHelpOn;
  CHAR16              *HiiString;
  BOOLEAN             Found;
  BOOLEAN             PrintCommandText;
  UINTN               SortedCommandListSize;

  PrintCommandText    = TRUE;
  ProblemParam        = NULL;
  ShellStatus         = SHELL_SUCCESS;
  CommandToGetHelpOn  = NULL;
  SectionToGetHelpOn  = NULL;
  SortedCommandList   = NULL;
  Found               = FALSE;

  //
  // initialize the shell lib (we must be in non-auto-init...)
  //
  Status = ShellInitialize();
  ASSERT_EFI_ERROR(Status);

  Status = CommandInit();
  ASSERT_EFI_ERROR(Status);

  //
  // parse the command line
  //
  Status = ShellCommandLineParse (ParamList, &Package, &ProblemParam, TRUE);
  if (EFI_ERROR(Status)) {
    if (Status == EFI_VOLUME_CORRUPTED && ProblemParam != NULL) {
      ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_PROBLEM), gShellLevel3HiiHandle, L"help", ProblemParam);  
      FreePool(ProblemParam);
      ShellStatus = SHELL_INVALID_PARAMETER;
    } else {
      ASSERT(FALSE);
    }
  } else {
    //
    // Check for conflicting parameters.
    //
    if (ShellCommandLineGetFlag(Package, L"-usage")
      &&ShellCommandLineGetFlag(Package, L"-section")
      &&(ShellCommandLineGetFlag(Package, L"-verbose") || ShellCommandLineGetFlag(Package, L"-v"))
     ){
      ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_PARAM_CON), gShellLevel3HiiHandle, L"help");  
      ShellStatus = SHELL_INVALID_PARAMETER;
    } else if (ShellCommandLineGetRawValue(Package, 2) != NULL) {
      ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_TOO_MANY), gShellLevel3HiiHandle, L"help");  
      ShellStatus = SHELL_INVALID_PARAMETER;
    } else {
      //
      // Get the command name we are getting help on
      //
      ASSERT(CommandToGetHelpOn == NULL);
      StrnCatGrow(&CommandToGetHelpOn, NULL, ShellCommandLineGetRawValue(Package, 1), 0);
      if (CommandToGetHelpOn == NULL && ShellCommandLineGetFlag(Package, L"-?")) {
        //
        // If we dont have a command and we got a simple -?
        // we are looking for help on help command.
        //
        StrnCatGrow(&CommandToGetHelpOn, NULL, L"help", 0);
      }

      if (CommandToGetHelpOn == NULL) {
        StrnCatGrow(&CommandToGetHelpOn, NULL, L"*", 0);
        ASSERT(SectionToGetHelpOn == NULL);
        StrnCatGrow(&SectionToGetHelpOn, NULL, L"NAME", 0);
      } else {
        PrintCommandText = FALSE;
        ASSERT(SectionToGetHelpOn == NULL);
        //
        // Get the section name for the given command name
        //
        if (ShellCommandLineGetFlag(Package, L"-section")) {
          StrnCatGrow(&SectionToGetHelpOn, NULL, ShellCommandLineGetValue(Package, L"-section"), 0);
        } else if (ShellCommandLineGetFlag(Package, L"-usage")) {
          StrnCatGrow(&SectionToGetHelpOn, NULL, L"NAME,SYNOPSIS", 0);
        } else if (ShellCommandLineGetFlag(Package, L"-verbose") || ShellCommandLineGetFlag(Package, L"-v")) {
        } else {
          //
          // The output of help <command> will display NAME, SYNOPSIS, OPTIONS, DESCRIPTION, and EXAMPLES sections.
          //
          StrnCatGrow (&SectionToGetHelpOn, NULL, L"NAME,SYNOPSIS,OPTIONS,DESCRIPTION,EXAMPLES", 0);
        }
      }

      if (gUnicodeCollation->StriColl(gUnicodeCollation, CommandToGetHelpOn, L"special") == 0) {
        //
        // we need info on the special characters
        //
        ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_HELP_SC_HEADER), gShellLevel3HiiHandle);
        HiiString = HiiGetString(gShellLevel3HiiHandle, STRING_TOKEN(STR_HELP_SC_DATA), NULL);
        ShellPrintEx(-1, -1, L"%s", HiiString);
        FreePool(HiiString);
        Found = TRUE;
      } else {
        SortedCommandList = NULL;
        SortedCommandListSize = 0;
        CopyListOfCommandNames(&SortedCommandList, &SortedCommandListSize, ShellCommandGetCommandList(TRUE));
        CopyListOfCommandNamesWithDynamic(&SortedCommandList, &SortedCommandListSize);

        for (CurrentCommand = SortedCommandList 
          ; CurrentCommand != NULL && *CurrentCommand != CHAR_NULL && CurrentCommand < SortedCommandList + SortedCommandListSize/sizeof(CHAR16)
          ; CurrentCommand += StrLen(CurrentCommand) + 1
          ) {
          //
          // Checking execution break flag when print multiple command help information.
          //
          if (ShellGetExecutionBreakFlag ()) {
            break;
          } 

          if ((gUnicodeCollation->MetaiMatch(gUnicodeCollation, (CHAR16*)CurrentCommand, CommandToGetHelpOn)) ||
             (gEfiShellProtocol->GetAlias(CommandToGetHelpOn, NULL) != NULL && (gUnicodeCollation->MetaiMatch(gUnicodeCollation, (CHAR16*)CurrentCommand, (CHAR16*)(gEfiShellProtocol->GetAlias(CommandToGetHelpOn, NULL)))))) {
            //
            // We have a command to look for help on.
            //
            Status = ShellPrintHelp(CurrentCommand, SectionToGetHelpOn, PrintCommandText);
            if (EFI_ERROR(Status)) {
              //
              // now try to match against the dynamic command list and print help
              //
              Status = PrintDynamicCommandHelp (CurrentCommand, SectionToGetHelpOn, PrintCommandText);
            }
            if (Status == EFI_DEVICE_ERROR) {
                ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_HELP_INV), gShellLevel3HiiHandle, CurrentCommand);
            } else if (EFI_ERROR(Status)) {
                ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_HELP_NF), gShellLevel3HiiHandle, CurrentCommand);
            } else {
                Found = TRUE;
            }
          }
        }

        //
        // Search the .man file for Shell applications (Shell external commands).
        //
        if (!Found) {
          Status = ShellPrintHelp(CommandToGetHelpOn, SectionToGetHelpOn, FALSE);
          if (Status == EFI_DEVICE_ERROR) {
              ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_HELP_INV), gShellLevel3HiiHandle, CommandToGetHelpOn);
          } else if (EFI_ERROR(Status)) {
              ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_HELP_NF), gShellLevel3HiiHandle, CommandToGetHelpOn);
          } else {
            Found = TRUE;
          }
        }
      }

      if (!Found) {
        ShellStatus = SHELL_NOT_FOUND;
      }

      //
      // free the command line package
      //
      ShellCommandLineFreeVarList (Package);
    }
  }

  if (CommandToGetHelpOn != NULL && StrCmp(CommandToGetHelpOn, L"*") == 0){
    //
    // If '*' then the command entered was 'Help' without qualifiers, This footer
    // provides additional info on help switches
    //
    ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_HELP_FOOTER), gShellLevel3HiiHandle);
  }
  if (CommandToGetHelpOn != NULL) {
    FreePool(CommandToGetHelpOn);
  }
  if (SectionToGetHelpOn != NULL) {
    FreePool(SectionToGetHelpOn);
  }
  SHELL_FREE_NON_NULL(SortedCommandList);

  return (ShellStatus);
}