CommandLine.h

#ifndef __COMMANDLINE_H__
#define __COMMANDLINE_H__

#include <inttypes.h>
#include <string.h>

#include "Arduino.h"

// Number of commands to support.
#ifndef COMMANDLINE_COUNT
#define COMMANDLINE_COUNT 8
#endif

// Maximum number of characters in input buffer.
#ifndef COMMANDLINE_BUFFER
#define COMMANDLINE_BUFFER 32
#endif

// Maximum number of commands to keep in history (for up/down support).
#ifndef COMMANDLINE_HISTORY
#define COMMANDLINE_HISTORY 2
#endif

// Add support for pre and post command execution.
#define COMMANDLINE_PRE_POST

// Keycode defines.
#define KEYCODE_BACKSPACE 8
#define KEYCODE_TAB 9
#define KEYCODE_ENTER 13
#define KEYCODE_SPACE 32
#define KEYCODE_UP 65
#define KEYCODE_DOWN 66
#define KEYCODE_DELETE 127

/**
 * Command definition
 */
struct Command {
    char *command;
    void (*callback)(char *);

    /**
     * Construct a new command
     *
     * @param command Name of the command
     * @param callback Function pointer
     */
    Command(char *_command, void (*_callback)(char *))
        : command(_command), callback(_callback) {}
};

/**
 * CommandLine instance.
 */
class CommandLine {
  public:
    /**
     * Construct a new CommandLine instance
     *
     * @param serial Serial stream to wrap
     * @param token Command line token to indicate new line (e.g. "> ")
     */
    CommandLine(Stream &serial, char *token);

    /**
     * Read the serial stream and evaluate commands.
     *
     * @return True if a command was evaluated and executed, false otherwise.
     */
    bool update(void);

    /**
     * Add a new command.
     *
     * @param Comand instance to add.
     * @return True on success, false otherwise.
     */
    bool add(Command &command);

    /**
     * Add a new command, dynamically.
     *
     * @param command Name of the command.
     * @param callback Function pointer.
     * @return True on success, false otherwise.
     */
    bool add(char *command, void (*callback)(char *));

    /**
     * Remove a command instance
     *
     * @param Comand instance to remove.
     * @return True on success, false otherwise.
     */
    bool remove(Command &command);

#ifdef COMMANDLINE_PRE_POST
    /**
     * Attach pre-command execution handler. This callback is invoked
     * before each non-empty input command. Set to NULL to clear.
     *
     * @param callback Function pointer callback. Parameter is input the
     *                 string.
     */
    void attachPre(void (*callback)(char *));

    /**
     * Attach post-command execution handler. This callback is invoked
     * after each non-empty input command. Set to NULL to clear.
     *
     * @param callback Function pointer callback. First parameter is the
     *                 input string, second parameter indicates success.
     */
    void attachPost(void (*callback)(char *, bool));
#endif

  private:
    Stream &serial;

    struct {
        uint8_t index;
        char buffer[COMMANDLINE_BUFFER + 1];
    } input;

    struct {
        uint8_t index;
        Command *items[COMMANDLINE_COUNT];
    } commands;

#if COMMANDLINE_HISTORY > 0
    struct {
        uint8_t current;
        uint8_t index;
        char items[COMMANDLINE_HISTORY][COMMANDLINE_BUFFER + 1];
    } history;

    void restore();
#endif

    char *token;

#ifdef COMMANDLINE_PRE_POST
    void (*preCallback)(char *);
    void (*postCallback)(char *, bool);
#endif
};

#endif