use crate::config::*;
use crate::core::{clash_api, handle, logger::Logger, service};
use crate::log_err;
use crate::utils::dirs;
use anyhow::{bail, Result};
use once_cell::sync::OnceCell;
use parking_lot::Mutex;
use serde_yaml::Mapping;
use std::{sync::Arc, time::Duration};
use sysinfo::System;
use tauri::api::process::{Command, CommandChild, CommandEvent};
use tokio::time::sleep;

#[derive(Debug)]
pub struct CoreManager {
    sidecar: Arc<Mutex<Option<CommandChild>>>,

    #[allow(unused)]
    use_service_mode: Arc<Mutex<bool>>,
}

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

        CORE_MANAGER.get_or_init(|| CoreManager {
            sidecar: Arc::new(Mutex::new(None)),
            use_service_mode: Arc::new(Mutex::new(false)),
        })
    }

    pub fn init(&self) -> Result<()> {
        tauri::async_runtime::spawn(async {
            // 启动clash
            log_err!(Self::global().run_core().await);
        });

        Ok(())
    }

    /// 检查订阅是否正确
    pub fn check_config(&self) -> Result<()> {
        let config_path = Config::generate_file(ConfigType::Check)?;
        let config_path = dirs::path_to_str(&config_path)?;

        let clash_core = { Config::verge().latest().clash_core.clone() };
        let clash_core = clash_core.unwrap_or("clash".into());

        let app_dir = dirs::app_home_dir()?;
        let app_dir = dirs::path_to_str(&app_dir)?;

        let output = Command::new_sidecar(clash_core)?
            .args(["-t", "-d", app_dir, "-f", config_path])
            .output()?;

        if !output.status.success() {
            let error = clash_api::parse_check_output(output.stdout.clone());
            let error = match !error.is_empty() {
                true => error,
                false => output.stdout.clone(),
            };
            Logger::global().set_log(output.stdout);
            bail!("{error}");
        }

        Ok(())
    }

    /// 启动核心
    pub async fn run_core(&self) -> Result<()> {
        let config_path = Config::generate_file(ConfigType::Run)?;

        #[allow(unused_mut)]
        let mut should_kill = match self.sidecar.lock().take() {
            Some(_) => true,
            None => false,
        };

        // 关闭tun模式
        let mut disable = Mapping::new();
        let mut tun = Mapping::new();
        tun.insert("enable".into(), false.into());
        disable.insert("tun".into(), tun.into());
        log::debug!(target: "app", "disable tun mode");
        let _ = clash_api::patch_configs(&disable).await;

        let mut system = System::new();
        system.refresh_all();
        let procs = system.processes_by_name("verge-mihomo");
        for proc in procs {
            log::debug!(target: "app", "kill all clash process");
            proc.kill();
        }

        if *self.use_service_mode.lock() {
            log::debug!(target: "app", "stop the core by service");
            log_err!(service::stop_core_by_service().await);
            should_kill = true;
        }

        // 这里得等一会儿
        if should_kill {
            sleep(Duration::from_millis(500)).await;
        }

        // 服务模式
        let enable = { Config::verge().latest().enable_service_mode };
        let enable = enable.unwrap_or(false);

        *self.use_service_mode.lock() = enable;

        if enable {
            // 服务模式启动失败就直接运行sidecar
            log::debug!(target: "app", "try to run core in service mode");

            let res = async {
                service::check_service().await?;
                service::run_core_by_service(&config_path).await
            }
            .await;
            match res {
                Ok(_) => return Ok(()),
                Err(err) => {
                    // 修改这个值，免得stop出错
                    *self.use_service_mode.lock() = false;
                    log::error!(target: "app", "{err}");
                }
            }
        }

        let app_dir = dirs::app_home_dir()?;
        let app_dir = dirs::path_to_str(&app_dir)?;

        let clash_core = { Config::verge().latest().clash_core.clone() };
        let mut clash_core = clash_core.unwrap_or("verge-mihomo".into());

        // compatibility
        if clash_core.contains("clash") {
            clash_core = "verge-mihomo".to_string();
            Config::verge().draft().patch_config(IVerge {
                clash_core: Some("verge-mihomo".to_string()),
                ..IVerge::default()
            });
            Config::verge().apply();
            match Config::verge().data().save_file() {
                Ok(_) => handle::Handle::refresh_verge(),
                Err(err) => log::error!(target: "app", "{err}"),
            }
        }

        let config_path = dirs::path_to_str(&config_path)?;

        let args = vec!["-d", app_dir, "-f", config_path];

        let cmd = Command::new_sidecar(clash_core)?;
        let (mut rx, cmd_child) = cmd.args(args).spawn()?;

        let mut sidecar = self.sidecar.lock();
        *sidecar = Some(cmd_child);
        drop(sidecar);

        tauri::async_runtime::spawn(async move {
            while let Some(event) = rx.recv().await {
                match event {
                    CommandEvent::Stdout(line) => {
                        log::info!(target: "app", "[mihomo]: {line}");
                        Logger::global().set_log(line);
                    }
                    CommandEvent::Stderr(err) => {
                        log::error!(target: "app", "[mihomo]: {err}");
                        Logger::global().set_log(err);
                    }
                    CommandEvent::Error(err) => {
                        log::error!(target: "app", "[mihomo]: {err}");
                        Logger::global().set_log(err);
                    }
                    CommandEvent::Terminated(_) => {
                        log::info!(target: "app", "mihomo core terminated");
                        let _ = CoreManager::global().recover_core();
                        break;
                    }
                    _ => {}
                }
            }
        });

        Ok(())
    }

    /// 重启内核
    pub fn recover_core(&'static self) -> Result<()> {
        // 服务模式不管
        if *self.use_service_mode.lock() {
            return Ok(());
        }

        // 清空原来的sidecar值
        let _ = self.sidecar.lock().take();

        tauri::async_runtime::spawn(async move {
            // 6秒之后再查看服务是否正常 (时间随便搞的)
            // terminated 可能是切换内核 (切换内核已经有500ms的延迟)
            sleep(Duration::from_millis(6666)).await;

            if self.sidecar.lock().is_none() {
                log::info!(target: "app", "recover clash core");

                // 重新启动app
                if let Err(err) = self.run_core().await {
                    log::error!(target: "app", "failed to recover clash core");
                    log::error!(target: "app", "{err}");

                    let _ = self.recover_core();
                }
            }
        });

        Ok(())
    }

    /// 停止核心运行
    pub fn stop_core(&self) -> Result<()> {
        // 关闭tun模式
        tauri::async_runtime::block_on(async move {
            let mut disable = Mapping::new();
            let mut tun = Mapping::new();
            tun.insert("enable".into(), false.into());
            disable.insert("tun".into(), tun.into());
            log::debug!(target: "app", "disable tun mode");
            let _ = clash_api::patch_configs(&disable).await;
        });

        if *self.use_service_mode.lock() {
            log::debug!(target: "app", "stop the core by service");
            tauri::async_runtime::block_on(async move {
                log_err!(service::stop_core_by_service().await);
            });
            return Ok(());
        }

        let mut sidecar = self.sidecar.lock();
        let _ = sidecar.take();

        let mut system = System::new();
        system.refresh_all();
        let procs = system.processes_by_name("verge-mihomo");
        for proc in procs {
            log::debug!(target: "app", "kill all clash process");
            proc.kill();
        }
        Ok(())
    }

    /// 切换核心
    pub async fn change_core(&self, clash_core: Option<String>) -> Result<()> {
        let clash_core = clash_core.ok_or(anyhow::anyhow!("clash core is null"))?;
        const CLASH_CORES: [&str; 2] = ["verge-mihomo", "verge-mihomo-alpha"];

        if !CLASH_CORES.contains(&clash_core.as_str()) {
            bail!("invalid clash core name \"{clash_core}\"");
        }

        log::debug!(target: "app", "change core to `{clash_core}`");

        Config::verge().draft().clash_core = Some(clash_core);

        // 更新订阅
        Config::generate()?;

        self.check_config()?;

        // 清掉旧日志
        Logger::global().clear_log();

        match self.run_core().await {
            Ok(_) => {
                Config::verge().apply();
                Config::runtime().apply();
                log_err!(Config::verge().latest().save_file());
                Ok(())
            }
            Err(err) => {
                Config::verge().discard();
                Config::runtime().discard();
                Err(err)
            }
        }
    }

    /// 更新proxies那些
    /// 如果涉及端口和外部控制则需要重启
    pub async fn update_config(&self) -> Result<()> {
        log::debug!(target: "app", "try to update clash config");

        // 更新订阅
        Config::generate()?;

        // 检查订阅是否正常
        self.check_config()?;

        // 更新运行时订阅
        let path = Config::generate_file(ConfigType::Run)?;
        let path = dirs::path_to_str(&path)?;

        // 发送请求 发送5次
        for i in 0..5 {
            match clash_api::put_configs(path).await {
                Ok(_) => break,
                Err(err) => {
                    if i < 4 {
                        log::info!(target: "app", "{err}");
                    } else {
                        bail!(err);
                    }
                }
            }
            sleep(Duration::from_millis(250)).await;
        }

        Ok(())
    }
}