"""
This table presents the 10 largest or smallest differences
between the lowest and highest air temperature for a local calendar
day.  Some stations have auxillary products that provide 'daily' values
over a date defined always in standard time.  This plot also presents
sprites of the temperature time series starting at 12 hours before the
denoted date and ending at 12 hours after the date.  The sprite often
quickly points out bad data points, sigh, but also easily shows if the
temperature change was an increase during the day or decrease.

<p><a href="/plotting/auto/?q=169">Autoplot 169</a> is similar to this
plot, but computes the change over arbitrary time windows.</p>
"""

from datetime import date, datetime, timedelta, timezone
from zoneinfo import ZoneInfo

import pandas as pd
from pyiem.database import get_sqlalchemy_conn, sql_helper
from pyiem.exceptions import NoDataFound
from pyiem.plot import figure

from iemweb.autoplot import get_monofont
from iemweb.util import month2months

MDICT = {
    "all": "No Month/Time Limit",
    "spring": "Spring (MAM)",
    "fall": "Fall (SON)",
    "winter": "Winter (DJF)",
    "summer": "Summer (JJA)",
    "jan": "January",
    "feb": "February",
    "mar": "March",
    "apr": "April",
    "may": "May",
    "jun": "June",
    "jul": "July",
    "aug": "August",
    "sep": "September",
    "oct": "October",
    "nov": "November",
    "dec": "December",
}

PDICT = {"largest": "Largest", "smallest": "Smallest"}


def get_description():
    """Return a dict describing how to call this plotter"""
    desc = {"description": __doc__, "data": True, "cache": 86400}
    desc["arguments"] = [
        dict(
            type="zstation",
            name="zstation",
            default="AMW",
            label="Select Station:",
            network="IA_ASOS",
        ),
        dict(
            type="select",
            name="v",
            default="largest",
            label="Show largest or smallest differences?",
            options=PDICT,
        ),
        dict(
            type="select",
            name="month",
            default="all",
            label="Month Limiter",
            options=MDICT,
        ),
    ]
    return desc


def plot_date(ax, i, dt: date, station, tz) -> bool:
    """plot date."""
    # request 36 hours
    sts = datetime(dt.year, dt.month, dt.day, tzinfo=tz)
    sts = sts - timedelta(hours=12)
    ets = sts + timedelta(hours=48)
    with get_sqlalchemy_conn("asos") as conn:
        df = pd.read_sql(
            sql_helper("""
        SELECT valid at time zone 'UTC' as valid, tmpf from alldata
        where station = :station and valid >= :sts and valid <= :ets and
        tmpf is not null ORDER by valid ASC"""),
            conn,
            params={"station": station, "sts": sts, "ets": ets},
            index_col=None,
        )
    if df.empty:
        return False
    df["valid"] = df["valid"].dt.tz_localize(timezone.utc)
    # Ensure that we have at least one ob within six hours to start and end
    h6 = timedelta(hours=6)
    dv = df["valid"]
    if df[(dv >= sts) & (dv < (sts + h6))].empty:
        return False
    h18 = timedelta(hours=18)
    if df[(dv >= (sts + h18)) & (dv < (sts + h6 + h18))].empty:
        return False
    df["norm"] = (df["tmpf"] - df["tmpf"].min()) / (
        df["tmpf"].max() - df["tmpf"].min()
    )
    df["xnorm"] = [
        x.total_seconds() for x in (df["valid"] - pd.Timestamp(sts))
    ]

    lp = ax.plot(df["xnorm"], df["norm"] + i)
    ax.text(
        df["xnorm"].values[-1],
        df["norm"].values[-1] + i,
        dt.strftime("%-d %b %Y"),
        va="bottom" if df["norm"].values[-1] < 0.5 else "top",
        color=lp[0].get_color(),
    )
    return True


def plotter(ctx: dict):
    """Go"""
    font0 = get_monofont()
    font0.set_size(16)
    station = ctx["zstation"]
    month = ctx["month"]
    months = month2months(month)

    order = "DESC" if ctx["v"] == "largest" else "ASC"
    with get_sqlalchemy_conn("iem") as conn:
        # Over-sample as we may get some DQ's due to lack of data
        df = pd.read_sql(
            sql_helper(
                """
            SELECT day as date, max_tmpf as max, min_tmpf as min,
            max_tmpf::int - min_tmpf::int as difference
            from summary s JOIN stations t on (s.iemid = t.iemid)
            where t.id = :station and t.network = :network
            and extract(month from day) = ANY(:months)
            and max_tmpf is not null and min_tmpf is not null
            ORDER by difference {order}, date DESC LIMIT 50
        """,
                order=order,
            ),
            conn,
            params={
                "station": station,
                "network": ctx["network"],
                "months": months,
            },
            parse_dates=("date",),
            index_col=None,
        )
    if df.empty:
        raise NoDataFound("No Data Found,")
    ab = ctx["_nt"].sts[station]["archive_begin"]
    if ab is None:
        raise NoDataFound("Unknown station metadata.")
    tz = ZoneInfo(ctx["_nt"].sts[station]["tzname"])
    title = (
        f"{ctx['_sname']} ({ab.year}-{date.today().year})\n"
        f"Top 10 {PDICT[ctx['v']]} Local Calendar Day "
        f"[{month.capitalize()}] Temperature Differences"
    )
    fig = figure(title=title, apctx=ctx)
    fig.text(
        0.1, 0.81, " #  Date         Diff   Low High", fontproperties=font0
    )
    y = 0.74
    ax = fig.add_axes((0.5, 0.1, 0.3, 0.69))
    i = 10
    hits = 0
    rank = 0
    rankval = 0.120
    for _, row in df.iterrows():
        if hits >= 10:
            break
        if not plot_date(ax, i, row["date"], station, tz):
            continue
        if row["difference"] != rankval:
            rank += 1
            rankval = row["difference"]
        hits += 1
        fig.text(
            0.1,
            y,
            (
                f"{rank:2.0f}  {row['date']:%d %b %Y}   "
                f"{row['difference']:3.0f}   "
                f"{row['min']:3.0f}  {row['max']:3.0f}"
            ),
            fontproperties=font0,
        )
        y -= 0.07
        i -= 1
    ax.set_title("Hourly Temps On Date & +/-12 Hrs")
    ax.set_ylim(1, 11)
    ax.axvline(12 * 3600, color="tan")
    ax.axvline(36 * 3600, color="tan")
    ax.axis("off")
    return fig, df
