#!/usr/bin/env python3
from __future__ import annotations

import argparse
import json
from dataclasses import asdict
from datetime import datetime
from pathlib import Path
from time import perf_counter

from inire.tests.example_scenarios import _run_example_07_variant


def _parse_csv_ints(raw: str) -> tuple[int, ...]:
    return tuple(int(part) for part in raw.split(",") if part.strip())


def _run_case(num_nets: int, seed: int) -> dict[str, object]:
    t0 = perf_counter()
    run = _run_example_07_variant(
        num_nets=num_nets,
        seed=seed,
        warm_start_enabled=False,
    )
    duration_s = perf_counter() - t0
    return {
        "duration_s": duration_s,
        "summary": {
            "total_results": len(run.results_by_net),
            "valid_results": sum(1 for result in run.results_by_net.values() if result.is_valid),
            "reached_targets": sum(1 for result in run.results_by_net.values() if result.reached_target),
        },
        "metrics": asdict(run.metrics),
    }


def _is_smoke_candidate(entry: dict[str, object]) -> bool:
    summary = entry["summary"]
    metrics = entry["metrics"]
    return (
        summary["valid_results"] == summary["total_results"]
        and metrics["pair_local_search_accepts"] >= 1
        and entry["duration_s"] <= 1.0
    )


def _select_smoke_case(cases: list[dict[str, object]]) -> dict[str, object] | None:
    grouped: dict[tuple[int, int], list[dict[str, object]]] = {}
    for case in cases:
        key = (case["num_nets"], case["seed"])
        grouped.setdefault(key, []).append(case)

    candidates = []
    for (num_nets, seed), repeats in grouped.items():
        if repeats and all(_is_smoke_candidate(repeat) for repeat in repeats):
            candidates.append({"num_nets": num_nets, "seed": seed})
    if not candidates:
        return None
    candidates.sort(key=lambda item: (item["num_nets"], item["seed"]))
    return candidates[0]


def _render_markdown(payload: dict[str, object]) -> str:
    lines = [
        "# Pair-Local Search Characterization",
        "",
        f"Generated at {payload['generated_at']} by `{payload['generator']}`.",
        "",
        f"Grid: `num_nets={payload['grid']['num_nets']}`, `seed={payload['grid']['seeds']}`, repeats={payload['grid']['repeats']}.",
        "",
        "| Nets | Seed | Repeat | Duration (s) | Valid | Reached | Pair Pairs | Pair Accepts | Pair Nodes | Nodes | Checks |",
        "| :-- | :-- | :-- | --: | --: | --: | --: | --: | --: | --: | --: |",
    ]
    for case in payload["cases"]:
        summary = case["summary"]
        metrics = case["metrics"]
        lines.append(
            "| "
            f"{case['num_nets']} | "
            f"{case['seed']} | "
            f"{case['repeat']} | "
            f"{case['duration_s']:.4f} | "
            f"{summary['valid_results']} | "
            f"{summary['reached_targets']} | "
            f"{metrics['pair_local_search_pairs_considered']} | "
            f"{metrics['pair_local_search_accepts']} | "
            f"{metrics['pair_local_search_nodes_expanded']} | "
            f"{metrics['nodes_expanded']} | "
            f"{metrics['congestion_check_calls']} |"
        )

    lines.extend(["", "## Recommendation", ""])
    recommended = payload["recommended_smoke_scenario"]
    if recommended is None:
        lines.append(
            "No smaller stable pair-local smoke scenario satisfied the rule "
            "`valid_results == total_results`, `pair_local_search_accepts >= 1`, and `duration_s <= 1.0` across all repeats."
        )
    else:
        lines.append(
            f"Recommended smoke scenario: `num_nets={recommended['num_nets']}`, `seed={recommended['seed']}`."
        )
    return "\n".join(lines)


def main() -> None:
    parser = argparse.ArgumentParser(description="Characterize pair-local search across example_07-style no-warm runs.")
    parser.add_argument(
        "--num-nets",
        default="6,8,10",
        help="Comma-separated num_nets values to sweep. Default: 6,8,10.",
    )
    parser.add_argument(
        "--seeds",
        default="41,42,43",
        help="Comma-separated seed values to sweep. Default: 41,42,43.",
    )
    parser.add_argument(
        "--repeats",
        type=int,
        default=2,
        help="Number of repeated runs per (num_nets, seed). Default: 2.",
    )
    parser.add_argument(
        "--output-dir",
        type=Path,
        default=None,
        help="Directory to write pair_local_characterization.json and .md into. Defaults to <repo>/docs.",
    )
    args = parser.parse_args()

    repo_root = Path(__file__).resolve().parents[1]
    output_dir = repo_root / "docs" if args.output_dir is None else args.output_dir.resolve()
    output_dir.mkdir(exist_ok=True)

    num_nets_values = _parse_csv_ints(args.num_nets)
    seed_values = _parse_csv_ints(args.seeds)

    cases: list[dict[str, object]] = []
    for num_nets in num_nets_values:
        for seed in seed_values:
            for repeat in range(args.repeats):
                case = _run_case(num_nets, seed)
                case["num_nets"] = num_nets
                case["seed"] = seed
                case["repeat"] = repeat
                cases.append(case)

    payload = {
        "generated_at": datetime.now().astimezone().isoformat(timespec="seconds"),
        "generator": "scripts/characterize_pair_local_search.py",
        "grid": {
            "num_nets": list(num_nets_values),
            "seeds": list(seed_values),
            "repeats": args.repeats,
        },
        "cases": cases,
        "recommended_smoke_scenario": _select_smoke_case(cases),
    }

    json_path = output_dir / "pair_local_characterization.json"
    markdown_path = output_dir / "pair_local_characterization.md"
    json_path.write_text(json.dumps(payload, indent=2, sort_keys=True) + "\n")
    markdown_path.write_text(_render_markdown(payload) + "\n")

    if json_path.is_relative_to(repo_root):
        print(f"Wrote {json_path.relative_to(repo_root)}")
    else:
        print(f"Wrote {json_path}")
    if markdown_path.is_relative_to(repo_root):
        print(f"Wrote {markdown_path.relative_to(repo_root)}")
    else:
        print(f"Wrote {markdown_path}")


if __name__ == "__main__":
    main()