import asyncio
from LCD import LCD

class display:
    def __init__(self, width=20, height=4, i2c_addr=0x27):
        self.width = width
        self.height = height
        self.device = LCD(2, i2c_addr, True)
        self.contents = [""] * self.height
    
    async def redraw(self, row = None):
        if row == None:
            for row, line in enumerate(self.contents):
                await self.device.async_message(row + 1, line)
        else:
            await self.device.async_message(row + 1, self.contents[row])
    
    async def read(self, row):
        return self.contents[row]
    
    async def write(self, row, data, offset = 0):
        self.contents[row] = f'{self.contents[row][:offset]}{data}{self.contents[row][offset+len(data):]}'
        await self.redraw(row)