# Libraries Import
from machine import Pin, I2C
from time import sleep_ms
from lcd_api import LcdApi
from pico_i2c_lcd import I2cLcd

# LCD Screen Configuration
LCD_I2C_ADDR = 39       # I2C address
LCD_NUM_ROWS = 2        # number of rows
LCD_NUM_COLS = 16       # number of columns

i2c = I2C(1, sda=Pin(2, Pin.OUT), scl=Pin(3, Pin.OUT), freq=400000)
lcd = I2cLcd(i2c, LCD_I2C_ADDR, LCD_NUM_ROWS, LCD_NUM_COLS)

# Button Inputs Configuration
BUTTON_1 = Pin(10, Pin.IN, Pin.PULL_UP)
BUTTON_2 = Pin(9, Pin.IN, Pin.PULL_UP)
BUTTON_3 = Pin(8, Pin.IN, Pin.PULL_UP)

# Current scrolling process flag
scrolling_process = None

# Function Definitions
def clear_lcd():
    lcd.clear()
    print("LCD screen cleared")

def scroll_text_line_right_to_left(text):
    global scrolling_process
    scrolling_process = "button 1"
    text_list = list(text)
    virtual_char_count = LCD_NUM_COLS + 2 * len(text_list) - 1
    screen_list = [""] * LCD_NUM_COLS
    text_list_reversed = text_list[::-1]
    print("Scrolling text line from right to left")
    clear_lcd()
    for j in range(virtual_char_count - len(text_list)):
        if scrolling_process != "button 1":
            return
        temp_list = [""] * virtual_char_count
        for i in range(len(text_list)):
            temp_list[virtual_char_count - i - 1 - j] = text_list_reversed[i]
        for k in range(LCD_NUM_COLS):
            screen_list[k] = temp_list[k + len(text_list)]
            lcd.move_to(k, 0)
            lcd.putstr(screen_list[k])
        sleep_ms(100)
        clear_lcd()

def scroll_text_line_left_to_right(text):
    global scrolling_process
    scrolling_process = "button 2"
    text_list = list(text)
    virtual_char_count = LCD_NUM_COLS + 2 * len(text_list) - 1
    screen_list = [""] * LCD_NUM_COLS
    print("Scrolling text line from left to right")
    clear_lcd()
    for j in range(virtual_char_count - len(text_list)):
        if scrolling_process != "button 2":
            return
        temp_list = [""] * virtual_char_count
        for i in range(len(text_list)):
            temp_list[i + j + 1] = text_list[i]
        for k in range(LCD_NUM_COLS):
            screen_list[k] = temp_list[k + len(text_list)]
            lcd.move_to(k, 1)
            lcd.putstr(screen_list[k])
        sleep_ms(100)
        clear_lcd()

def scroll_text_two_lines(text):
    global scrolling_process
    scrolling_process = "button 3"
    print("Scrolling text across two lines")
    text_list = list(text)
    virtual_char_count = LCD_NUM_COLS + 2 * len(text_list) - 1
    screen_list_line1 = [""] * LCD_NUM_COLS
    screen_list_line2 = [""] * LCD_NUM_COLS
    text_list_reversed = text_list[::-1]
    clear_lcd()
    for j in range(virtual_char_count - len(text_list)):
        if scrolling_process != "button 3":
            return
        temp_list_line1 = [""] * virtual_char_count
        temp_list_line2 = [""] * virtual_char_count
        for i in range(len(text_list)):
            temp_list_line1[virtual_char_count - i - 1 - j] = text_list_reversed[i]
            temp_list_line2[i + j + 1] = text_list[i]
        for k in range(LCD_NUM_COLS):
            screen_list_line1[k] = temp_list_line1[k + len(text_list)]
            lcd.move_to(k, 0)
            lcd.putstr(screen_list_line1[k])
            screen_list_line2[k] = temp_list_line2[k + len(text_list)]
            lcd.move_to(k, 1)
            lcd.putstr(screen_list_line2[k])
        sleep_ms(500)
        clear_lcd()

# Main Program Loop
while True:
    if not BUTTON_1.value():
        print("Button 1 pressed")
        scrolling_process = None
        text = input("Enter text to scroll: ")
        scroll_text_line_right_to_left(text)
    
    if not BUTTON_2.value():
        print("Button 2 pressed")
        scrolling_process = None
        text = input("Enter text to scroll: ")
        scroll_text_line_left_to_right(text)
    
    if not BUTTON_3.value():
        print("Button 3 pressed")
        scrolling_process = None
        text = input("Enter text to scroll: ")
        scroll_text_two_lines(text)