import json
import os
from typing import Any, Dict, List, Optional

import app.utils.paths as paths


class Theme:
    def __init__(self, name: str, colors: Dict[str, str]) -> None:
        self.name: str = name
        self.colors: Dict[str, str] = colors

    def get_color(self, element: str) -> str:
        return self.colors.get(element, "#FFFFFF")


class ThemeManager:
    def __init__(self) -> None:
        theme_path: str = os.path.join(paths.get_data_dir(), "themes")
        base_theme_path: str = os.path.join(theme_path, "base.qss")

        with open(base_theme_path, "r", encoding="utf-8") as theme_file:
            self.base_sheet: str = theme_file.read()

        self.themes: List[Theme] = []
        for theme_file in sorted(os.listdir(theme_path)):
            if not theme_file.endswith(".json"):
                continue

            with open(os.path.join(theme_path, theme_file), "r", encoding="utf-8") as file:
                theme_data: Dict[str, Any] = json.load(file)
                self.themes.append(Theme(theme_data["theme_name"], theme_data["colors"]))

        self.current_theme: Theme = self.themes[0]

    def set_theme(self, theme: str) -> None:
        if theme != self.current_theme.name:
            found_theme: Optional[Theme] = next(
                (available_theme for available_theme in self.themes if available_theme.name == theme),
                None,
            )
            if found_theme:
                self.current_theme = found_theme

    def get_theme(self) -> Theme:
        return self.current_theme

    def get_themes(self) -> List[Theme]:
        return self.themes

    def get_sheet(self) -> str:
        sheet: str = self.base_sheet
        for color_name, color_value in self.current_theme.colors.items():
            sheet = sheet.replace("{{" + color_name + "}}", color_value)
        return sheet