"""
This app generates a heatmap-like presentation of daily climate data
of your choice.  In the case of 'Trailing XX Days', you will want to set
a trailing number of days to evaluate the metric for.
"""

import calendar
from datetime import date

import matplotlib.colors as mpcolors
import numpy as np
import pandas as pd
from pyiem.database import get_sqlalchemy_conn, sql_helper
from pyiem.exceptions import NoDataFound
from pyiem.plot import figure_axes, get_cmap
from seaborn import heatmap

from iemweb.autoplot import ARG_STATION

PDICT = {
    "trail_precip_percent": "Trailing XX Days Precip Percent of Average",
    "daily_high_depart": "Daily High Temperature Departure",
}


def get_description():
    """Return a dict describing how to call this plotter"""
    desc = {"description": __doc__, "data": True, "cache": 86400}
    today = date.today()
    desc["arguments"] = [
        dict(
            type="select",
            options=PDICT,
            default="trail_precip_percent",
            name="var",
            label="Available variables to plot:",
        ),
        ARG_STATION,
        dict(
            type="int",
            name="days",
            default="31",
            label="Trailing Number of Days (when appropriate):",
        ),
        dict(
            type="year",
            default=(today.year - 20),
            label="Start Year of Plot:",
            name="syear",
        ),
        dict(
            type="year",
            default=today.year,
            label="End Year (inclusive) of Plot:",
            name="eyear",
        ),
        dict(type="cmap", name="cmap", default="RdBu", label="Color Ramp:"),
    ]
    return desc


def plotter(ctx: dict):
    """Go"""
    with get_sqlalchemy_conn("coop") as conn:
        df = pd.read_sql(
            sql_helper("""
            select day, sday, precip, high,
            extract(doy from day)::int as doy,
            year from alldata WHERE station = :station ORDER by day ASC
            """),
            conn,
            params={"station": ctx["station"]},
            index_col="day",
            parse_dates="day",
        )
    if df.empty:
        raise NoDataFound("Did not find any data for station!")
    if ctx["var"] == "trail_precip_percent":
        climo = df[["precip", "sday"]].groupby("sday").mean()
        df["precip_avg"] = df.merge(
            climo, left_on="sday", right_index=True, suffixes=("", "_avg")
        )["precip_avg"]
        df["trail_precip_percent"] = (
            df["precip"].rolling(ctx["days"]).sum()
            / df["precip_avg"].rolling(ctx["days"]).sum()
            * 100.0
        )
        levels = [0, 25, 50, 75, 100, 150, 200, 250, 300]
        label = "Percent"
    else:  # daily_high_depart
        climo = df[["high", "sday"]].groupby("sday").mean()
        df["high_avg"] = df.merge(
            climo, left_on="sday", right_index=True, suffixes=("", "_avg")
        )["high_avg"]
        df["daily_high_depart"] = df["high"] - df["high_avg"]
        levels = list(range(-20, 21, 4))
        label = "Temperature [°F] Departure"

    baseyear = max([df["year"].min(), ctx["syear"]])
    endyear = min([df["year"].max(), ctx["eyear"]])
    years = endyear - baseyear + 1
    if years < 1:
        raise NoDataFound("Station data does not exist for the period picked.")
    cmap = get_cmap(ctx["cmap"])
    norm = mpcolors.BoundaryNorm(levels, cmap.N)
    data = np.full((years, 366), np.nan)
    df2 = df[(df["year"] >= baseyear) & (df["year"] <= endyear)]
    for day, row in df2.iterrows():
        data[day.year - baseyear, row["doy"] - 1] = row[ctx["var"]]

    title = (
        f"{ctx['_sname']} ({ctx['syear']}-{ctx['eyear']})\n"
        f"{PDICT[ctx['var']].replace('XX', str(ctx['days']))}"
    )
    fig, ax = figure_axes(title=title, apctx=ctx)
    heatmap(
        data,
        cmap=cmap,
        norm=norm,
        ax=ax,
        cbar_kws={"spacing": "proportional", "label": label},
    )
    ax.set_xticks((1, 32, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335))
    ax.set_xticklabels(calendar.month_abbr[1:], rotation=0)
    yticks = []
    yticklabels = []
    delta = 5 if (endyear - baseyear) < 30 else 10
    for i, year in enumerate(range(baseyear, endyear + 1)):
        if year % delta == 0:
            yticks.append(i + 0.5)
            yticklabels.append(year)
    ax.set_yticks(yticks[::-1])
    ax.set_yticklabels(yticklabels[::-1], rotation=0)
    ax.xaxis.grid(True, color="k")
    return fig, df
