/*-----------------------------------------------------------------------------
 *  Author: Nelso G. Jost (nelsojost@gmail.com)
 *  License: GPLv2
 *  Purpose: Provide basic GPIO control commands for the REPL.
 *---------------------------------------------------------------------------*/
#include <Arduino.h>

#include "repl.h"


REPL::REPL(REPL_COMMAND * command_map)
{
    this->_fp_map = command_map;
    this->_history[0] = "";
}


void REPL::update(void)
{
    char c;

    if (!Serial.available()) { yield(); return; }

    c = Serial.read();

    if (c == 8)
        this->_backspace();

    else if (c == 9)
        this->_clear_line();

    else if (c == '[')
        this->_history_previous();

    else if (c == ']')
        this->_history_next();

    else if (c == 32 && !this->_command_buffer.length())
        return;
    else
    {
        this->_command_buffer += c;
        if (c != 13) Serial.write(c);
    }

    //Serial.println(int(c));

    if (this->_command_buffer.indexOf("\r") != -1 ||
        this->_command_buffer.indexOf("\n") != -1)
    {
        this->_command_buffer.trim();
        if (this->_command_buffer != "")
        {
            if (this->_command_buffer == "help") this->print_help();
            else this->_execute_command();
            this->_command_buffer = "";
        }
        if (c != 13) Serial.print(this->prompt + " ");
    }
    Serial.flush();
}


void REPL::_clear_line(void)
{
    if (this->_command_buffer.length())
    {
        this->_complete();
        return;
    }
    Serial.print("\r                                         \r");
    Serial.print("> ");
    this->_command_buffer = "";
}


void REPL::_complete(void)
{
    String partial_name = this->get_arg(0);
    REPL_COMMAND * rc = this->_fp_map;
    String full_name;

    while (rc->name != NULL)
    {
        full_name = String(rc->name);
        if (full_name.startsWith(partial_name))
        {
             Serial.print("\n\n[HELP] " + String(rc->prototype) + "\n" +
                          this->prompt + " " + full_name + " ");
             this->_command_buffer = full_name + " ";
        }
        rc++;
    }
}


void REPL::_backspace(void)
{
    if (this->_command_buffer.length() != 0)
    {
        Serial.write(8);
        Serial.write(32);
        Serial.write(8);
        this->_history_index = 0;
        this->_command_buffer.remove(this->_command_buffer.length() - 1);
    }
}


void REPL::_history_previous(void)
{
    if (this->_history_index < HISTORY_MAX - 1 && \
        this->_history[this->_history_index] != "")
    {
        this->_command_buffer = this->_history[this->_history_index];
        this->_history_index++;
        Serial.print("\r                                         \r");
        Serial.print(this->prompt + " [" + this->_history_index + "] ");
        Serial.print(this->_command_buffer);
    }
    //this->log("history previous" + String(this->_history_index));
}


void REPL::_history_next(void)
{
    if (this->_history_index > 0 && \
        this->_history[this->_history_index] != "")
    {
        this->_command_buffer = this->_history[this->_history_index];
        this->_history_index--;
        Serial.print("\r                                         \r");
        Serial.print(this->prompt + " [" + this->_history_index + "] ");
        Serial.print(this->_command_buffer);
    }
    //this->log("history next" + String(this->_history_index));
}


void REPL::_history_save(void)
{
    this->_history_index = 0;
    if (this->_history[0] != this->_command_buffer)
    {
        for (int i=0; i < HISTORY_MAX - 2; i++)
        {
            this->_history[i+1] = this->_history[i];
        }
        this->_history[0] = this->_command_buffer;
    }
}


int REPL::_execute_command(void)
{
    String command_name = get_arg(0);
    bool show_help=false;

    if (command_name.endsWith("?"))
    {
        show_help = true;
        command_name.remove(command_name.length() - 1);
    }

    //Serial.print("\n[INFO] executing command \"");
    //Serial.print(command_str);
    //Serial.print("\"");

    REPL_COMMAND * rc = this->_fp_map;

    while (rc->name != NULL)
    {
        if (command_name == rc->name)
        {
             if (show_help)
             {
                 Serial.print("\n\n[HELP] Syntax: ");
                 Serial.println(rc->prototype);
                 Serial.print("\n    ");
                 Serial.println(rc->help);
                 return 0;
             }
             rc->func(this);
             this->_history_save();
             return 0;
        }
        rc++;
    }

    Serial.print("\n[ERROR] invalid command \"");
    Serial.print(command_name);
    Serial.print("\"");

    return -1;
}


void REPL::print_help(void)
{
    REPL_COMMAND * rc = this->_fp_map;
    Serial.print("\n------------------");
    Serial.print("\nAvailable commands");
    Serial.print("\n------------------");
    while (rc->name != NULL)
    {
        Serial.print("\n  ");
        Serial.print(rc->prototype);
        rc++;
    }
    Serial.print("\n------------------");
    Serial.print("\nType \"command?\" for more details on the command.");
    Serial.print("\n------------------");
}


void REPL::log(String msg, bool show_buffer)
{
    Serial.print(msg);
    if (this->_command_buffer.length() > 0 and show_buffer)
    {
        Serial.print("\n" + this->prompt + " " + this->_command_buffer);
    }
}


String REPL::get_arg(int index)
{
    String arg="";
    int count=-1;
    bool found=false;
    for (int i=0; i < this->_command_buffer.length(); i++)
    {
        if (this->_command_buffer[i] != ' ')
        {
            found = true;
            arg += this->_command_buffer[i];
        }
        else if (found == true)
        {
            count += 1;
            if (count == index) return arg;
            found = false;
            arg = "";
        }
    }
}