"""
FactoryNet Loader - Easy access to hackathon datasets.

Usage:
    from factorynet_loader import load_factorynet

    # Load AURSAD data
    df, metadata = load_factorynet("aursad")

    # Get specific columns
    setpoints = df[[c for c in df.columns if c.startswith("setpoint_")]]
    efforts = df[[c for c in df.columns if c.startswith("effort_")]]
    feedback = df[[c for c in df.columns if c.startswith("feedback_")]]
"""

import pandas as pd
import json
from pathlib import Path
from typing import Tuple, List, Optional, Dict
import numpy as np

try:
    from datasets import load_dataset
    HF_AVAILABLE = True
except ImportError:
    HF_AVAILABLE = False


# HuggingFace repo
HF_REPO = "Forgis/factorynet-hackathon"


def load_factorynet(
    dataset: str = "aursad",
    split: str = "train",
    from_hf: bool = True,
    local_path: Optional[Path] = None,
) -> Tuple[pd.DataFrame, List[Dict]]:
    """
    Load FactoryNet dataset.

    Args:
        dataset: "aursad" or "voraus"
        split: "train" (full data) or future splits
        from_hf: If True, load from HuggingFace Hub
        local_path: Local path override

    Returns:
        df: DataFrame with time series
        metadata: List of episode metadata dicts
    """
    if from_hf and HF_AVAILABLE:
        return _load_from_hf(dataset, split)
    elif local_path:
        return _load_from_local(local_path, dataset)
    else:
        raise ValueError("Either set from_hf=True or provide local_path")


def _load_from_hf(dataset: str, split: str) -> Tuple[pd.DataFrame, List[Dict]]:
    """Load from HuggingFace Hub."""
    ds = load_dataset(HF_REPO, data_dir=dataset, split=split)
    df = ds.to_pandas()

    # Try to load metadata
    try:
        from huggingface_hub import hf_hub_download
        meta_file = hf_hub_download(
            repo_id=HF_REPO,
            filename=f"{dataset}/{dataset}_metadata.json",
            repo_type="dataset"
        )
        with open(meta_file) as f:
            metadata = json.load(f)
    except:
        metadata = []

    return df, metadata


def _load_from_local(local_path: Path, dataset: str) -> Tuple[pd.DataFrame, List[Dict]]:
    """Load from local files."""
    local_path = Path(local_path)

    # Find parquet file
    parquet_files = list(local_path.glob(f"**/*{dataset}*factorynet*.parquet"))
    if not parquet_files:
        parquet_files = list(local_path.glob("**/*.parquet"))

    if not parquet_files:
        raise FileNotFoundError(f"No parquet files found in {local_path}")

    df = pd.read_parquet(parquet_files[0])

    # Load metadata
    meta_files = list(local_path.glob(f"**/*{dataset}*metadata*.json"))
    if meta_files:
        with open(meta_files[0]) as f:
            metadata = json.load(f)
    else:
        metadata = []

    return df, metadata


def get_episode(df: pd.DataFrame, episode_id: str) -> pd.DataFrame:
    """Extract a single episode from the dataset."""
    return df[df["episode_id"] == episode_id].copy()


def get_episodes_by_fault(df: pd.DataFrame, metadata: List[Dict], fault_type: str) -> pd.DataFrame:
    """Get all episodes of a specific fault type."""
    fault_episodes = [m["episode_id"] for m in metadata if m.get("fault_type") == fault_type]
    return df[df["episode_id"].isin(fault_episodes)].copy()


def extract_features(df: pd.DataFrame, window_size: int = 100) -> np.ndarray:
    """
    Extract basic features for anomaly detection.

    Returns array of shape (n_windows, n_features).
    """
    # Get signal columns
    signal_cols = [c for c in df.columns if any(
        c.startswith(p) for p in ["setpoint_", "effort_", "feedback_"]
    )]

    data = df[signal_cols].values

    # Sliding window features
    n_windows = len(data) // window_size
    features = []

    for i in range(n_windows):
        window = data[i * window_size : (i + 1) * window_size]
        # Basic stats per column
        feat = np.concatenate([
            window.mean(axis=0),    # Mean
            window.std(axis=0),     # Std
            window.max(axis=0),     # Max
            window.min(axis=0),     # Min
            np.abs(np.diff(window, axis=0)).mean(axis=0),  # Mean absolute diff
        ])
        features.append(feat)

    return np.array(features)


def compute_causal_residual(df: pd.DataFrame, axis: int = 0) -> pd.Series:
    """
    Compute causal residual: effort that can't be explained by setpoint.

    High residual = anomaly (effort without command, or command without effort).
    """
    setpoint = df[f"setpoint_pos_{axis}"]
    effort = df[f"effort_torque_{axis}"] if f"effort_torque_{axis}" in df.columns else df[f"effort_current_{axis}"]

    # Simple approach: effort should correlate with setpoint change
    setpoint_diff = setpoint.diff().abs()
    effort_normalized = (effort - effort.mean()) / effort.std()

    # Residual: effort that doesn't match setpoint activity
    residual = effort_normalized - setpoint_diff / (setpoint_diff.max() + 1e-6)

    return residual


# Quick test
if __name__ == "__main__":
    print("Testing FactoryNet loader...")

    # Try local load
    try:
        df, meta = load_factorynet("aursad", from_hf=False,
                                    local_path=Path(__file__).parent.parent / "output" / "aursad_real")
        print(f"Loaded {len(df)} rows, {len(df.columns)} columns")
        print(f"Metadata for {len(meta)} episodes")
        print(f"Columns: {df.columns.tolist()[:10]}...")

        # Test feature extraction
        features = extract_features(df)
        print(f"Extracted features: {features.shape}")

    except Exception as e:
        print(f"Local load failed: {e}")
        print("Try: pip install datasets && load with from_hf=True")