"""Genera un grafico Potenziale normalizzato vs Current/sqrt(v)/v per ogni ciclo.

Legge la colonna C (Potential normalized/V) e la colonna E
(Current/sqrt(scan rate)/scan rate) dai file *_ultimo_ciclo.csv e salva,
per ciascuno, un PNG ad alta risoluzione con lo stesso nome del CSV.
"""

import csv
import sys
from pathlib import Path

import matplotlib
matplotlib.use("Agg")
import matplotlib.pyplot as plt
import matplotlib.ticker as mticker

INPUT_SUFFIX = "_ultimo_ciclo"
X_COLUMN = "Potential normalized/V"
Y_COLUMN = "Current/sqrt(scan rate)/scan rate"

X_LABEL = "$E - E_{ref}$ (V)"
Y_LABEL = r"$i \, / \, v^{3/2}$ (A$\cdot$V$^{-3/2}\cdot$s$^{3/2}$)"


def read_columns(path: Path) -> tuple[list[float], list[float]]:
    with path.open("r", encoding="utf-8", newline="") as f:
        reader = csv.reader(f, delimiter=";")
        header = next(reader)
        try:
            x_idx = header.index(X_COLUMN)
            y_idx = header.index(Y_COLUMN)
        except ValueError as e:
            raise ValueError(
                f"colonna mancante ({e}); esegui prima cv_normalize_potential.py e cv_current_over_sqrt_scanrate.py"
            )

        x_vals, y_vals = [], []
        for row in reader:
            x_vals.append(float(row[x_idx].replace(",", ".")))
            y_vals.append(float(row[y_idx].replace(",", ".")))

    return x_vals, y_vals


def plot_file(csv_path: Path, output_path: Path) -> None:
    x_vals, y_vals = read_columns(csv_path)

    fig, ax = plt.subplots(figsize=(8, 6), dpi=300)

    ax.plot(x_vals, y_vals, color="#1f4e79", linewidth=1.6)

    ax.set_title(csv_path.stem.replace(INPUT_SUFFIX, ""), fontsize=13, fontweight="bold", pad=12)
    ax.set_xlabel(X_LABEL, fontsize=11)
    ax.set_ylabel(Y_LABEL, fontsize=11)

    ax.axhline(0, color="black", linewidth=0.8, alpha=0.5)
    ax.axvline(0, color="black", linewidth=0.8, alpha=0.5)

    ax.yaxis.set_major_formatter(mticker.ScalarFormatter(useMathText=True))
    ax.ticklabel_format(axis="y", style="sci", scilimits=(0, 0))

    ax.grid(True, linestyle="--", linewidth=0.5, alpha=0.6)
    ax.spines["top"].set_visible(False)
    ax.spines["right"].set_visible(False)

    fig.tight_layout()
    fig.savefig(output_path, dpi=300)
    plt.close(fig)


def main(argv: list[str]) -> None:
    folder = Path(argv[1]) if len(argv) > 1 else Path(__file__).parent
    csv_files = sorted(
        p for p in folder.glob("*.csv") if p.stem.endswith(INPUT_SUFFIX)
    )

    if not csv_files:
        print(f"Nessun file *{INPUT_SUFFIX}.csv trovato in {folder}")
        return

    for csv_file in csv_files:
        output_path = csv_file.with_suffix(".png")
        try:
            plot_file(csv_file, output_path)
            print(f"OK  {csv_file.name} -> {output_path.name}")
        except ValueError as e:
            print(f"SKIP {csv_file.name}: {e}")


if __name__ == "__main__":
    main(sys.argv)