// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: dbhistry - debugger HISTORY command
 *
 * Copyright (C) 2000 - 2025, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "acdebug.h"

#define _COMPONENT          ACPI_CA_DEBUGGER
ACPI_MODULE_NAME("dbhistry")

#define HI_NO_HISTORY       0
#define HI_RECORD_HISTORY   1
#define HISTORY_SIZE        40
typedef struct history_info {
 char *command;
 u32 cmd_num;

} HISTORY_INFO;

static HISTORY_INFO acpi_gbl_history_buffer[HISTORY_SIZE];
static u16 acpi_gbl_lo_history = 0;
static u16 acpi_gbl_num_history = 0;
static u16 acpi_gbl_next_history_index = 0;

/*******************************************************************************
 *
 * FUNCTION:    acpi_db_add_to_history
 *
 * PARAMETERS:  command_line    - Command to add
 *
 * RETURN:      None
 *
 * DESCRIPTION: Add a command line to the history buffer.
 *
 ******************************************************************************/

void acpi_db_add_to_history(char *command_line)
{
 u16 cmd_len;
 u16 buffer_len;

 /* Put command into the next available slot */

 cmd_len = (u16)strlen(command_line);
 if (!cmd_len) {
  return;
 }

 if (acpi_gbl_history_buffer[acpi_gbl_next_history_index].command !=
     NULL) {
  buffer_len =
      (u16)
      strlen(acpi_gbl_history_buffer[acpi_gbl_next_history_index].
      command);

  if (cmd_len > buffer_len) {
   acpi_os_free(acpi_gbl_history_buffer
         [acpi_gbl_next_history_index].command);
   acpi_gbl_history_buffer[acpi_gbl_next_history_index].
       command = acpi_os_allocate(cmd_len + 1);
  }
 } else {
  acpi_gbl_history_buffer[acpi_gbl_next_history_index].command =
      acpi_os_allocate(cmd_len + 1);
 }

 strcpy(acpi_gbl_history_buffer[acpi_gbl_next_history_index].command,
        command_line);

 acpi_gbl_history_buffer[acpi_gbl_next_history_index].cmd_num =
     acpi_gbl_next_cmd_num;

 /* Adjust indexes */

 if ((acpi_gbl_num_history == HISTORY_SIZE) &&
     (acpi_gbl_next_history_index == acpi_gbl_lo_history)) {
  acpi_gbl_lo_history++;
  if (acpi_gbl_lo_history >= HISTORY_SIZE) {
   acpi_gbl_lo_history = 0;
  }
 }

 acpi_gbl_next_history_index++;
 if (acpi_gbl_next_history_index >= HISTORY_SIZE) {
  acpi_gbl_next_history_index = 0;
 }

 acpi_gbl_next_cmd_num++;
 if (acpi_gbl_num_history < HISTORY_SIZE) {
  acpi_gbl_num_history++;
 }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_db_display_history
 *
 * PARAMETERS:  None
 *
 * RETURN:      None
 *
 * DESCRIPTION: Display the contents of the history buffer
 *
 ******************************************************************************/

void acpi_db_display_history(void)
{
 u32 i;
 u16 history_index;

 history_index = acpi_gbl_lo_history;

 /* Dump entire history buffer */

 for (i = 0; i < acpi_gbl_num_history; i++) {
  if (acpi_gbl_history_buffer[history_index].command) {
   acpi_os_printf("%3u %s\n",
           acpi_gbl_history_buffer[history_index].
           cmd_num,
           acpi_gbl_history_buffer[history_index].
           command);
  }

  history_index++;
  if (history_index >= HISTORY_SIZE) {
   history_index = 0;
  }
 }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_db_get_from_history
 *
 * PARAMETERS:  command_num_arg         - String containing the number of the
 *                                        command to be retrieved
 *
 * RETURN:      Pointer to the retrieved command. Null on error.
 *
 * DESCRIPTION: Get a command from the history buffer
 *
 ******************************************************************************/

char *acpi_db_get_from_history(char *command_num_arg)
{
 u32 cmd_num;

 if (command_num_arg == NULL) {
  cmd_num = acpi_gbl_next_cmd_num - 1;
 }

 else {
  cmd_num = strtoul(command_num_arg, NULL, 0);
 }

 return (acpi_db_get_history_by_index(cmd_num));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_db_get_history_by_index
 *
 * PARAMETERS:  cmd_num             - Index of the desired history entry.
 *                                    Values are 0...(acpi_gbl_next_cmd_num - 1)
 *
 * RETURN:      Pointer to the retrieved command. Null on error.
 *
 * DESCRIPTION: Get a command from the history buffer
 *
 ******************************************************************************/

char *acpi_db_get_history_by_index(u32 cmd_num)
{
 u32 i;
 u16 history_index;

 /* Search history buffer */

 history_index = acpi_gbl_lo_history;
 for (i = 0; i < acpi_gbl_num_history; i++) {
  if (acpi_gbl_history_buffer[history_index].cmd_num == cmd_num) {

   /* Found the command, return it */

   return (acpi_gbl_history_buffer[history_index].command);
  }

  /* History buffer is circular */

  history_index++;
  if (history_index >= HISTORY_SIZE) {
   history_index = 0;
  }
 }

 acpi_os_printf("Invalid history number: %u\n", history_index);
 return (NULL);
}