/**
 * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <stdio.h>
#include <string.h>
#include "pico/stdlib.h"
#include "hardware/adc.h"
#include "hardware/i2c.h"
#include "hardware/pwm.h"
#include "pico/binary_info.h"

// LCD commands
const int LCD_CLEARDISPLAY = 0x01;
const int LCD_RETURNHOME = 0x02;
const int LCD_ENTRYMODESET = 0x04;
const int LCD_DISPLAYCONTROL = 0x08;
const int LCD_CURSORSHIFT = 0x10;
const int LCD_FUNCTIONSET = 0x20;
const int LCD_SETCGRAMADDR = 0x40;
const int LCD_SETDDRAMADDR = 0x80;

// flags for display entry mode
const int LCD_ENTRYSHIFTINCREMENT = 0x01;
const int LCD_ENTRYLEFT = 0x02;

// flags for display and cursor control
const int LCD_BLINKON = 0x01;
const int LCD_CURSORON = 0x02;
const int LCD_DISPLAYON = 0x04;

// flags for display and cursor shift
const int LCD_MOVERIGHT = 0x04;
const int LCD_DISPLAYMOVE = 0x08;

// flags for function set
const int LCD_5x10DOTS = 0x04;
const int LCD_2LINE = 0x08;
const int LCD_8BITMODE = 0x10;

// flag for backlight control
const int LCD_BACKLIGHT = 0x08;

const int LCD_ENABLE_BIT = 0x04;

// By default these LCD display drivers are on bus address 0x27
static int addr = 0x27;

// Modes for lcd_send_byte
#define LCD_CHARACTER  1
#define LCD_COMMAND    0

#define MAX_LINES      2
#define MAX_CHARS      16

// Variables globales, constantes, funciones y interrupciones
#define R1 6
#define R2 7
#define R3 8
#define R4 9
#define C1 10
#define C2 11
#define C3 12
#define BUZZER_PIN 16
#define CLOCK_DIV 64

int waiter = 250;
int fila = 0;
int columna = 0;
int frecuencia = 0;
int frecuencia_real = 0;
int volumen = 0;
int unidad = 10000; // Changed from 100 to 10000 for 5 digits
int vil = 0;
int adc_inc = 0;

// Function declarations
void i2c_write_byte(uint8_t val);
void lcd_toggle_enable(uint8_t val);
void lcd_send_byte(uint8_t val, int mode);
void lcd_clear(void);
void lcd_set_cursor(int line, int position);
void lcd_char(char val);
void lcd_string(const char *s);
void lcd_init();
void detect_column(int fila);
bool incrementar_callback(struct repeating_timer *t);
void general_callback(uint gpio, uint32_t event_mask);
void cancelar_freq();
void aceptar_freq();
void unit_freq(int num);
void change_freq(int fila, int columna);

// Function implementations
void i2c_write_byte(uint8_t val) {
#ifdef i2c_default
    i2c_write_blocking(i2c_default, addr, &val, 1, false);
#endif
}

void lcd_toggle_enable(uint8_t val) {
    sleep_us(600);
    i2c_write_byte(val | LCD_ENABLE_BIT);
    sleep_us(600);
    i2c_write_byte(val & ~LCD_ENABLE_BIT);
    sleep_us(600);
}

void lcd_send_byte(uint8_t val, int mode) {
    uint8_t high = mode | (val & 0xF0) | LCD_BACKLIGHT;
    uint8_t low = mode | ((val << 4) & 0xF0) | LCD_BACKLIGHT;

    i2c_write_byte(high);
    lcd_toggle_enable(high);
    i2c_write_byte(low);
    lcd_toggle_enable(low);
}

void lcd_clear(void) {
    lcd_send_byte(LCD_CLEARDISPLAY, LCD_COMMAND);
}

void lcd_set_cursor(int line, int position) {
    int val = (line == 0) ? 0x80 + position : 0xC0 + position;
    lcd_send_byte(val, LCD_COMMAND);
}

void lcd_char(char val) {
    lcd_send_byte(val, LCD_CHARACTER);
}

void lcd_string(const char *s) {
    while (*s) {
        lcd_char(*s++);
    }
}

void lcd_init() {
    lcd_send_byte(0x03, LCD_COMMAND);
    lcd_send_byte(0x03, LCD_COMMAND);
    lcd_send_byte(0x03, LCD_COMMAND);
    lcd_send_byte(0x02, LCD_COMMAND);

    lcd_send_byte(LCD_ENTRYMODESET | LCD_ENTRYLEFT, LCD_COMMAND);
    lcd_send_byte(LCD_FUNCTIONSET | LCD_2LINE, LCD_COMMAND);
    lcd_send_byte(LCD_DISPLAYCONTROL | LCD_DISPLAYON, LCD_COMMAND);
    lcd_clear();
}

void detect_column(int fila) {
    for (int i = 0; i < 3; i++) {
        gpio_clr_mask(0x1C00);
        gpio_set_mask(1 << (i + C1));
        if (gpio_get(fila+R1-1) == 1) {
            columna = i+1;
            break;
        }
    }
    gpio_set_mask(0x1C00);
}

bool incrementar_callback(struct repeating_timer *t) {
    if (waiter != 0) waiter--;
    adc_inc--;
    return true;
}

void general_callback(uint gpio, uint32_t event_mask) {
    if (gpio==R1 && waiter == 0) {
        fila = 1;
    }
    if (gpio==R2 && waiter == 0) {
        fila = 2;
    }
    if (gpio==R3 && waiter == 0) {
        fila = 3;
    }
    if (gpio==R4 && waiter == 0) {
        fila = 4;
    }
    waiter = 50;
}

void cancelar_freq() {
    frecuencia = 0;
    unidad = 10000; // Reset to 10000 for 5 digits
    frecuencia_real = 0;
}

void aceptar_freq() {
    if (frecuencia <= 20000) { // Limit to 20,000 Hz
        frecuencia_real = frecuencia;
    } else {
        frecuencia_real = 20000; // Cap at 20,000 Hz
        frecuencia = 20000;
    }
}

void unit_freq(int num) {
    if (unidad < 1) unidad = 0;
    frecuencia += unidad * num;
    unidad /= 10;
}

void change_freq(int fila, int columna) {
    if (fila == 1 && columna == 1) unit_freq(1);
    if (fila == 1 && columna == 2) unit_freq(2);
    if (fila == 1 && columna == 3) unit_freq(3);
    if (fila == 2 && columna == 1) unit_freq(4);
    if (fila == 2 && columna == 2) unit_freq(5);
    if (fila == 2 && columna == 3) unit_freq(6);
    if (fila == 3 && columna == 1) unit_freq(7);
    if (fila == 3 && columna == 2) unit_freq(8);
    if (fila == 3 && columna == 3) unit_freq(9);
    if (fila == 4 && columna == 1) cancelar_freq();
    if (fila == 4 && columna == 2) unit_freq(0);
    if (fila == 4 && columna == 3) aceptar_freq();
}

int main() {
    stdio_init_all();
    gpio_init_mask(0xffff);
    // This example will use I2C0 on the default SDA and SCL pins (4, 5 on a Pico)
    i2c_init(i2c_default, 100 * 1000);
    gpio_set_function(PICO_DEFAULT_I2C_SDA_PIN, GPIO_FUNC_I2C);
    gpio_set_function(PICO_DEFAULT_I2C_SCL_PIN, GPIO_FUNC_I2C);
    gpio_pull_up(PICO_DEFAULT_I2C_SDA_PIN);
    gpio_pull_up(PICO_DEFAULT_I2C_SCL_PIN);
    // Make the I2C pins available to picotool
    bi_decl(bi_2pins_with_func(PICO_DEFAULT_I2C_SDA_PIN, PICO_DEFAULT_I2C_SCL_PIN, GPIO_FUNC_I2C));

    // Pines de entrada y salida
    gpio_set_dir_out_masked(0xf); //leds de prueba
    gpio_set_dir_in_masked(0x3C0); // Entradas
    gpio_set_dir_out_masked(0x3C00);

    // ADC
    adc_init();
    adc_gpio_init(26); //adc gpio 26 y adc 0
    
    //PWM
    gpio_set_function(BUZZER_PIN, GPIO_FUNC_PWM);
    uint slice_num = pwm_gpio_to_slice_num(BUZZER_PIN);
    pwm_set_clkdiv_int_frac(slice_num, CLOCK_DIV, 0);

    // Timer
    struct repeating_timer timer;
    add_repeating_timer_ms(1, incrementar_callback, NULL, &timer);
    // Botones
    gpio_set_mask(0x1C00);
    gpio_set_irq_enabled_with_callback(R1, GPIO_IRQ_EDGE_RISE, true, &general_callback);
    gpio_set_irq_enabled_with_callback(R2, GPIO_IRQ_EDGE_RISE, true, &general_callback);
    gpio_set_irq_enabled_with_callback(R3, GPIO_IRQ_EDGE_RISE, true, &general_callback);
    gpio_set_irq_enabled_with_callback(R4, GPIO_IRQ_EDGE_RISE, true, &general_callback);

    // Pantalla
    lcd_init();

    static char *message[] =
            {
                    "Freq: %05d Hz", // Changed to %05d for 5 digits
                    "Vol : %3d %%"
            };
    char buffer[100];

    while (1) {
        // Leer matriz
        if (fila != 0) {
            detect_column(fila);
            gpio_put(columna-1,!gpio_get(columna-1));//led
            gpio_set_mask(0x1C00); //prender columnas
            change_freq(fila,columna);
            fila = 0;
            columna = 0;
        }
        // ADC read
        if (adc_inc <= 0) {
            const float conversion_factor = 3.3f / (1 << 12);
            adc_inc = 200;
            adc_select_input(0);
            volumen = adc_read() * conversion_factor * 100 * 100 / 329;
        }
        // PWM values
        if (frecuencia_real >= 20) {  // Cambiado de 10 a 20 Hz
            uint32_t wrap = (125000000 / (frecuencia_real * CLOCK_DIV)) - 1;
            pwm_set_wrap(slice_num, wrap);
            pwm_set_chan_level(slice_num, PWM_CHAN_A, wrap * volumen / 100);
            pwm_set_enabled(slice_num, true);  // Habilitar PWM
        } else {
            pwm_set_enabled(slice_num, false);  // Deshabilitar PWM si la frecuencia es menor a 20 Hz
        }

        //Imprimir LCD
        sprintf(buffer,message[0],frecuencia);
        lcd_set_cursor(0,0);
        lcd_string(buffer);
        sprintf(buffer,message[1],volumen);
        lcd_set_cursor(1,0);
        lcd_string(buffer);
    }
}