"""LMR v2.1 vs LMR Seasonal vs Berkeley Earth, annual anomalies vs 1961-1990.

Top: the whole LMR Seasonal period (800-2024), with a long running mean.
Bottom: zoom from 1700, with a shorter one. Thin lines: annual values;
thick lines: centered running mean, full windows only.

Reads ``series/tas_annual_anom_1961-1990.csv`` (run regional.py first).

Usage: python plot_lmr_be.py [long_window] [short_window]
       (defaults: 31 11)
"""
import os
import sys

import matplotlib.pyplot as plt
import pandas as pd

HERE = os.path.dirname(os.path.abspath(__file__))

LABELS = {'lmr_v2.1': 'LMR v2.1', 'lmr_seas': 'LMR Seasonal',
          'berkeley-earth': 'Berkeley Earth'}
COLORS = {'lmr_v2.1': '#2a78d6', 'lmr_seas': '#4a3aa7',
          'berkeley-earth': '#eb6834'}

long_window = int(sys.argv[1]) if len(sys.argv) > 1 else 31
short_window = int(sys.argv[2]) if len(sys.argv) > 2 else 11

df = pd.read_csv(os.path.join(HERE, 'series', 'tas_annual_anom_1961-1990.csv'),
                 index_col=0)[list(LABELS)]

fig, axs = plt.subplots(2, 1, figsize=(11, 9))
for ax, start, window in [(axs[0], 800, long_window),
                          (axs[1], 1700, short_window)]:
    ax.axhline(0, color='#52514e', lw=0.8)
    ax.axvspan(1961, 1990, color='#d0cfc8', alpha=0.35, lw=0)
    ax.axvline(1850, color='k', lw=1)
    for name in LABELS:
        s = df[name].dropna()
        s = s.reindex(range(s.index[0], s.index[-1] + 1))
        # single missing years (BE 1752) are interpolated for the running
        # mean only, and it is computed before cutting at the start year
        sm = s.interpolate(limit=1, limit_area='inside').rolling(
            window, center=True, min_periods=window).mean().loc[start:]
        s = s.loc[start:]
        ax.plot(s.index, s, color=COLORS[name], lw=0.5, alpha=0.35)
        ax.plot(sm.index, sm, color=COLORS[name], lw=2,
                label=f'{LABELS[name]} ({s.dropna().index[0]}–'
                      f'{s.dropna().index[-1]})')
    ax.set_xlim(start, df.index[-1] + 2)
    ax.set_ylabel('Anomaly vs 1961–1990 (K)')
    ax.set_title(f'From {start}. Thin: yearly, thick: {window}-yr running '
                 'mean', loc='left', fontsize=10)
    ax.grid(axis='y', color='#e6e5e0', lw=0.6)
    for sp in ['top', 'right']:
        ax.spines[sp].set_visible(False)
axs[0].legend(frameon=False, loc='upper left', fontsize=9)
fig.suptitle('Annual temperature, glacier-area weighted over the Alps '
             '(RGI6.2 11-01)', x=0.01, ha='left', fontsize=11)
fig.tight_layout()
f = os.path.join(HERE, 'figs', 'lmr_be_annual_anom.png')
fig.savefig(f, dpi=150)
print(f)