#include <stdio.h>
#include "pico/stdlib.h"
#include "pico/cyw43_arch.h"

//Define all the different component pins
#define btn 1             //Red button
#define btn2 2            //Green button
#define led1 15           //Red LED
#define led2 16           //Green LED
#define bzr 27            //Buzzer
#define dot_dash_ms 300   //Length of time for button presses 
#define space_ms 500      //Time to print space

int main() 
{
    stdio_init_all();

    //--------------------------Initialise all of the pins being used --------------------------//

    gpio_init(btn);
    gpio_init(btn2);
    gpio_init(bzr);
    gpio_init(led1);
    gpio_init(led2);


    gpio_set_dir(btn, GPIO_IN);        //Pin button is wired to set as an input
    gpio_set_dir(btn2, GPIO_IN);       //Pin button is wired to set as an input
    gpio_set_dir(bzr, GPIO_OUT);       //Pin buzzer is wired to set as an output
    gpio_set_dir(led1, GPIO_OUT);      //Pin LED is wired to set as an output
    gpio_set_dir(led2, GPIO_OUT);      //Pin LED is wired to set as an output

    gpio_pull_up(btn);      //Button set to pull up so logic = 0 when pressed 
    gpio_pull_up(btn2);     //Button set to pull up so logic = 0 when pressed 



    //Timer functions ints created for start of timer functions

    int start = 0;           
    int stop = 0;
    int elapsed = 0;    



    //------Booleans created for button presses, messages being printed to monitor & space printing between words-------//

    bool pressed = 0;      
    bool space_printed = 0;    
    bool led2_on = 0;
    bool info = 0;
    bool msg_start = 0;
    bool msg_end = 0;
    



    // Morse table array made ('x' has been added to make all aspects of array the same length)

char morse_codes[36][6] = {
    {'.','-','x','x','x','x'},    // A
    {'-','.','.','.','x','x'},    // B
    {'-','.','-','.','x','x'},    // C
    {'-','.','.','x','x','x'},    // D
    {'.','x','x','x','x','x'},    // E
    {'.','.','-','.','x','x'},    // F
    {'-','-','.','x','x','x'},    // G
    {'.','.','.','.','x','x'},    // H
    {'.','.','x','x','x','x'},    // I
    {'.','-','-','-','x','x'},    // J
    {'-','.','-','x','x','x'},    // K
    {'.','-','.','.','x','x'},    // L
    {'-','-','x','x','x','x'},    // M
    {'-','.','x','x','x','x'},    // N
    {'-','-','-','x','x','x'},    // O
    {'.','-','-','.','x','x'},    // P
    {'-','-','.','-','x','x'},    // Q
    {'.','-','.','x','x','x'},    // R
    {'.','.','.','x','x','x'},    // S
    {'-','x','x','x','x','x'},    // T
    {'.','.','-','x','x','x'},    // U
    {'.','.','.','-','x','x'},    // V
    {'.','-','-','x','x','x'},    // W
    {'-','.','.','-','x','x'},    // X
    {'-','.','-','-','x','x'},    // Y
    {'-','-','.','.','x','x'},    // Z
    {'.','-','-','-','-','x'},    // 1
    {'.','.','-','-','-','x'},    // 2
    {'.','.','.','-','-','x'},    // 3
    {'.','.','.','.','-','x'},    // 4
    {'.','.','.','.','.','x'},    // 5
    {'-','.','.','.','.','x'},    // 6
    {'-','-','.','.','.','x'},    // 7
    {'-','-','-','.','.','x'},    // 8
    {'-','-','-','-','.','x'},    // 9
    {'-','-','-','-','-','x'}     // 0
};

char letters[36] = {
    'A','B','C','D','E','F','G','H','I',
    'J','K','L','M','N','O','P','Q','R',
    'S','T','U','V','W','X','Y','Z','1',
    '2','3','4','5','6','7','8','9','0'
};




//--------------------Create buffers for the morse codes to be inputted into when button is pressed ------------------//

char morse_buffer[5];   // Stores the morse codes set @ 5 because that is the maximum amount of symbols that should be inputted 
int morse_index = 0;    // Stores where the next morse code symbols go when inputted




//-------------------------------------Create buffers for the outputted code------------------------------------//

char text_line[40];   //The output buffer to hold the readable letters, set to 40 as we only need 36 characters (A-Z/0-9)
int text_line_index = 0;  //The line where the next char goes into before being outputted




//-----------------------------------Code to translate the morse to letters--------------------------------------//

char translate_morse(char *code, int code_len) //*code points to 1st symbol in the input buffer & code_len tells function how many symbols to read
{
    for (int i = 0; i < 36; i++)  //Loop through morse_codes array to see if input matches
    {
        int match = 1;    //Start by telling function there is a match

        for (int j = 0; j < code_len; j++)      //Loop to compare inputted symbols to the ones in the table
        {
            if (morse_codes[i][j] != code[j])  //If any of the symbols in the row don't match, match changes to 0
            {
                match = 0;

                break;  //This stops the function comparing this part of the array as soon as a mismatch is found so it moves onto the next
            }
        }

        //--------------Ensure stored code has no extra symbols beyond code_len-----------------//

        if (match == 1 && morse_codes[i][code_len] == 'x') 
        {
            return letters[i];  // When matched; letters can be returned immediately
        }
    }

    printf("\nInvalid Morse code!\n");   //If there isn't a matching letter you get an error message
}



    
    while (1) 
    { 

      //-------------Display operating instructions when button is pressed--------------//

      if ((gpio_get(btn2)==1) && (msg_start == 0))
      {
      printf("Press green button to begin message\n"); //First message on screen
      msg_start = 1;
      }

      else if (gpio_get(btn2) == 0)  //If button 2 pressed
      {          
            if ((led2_on == 0) && (info == 0)) //If LED2 & instructions arent printed to screen
            {
              gpio_put(led2, 1);   //Turn LED2 on 
              led2_on = 1;         //Leave LED2 on from now on until anything changes
            
            //------------Print operation instructions to screen--------------------//

              printf("Red button pressed <300ms = dit (.) & >300ms = dah (-)\r\n");
              printf("A character will be translated after 500ms\r\n");
              printf("Space between words will be printed after 1.5s\r\n\n");
              printf("Translation: ");
              info = 1;        //Keep instructions printed once
            }
        }



      //--------------------------Loops to start & stop timers when button is pressed--------------------------//


      if (info == 1)               //Loop only starts when operation instructions are printed to screen
      {
        if ((gpio_get(btn) == 1) && (pressed == 1))          //When button isn't pressed but pressed boolean now 1
        {
            stop = to_ms_since_boot(get_absolute_time());  //Get the time that the button was released
            gpio_put(led1, 0);                             //Turn LED off
            gpio_put(bzr, 0);                              //Turn buzzer off 
            pressed = 0;                                   //Now pressed boolean back to 0

            elapsed = stop - start;                    //Create an integer for how long the button has been pressed

            if (elapsed < dot_dash_ms)                     //If timer is <300ms
            {
                morse_buffer[morse_index++] = '.';         //Input '.' into buffer
                //printf(".");
            } 

            else 
            {
                morse_buffer[morse_index++] = '-';         //Otherwise input '-'
                //printf("-");
            }

            sleep_ms(50);
        }

        else if (gpio_get(btn) == 0)            //If button is pressed    
        {
            if (pressed == 0)                   //Pressed boolean is still 0
            {
                start = to_ms_since_boot(get_absolute_time());   //Start timer
                pressed = 1;                                     //Set pressed boolean to 1
            }

            gpio_put(led1, 1);      //Turn on red LED
            gpio_put(bzr, 1);       //Turn on buzzer

            sleep_ms(50);
        }


        //-----------------Detect end of a letter or end of a word----------------//


        if (pressed == 0)       //When pressed boolean is now back to 0 after button press 
        {
            int now = to_ms_since_boot(get_absolute_time());    //Get another time stamp


            //-----------End of a letter------------------//

            if (morse_index > 0 && (now - stop) > space_ms && (now - stop) < 3 * space_ms)  //If the morse buffer has at least 1 character in it, the time period taken is >500ms & >1.5s
            {
                char letter = translate_morse(morse_buffer, morse_index);       //Letter is now taken from inputting our morse codes into the 'translate_morse' function written earlier                 
                text_line[text_line_index++] = letter;    //Inputs the translated letter into the 'text_line' output buffer then moves onto the next space within it
                morse_index = 0;        //Morse index then reset
                space_printed = 0;      //Space printed set back to 0 so other spaces can be printed in message not just 1 space
            }

            //----------------End of word-----------------//

            if ((now - stop) >= 3 * space_ms)     //If time period taken >= 1.5s 
            {
                if (morse_index == 0 && space_printed == 0)     //Whilst no morse has been inputted & no spaces have been printed yet
                {
                    text_line[text_line_index++] = ' ';         //A space is added to the output buffer
                    //printf(" ");
                    space_printed = 1;        //Space printed is now 1 so no more are printed 
                }
            }

            //--------------If there is a pause, print the output to monitor---------------//

            if ((now - stop) > 10 && text_line_index > 0)    //If time stamp is greater than 10ms & there is a character in text line
            {
                text_line[text_line_index] = '\0';      //Null terminator to change text_line into a string
                printf("%s\r", text_line);              //Print the character inside the string
                text_line_index = 0;                    //Reset text_line back to 0
                sleep_ms(50);
            }

            if ((now-stop) >= (120 * space_ms) && (msg_end == 0) && (led2_on == 1))  //If time since last press is >1min & message end boolean still 0 & LED2 is still on
            {
              printf("\n\n----------Transmission terminated!----------\r\n");
              msg_end = 1;            //Change message end boolean to 1 so it only prints once
              gpio_put(led1, 0);      //Turn off red LED
              gpio_put(led2, 0);      //Turn off green LED
              gpio_put(bzr, 0);       //Turn off buzzer

              while (1)
              {
              sleep_ms (1000);        //While loop in 'if' statement to stop program running until restart
              }
            }
        }
    }
    }
}