use crate::client_api_connection::*;
use crate::settings::Settings;
use crate::tools::*;
use crate::ui::*;
use std::net::SocketAddr;
use std::time::SystemTime;
use veilid_tools::*;

pub fn convert_loglevel(s: &str) -> Result<String, String> {
    match s.to_ascii_lowercase().as_str() {
        "off" => Ok("Off".to_owned()),
        "error" => Ok("Error".to_owned()),
        "warn" => Ok("Warn".to_owned()),
        "info" => Ok("Info".to_owned()),
        "debug" => Ok("Debug".to_owned()),
        "trace" => Ok("Trace".to_owned()),
        _ => Err(format!("Invalid log level: {}", s)),
    }
}

#[derive(PartialEq, Clone)]
pub enum ConnectionState {
    Disconnected,
    Connected(SocketAddr, SystemTime),
    Retrying(SocketAddr, SystemTime),
}
impl ConnectionState {
    pub fn is_disconnected(&self) -> bool {
        matches!(*self, Self::Disconnected)
    }
    pub fn is_connected(&self) -> bool {
        matches!(*self, Self::Connected(_, _))
    }
    pub fn is_retrying(&self) -> bool {
        matches!(*self, Self::Retrying(_, _))
    }
}

struct CommandProcessorInner {
    ui_sender: UISender,
    capi: Option<ClientApiConnection>,
    reconnect: bool,
    finished: bool,
    autoconnect: bool,
    autoreconnect: bool,
    server_addr: Option<SocketAddr>,
    connection_waker: Eventual,
    last_call_id: Option<u64>,
    enable_app_messages: bool,
}

#[derive(Clone)]
pub struct CommandProcessor {
    inner: Arc<Mutex<CommandProcessorInner>>,
}

impl CommandProcessor {
    pub fn new(ui_sender: UISender, settings: &Settings) -> Self {
        Self {
            inner: Arc::new(Mutex::new(CommandProcessorInner {
                ui_sender,
                capi: None,
                reconnect: settings.autoreconnect,
                finished: false,
                autoconnect: settings.autoconnect,
                autoreconnect: settings.autoreconnect,
                server_addr: None,
                connection_waker: Eventual::new(),
                last_call_id: None,
                enable_app_messages: false,
            })),
        }
    }
    pub fn set_client_api_connection(&self, capi: ClientApiConnection) {
        self.inner.lock().capi = Some(capi);
    }
    fn inner(&self) -> MutexGuard<CommandProcessorInner> {
        self.inner.lock()
    }
    fn inner_mut(&self) -> MutexGuard<CommandProcessorInner> {
        self.inner.lock()
    }
    fn ui_sender(&self) -> UISender {
        self.inner.lock().ui_sender.clone()
    }
    fn capi(&self) -> ClientApiConnection {
        self.inner.lock().capi.as_ref().unwrap().clone()
    }

    fn word_split(line: &str) -> (String, Option<String>) {
        let trimmed = line.trim();
        if let Some(p) = trimmed.find(char::is_whitespace) {
            let first = trimmed[0..p].to_owned();
            let rest = trimmed[p..].trim_start().to_owned();
            (first, Some(rest))
        } else {
            (trimmed.to_owned(), None)
        }
    }

    pub fn cancel_command(&self) {
        trace!("CommandProcessor::cancel_command");
        let capi = self.capi();
        capi.cancel_all();
    }

    pub fn cmd_help(&self, _rest: Option<String>, callback: UICallback) -> Result<(), String> {
        trace!("CommandProcessor::cmd_help");
        self.ui_sender().add_node_event(
            Level::Info,
            r#"Commands:
exit/quit                           exit the client
disconnect                          disconnect the client from the Veilid node 
shutdown                            shut the server down
attach                              attach the server to the Veilid network
detach                              detach the server from the Veilid network
debug [command]                     send a debugging command to the Veilid server
change_log_level <layer> <level>    change the log level for a tracing layer
                                    layers include: 
                                       all, terminal, system, api, file, otlp
                                    levels include:
                                       error, warn, info, debug, trace
reply <call id> <message>           reply to an AppCall not handled directly by the server
                                    <call id> must be exact call id reported in VeilidUpdate
                                    <message> can be a string (left trimmed) or
                                    it can start with a '#' followed by a string of undelimited hex bytes
enable [flag]                       set a flag
disable [flag]                      unset a flag
                                    valid flags in include:
                                       app_messages
"#
            .to_owned(),
        );
        let ui = self.ui_sender();
        ui.send_callback(callback);
        Ok(())
    }

    pub fn cmd_exit(&self, callback: UICallback) -> Result<(), String> {
        trace!("CommandProcessor::cmd_exit");
        let ui = self.ui_sender();
        ui.send_callback(callback);
        ui.quit();
        Ok(())
    }

    pub fn cmd_shutdown(&self, callback: UICallback) -> Result<(), String> {
        trace!("CommandProcessor::cmd_shutdown");
        let capi = self.capi();
        let ui = self.ui_sender();
        spawn_detached_local(async move {
            if let Err(e) = capi.server_shutdown().await {
                error!("Server command 'shutdown' failed to execute: {}", e);
            }
            ui.send_callback(callback);
        });
        Ok(())
    }

    pub fn cmd_attach(&self, callback: UICallback) -> Result<(), String> {
        trace!("CommandProcessor::cmd_attach");
        let capi = self.capi();
        let ui = self.ui_sender();
        spawn_detached_local(async move {
            if let Err(e) = capi.server_attach().await {
                error!("Server command 'attach' failed: {}", e);
            }
            ui.send_callback(callback);
        });
        Ok(())
    }

    pub fn cmd_detach(&self, callback: UICallback) -> Result<(), String> {
        trace!("CommandProcessor::cmd_detach");
        let capi = self.capi();
        let ui = self.ui_sender();
        spawn_detached_local(async move {
            if let Err(e) = capi.server_detach().await {
                error!("Server command 'detach' failed: {}", e);
            }
            ui.send_callback(callback);
        });
        Ok(())
    }

    pub fn cmd_disconnect(&self, callback: UICallback) -> Result<(), String> {
        trace!("CommandProcessor::cmd_disconnect");
        let capi = self.capi();
        let ui = self.ui_sender();
        spawn_detached_local(async move {
            capi.disconnect().await;
            ui.send_callback(callback);
        });
        Ok(())
    }

    pub fn cmd_debug(&self, rest: Option<String>, callback: UICallback) -> Result<(), String> {
        trace!("CommandProcessor::cmd_debug");
        let capi = self.capi();
        let ui = self.ui_sender();
        spawn_detached_local(async move {
            match capi.server_debug(rest.unwrap_or_default()).await {
                Ok(output) => {
                    ui.add_node_event(Level::Info, output);
                    ui.send_callback(callback);
                }
                Err(e) => {
                    ui.add_node_event(Level::Error, e.to_string());
                    ui.send_callback(callback);
                }
            }
        });
        Ok(())
    }

    pub fn cmd_change_log_level(
        &self,
        rest: Option<String>,
        callback: UICallback,
    ) -> Result<(), String> {
        trace!("CommandProcessor::cmd_change_log_level");
        let capi = self.capi();
        let ui = self.ui_sender();
        spawn_detached_local(async move {
            let (layer, rest) = Self::word_split(&rest.unwrap_or_default());
            let log_level = match convert_loglevel(&rest.unwrap_or_default()) {
                Ok(v) => v,
                Err(e) => {
                    ui.add_node_event(Level::Error, format!("Failed to change log level: {}", e));
                    ui.send_callback(callback);
                    return;
                }
            };

            match capi.server_change_log_level(layer, log_level).await {
                Ok(()) => {
                    ui.display_string_dialog("Success", "Log level changed", callback);
                }
                Err(e) => {
                    ui.display_string_dialog(
                        "Server command 'change_log_level' failed",
                        e.to_string(),
                        callback,
                    );
                }
            }
        });
        Ok(())
    }

    pub fn cmd_reply(&self, rest: Option<String>, callback: UICallback) -> Result<(), String> {
        trace!("CommandProcessor::cmd_reply");

        let capi = self.capi();
        let ui = self.ui_sender();
        let some_last_id = self.inner_mut().last_call_id.take();
        spawn_detached_local(async move {
            let (first, second) = Self::word_split(&rest.clone().unwrap_or_default());
            let (id, msg) = if let Some(second) = second {
                let id = match u64::from_str(&first) {
                    Err(e) => {
                        ui.add_node_event(Level::Error, format!("invalid appcall id: {}", e));
                        ui.send_callback(callback);
                        return;
                    }
                    Ok(v) => v,
                };
                (id, second)
            } else {
                let id = match some_last_id {
                    None => {
                        ui.add_node_event(Level::Error, "must specify last call id".to_owned());
                        ui.send_callback(callback);
                        return;
                    }
                    Some(v) => v,
                };
                (id, rest.unwrap_or_default())
            };
            let msg = if msg[0..1] == "#".to_owned() {
                match hex::decode(msg[1..].as_bytes().to_vec()) {
                    Err(e) => {
                        ui.add_node_event(Level::Error, format!("invalid hex message: {}", e));
                        ui.send_callback(callback);
                        return;
                    }
                    Ok(v) => v,
                }
            } else {
                msg[1..].as_bytes().to_vec()
            };
            let msglen = msg.len();
            match capi.server_appcall_reply(id, msg).await {
                Ok(()) => {
                    ui.add_node_event(
                        Level::Info,
                        format!("reply sent to {} : {} bytes", id, msglen),
                    );
                    ui.send_callback(callback);
                    return;
                }
                Err(e) => {
                    ui.display_string_dialog(
                        "Server command 'appcall_reply' failed",
                        e.to_string(),
                        callback,
                    );
                }
            }
        });
        Ok(())
    }

    pub fn cmd_enable(&self, rest: Option<String>, callback: UICallback) -> Result<(), String> {
        trace!("CommandProcessor::cmd_enable");

        let ui = self.ui_sender();
        let this = self.clone();
        spawn_detached_local(async move {
            let flag = rest.clone().unwrap_or_default();
            match flag.as_str() {
                "app_messages" => {
                    this.inner.lock().enable_app_messages = true;
                    ui.add_node_event(Level::Info, format!("flag enabled: {}", flag));
                    ui.send_callback(callback);
                }
                _ => {
                    ui.add_node_event(Level::Error, format!("unknown flag: {}", flag));
                    ui.send_callback(callback);
                    return;
                }
            }
        });
        Ok(())
    }

    pub fn cmd_disable(&self, rest: Option<String>, callback: UICallback) -> Result<(), String> {
        trace!("CommandProcessor::cmd_disable");

        let ui = self.ui_sender();
        let this = self.clone();
        spawn_detached_local(async move {
            let flag = rest.clone().unwrap_or_default();
            match flag.as_str() {
                "app_messages" => {
                    this.inner.lock().enable_app_messages = false;
                    ui.add_node_event(Level::Info, format!("flag disabled: {}", flag));
                    ui.send_callback(callback);
                }
                _ => {
                    ui.add_node_event(Level::Error, format!("unknown flag: {}", flag));
                    ui.send_callback(callback);
                    return;
                }
            }
        });
        Ok(())
    }

    pub fn run_command(&self, command_line: &str, callback: UICallback) -> Result<(), String> {
        //
        let (cmd, rest) = Self::word_split(command_line);
        match cmd.as_str() {
            "help" => self.cmd_help(rest, callback),
            "exit" => self.cmd_exit(callback),
            "quit" => self.cmd_exit(callback),
            "disconnect" => self.cmd_disconnect(callback),
            "shutdown" => self.cmd_shutdown(callback),
            "attach" => self.cmd_attach(callback),
            "detach" => self.cmd_detach(callback),
            "debug" => self.cmd_debug(rest, callback),
            "change_log_level" => self.cmd_change_log_level(rest, callback),
            "reply" => self.cmd_reply(rest, callback),
            "enable" => self.cmd_enable(rest, callback),
            "disable" => self.cmd_disable(rest, callback),
            _ => {
                let ui = self.ui_sender();
                ui.send_callback(callback);
                Err(format!("Invalid command: {}", cmd))
            }
        }
    }

    pub async fn connection_manager(&self) {
        // Connect until we're done
        while !self.inner_mut().finished {
            // Wait for connection request
            if !self.inner().autoconnect {
                let waker = self.inner_mut().connection_waker.instance_clone(());
                waker.await;
            } else {
                self.inner_mut().autoconnect = false;
            }
            self.inner_mut().connection_waker.reset();
            // Loop while we want to keep the connection
            let mut first = true;
            while self.inner().reconnect {
                let server_addr_opt = self.inner_mut().server_addr;
                let server_addr = match server_addr_opt {
                    None => break,
                    Some(addr) => addr,
                };
                if first {
                    info!("Connecting to server at {}", server_addr);
                    self.set_connection_state(ConnectionState::Retrying(
                        server_addr,
                        SystemTime::now(),
                    ));
                } else {
                    debug!("Retrying connection to {}", server_addr);
                }
                let capi = self.capi();
                let res = capi.connect(server_addr).await;
                if res.is_ok() {
                    info!(
                        "Connection to server at {} terminated normally",
                        server_addr
                    );
                    break;
                }
                if !self.inner().autoreconnect {
                    info!("Connection to server lost.");
                    break;
                }

                self.set_connection_state(ConnectionState::Retrying(
                    server_addr,
                    SystemTime::now(),
                ));

                debug!("Connection lost, retrying in 2 seconds");
                {
                    let waker = self.inner_mut().connection_waker.instance_clone(());
                    let _ = timeout(2000, waker).await;
                }
                self.inner_mut().connection_waker.reset();
                first = false;
            }
            info!("Disconnected.");
            self.set_connection_state(ConnectionState::Disconnected);
            self.inner_mut().reconnect = true;
        }
    }

    // called by ui
    ////////////////////////////////////////////
    pub fn set_server_address(&self, server_addr: Option<SocketAddr>) {
        self.inner_mut().server_addr = server_addr;
    }
    pub fn get_server_address(&self) -> Option<SocketAddr> {
        self.inner().server_addr
    }
    // called by client_api_connection
    // calls into ui
    ////////////////////////////////////////////

    pub fn log_message(&self, log_level: Level, message: String) {
        self.inner().ui_sender.add_node_event(log_level, message);
    }

    pub fn update_attachment(&self, attachment: &json::JsonValue) {
        self.inner_mut().ui_sender.set_attachment_state(
            attachment["state"].as_str().unwrap_or_default().to_owned(),
            attachment["public_internet_ready"]
                .as_bool()
                .unwrap_or_default(),
            attachment["local_network_ready"]
                .as_bool()
                .unwrap_or_default(),
        );
    }

    pub fn update_network_status(&self, network: &json::JsonValue) {
        self.inner_mut().ui_sender.set_network_status(
            network["started"].as_bool().unwrap_or_default(),
            json_str_u64(&network["bps_down"]),
            json_str_u64(&network["bps_up"]),
            network["peers"]
                .members()
                .cloned()
                .collect::<Vec<json::JsonValue>>(),
        );
    }
    pub fn update_config(&self, config: &json::JsonValue) {
        self.inner_mut().ui_sender.set_config(&config["config"])
    }
    pub fn update_route(&self, route: &json::JsonValue) {
        let mut out = String::new();
        if route["dead_routes"].len() != 0 {
            out.push_str(&format!("Dead routes: {:?}", route["dead_routes"]));
        }
        if route["dead_routes"].len() != 0 {
            if !out.is_empty() {
                out.push_str("\n");
            }
            out.push_str(&format!(
                "Dead remote routes: {:?}",
                route["dead_remote_routes"]
            ));
        }
        if !out.is_empty() {
            self.inner().ui_sender.add_node_event(Level::Info, out);
        }
    }
    pub fn update_value_change(&self, value_change: &json::JsonValue) {
        let out = format!("Value change: {:?}", value_change.as_str().unwrap_or("???"));
        self.inner().ui_sender.add_node_event(Level::Info, out);
    }

    pub fn update_log(&self, log: &json::JsonValue) {
        let log_level =
            Level::from_str(log["log_level"].as_str().unwrap_or("error")).unwrap_or(Level::Error);
        self.inner().ui_sender.add_node_event(
            log_level,
            format!(
                "{}: {}{}",
                log["log_level"].as_str().unwrap_or("???"),
                log["message"].as_str().unwrap_or("???"),
                if let Some(bt) = log["backtrace"].as_str() {
                    format!("\nBacktrace:\n{}", bt)
                } else {
                    "".to_owned()
                }
            ),
        );
    }

    pub fn update_app_message(&self, msg: &json::JsonValue) {
        if !self.inner.lock().enable_app_messages {
            return;
        }

        let message = json_str_vec_u8(&msg["message"]);

        // check is message body is ascii printable
        let mut printable = true;
        for c in &message {
            if *c < 32 || *c > 126 {
                printable = false;
            }
        }

        let (message, truncated) = if message.len() > 64 {
            (&message[0..64], true)
        } else {
            (&message[..], false)
        };

        let strmsg = if printable {
            format!("\"{}\"", String::from_utf8_lossy(&message).to_string())
        } else {
            hex::encode(message)
        };

        self.inner().ui_sender.add_node_event(
            Level::Info,
            format!(
                "AppMessage ({:?}): {}{}",
                msg["sender"],
                strmsg,
                if truncated { "..." } else { "" }
            ),
        );
    }

    pub fn update_app_call(&self, call: &json::JsonValue) {
        if !self.inner.lock().enable_app_messages {
            return;
        }

        let message = json_str_vec_u8(&call["message"]);

        // check is message body is ascii printable
        let mut printable = true;
        for c in &message {
            if *c < 32 || *c > 126 {
                printable = false;
            }
        }

        let (message, truncated) = if message.len() > 64 {
            (&message[0..64], true)
        } else {
            (&message[..], false)
        };

        let strmsg = if printable {
            format!("\"{}\"", String::from_utf8_lossy(&message).to_string())
        } else {
            hex::encode(message)
        };

        let id = json_str_u64(&call["call_id"]);

        self.inner().ui_sender.add_node_event(
            Level::Info,
            format!(
                "AppCall ({:?}) id = {:016x} : {}{}",
                call["sender"],
                id,
                strmsg,
                if truncated { "..." } else { "" }
            ),
        );

        self.inner_mut().last_call_id = Some(id);
    }

    pub fn update_shutdown(&self) {
        // Do nothing with this, we'll process shutdown when rpc connection closes
    }

    // called by client_api_connection
    // calls into ui
    ////////////////////////////////////////////
    pub fn set_connection_state(&self, state: ConnectionState) {
        self.inner_mut().ui_sender.set_connection_state(state);
    }
    // called by ui
    ////////////////////////////////////////////
    pub fn start_connection(&self) {
        self.inner_mut().reconnect = true;
        self.inner_mut().connection_waker.resolve();
    }
    // pub fn stop_connection(&self) {
    //     self.inner_mut().reconnect = false;
    //     let mut capi = self.capi().clone();
    //     spawn_detached(async move {
    //         capi.disconnect().await;
    //     });
    // }
    pub fn cancel_reconnect(&self) {
        self.inner_mut().reconnect = false;
        self.inner_mut().connection_waker.resolve();
    }
    pub fn quit(&self) {
        self.inner_mut().finished = true;
        self.inner_mut().reconnect = false;
        self.inner_mut().connection_waker.resolve();
    }

    // called by ui
    // calls into client_api_connection
    ////////////////////////////////////////////
    pub fn attach(&self) {
        let capi = self.capi();

        spawn_detached_local(async move {
            if let Err(e) = capi.server_attach().await {
                error!("Server command 'attach' failed to execute: {}", e);
            }
        });
    }

    pub fn detach(&self) {
        let capi = self.capi();

        spawn_detached_local(async move {
            if let Err(e) = capi.server_detach().await {
                error!("Server command 'detach' failed to execute: {}", e);
            }
        });
    }
}