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

Reads every specimen JSONL under data/{standard}/*.jsonl, overlays all curves
onto one figure per standard, color-codes by batch_label, and uses linestyle
to distinguish SLS from PLA/PETG controls. Writes to assets/{standard}_composite.png.
"""
import json
from pathlib import Path

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

ROOT = Path(__file__).parent.parent.parent
DATA_DIR = ROOT / "data"
OUT_DIR = ROOT / "assets"

# Tab10 palette — kept consistent across both plots so batch C in the D638
# plot matches batch C in the D790 plot.
BATCH_COLORS = {
    "A": "#1f77b4",  # blue
    "B": "#ff7f0e",  # orange
    "C": "#2ca02c",  # green
    "D": "#d62728",  # red
    "E": "#9467bd",  # purple
}
CONTROL_COLOR = "#7f7f7f"  # gray for PLA/PETG

MATERIAL_STYLES = {"SLS": "-", "PLA": "--", "PETG": ":"}


def load_specimen(path: Path) -> dict | None:
    with path.open() as f:
        row = json.loads(f.readline())
    pairs = [
        (s, t)
        for s, t in zip(row["curves"]["strain"], row["curves"]["stress_pa"])
        if s is not None and t is not None
    ]
    if not pairs:
        return None
    strain, stress_pa = zip(*pairs)
    return {
        "row": row,
        "strain": list(strain),
        "stress_mpa": [t / 1e6 for t in stress_pa],
    }


def style_for(row: dict) -> tuple[str, str]:
    material = row["material_class"]
    batch = row["batch_label"]
    color = BATCH_COLORS.get(batch, CONTROL_COLOR) if batch else CONTROL_COLOR
    linestyle = MATERIAL_STYLES.get(material, "-")
    return color, linestyle


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 plot_standard(standard: str) -> Path:
    paths = sorted((DATA_DIR / standard).glob("*.jsonl"))
    specs = [s for p in paths if (s := load_specimen(p))]
    if not specs:
        raise RuntimeError(f"No specimens found in data/{standard}/")

    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)")
    title_map = {"D638": "ASTM D638 — tensile composite",
                 "D790": "ASTM D790 — three-point flex composite"}
    ax.set_title(f"{title_map.get(standard, standard)}  ({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="lower right", fontsize=9, framealpha=0.9)

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


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