"""Run a saved Q2 model on the unlabeled Attachment 3 cases."""
from __future__ import annotations

import argparse
import json
import time
from pathlib import Path

import numpy as np
import torch

from data_paths import PROJECT_ROOT
from model.crg import INPUT_DIMS, MODALITIES, StructuredGaussianImputer
from .train import (
    _make_variant,
    infer_attachment3,
    reencode_attachment3,
    validate_attachment3_predictions,
    write_csv,
)

DEFAULT_RESULTS_DIR = PROJECT_ROOT / "experiments" / "q2" / "unaligned_math_all_b128"
DEFAULT_OUTPUT_DIR = PROJECT_ROOT / "output" / "q2"


def main() -> None:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--input-version", choices=("aligned_50", "unaligned_50"), default="unaligned_50")
    parser.add_argument("--results-dir", type=Path, default=DEFAULT_RESULTS_DIR,
                        help="saved Q2 checkpoint and calibration directory")
    parser.add_argument("--output-dir", type=Path, default=DEFAULT_OUTPUT_DIR)
    parser.add_argument("--device", choices=("auto", "cpu", "cuda"), default="auto")
    args = parser.parse_args()

    if args.device == "cuda" and not torch.cuda.is_available():
        parser.error("CUDA was requested but is not available")
    device_name = "cuda" if args.device == "auto" and torch.cuda.is_available() else args.device
    if device_name == "auto":
        device_name = "cpu"
    device = torch.device(device_name)

    results_dir = args.results_dir.expanduser().resolve()
    output_dir = args.output_dir.expanduser().resolve()
    manifest_path = results_dir / "run_manifest.json"
    calibration_path = results_dir / "validation_metrics.json"
    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
    calibration = json.loads(calibration_path.read_text(encoding="utf-8"))
    selected = calibration.get("selected_model", manifest.get("selected_model"))
    if not selected:
        raise ValueError(f"no selected_model recorded in {calibration_path}")

    imputer = StructuredGaussianImputer(INPUT_DIMS).to(device)
    imputer.load_state_dict(torch.load(results_dir / "structured_imputer.pt", map_location=device, weights_only=True))
    model = _make_variant(selected, imputer).to(device)
    model.load_state_dict(torch.load(results_dir / "crg_student.pt", map_location=device, weights_only=True))

    with np.load(results_dir / "preprocessor.npz", allow_pickle=False) as archive:
        fitted = {m: {k: archive[f"{m}_{k}"].copy() for k in ("mean", "std")} for m in MODALITIES}
    priors = manifest["attachment3_low_information_priors"]
    temperature = float(calibration["temperature"])
    class_prior = np.asarray(priors["class_probability_values"], dtype=np.float64)
    magnitude_priors = np.asarray((priors["negative_beta"], priors["positive_beta"]), dtype=np.float32)

    cases, source_audit = reencode_attachment3(device, input_version=args.input_version)
    predictions, inference_audit = infer_attachment3(
        model, cases, fitted, device, temperature, class_prior, magnitude_priors,
    )
    validate_attachment3_predictions([case["case_id"] for case in cases], predictions)

    output_dir.mkdir(parents=True, exist_ok=True)
    inference_by_id = {row["case_id"]: row for row in inference_audit}
    predictions_path = output_dir / "attachment3_predictions.csv"
    audit_path = output_dir / "attachment3_audit.csv"
    manifest_out_path = output_dir / "attachment3_prediction_manifest.json"
    write_csv(predictions_path, predictions)
    write_csv(audit_path, [{**source, **inference_by_id[source["case_id"]]} for source in source_audit])

    try:
        results_reference = results_dir.relative_to(PROJECT_ROOT).as_posix()
    except ValueError:
        results_reference = "external checkpoint directory"
    prediction_manifest = {
        "task": "unlabeled Attachment 3 inference",
        "input_version": args.input_version,
        "selected_model": selected,
        "checkpoint_run": results_reference,
        "prediction_count": len(predictions),
        "temperature": temperature,
        "labels_available": False,
        "prediction_file": predictions_path.name,
        "audit_file": audit_path.name,
        "completed_utc": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()),
    }
    manifest_out_path.write_text(json.dumps(prediction_manifest, ensure_ascii=False, indent=2), encoding="utf-8")
    print(f"Wrote {len(predictions)} unlabeled Attachment 3 predictions to {output_dir}", flush=True)


if __name__ == "__main__":
    main()