"""Simplified HDF5 storage for data persistence."""
import os
import pandas as pd
from pathlib import Path
from typing import Optional
from src.data.config import get_config


class Storage:
    """HDF5 storage manager for saving and loading data."""

    def __init__(self, path: Optional[Path] = None):
        """Initialize storage.

        Args:
            path: Base path for data storage (auto-loaded from config if not provided)
        """
        cfg = get_config()
        self.base_path = path or cfg.data_path_resolved
        self.base_path.mkdir(parents=True, exist_ok=True)

    def _get_file_path(self, name: str) -> Path:
        """Get full path for an HDF5 file."""
        return self.base_path / f"{name}.h5"

    def save(self, name: str, data: pd.DataFrame, mode: str = "append") -> dict:
        """Save data to HDF5 file.

        Args:
            name: Dataset name (also used as filename)
            data: DataFrame to save
            mode: 'append' or 'replace'

        Returns:
            Dict with save result
        """
        if data.empty:
            return {"status": "skipped", "rows": 0}

        file_path = self._get_file_path(name)

        try:
            with pd.HDFStore(file_path, mode="a") as store:
                if mode == "replace" or name not in store.keys():
                    store.put(name, data, format="table")
                else:
                    # Merge with existing data
                    existing = store[name]
                    combined = pd.concat([existing, data], ignore_index=True)
                    combined = combined.drop_duplicates(subset=["ts_code", "trade_date"], keep="last")
                    store.put(name, combined, format="table")

            print(f"[Storage] Saved {len(data)} rows to {file_path}")
            return {"status": "success", "rows": len(data), "path": str(file_path)}

        except Exception as e:
            print(f"[Storage] Error saving {name}: {e}")
            return {"status": "error", "error": str(e)}

    def load(self, name: str,
             start_date: Optional[str] = None,
             end_date: Optional[str] = None,
             ts_code: Optional[str] = None) -> pd.DataFrame:
        """Load data from HDF5 file.

        Args:
            name: Dataset name
            start_date: Start date filter (YYYYMMDD)
            end_date: End date filter (YYYYMMDD)
            ts_code: Stock code filter

        Returns:
            DataFrame with loaded data
        """
        file_path = self._get_file_path(name)

        if not file_path.exists():
            print(f"[Storage] File not found: {file_path}")
            return pd.DataFrame()

        try:
            with pd.HDFStore(file_path, mode="r") as store:
                if name not in store.keys():
                    return pd.DataFrame()

                data = store[name]

                # Apply filters
                if start_date and end_date and "trade_date" in data.columns:
                    data = data[(data["trade_date"] >= start_date) & (data["trade_date"] <= end_date)]

                if ts_code and "ts_code" in data.columns:
                    data = data[data["ts_code"] == ts_code]

                return data

        except Exception as e:
            print(f"[Storage] Error loading {name}: {e}")
            return pd.DataFrame()

    def get_last_date(self, name: str) -> Optional[str]:
        """Get the latest date in storage.

        Args:
            name: Dataset name

        Returns:
            Latest date string or None
        """
        data = self.load(name)
        if data.empty or "trade_date" not in data.columns:
            return None
        return str(data["trade_date"].max())

    def exists(self, name: str) -> bool:
        """Check if dataset exists."""
        return self._get_file_path(name).exists()

    def delete(self, name: str) -> bool:
        """Delete a dataset.

        Args:
            name: Dataset name

        Returns:
            True if deleted
        """
        file_path = self._get_file_path(name)
        if file_path.exists():
            file_path.unlink()
            print(f"[Storage] Deleted {file_path}")
            return True
        return False