"""Plot pid-results.csv. Tested with matplotlib 3.6.3; labels are shared in JA/EN."""
import csv
from collections import defaultdict
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
plt.rcParams.update({'font.size': 14})
rows=defaultdict(list)
with open('pid-results.csv') as source:
    for row in csv.DictReader(source):
        rows[row['scenario']].append({k: float(v) for k,v in row.items() if k!='scenario'})
fig, axes=plt.subplots(2, 1, figsize=(10, 7), sharex=True)
styles=['-', '--', '-.', ':']
for (name, data), style in zip(rows.items(), styles):
    for ax, key in zip(axes, ['output', 'control']):
        ax.plot([r['time_s'] for r in data], [r[key] for r in data], style, label=name, linewidth=2)
data=rows['nominal']
axes[0].plot([r['time_s'] for r in data], [r['target'] for r in data], color='black', linewidth=1, label='target')
axes[0].set_ylabel('Output (normalized)');axes[1].set_ylabel('Control (normalized)')
axes[1].set_xlabel('Time (s)')
for ax in axes:
    ax.grid(alpha=.3); ax.legend(loc='best', fontsize=12)
fig.suptitle('PID simulation: Kp=3, Ki=2, Kd=1; dt=0.005 s; 2,401 samples/case')
fig.tight_layout()
fig.savefig('pid-response.svg', metadata={'Description':'Simulation of a normalized second-order plant, with measurement delay and saturation; not hardware measurements.'})

from pathlib import Path
p=Path("pid-response.svg")
s=p.read_text().replace("<svg ", '<svg role="img" aria-labelledby="pid-title pid-desc" ', 1)
pos=s.index(">", s.index("<svg "))+1
s=s[:pos]+'<title id="pid-title">PID simulation with delay and saturation</title><desc id="pid-desc">Output and control from 0 to 12 seconds; target changes from 1 to 0.4 at 6 seconds. Conditional integration reduces windup under a 0.8 control limit.</desc>'+s[pos:]
p.write_text(s)