#include <stdio.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"

// Pin Definitions
#define RS 12   // Register Select pin
#define E  13   // Enable pin
#define D4 14   // Data pin 4
#define D5 17   // Data pin 5
#define D6 18   // Data pin 6
#define D7 19   // Data pin 7

// LCD Commands
#define LCD_CLEAR 0x01
#define LCD_HOME 0x02
#define LCD_ENTRY_MODE 0x06
#define LCD_DISPLAY_ON 0x0C
#define LCD_FUNCTION_SET 0x28
#define LCD_SET_CURSOR 0x80

void lcd_send_command(uint8_t command) {
    gpio_set_level(RS, 0); // Command mode
    gpio_set_level(E, 1);
    gpio_set_level(D4, (command >> 4) & 0x01);
    gpio_set_level(D5, (command >> 5) & 0x01);
    gpio_set_level(D6, (command >> 6) & 0x01);
    gpio_set_level(D7, (command >> 7) & 0x01);
    gpio_set_level(E, 0);
    vTaskDelay(1 / portTICK_PERIOD_MS);
    
    gpio_set_level(E, 1);
    gpio_set_level(D4, command & 0x01);
    gpio_set_level(D5, (command >> 1) & 0x01);
    gpio_set_level(D6, (command >> 2) & 0x01);
    gpio_set_level(D7, (command >> 3) & 0x01);
    gpio_set_level(E, 0);
    vTaskDelay(1 / portTICK_PERIOD_MS);
}

void lcd_send_data(uint8_t data) {
    gpio_set_level(RS, 1); // Data mode
    gpio_set_level(E, 1);
    gpio_set_level(D4, (data >> 4) & 0x01);
    gpio_set_level(D5, (data >> 5) & 0x01);
    gpio_set_level(D6, (data >> 6) & 0x01);
    gpio_set_level(D7, (data >> 7) & 0x01);
    gpio_set_level(E, 0);
    vTaskDelay(1 / portTICK_PERIOD_MS);
    
    gpio_set_level(E, 1);
    gpio_set_level(D4, data & 0x01);
    gpio_set_level(D5, (data >> 1) & 0x01);
    gpio_set_level(D6, (data >> 2) & 0x01);
    gpio_set_level(D7, (data >> 3) & 0x01);
    gpio_set_level(E, 0);
    vTaskDelay(1 / portTICK_PERIOD_MS);
}

void lcd_init() {
    gpio_set_direction(RS, GPIO_MODE_OUTPUT);
    gpio_set_direction(E, GPIO_MODE_OUTPUT);
    gpio_set_direction(D4, GPIO_MODE_OUTPUT);
    gpio_set_direction(D5, GPIO_MODE_OUTPUT);
    gpio_set_direction(D6, GPIO_MODE_OUTPUT);
    gpio_set_direction(D7, GPIO_MODE_OUTPUT);

    vTaskDelay(20 / portTICK_PERIOD_MS); // Wait for LCD to power up
    lcd_send_command(0x33); // Initialization sequence
    vTaskDelay(5 / portTICK_PERIOD_MS); // Wait before next command
    lcd_send_command(0x32); // Set to 4-bit mode
    vTaskDelay(5 / portTICK_PERIOD_MS); // Wait before next command
    lcd_send_command(LCD_FUNCTION_SET); // 4-bit mode, 2-line, 5x8 dots
    vTaskDelay(5 / portTICK_PERIOD_MS); // Wait before next command
    lcd_send_command(LCD_DISPLAY_ON);    // Display ON
    vTaskDelay(5 / portTICK_PERIOD_MS); // Wait before next command
    lcd_send_command(LCD_CLEAR);          // Clear display
    vTaskDelay(5 / portTICK_PERIOD_MS); // Wait before next command
    lcd_send_command(LCD_ENTRY_MODE);     // Entry mode
}

void lcd_print(const char* str) {
    for (int i = 0; i < strlen(str); i++) {
        lcd_send_data(str[i]); // Use lcd_send_data for printing characters
    }
}

void app_main() {
    lcd_init(); // Initialize the LCD
    printf("LCD Initialized\n"); // Debug info
    lcd_send_command(LCD_CLEAR); // Clear the display to avoid garbage values
    lcd_print("Hello, Wokwi!"); // Print a message on the first line
    vTaskDelay(1000 / portTICK_PERIOD_MS); // Wait for a moment
    lcd_send_command(LCD_SET_CURSOR | 0x40); // Move to the beginning of the second line
    lcd_print("ESP32 + LCD"); // Print on second line
    printf("Message printed to LCD\n"); // Debug info
}