// 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);
}