command.c

#pragma once

#include "global.h"
#include <stdint.h>
#include <string.h>

#define CMD_HISTORY_MAX 10

static struct {
  char history[CMD_HISTORY_MAX][BUF_SIZE]; // ~40KB
  int count;
  int cursor;
} command_history;

static void string_insert_at(char *text, const int idx, const char c) {
  for (int i = strlen(text) + 1; i > idx; --i) {
    text[i] = text[i - 1];
  }

  text[idx] = c;
}

static void string_remove_at(char *text, const int idx) {
  for (int i = idx;; i++) {
    text[i] = text[i + 1];
    if (text[i] == '\0') {
      return;
    }
  }
}

void command_mode_enter(void) {
  g_msg[0] = '\0';
  g_msg_line_count = 0;
  g_current_command.cursor = 0;
  g_current_command.chars[0] = '\0';
  g_current_command.len = 0;
  command_history.cursor = command_history.count;
}

void command_history_prev(void) {
  if (!OPT_CMD_HISTORY || command_history.cursor == 0)
    return;
  int oldest = command_history.count > CMD_HISTORY_MAX ? command_history.count - CMD_HISTORY_MAX : 0;
  if (command_history.cursor <= oldest)
    return;
  command_history.cursor--;
  strlcpy(g_current_command.chars, command_history.history[command_history.cursor % CMD_HISTORY_MAX],
          sizeof(g_current_command.chars));
  const int len = strlen(g_current_command.chars);
  g_current_command.len = len;
  g_current_command.cursor = len;
}

void command_history_next(void) {
  if (!OPT_CMD_HISTORY || command_history.cursor >= command_history.count)
    return;
  command_history.cursor++;
  if (command_history.cursor >= command_history.count) {
    g_current_command.chars[0] = '\0';
    g_current_command.len = 0;
    g_current_command.cursor = 0;
    return;
  }
  strlcpy(g_current_command.chars, command_history.history[command_history.cursor % CMD_HISTORY_MAX],
          sizeof(g_current_command.chars));
  const int len = strlen(g_current_command.chars);
  g_current_command.len = len;
  g_current_command.cursor = len;
}

void command_history_add(void) {
  if (!OPT_CMD_HISTORY)
    return;
  strlcpy(command_history.history[command_history.count % CMD_HISTORY_MAX], g_current_command.chars,
          sizeof(command_history.history[0]));
  command_history.count++;
}