"""Plot Step 3 A/B/C trajectories: λ and acc over training."""
import json, os
import numpy as np
import matplotlib
matplotlib.use("Agg")
import matplotlib.pyplot as plt

ROOT = "/home/yurenh2/rrm/research/flossing"
OUT = f"{ROOT}/plots_step3"
os.makedirs(OUT, exist_ok=True)

runs = {
    "A: baseline (α=0)\nfrom step_18228": "step3_A_baseline_18228.json",
    "B: CF α=10 λ*=-0.15\nfrom step_18228": "step3_B_rf_18228.json",
    "C: CF α=10 λ*=-0.05\nfrom step_26040": "step3_C_rf_26040.json",
}
colors = {"A": "C0", "B": "C3", "C": "C2"}

fig, axes = plt.subplots(2, 2, figsize=(13, 9))

for label, fn in runs.items():
    d = json.loads(open(f"{ROOT}/{fn}").read())
    key = label.split(":")[0]
    steps = [r["step"] for r in d["steps"]]
    sup = np.array([r["sup_loss"] for r in d["steps"]])
    rf = np.array([r["rf_loss"] for r in d["steps"]])
    lyap_mean = np.array([r["lyap1_mean"] for r in d["steps"]])
    lyap_max = np.array([r["lyap1_max"] for r in d["steps"]])
    frac = np.array([r["frac_above_star"] for r in d["steps"]])

    # Smooth (moving average)
    def smooth(x, w=20):
        if len(x) < w: return x
        kernel = np.ones(w) / w
        return np.convolve(x, kernel, mode="same")

    # acc evals
    eval_steps = [e["step"] for e in d["evals"]]
    eval_accs = [e["acc"] for e in d["evals"]]

    axes[0,0].plot(eval_steps, eval_accs, f"{colors[key]}-o", label=label)
    axes[0,1].plot(steps, smooth(sup), f"{colors[key]}-", label=label, alpha=0.8)
    axes[1,0].plot(steps, smooth(lyap_mean), f"{colors[key]}-", label=f"{key} mean", alpha=0.8)
    axes[1,0].plot(steps, smooth(lyap_max), f"{colors[key]}--", label=f"{key} max", alpha=0.4)
    axes[1,1].plot(steps, smooth(frac), f"{colors[key]}-", label=label, alpha=0.8)

axes[0,0].set_title("Test exact accuracy vs training step")
axes[0,0].set_xlabel("step"); axes[0,0].set_ylabel("exact_acc"); axes[0,0].legend(fontsize=8, loc="best"); axes[0,0].grid(alpha=0.3)

axes[0,1].set_title("Supervised loss (smoothed, w=20)")
axes[0,1].set_xlabel("step"); axes[0,1].set_ylabel("sup_loss"); axes[0,1].legend(fontsize=8); axes[0,1].grid(alpha=0.3)

axes[1,0].set_title("λ_joint_1 trajectory (smoothed)")
axes[1,0].axhline(0, color="k", ls=":", lw=0.6)
axes[1,0].axhline(-0.05, color="C2", ls="--", lw=0.5, label="C λ*")
axes[1,0].axhline(-0.15, color="C3", ls="--", lw=0.5, label="B λ*")
axes[1,0].set_xlabel("step"); axes[1,0].set_ylabel(r"$\lambda_{joint,1}$"); axes[1,0].legend(fontsize=7); axes[1,0].grid(alpha=0.3)

axes[1,1].set_title(r"fraction of batch samples with $\lambda > \lambda^*$")
axes[1,1].set_xlabel("step"); axes[1,1].set_ylabel("fraction"); axes[1,1].legend(fontsize=8); axes[1,1].grid(alpha=0.3)

fig.suptitle("Step 3: contractive flossing as training-time regularizer on HRM")
fig.tight_layout()
fig.savefig(f"{OUT}/step3_trajectories.png", dpi=130)
plt.close()

print(f"\n== summary ==")
for label, fn in runs.items():
    d = json.loads(open(f"{ROOT}/{fn}").read())
    init = d["initial_acc"]; fin = d["final_acc"]
    last_lyap = d["steps"][-1]
    print(f"  {label.split(':')[0]}: acc {init:.3f} → {fin:.3f} (Δ {fin-init:+.4f})  "
          f"final λ_mean={last_lyap['lyap1_mean']:+.3f} max={last_lyap['lyap1_max']:+.3f}  "
          f"final frac>λ*={last_lyap['frac_above_star']:.2f}")

print(f"\nplots → {OUT}/")