#!/usr/bin/env python3
"""Render composite stress-strain plots for the D638 and D790 configs.

Reads every specimen JSONL under data/{standard}/*.jsonl and splits it into
two figures per standard: the main composite (SLS batches + FormLabs PA12GF
benchtop control) at assets/{standard}_composite.png, and — only if the
standard has any — a separate figure for the PLA/PETG filament controls at
assets/{standard}_controls.png. PLA/PETG print at much higher stress/strain
than the SLS specimens, which squashed the SLS curves near the origin when
they shared an axis with the main composite.
"""
from pathlib import Path

import matplotlib.pyplot as plt
from matplotlib.lines import Line2D

from _lib import OUT_DIR, ROOT, FILAMENT_CONTROLS, load_standard, style_for


def legend_handles(rows: list[dict]) -> list[Line2D]:
    """One legend entry per unique (batch, material) combination."""
    seen = {}
    for row in rows:
        key = (row["batch_label"], row["material_class"])
        if key in seen:
            continue
        color, linestyle = style_for(row)
        if row["batch_label"]:
            label = f"Batch {row['batch_label']}"
            if row["material_class"] != "SLS":
                label += f" ({row['material_class']})"
        else:
            label = row["material_class"]  # PLA / PETG controls
        seen[key] = Line2D([0], [0], color=color, linestyle=linestyle,
                           linewidth=1.6, label=label)
    # Sort: SLS batches A..E first, controls last.
    sort_key = lambda kv: (kv[0][1] != "SLS", kv[0][0] or "ZZ", kv[0][1])
    return [h for _, h in sorted(seen.items(), key=sort_key)]


def render(standard: str, specs: list[dict], title: str, out_name: str) -> Path | None:
    if not specs:
        return None

    fig, ax = plt.subplots(figsize=(9, 6))
    for s in specs:
        color, linestyle = style_for(s["row"])
        ax.plot(s["strain"], s["stress_mpa"],
                color=color, linestyle=linestyle, linewidth=1.2, alpha=0.75)

    ax.set_xlabel("Strain (mm/mm)")
    ax.set_ylabel("Stress (MPa)")
    ax.set_title(f"{title}  ({len(specs)} specimens)")
    ax.grid(True, alpha=0.3)
    ax.set_xlim(left=0)
    ax.set_ylim(bottom=0)

    ax.legend(handles=legend_handles([s["row"] for s in specs]),
              loc="upper left", bbox_to_anchor=(1.02, 1.0), borderaxespad=0,
              fontsize=9, framealpha=0.9)

    OUT_DIR.mkdir(parents=True, exist_ok=True)
    out_path = OUT_DIR / f"{standard}_{out_name}.png"
    fig.savefig(out_path, dpi=150, bbox_inches="tight")
    plt.close(fig)
    print(f"wrote {out_path.relative_to(ROOT)}  ({len(specs)} curves)")
    return out_path


def plot_standard(standard: str) -> None:
    specs = load_standard(standard)
    if not specs:
        raise RuntimeError(f"No specimens found in data/{standard}/")

    main_specs = [s for s in specs if s["row"]["material_class"] not in FILAMENT_CONTROLS]
    control_specs = [s for s in specs if s["row"]["material_class"] in FILAMENT_CONTROLS]

    title_map = {"D638": "ASTM D638 — tensile composite",
                 "D790": "ASTM D790 — three-point flex composite"}
    render(standard, main_specs, title_map.get(standard, standard), "composite")

    controls_title_map = {"D638": "ASTM D638 — PLA/PETG filament controls",
                           "D790": "ASTM D790 — PLA/PETG filament controls"}
    render(standard, control_specs, controls_title_map.get(standard, standard), "controls")


if __name__ == "__main__":
    plot_standard("D638")
    plot_standard("D790")