"""Log avatar generation results to MLflow via REST API.

Uses the same lightweight REST-only approach as ray-serve's
mlflow_logger.py — no heavyweight mlflow SDK dependency.

Usage:
    from avatar_pipeline.log_mlflow import log_generation

    log_generation(
        avatar_name="Silver-Mage",
        params={"trellis_seed": 42, "trellis_simplify": 0.95},
        metrics={"vertex_count": 12345, "face_count": 8000, "duration_s": 45.2},
        artifacts={"vrm": Path("exports/Silver-Mage.vrm")},
    )
"""

from __future__ import annotations

import json
import logging
import os
import time
import urllib.error
import urllib.request
from pathlib import Path

logger = logging.getLogger(__name__)

DEFAULT_TRACKING_URI = "http://mlflow.mlflow.svc.cluster.local:80"
EXPERIMENT_NAME = "3d-avatar-generation"


def _base_url() -> str:
    return os.environ.get("MLFLOW_TRACKING_URI", DEFAULT_TRACKING_URI).rstrip("/")


def _post(path: str, body: dict) -> dict:
    url = f"{_base_url()}/api/2.0/mlflow/{path}"
    data = json.dumps(body).encode()
    req = urllib.request.Request(
        url, data=data, headers={"Content-Type": "application/json"}, method="POST"
    )
    with urllib.request.urlopen(req, timeout=15) as resp:
        return json.loads(resp.read().decode())


def _get_or_create_experiment(name: str) -> str:
    try:
        resp = _post("experiments/get-by-name", {"experiment_name": name})
        return resp["experiment"]["experiment_id"]
    except urllib.error.HTTPError:
        resp = _post("experiments/create", {"name": name})
        return resp["experiment_id"]


def _create_run(experiment_id: str, run_name: str, tags: dict[str, str]) -> str:
    tag_list = [
        {"key": k, "value": v}
        for k, v in {
            "mlflow.runName": run_name,
            "mlflow.source.type": "LOCAL",
            "mlflow.source.name": "avatar-pipeline",
            "hostname": os.environ.get("HOSTNAME", "desktop"),
            **tags,
        }.items()
    ]
    resp = _post(
        "runs/create",
        {
            "experiment_id": experiment_id,
            "run_name": run_name,
            "start_time": int(time.time() * 1000),
            "tags": tag_list,
        },
    )
    return resp["run"]["info"]["run_id"]


def _log_params(run_id: str, params: dict[str, str | int | float]) -> None:
    param_list = [{"key": k, "value": str(v)[:500]} for k, v in params.items()]
    _post("runs/log-batch", {"run_id": run_id, "params": param_list})


def _log_metrics(run_id: str, metrics: dict[str, float]) -> None:
    ts = int(time.time() * 1000)
    metric_list = [
        {"key": k, "value": float(v), "timestamp": ts, "step": 0} for k, v in metrics.items()
    ]
    _post("runs/log-batch", {"run_id": run_id, "metrics": metric_list})


def _log_artifact(run_id: str, key: str, path: Path) -> None:
    """Log an artifact path as a tag (actual artifact upload requires artifact store).

    For local files, we record the path. For S3-promoted files, the caller
    should include the S3 URI in params instead.
    """
    _post(
        "runs/log-batch",
        {
            "run_id": run_id,
            "tags": [{"key": f"artifact.{key}", "value": str(path)}],
        },
    )


def _end_run(run_id: str) -> None:
    _post(
        "runs/update",
        {
            "run_id": run_id,
            "status": "FINISHED",
            "end_time": int(time.time() * 1000),
        },
    )


def log_generation(
    avatar_name: str,
    params: dict[str, str | int | float] | None = None,
    metrics: dict[str, float] | None = None,
    artifacts: dict[str, Path] | None = None,
    tags: dict[str, str] | None = None,
    experiment_name: str = EXPERIMENT_NAME,
) -> str | None:
    """Log a complete avatar generation run to MLflow.

    Returns the MLflow run_id on success, None on failure.
    """
    try:
        exp_id = _get_or_create_experiment(experiment_name)
        run_id = _create_run(exp_id, run_name=avatar_name, tags=tags or {})

        if params:
            _log_params(run_id, params)

        if metrics:
            _log_metrics(run_id, metrics)

        if artifacts:
            for key, path in artifacts.items():
                _log_artifact(run_id, key, path)

        _end_run(run_id)
        logger.info("Logged to MLflow: run_id=%s, experiment=%s", run_id, experiment_name)
        return run_id

    except Exception:
        logger.warning("MLflow logging failed — generation still succeeded", exc_info=True)
        return None