from __future__ import annotations

import argparse
import csv
import json
from collections import defaultdict
from pathlib import Path
from typing import Any


ROOT = Path(__file__).resolve().parents[1]
DEFAULT_REPORT_DIR = ROOT / "reports" / "model-chat"


def iter_records(report_dir: Path) -> list[dict[str, Any]]:
    records: list[dict[str, Any]] = []
    if not report_dir.exists():
        return records
    for path in sorted(report_dir.glob("*.jsonl")):
        with path.open("r", encoding="utf-8") as handle:
            for line_number, line in enumerate(handle, start=1):
                line = line.strip()
                if not line:
                    continue
                try:
                    record = json.loads(line)
                except json.JSONDecodeError as exc:
                    raise ValueError(f"{path}:{line_number}: invalid JSONL: {exc}") from exc
                if isinstance(record, dict):
                    records.append(record)
    return records


def collect_rows(records: list[dict[str, Any]]) -> list[dict[str, Any]]:
    rows = []
    for record in records:
        record_type = record.get("type")
        if record_type == "chat":
            rows.append(
                {
                    "type": "chat",
                    "plugin": record.get("plugin"),
                    "registry_model_id": record.get("registry_model_id"),
                    "served_model_name": record.get("served_model_name"),
                    "status": record.get("status"),
                    "latency_ms": record.get("latency_ms"),
                    "error": record.get("error"),
                }
            )
        elif record_type == "compare":
            for result in record.get("results") or []:
                if not isinstance(result, dict):
                    continue
                rows.append(
                    {
                        "type": "compare",
                        "plugin": record.get("plugin"),
                        "registry_model_id": result.get("registry_model_id"),
                        "served_model_name": result.get("served_model_name"),
                        "status": result.get("status"),
                        "latency_ms": result.get("latency_ms"),
                        "error": result.get("error"),
                    }
                )
    return rows


def summarize(rows: list[dict[str, Any]]) -> list[dict[str, Any]]:
    groups: dict[tuple[str, str], dict[str, Any]] = defaultdict(
        lambda: {"requests": 0, "answered": 0, "errors": 0, "latencies": []}
    )
    for row in rows:
        key = (str(row.get("plugin") or ""), str(row.get("served_model_name") or ""))
        group = groups[key]
        group["plugin"], group["served_model_name"] = key
        group["registry_model_id"] = row.get("registry_model_id")
        group["requests"] += 1
        if row.get("status") == "answered":
            group["answered"] += 1
        if row.get("status") == "error":
            group["errors"] += 1
        latency = row.get("latency_ms")
        if isinstance(latency, int | float):
            group["latencies"].append(float(latency))

    summary = []
    for group in groups.values():
        latencies = group.pop("latencies")
        group["avg_latency_ms"] = round(sum(latencies) / len(latencies)) if latencies else None
        summary.append(group)
    return sorted(summary, key=lambda item: (item["plugin"], item["served_model_name"]))


def write_csv(path: Path, rows: list[dict[str, Any]]) -> None:
    fields = ["plugin", "served_model_name", "registry_model_id", "requests", "answered", "errors", "avg_latency_ms"]
    path.parent.mkdir(parents=True, exist_ok=True)
    with path.open("w", encoding="utf-8", newline="") as handle:
        writer = csv.DictWriter(handle, fieldnames=fields)
        writer.writeheader()
        writer.writerows(rows)


def main() -> int:
    parser = argparse.ArgumentParser(description="Summarize model-chat JSONL reports.")
    parser.add_argument("--report-dir", type=Path, default=DEFAULT_REPORT_DIR)
    parser.add_argument("--csv", type=Path, help="Optional CSV output path.")
    args = parser.parse_args()

    records = iter_records(args.report_dir)
    rows = collect_rows(records)
    summary = summarize(rows)
    print(json.dumps({"records": len(records), "rows": len(rows), "models": summary}, ensure_ascii=False, indent=2))
    if args.csv:
        write_csv(args.csv, summary)
    return 0


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