import pandas as pd
import numpy as np

WEIGHT_RANGE = [75, 85]


def to_date(date):
    return (date - pd.to_datetime("1900-01-01").date()).days


def get_weight_measures():
    # query non-zero
    data = pd.DataFrame(GC.seasonMeasures(group="Body")).query("WEIGHTKG != 0.0")[
        ["date", "WEIGHTKG"]
    ]
    data.reset_index(inplace=True)
    print(data)
    weight = data["WEIGHTKG"].to_numpy().flatten()
    weight_shifted = data["WEIGHTKG"].shift(periods=1).to_numpy().flatten()
    weight_shifted[0] = 0.0
    change = weight - weight_shifted
    indices = np.argwhere(change != 0.0).flatten()
    weight = weight[indices]
    print(data["date"])
    print(indices)
    date = (
        data["date"].loc[indices] - pd.to_datetime("1900-01-01").date()
    ).dt.days.to_numpy()
    return pd.DataFrame(
        np.hstack([date.reshape([-1, 1]), weight.reshape([-1, 1])]),
        columns=["date", "WEIGHTKG"],
    )


def trendline(weight_data, start, end):
    weight = weight_data["WEIGHTKG"]
    date = weight_data["date"]
    y = weight.to_numpy()
    x = date.to_numpy()
    coeffs = np.polyfit(x[1:], y[1:], 1)
    poly = np.poly1d(coeffs)
    trend = poly([start, end])
    trend_x = np.array([start, end])
    return pd.DataFrame(
        np.hstack([trend_x.reshape([-1, 1]), trend.reshape([-1, 1])]),
        columns=["date", "trend"],
    ), (trend[0], (trend[-1] - trend[0]) / (trend_x[-1] - trend_x[0]))


season = GC.season()
t_min = to_date(season["start"][0])
t_max = to_date(season["end"][0])
weight_data = get_weight_measures()
trend_data, trend_coeffs = trendline(weight_data, t_min, t_max)
GC.setChart(
    type=GC.CHART_LINE,
    orientation=GC_VERTICAL,
    legpos=GC_ALIGN_RIGHT,
    stack=False,
    animate=True,
)
settings = {
    "symbol": GC_SYMBOL_CIRCLE,
    "line": GC_LINE_SOLID,
    "color": "red",
    "opacity": 100,
    "xaxis": "Date",
    "yaxis": "Weight",
    "size": 3,
    "opengl": False,
}
GC.addCurve(name="Weight", x=weight_data["date"], y=weight_data["WEIGHTKG"], **settings)
settings["symbol"] = GC_SYMBOL_NONE
settings["line"] = GC_LINE_SOLID
settings["color"] = "yellow"
GC.addCurve(
    name=f"Trend: {trend_coeffs[0]:.2f} {trend_coeffs[1]*7:+.2f}/week",
    x=trend_data["date"],
    y=trend_data["trend"],
    **settings,
)
GC.setAxis("Date", type=GC.AXIS_DATE, min=t_min, max=t_max)
GC.setAxis(
    "Weight",
    type=GC.AXIS_CONTINUOUS,
    min=WEIGHT_RANGE[0],
    max=WEIGHT_RANGE[1],
    color="red",
)