from fastapi.responses import HTMLResponse, JSONResponse
from fastapi import APIRouter

from datetime import datetime
import os
import csv


router = APIRouter()

file_path = "bettwaage.csv"
header = "timestamp;tl;tr;bl;br;total;"

latest_values = []
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") as fp:
        fp.write(line + "\n")


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


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


@router.get("/history")
async def get_history(count: int = None) -> []:
    points = []
    with open(file_path, "r", encoding="UTF-8") as fp:
        reader = csv.DictReader(fp, delimiter=";")
        for row in reader:
            if not row:
                continue

            points.append(
                {
                    "timestamp": row["timestamp"],
                    "total": float(row["total"]),
                    "tl": float(row["tl"]),
                    "tr": float(row["tr"]),
                    "bl": float(row["bl"]),
                    "br": float(row["br"]),
                }
            )

    if count:
        return points[-count]
    else:
        return points


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

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


@router.get("/latest")
async def get_latest():
    if not latest_values:
        return HTMLResponse(status_code=200, content="No data given yet")
    total = sum(latest_values)
    return JSONResponse(
        {
            "tl": latest_values[0],
            "tr": latest_values[1],
            "bl": latest_values[2],
            "br": latest_values[3],
            "total": total,
        }
    )


@router.delete("/delete", tags=["file"])
async def delete_file():
    os.remove(file_path)
    add_line_to_history(header)
    return "Deleted file and created new file with headers"


@router.post("/zero", tags=["calibration"])
async def set_zero():
    if not latest_values:
        return HTMLResponse(
            status_code=400, content="Requiring data before setting zeros."
        )
    global zero_values
    zero_values = latest_values
    return "Set zeroes to: " + " | ".join(str(v) for v in zero_values)


@router.post("/scales", tags=["calibration"])
async def set_scales(tl: float, tr: float, bl: float, br: float):
    global scale_values
    scale_values = [tl, tr, bl, br]
    return "Set scales to: " + " | ".join(str(v) for v in scale_values)


if not os.path.exists(file_path):
    add_line_to_history(header)