UARTCommandHandler.h

#ifndef UARTCOMMANDHANDLER_H
#define UARTCOMMANDHANDLER_H

#include <functional>
#include <queue>
#include <string>
#include <vector>

#include "ArduinoHAL.h"

constexpr const char* kShellPrompt = "AS> ";  // AS = Avionics Shell

enum class AsciiKey : uint8_t {
    Escape      = 27,
    UpArrow     = 65,
    DownArrow   = 66,
    Backspace   = 8,
    Delete      = 127
};

constexpr int kUartBufferSize = 128;
constexpr int kMaxArguments = 5;
constexpr int kMaxRowLength = 40;

/**
 * @brief Lightweight UART command-line interface with history and parsing.
 * @note When to use: add interactive commands for debugging or configuration
 *       over a serial terminal without bringing in a full shell.
 */
class CommandLine {

public:
    CommandLine(Stream* uartStream);  // Constructor
    void addCommand(const std::string& longName, const std::string& shortName, std::function<void(std::queue<std::string> argumentQueue ,std::string&)> funcPtr);
    void executeCommand(const std::string& command, std::queue<std::string> arguments);
    void readInput();
    void processCommand(const std::string& command);
    void begin();
    void switchUART(Stream* newUart);
    void useDefaultUART();
    Stream* getDefaultUART() const { return defaultUart_; }
    Stream* getActiveUART() const { return uart_; }
    uint32_t getLastInteractionTimestamp() const { return lastInteractionTimestamp_; }

    // Pass-through functions for the UART object
    void println(const std::string& message){
        uart_->println(message.c_str());
    }
    void print(const std::string& message){
        uart_->print(message.c_str());
    }

private:
    Stream* uart_;  // Pointer to the UART object
    Stream* defaultUart_;  // Stream provided at construction; used by useDefaultUART()
    struct Command {
        std::string longName;             
        std::string shortName;           
        std::function<void(std::queue<std::string>, std::string&)> funcPtr; // Function pointer to the command handler
    };
    std::vector<Command> commands_{};  // Vector to store the list of commands

    // Class member variables for buffering and history
    std::string fullLine_ = {""}; 


    void help();
    void trimSpaces(std::string& str);

    void handleBackspace_();
    void handleNewline_();
    void handleChar_(char receivedChar);

    bool lastWasCR_ = false;  // Track if the last character was a carriage return for proper newline handling
    uint32_t lastInteractionTimestamp_ = 0;  // millis() when input bytes were last consumed
};

#endif