use crate::{config::Config, feat, log_err};
use anyhow::{bail, Result};
use once_cell::sync::OnceCell;
use parking_lot::Mutex;
use std::{collections::HashMap, sync::Arc};
use tauri::{AppHandle, GlobalShortcutManager};
use wry::application::accelerator::Accelerator;

pub struct Hotkey {
    current: Arc<Mutex<Vec<String>>>, // 保存当前的热键设置

    app_handle: Arc<Mutex<Option<AppHandle>>>,
}

impl Hotkey {
    pub fn global() -> &'static Hotkey {
        static HOTKEY: OnceCell<Hotkey> = OnceCell::new();

        HOTKEY.get_or_init(|| Hotkey {
            current: Arc::new(Mutex::new(Vec::new())),
            app_handle: Arc::new(Mutex::new(None)),
        })
    }

    pub fn init(&self, app_handle: AppHandle) -> Result<()> {
        *self.app_handle.lock() = Some(app_handle);

        let verge = Config::verge();

        if let Some(hotkeys) = verge.latest().hotkeys.as_ref() {
            for hotkey in hotkeys.iter() {
                let mut iter = hotkey.split(',');
                let func = iter.next();
                let key = iter.next();

                match (key, func) {
                    (Some(key), Some(func)) => {
                        log_err!(Self::check_key(key).and_then(|_| self.register(key, func)));
                    }
                    _ => {
                        let key = key.unwrap_or("None");
                        let func = func.unwrap_or("None");
                        log::error!(target: "app", "invalid hotkey `{key}`:`{func}`");
                    }
                }
            }
            *self.current.lock() = hotkeys.clone();
        }

        Ok(())
    }

    /// 检查一个键是否合法
    fn check_key(hotkey: &str) -> Result<()> {
        // fix #287
        // tauri的这几个方法全部有Result expect，会panic，先检测一遍避免挂了
        if hotkey.parse::<Accelerator>().is_err() {
            bail!("invalid hotkey `{hotkey}`");
        }
        Ok(())
    }

    fn get_manager(&self) -> Result<impl GlobalShortcutManager> {
        let app_handle = self.app_handle.lock();
        if app_handle.is_none() {
            bail!("failed to get the hotkey manager");
        }
        Ok(app_handle.as_ref().unwrap().global_shortcut_manager())
    }

    fn register(&self, hotkey: &str, func: &str) -> Result<()> {
        let mut manager = self.get_manager()?;

        if manager.is_registered(hotkey)? {
            manager.unregister(hotkey)?;
        }

        let f = match func.trim() {
            "clash_mode_rule" => || feat::change_clash_mode("rule".into()),
            "clash_mode_global" => || feat::change_clash_mode("global".into()),
            "clash_mode_direct" => || feat::change_clash_mode("direct".into()),
            "clash_mode_script" => || feat::change_clash_mode("script".into()),
            "toggle_system_proxy" => || feat::toggle_system_proxy(),
            "enable_system_proxy" => || feat::enable_system_proxy(),
            "disable_system_proxy" => || feat::disable_system_proxy(),
            "toggle_tun_mode" => || feat::toggle_tun_mode(),
            "enable_tun_mode" => || feat::enable_tun_mode(),
            "disable_tun_mode" => || feat::disable_tun_mode(),

            _ => bail!("invalid function \"{func}\""),
        };

        manager.register(hotkey, f)?;
        log::info!(target: "app", "register hotkey {hotkey} {func}");
        Ok(())
    }

    fn unregister(&self, hotkey: &str) -> Result<()> {
        self.get_manager()?.unregister(&hotkey)?;
        log::info!(target: "app", "unregister hotkey {hotkey}");
        Ok(())
    }

    pub fn update(&self, new_hotkeys: Vec<String>) -> Result<()> {
        let mut current = self.current.lock();
        let old_map = Self::get_map_from_vec(&current);
        let new_map = Self::get_map_from_vec(&new_hotkeys);

        let (del, add) = Self::get_diff(old_map, new_map);

        // 先检查一遍所有新的热键是不是可以用的
        for (hotkey, _) in add.iter() {
            Self::check_key(hotkey)?;
        }

        del.iter().for_each(|key| {
            let _ = self.unregister(key);
        });

        add.iter().for_each(|(key, func)| {
            log_err!(self.register(key, func));
        });

        *current = new_hotkeys;
        Ok(())
    }

    fn get_map_from_vec<'a>(hotkeys: &'a Vec<String>) -> HashMap<&'a str, &'a str> {
        let mut map = HashMap::new();

        hotkeys.iter().for_each(|hotkey| {
            let mut iter = hotkey.split(',');
            let func = iter.next();
            let key = iter.next();

            if func.is_some() && key.is_some() {
                let func = func.unwrap().trim();
                let key = key.unwrap().trim();
                map.insert(key, func);
            }
        });
        map
    }

    fn get_diff<'a>(
        old_map: HashMap<&'a str, &'a str>,
        new_map: HashMap<&'a str, &'a str>,
    ) -> (Vec<&'a str>, Vec<(&'a str, &'a str)>) {
        let mut del_list = vec![];
        let mut add_list = vec![];

        old_map.iter().for_each(|(&key, func)| {
            match new_map.get(key) {
                Some(new_func) => {
                    if new_func != func {
                        del_list.push(key);
                        add_list.push((key, *new_func));
                    }
                }
                None => del_list.push(key),
            };
        });

        new_map.iter().for_each(|(&key, &func)| {
            if old_map.get(key).is_none() {
                add_list.push((key, func));
            }
        });

        (del_list, add_list)
    }
}

impl Drop for Hotkey {
    fn drop(&mut self) {
        if let Ok(mut manager) = self.get_manager() {
            let _ = manager.unregister_all();
        }
    }
}
