use serde::{Deserialize, Serialize};
use anyhow::Result;
use std::fs;
use std::path::PathBuf;

#[derive(Debug, Deserialize, Serialize, Clone)]
pub struct Config {
    pub server_url: String,
    pub timeout_sec: u64,
    #[serde(default = "default_theme")]
    pub theme: Theme,
    #[serde(default)]
    pub update_api: Option<String>,
}

#[derive(Debug, Deserialize, Serialize, Clone)]
pub struct Theme {
    #[serde(default = "default_selected_bg")]
    pub selected_bg: String,
}

fn default_selected_bg() -> String {
    "blue".to_string()
}

fn default_theme() -> Theme {
    Theme {
        selected_bg: default_selected_bg(),
    }
}

impl Config {
    pub fn load() -> Result<Self> {
        // Respect XDG_CONFIG_HOME; fall back to ~/.config on all platforms.
        let config_base = std::env::var("XDG_CONFIG_HOME")
            .map(PathBuf::from)
            .unwrap_or_else(|_| {
                dirs::home_dir()
                    .unwrap_or_else(|| PathBuf::from("."))
                    .join(".config")
            });
        let config_path = config_base
            .join(env!("CARGO_PKG_NAME"))
            .join("config.toml");

        if !config_path.exists() {
            let default = Config {
                server_url: "http://localhost:8080/api/menu".to_string(),
                timeout_sec: 10,
                theme: default_theme(),
                update_api: None,
            };
            fs::create_dir_all(config_path.parent().unwrap())?;
            fs::write(config_path, toml::to_string_pretty(&default)?)?;
            return Ok(default);
        }

        let content = fs::read_to_string(config_path)?;
        Ok(toml::from_str(&content)?)
    }
}