"""
evaluate.py - Run test sweep on a trained cd-model checkpoint.

Usage:
    python evaluate.py --model changemamba --dataset levir_cd
    python evaluate.py --model all --dataset all
    python evaluate.py --checkpoint results/bifa/levir_cd/checkpoints/best_model.pth --model bifa --dataset levir_cd
"""
from __future__ import annotations

import argparse
import sys
from pathlib import Path

import torch
import yaml

from utils.config_loader import load_dataset_config, load_model_config
from utils.gpu_utils import print_gpu_diagnostics, resolve_gpu
from utils.model_adapters import get_model_adapter
from utils.results_writer import append_to_comparison_table
from utils.unified_evaluator import evaluate_with_adapter


ROOT = Path(__file__).resolve().parent
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

class ModelEvaluationUnavailable(RuntimeError):
    pass


def _load_datasets() -> list[str]:
    return sorted(path.stem for path in (ROOT / "configs" / "datasets").glob("*.yaml"))


def _load_registry() -> dict:
    with (ROOT / "configs" / "models" / "registry.yaml").open("r", encoding="utf-8") as f:
        return yaml.safe_load(f)["models"]


def _best_checkpoint(model: str, dataset: str) -> Path:
    ckpt_dir = ROOT / "results" / model / dataset / "checkpoints"
    direct = ckpt_dir / "best_model.pth"
    if direct.exists():
        return direct
    candidates = (
        sorted(ckpt_dir.glob("*F1*.pth"))
        + sorted(ckpt_dir.glob("*.pth"))
        + sorted(ckpt_dir.glob("**/best_ckpt.pth"))
        + sorted(ckpt_dir.glob("**/best_ckpt.pt"))
        + sorted(ckpt_dir.glob("**/*best*.pth"))
        + sorted(ckpt_dir.glob("**/*best*.pt"))
    )
    if not candidates:
        raise FileNotFoundError(f"No checkpoint found under {ckpt_dir}")
    return candidates[-1]


def _parse_args() -> argparse.Namespace:
    registry = _load_registry()
    datasets = _load_datasets()
    parser = argparse.ArgumentParser(description="Run a test sweep on a trained cd-model checkpoint.")
    parser.add_argument("--model", required=True, choices=sorted(registry) + ["all"])
    parser.add_argument("--dataset", required=True, choices=datasets + ["all"])
    parser.add_argument("--checkpoint", default=None)
    parser.add_argument("--gpu", default="0")
    parser.add_argument("--dry-run", action="store_true")
    parser.add_argument("--allow-missing-profilers", action="store_true")
    return parser.parse_args()


def _evaluate_one(
    model: str,
    dataset: str,
    checkpoint: str | None,
    gpu: str,
    dry_run: bool,
    allow_missing_profilers: bool,
) -> int:
    cfg = load_dataset_config(dataset)
    gpu_resolution = resolve_gpu(gpu)
    print_gpu_diagnostics(gpu_resolution)
    if dry_run:
        print(f"[EVAL-DRY-RUN] model={model} dataset={dataset} data_root={cfg['data_root']}")
        return 0
    ckpt = Path(checkpoint) if checkpoint else _best_checkpoint(model, dataset)
    if not ckpt.is_absolute():
        ckpt = ROOT / ckpt
    print(f"[EVAL] model={model} dataset={dataset} checkpoint={ckpt}")
    adapter = get_model_adapter(model)
    if not adapter.supports_inprocess_eval:
        raise ModelEvaluationUnavailable(adapter.notes_or_failure_reason)
    device = torch.device(gpu_resolution.local_device)
    _, code = evaluate_with_adapter(
        model_name=model,
        dataset_cfg=cfg,
        model_config=load_model_config(model),
        adapter=adapter,
        checkpoint_path=ckpt,
        device=device,
        strict_profiling=not allow_missing_profilers,
    )
    return code


def main() -> int:
    args = _parse_args()
    models = sorted(_load_registry()) if args.model == "all" else [args.model]
    datasets = _load_datasets() if args.dataset == "all" else [args.dataset]
    rows = []
    for model in models:
        for dataset in datasets:
            try:
                code = _evaluate_one(
                    model,
                    dataset,
                    args.checkpoint,
                    args.gpu,
                    args.dry_run,
                    args.allow_missing_profilers,
                )
                rows.append((model, dataset, "complete" if code == 0 else "failed"))
            except FileNotFoundError as exc:
                print(f"[MISSING] {model}/{dataset}: {exc}")
                rows.append((model, dataset, "missing"))
            except ModelEvaluationUnavailable as exc:
                print(f"[UNAVAILABLE] {model}/{dataset}: {exc}")
                rows.append((model, dataset, "unavailable"))
            except RuntimeError as exc:
                print(f"[FAILED] {model}/{dataset}: {exc}")
                rows.append((model, dataset, "failed"))
    append_to_comparison_table()
    print("\nModel | Dataset | Status")
    print("--- | --- | ---")
    for model, dataset, status in rows:
        print(f"{model} | {dataset} | {status}")
    return 0 if all(status == "complete" for _, _, status in rows) else 1


if __name__ == "__main__":
    raise SystemExit(main())