use std::fs;
use std::path::PathBuf;
use tauri::{AppHandle, Manager};

const SERVICE: &str = "app.pipu.music.desktop";

fn config_dir(app: &AppHandle) -> Result<PathBuf, String> {
    let dir = app.path().app_config_dir().map_err(|e| e.to_string())?;
    fs::create_dir_all(&dir).map_err(|e| e.to_string())?;
    Ok(dir)
}

pub fn load_server(app: &AppHandle) -> Result<Option<String>, String> {
    let path = config_dir(app)?.join("server.txt");
    match fs::read_to_string(path) {
        Ok(s) => {
            let s = s.trim().to_string();
            Ok((!s.is_empty()).then_some(s))
        }
        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(None),
        Err(e) => Err(e.to_string()),
    }
}

pub fn save_server(app: &AppHandle, server: Option<&str>) -> Result<(), String> {
    let path = config_dir(app)?.join("server.txt");
    match server {
        Some(s) => fs::write(path, s).map_err(|e| e.to_string()),
        None => match fs::remove_file(path) {
            Ok(()) => Ok(()),
            Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(()),
            Err(e) => Err(e.to_string()),
        },
    }
}

fn refresh_entry() -> Result<keyring::Entry, String> {
    keyring::Entry::new(SERVICE, "refresh").map_err(|e| e.to_string())
}

pub fn load_refresh() -> Result<Option<String>, String> {
    match refresh_entry()?.get_password() {
        Ok(s) => Ok(Some(s)),
        Err(keyring::Error::NoEntry) => Ok(None),
        Err(e) => Err(e.to_string()),
    }
}

pub fn save_refresh(token: Option<&str>) -> Result<(), String> {
    let entry = refresh_entry()?;
    match token {
        Some(t) => entry.set_password(t).map_err(|e| e.to_string()),
        None => match entry.delete_credential() {
            Ok(()) => Ok(()),
            Err(keyring::Error::NoEntry) => Ok(()),
            Err(e) => Err(e.to_string()),
        },
    }
}

pub fn load_user(app: &AppHandle) -> Result<Option<String>, String> {
    let path = config_dir(app)?.join("user.json");
    match fs::read_to_string(path) {
        Ok(s) => Ok(Some(s)),
        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(None),
        Err(e) => Err(e.to_string()),
    }
}

pub fn save_user(app: &AppHandle, json: Option<&str>) -> Result<(), String> {
    let path = config_dir(app)?.join("user.json");
    match json {
        Some(s) => fs::write(path, s).map_err(|e| e.to_string()),
        None => match fs::remove_file(path) {
            Ok(()) => Ok(()),
            Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(()),
            Err(e) => Err(e.to_string()),
        },
    }
}