from __future__ import annotations

import json
import subprocess
import sys
from datetime import UTC, datetime
from pathlib import Path
from typing import Any

from .config import LoadConfig


def write_event(config: LoadConfig, manifest: dict, event: dict[str, Any]) -> dict[str, str]:
    """Append one event to the local run log. The log is uploaded once at the end of the
    run by ``upload_runtime_log`` — not per event — so an N-table run does not re-send a
    steadily growing object N times (O(N^2) bytes)."""
    run_date = manifest["run_date"]
    run_id = manifest["run_id"]
    record = {
        "event_schema_version": 1,
        "source_name": manifest["source_name"],
        "dataset": manifest.get("dataset", ""),
        "run_date": run_date,
        "run_id": run_id,
        "created_at": datetime.now(UTC).isoformat(),
        **event,
    }

    output_path = runtime_log_path(config, run_date, run_id)
    output_path.parent.mkdir(parents=True, exist_ok=True)
    with output_path.open("a") as file:
        file.write(json.dumps(record, sort_keys=True) + "\n")

    return {"local_path": str(output_path), "gcs_uri": manifest["runtime_log_uri"]}


def upload_runtime_log(config: LoadConfig, manifest: dict) -> dict[str, str] | None:
    """Upload the complete run log to GCS once, after the run.

    Best-effort: a failed upload must not abort an otherwise-successful load — the raw
    data has already landed and the log remains on local disk. Returns the destination
    (with an ``uploaded`` flag), or None if there is nothing to upload.
    """
    output_path = runtime_log_path(config, manifest["run_date"], manifest["run_id"])
    if not output_path.exists():
        return None
    gcs_uri = manifest["runtime_log_uri"]
    try:
        subprocess.run(
            ["gcloud", "storage", "cp", str(output_path), gcs_uri],
            check=True,
            capture_output=True,
            text=True,
        )
    except (subprocess.CalledProcessError, OSError) as error:
        print(
            json.dumps({"runtime_log_upload_failed": gcs_uri, "error": str(error)}),
            file=sys.stderr,
        )
        return {"local_path": str(output_path), "gcs_uri": gcs_uri, "uploaded": "false"}
    return {"local_path": str(output_path), "gcs_uri": gcs_uri, "uploaded": "true"}


def runtime_log_path(config: LoadConfig, run_date: str, run_id: str) -> Path:
    return config.root / "runs" / run_date / run_id / "events.jsonl"