from fastapi import APIRouter

from datetime import datetime
import os

from fastapi.responses import HTMLResponse

router = APIRouter()

file_path = "bettwaage.csv"

latest_values = None
zero_values = [0, 0, 0, 0]
scale_values = [1, 1, 1, 1]


def add_line_to_history(line: str) -> None:
    with open(file_path, "+a", encoding="UTF-8") as fp:
        fp.write(line)


def convert_to_weight(value: int, zero_value: int, scale: float) -> float:
    return (value - zero_value) * scale


@router.get("/file")
async def get_file():
    with open(file_path, "r", encoding="UTF-8") as fp:
        return HTMLResponse("\n".join(fp.readlines()))


@router.post("/add")
async def add_weight(tl: int, tr: int, bl: int, br: int):
    global latest_values
    latest_values = [tl, tr, bl, br]

    tl = convert_to_weight(tl, zero_values[0], scale_values[0])
    tr = convert_to_weight(tl, zero_values[1], scale_values[1])
    bl = convert_to_weight(tl, zero_values[2], scale_values[2])
    br = convert_to_weight(tl, zero_values[3], scale_values[3])

    sum = tl + tr + bl + br
    add_line_to_history(f"{str(datetime.now())};{tl};{tr};{bl};{br};{sum};")


@router.post("/delete")
async def delete_file():
    os.remove(file_path)


@router.post("/zero")
async def set_zero():
    if latest_values is None:
        return HTMLResponse(
            status_code=400, content="Requiring data before setting zeros."
        )
    global zero_values
    zero_values = latest_values


@router.post("/scales")
async def set_scales(tl: float, tr: float, bl: float, br: float):
    global scale_values
    scale_values = [tl, tr, bl, br]


if not os.path.exists(file_path):
    add_line_to_history("timestamp;tl;tr;bl;br;total;")