"""Calendar TUI configuration."""

import os
from pathlib import Path
from typing import Optional

try:
    import toml
except ImportError:
    toml = None  # type: ignore


# Default configuration values
DEFAULT_CONFIG = {
    "display": {
        "work_day_start_hour": 7,  # 7 AM
        "work_day_end_hour": 19,  # 7 PM
        "include_weekends": True,
        "minutes_per_row": 30,
        "day_column_width": 20,
        "week_start_day": 0,  # 0=Sunday, 1=Monday, ..., 6=Saturday
    },
    "backend": {
        "type": "khal",  # khal, calcurse, etc.
        "calendar_path": "~/Calendar/corteva",
    },
    "theme": {
        "event_color": "blue",
        "overlap_color": "dark_orange",
        "cursor_style": "reverse",
        "work_hours_time_color": "blue",
        "off_hours_time_color": "bright_black",
    },
}


def get_config_path() -> Path:
    """Get the calendar config file path."""
    # Check XDG_CONFIG_HOME first, then fall back to ~/.config
    config_home = os.environ.get("XDG_CONFIG_HOME", os.path.expanduser("~/.config"))
    return Path(config_home) / "luk" / "calendar.toml"


def load_config() -> dict:
    """Load calendar configuration from TOML file.

    Returns merged config with defaults for any missing values.
    """
    config = DEFAULT_CONFIG.copy()

    config_path = get_config_path()
    if config_path.exists() and toml is not None:
        try:
            user_config = toml.load(config_path)
            # Deep merge user config into defaults
            for section, values in user_config.items():
                if section in config and isinstance(config[section], dict):
                    config[section].update(values)
                else:
                    config[section] = values
        except Exception:
            pass  # Use defaults on error

    return config


def get_display_config() -> dict:
    """Get display-related configuration."""
    return load_config().get("display", DEFAULT_CONFIG["display"])


def get_backend_config() -> dict:
    """Get backend-related configuration."""
    return load_config().get("backend", DEFAULT_CONFIG["backend"])


def get_theme_config() -> dict:
    """Get theme-related configuration."""
    return load_config().get("theme", DEFAULT_CONFIG["theme"])


# Convenience accessors
def work_day_start_hour() -> int:
    """Get the work day start hour (for initial scroll position)."""
    return get_display_config().get("work_day_start_hour", 7)


def work_day_end_hour() -> int:
    """Get the work day end hour."""
    return get_display_config().get("work_day_end_hour", 19)


def include_weekends_default() -> bool:
    """Get default for including weekends."""
    return get_display_config().get("include_weekends", True)


def minutes_per_row() -> int:
    """Get minutes per row (default 30)."""
    return get_display_config().get("minutes_per_row", 30)


def day_column_width() -> int:
    """Get day column width."""
    return get_display_config().get("day_column_width", 20)


def week_start_day() -> int:
    """Get the week start day (0=Sunday, 1=Monday, ..., 6=Saturday)."""
    return get_display_config().get("week_start_day", 0)