batch_plot_uv.py

"""
Batch-plot optical-power CSV files.

Each CSV must have three columns:
1. ISO-8601 timestamp  (YYYY-MM-DD HH:MM:SS)
2. Power in watts      (blank rows mark UV-state changes)
3. UV state string     ("ON" or "OFF"  in rows that have blank power)

Usage
-----
$ python batch_plot_uv.py        # assuming you save this as batch_plot_uv.py
"""

import numpy as np
import matplotlib.pyplot as plt
from datetime import datetime
from pathlib import Path

def plot_one_csv(path: Path) -> None:
    """Read *path*, make the plot, show it, and save PNG next to the CSV."""
    # -------------------- Load the CSV ------------------------------
    raw = np.genfromtxt(path, delimiter=",", dtype=str, skip_header=1)
    if raw.ndim == 1:                           # in case file has only one data row
        raw = raw.reshape(1, -1)

    ts_str, power_str, state_str = raw[:, 0], raw[:, 1], raw[:, 2]
    data_mask   = power_str != ""               # rows carrying numeric power

    # Guard against empty numeric section
    if not data_mask.any():
        print(f"[WARN] No numeric power rows found in {path.name}. Skipped.")
        return

    # -------------------- Time & power arrays -----------------------
    t_datetimes = [datetime.fromisoformat(t) for t in ts_str[data_mask]]
    t0          = t_datetimes[0]
    t_elapsed_s = np.array([(t - t0).total_seconds() for t in t_datetimes])
    power_mw    = power_str[data_mask].astype(float) * 1_000.0  # W → mW

    # -------------------- UV-state shading intervals ----------------
    intervals, curr_state, curr_start = [], None, 0.0
    for t_txt, st in zip(ts_str, state_str):
        if st in ("ON", "OFF"):
            t_now = (datetime.fromisoformat(t_txt) - t0).total_seconds()
            if curr_state is not None:
                intervals.append((curr_start, t_now, curr_state))
            curr_state, curr_start = st, t_now
    if curr_state is not None:
        t_final = (datetime.fromisoformat(ts_str[-1]) - t0).total_seconds()
        intervals.append((curr_start, t_final, curr_state))

    # -------------------- Plot --------------------------------------
    fig, ax = plt.subplots()
    ax.plot(t_elapsed_s, power_mw, lw=1.0, label="Optical Power (mW)")

    for start, end, st in intervals:
        color = "lightgreen" if st == "ON" else "lightcoral"
        ax.axvspan(start, end, facecolor=color, alpha=0.30)

    ax.set_xlabel("Time (s)")
    ax.set_ylabel("Optical Power (mW)")
    title = f"Optical Power vs Time"
    ax.set_title(title)
    ax.legend()
    plt.tight_layout()

    # -------------------- Save & show -------------------------------
    png_path = path.with_suffix(".png")
    plt.savefig(png_path, dpi=300)
    print(f"[OK] Saved: {png_path}")
    plt.show()          # remove if you don’t want interactive windows

def main():
    csv_files = sorted(Path(".").glob("*.csv"))
    if not csv_files:
        print("[INFO] No CSV files found in the current directory.")
        return
    for f in csv_files:
        print(f"[INFO] Processing {f.name}")
        plot_one_csv(f)

if __name__ == "__main__":
    main()