"""
General project settings: visualisation, paths, constants
"""

import warnings
import matplotlib.pyplot as plt
import seaborn as sns
from pathlib import Path
from typing import Dict, Any, Optional
import yaml
import json
import os

# ============================================================================
# PATHS AND DIRECTORIES
# ============================================================================

PROJECT_ROOT = Path(__file__).parent.parent.parent
DATA_DIR = PROJECT_ROOT / "data"
RAW_DATA_DIR = DATA_DIR / "raw"
PROCESSED_DATA_DIR = DATA_DIR / "processed"
EXTERNAL_DATA_DIR = DATA_DIR / "external"

RESULTS_DIR = PROJECT_ROOT / "results"
PLOTS_DIR = RESULTS_DIR / "plots"
MODELS_DIR = RESULTS_DIR / "models"
REPORTS_DIR = RESULTS_DIR / "reports"
LOGS_DIR = RESULTS_DIR / "logs"

CONFIGS_DIR = PROJECT_ROOT / "configs"
NOTEBOOKS_DIR = PROJECT_ROOT / "notebooks"
TESTS_DIR = PROJECT_ROOT / "tests"

# Create directories on import
for directory in [RAW_DATA_DIR, PROCESSED_DATA_DIR, EXTERNAL_DATA_DIR,
                  PLOTS_DIR, MODELS_DIR, REPORTS_DIR, LOGS_DIR]:
    directory.mkdir(parents=True, exist_ok=True)

# ============================================================================
# VISUALISATION SETTINGS
# ============================================================================

def setup_visualization(
    style: str = "seaborn-whitegrid",
    palette: str = "husl",
    context: str = "notebook",
    font_scale: float = 1.0,
    dpi: int = 150,
    figsize: tuple = (12, 6),
    **kwargs
):
    """
    Configure visualisation parameters for matplotlib and seaborn
    
    Parameters:
    -----------
    style : str
        Matplotlib style: 'seaborn-whitegrid', 'ggplot', 'bmh', 'dark_background'
    palette : str
        Seaborn palette: 'husl', 'Set2', 'viridis', 'mako'
    context : str
        Seaborn context: 'paper', 'notebook', 'talk', 'poster'
    font_scale : float
        Font scale
    dpi : int
        Plot resolution
    figsize : tuple
        Default figure size
    """
    # Ignore warnings
    warnings.filterwarnings('ignore')
    
    # Matplotlib settings
    plt.style.use(style)
    
    # RC parameters
    rc_params = {
        'font.size': 10,
        'figure.figsize': figsize,
        'figure.dpi': dpi,
        'savefig.dpi': 300,
        'savefig.bbox': 'tight',
        'savefig.format': 'png',
        'axes.titlesize': 12,
        'axes.labelsize': 10,
        'xtick.labelsize': 9,
        'ytick.labelsize': 9,
        'legend.fontsize': 9,
        'font.family': ['DejaVu Sans', 'Arial', 'sans-serif'],
        'figure.titlesize': 14,
        'axes.grid': True,
        'grid.alpha': 0.3,
        'lines.linewidth': 1.5,
        'lines.markersize': 6,
        'patch.edgecolor': 'black',
        'patch.force_edgecolor': True,
        'xtick.top': False,
        'ytick.right': False,
        'axes.spines.top': False,
        'axes.spines.right': False
    }
    
    # Update additional parameters
    rc_params.update(kwargs)
    plt.rcParams.update(rc_params)
    
    # Seaborn settings
    sns.set_style(style.replace('seaborn-', ''))
    sns.set_palette(palette)
    sns.set_context(context, font_scale=font_scale)
    
    print(f"✓ Visualisation settings applied: style={style}, palette={palette}")


def get_color_palette(name: str = "husl", n_colors: int = 8) -> list:
    """
    Get colour palette
    
    Parameters:
    -----------
    name : str
        Palette name
    n_colors : int
        Number of colours
    
    Returns:
    --------
    list
        List of colours in HEX format
    """
    palette_map = {
        "husl": sns.color_palette("husl", n_colors),
        "Set2": sns.color_palette("Set2", n_colors),
        "Set3": sns.color_palette("Set3", n_colors),
        "viridis": sns.color_palette("viridis", n_colors),
        "plasma": sns.color_palette("plasma", n_colors),
        "coolwarm": sns.color_palette("coolwarm", n_colors),
        "RdYlBu": sns.color_palette("RdYlBu", n_colors),
        "Spectral": sns.color_palette("Spectral", n_colors),
        "tab10": sns.color_palette("tab10", n_colors),
        "tab20": sns.color_palette("tab20", n_colors),
    }
    
    palette = palette_map.get(name, sns.color_palette("husl", n_colors))
    return [f"#{int(r*255):02x}{int(g*255):02x}{int(b*255):02x}" 
            for r, g, b in palette]


# ============================================================================
# CONSTANTS
# ============================================================================

# Data types
DATETIME_FORMATS = [
    "%Y-%m-%d", "%Y/%m/%d", "%d.%m.%Y", "%d/%m/%Y",
    "%Y-%m-%d %H:%M:%S", "%Y/%m/%d %H:%M:%S",
    "%d.%m.%Y %H:%M:%S", "%d/%m/%Y %H:%M:%S"
]

# Metrics
METRICS = {
    "regression": ["mse", "rmse", "mae", "mape", "r2", "explained_variance"],
    "classification": ["accuracy", "precision", "recall", "f1", "roc_auc"]
}

# Statistical constants
STATS_CONSTANTS = {
    "confidence_levels": [0.9, 0.95, 0.99],
    "z_scores": {0.9: 1.645, 0.95: 1.96, 0.99: 2.576},
    "outlier_multipliers": {"mild": 1.5, "extreme": 3.0}
}

# Time series parameters
TIME_SERIES_CONSTANTS = {
    "frequencies": {
        "H": "hourly",
        "D": "daily", 
        "W": "weekly",
        "M": "monthly",
        "Q": "quarterly",
        "Y": "yearly"
    },
    "seasonal_periods": {
        "hourly": 24,
        "daily": 7,
        "weekly": 52,
        "monthly": 12,
        "quarterly": 4,
        "yearly": 1
    }
}

# ============================================================================
# CONFIGURATION UTILITIES
# ============================================================================

def load_config(config_path: Optional[str] = None) -> Dict[str, Any]:
    """
    Load configuration from file
    
    Parameters:
    -----------
    config_path : str, optional
        Path to configuration file
    
    Returns:
    --------
    Dict[str, Any]
        Configuration dictionary
    """
    if config_path is None:
        config_path = CONFIGS_DIR / "default_config.json"
    
    config_path = Path(config_path)
    
    if not config_path.exists():
        print(f"⚠ Configuration file not found: {config_path}")
        return {}
    
    # Determine file format
    if config_path.suffix.lower() in ['.json']:
        with open(config_path, 'r', encoding='utf-8') as f:
            config = json.load(f)
    elif config_path.suffix.lower() in ['.yaml', '.yml']:
        with open(config_path, 'r', encoding='utf-8') as f:
            config = yaml.safe_load(f)
    else:
        raise ValueError(f"Unsupported file format: {config_path.suffix}")
    
    print(f"✓ Configuration loaded from: {config_path}")
    return config


def save_config(config: Dict[str, Any], config_path: str) -> None:
    """
    Save configuration to file
    
    Parameters:
    -----------
    config : Dict[str, Any]
        Configuration to save
    config_path : str
        Save path
    """
    config_path = Path(config_path)
    config_path.parent.mkdir(parents=True, exist_ok=True)
    
    # Determine format
    if config_path.suffix.lower() in ['.json']:
        with open(config_path, 'w', encoding='utf-8') as f:
            json.dump(config, f, indent=2, ensure_ascii=False)
    elif config_path.suffix.lower() in ['.yaml', '.yml']:
        with open(config_path, 'w', encoding='utf-8') as f:
            yaml.dump(config, f, default_flow_style=False, allow_unicode=True)
    else:
        raise ValueError(f"Unsupported file format: {config_path.suffix}")
    
    print(f"✓ Configuration saved to: {config_path}")


def merge_configs(base_config: Dict[str, Any], 
                  override_config: Dict[str, Any]) -> Dict[str, Any]:
    """
    Recursive configuration merging
    
    Parameters:
    -----------
    base_config : Dict[str, Any]
        Base configuration
    override_config : Dict[str, Any]
        Override configuration
    
    Returns:
    --------
    Dict[str, Any]
        Merged configuration
    """
    result = base_config.copy()
    
    for key, value in override_config.items():
        if (key in result and isinstance(result[key], dict) 
            and isinstance(value, dict)):
            result[key] = merge_configs(result[key], value)
        else:
            result[key] = value
    
    return result


# ============================================================================
# ENVIRONMENT SETUP
# ============================================================================

def setup_environment(
    log_level: str = "INFO",
    random_seed: int = 42,
    enable_warnings: bool = False,
    memory_limit_gb: Optional[int] = None
) -> None:
    """
    Set up environment for reproducibility
    
    Parameters:
    -----------
    log_level : str
        Logging level
    random_seed : int
        Seed for random generators
    enable_warnings : bool
        Enable warnings
    memory_limit_gb : int, optional
        Memory limit in GB
    """
    import numpy as np
    import random
    import torch
    import tensorflow as tf
    
    # Set seeds
    np.random.seed(random_seed)
    random.seed(random_seed)
    
    try:
        torch.manual_seed(random_seed)
    except:
        pass
    
    try:
        tf.random.set_seed(random_seed)
    except:
        pass
    
    # Configure warnings
    if enable_warnings:
        warnings.filterwarnings('default')
    else:
        warnings.filterwarnings('ignore')
    
    # Memory limit (if specified)
    if memory_limit_gb:
        import resource
        soft, hard = resource.getrlimit(resource.RLIMIT_AS)
        memory_limit = memory_limit_gb * 1024**3  # GB to bytes
        resource.setrlimit(resource.RLIMIT_AS, (memory_limit, hard))
        print(f"✓ Memory limit set: {memory_limit_gb} GB")
    
    print(f"✓ Environment configured. Random seed: {random_seed}")


# ============================================================================
# AUTOMATIC SETUP ON IMPORT
# ============================================================================

# Automatically apply visualisation settings
setup_visualization()

# Export useful variables
__all__ = [
    'setup_visualization',
    'get_color_palette',
    'load_config',
    'save_config',
    'merge_configs',
    'setup_environment',
    'PROJECT_ROOT',
    'DATA_DIR',
    'RAW_DATA_DIR',
    'PROCESSED_DATA_DIR',
    'RESULTS_DIR',
    'PLOTS_DIR',
    'DATETIME_FORMATS',
    'METRICS',
    'STATS_CONSTANTS',
    'TIME_SERIES_CONSTANTS'
]