use bollard::{
    container::{ListContainersOptions, LogsOptions, StartContainerOptions, Stats, StatsOptions},
    Docker,
};
use futures_util::StreamExt;
use parking_lot::Mutex;
use std::{
    collections::HashMap,
    fmt,
    sync::{
        atomic::{AtomicBool, Ordering},
        Arc,
    },
};
use tokio::{sync::mpsc::Receiver, task::JoinHandle};

use crate::{
    app_data::{AppData, DockerControls},
    app_error::AppError,
    parse_args::CliArgs,
    ui::GuiState,
};
mod message;
pub use message::DockerMessage;

#[derive(Debug, Hash, Clone, PartialEq, Eq)]
enum SpawnId {
    Stats(String),
    Log(String),
}

impl fmt::Display for SpawnId {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        let disp = match self {
            Self::Stats(id) => format!("stats::{id}"),
            Self::Log(id) => format!("logs::{id}"),
        };
        write!(f, "{}", disp)
    }
}

pub struct DockerData {
    app_data: Arc<Mutex<AppData>>,
    docker: Arc<Docker>,
    gui_state: Arc<Mutex<GuiState>>,
    initialised: bool,
    is_running: Arc<AtomicBool>,
    receiver: Receiver<DockerMessage>,
    spawns: Arc<Mutex<HashMap<SpawnId, JoinHandle<()>>>>,
    timestamps: bool,
}

impl DockerData {
    /// Use docker stats for work out current cpu usage
    fn calculate_usage(stats: &Stats) -> f64 {
        let mut cpu_percentage = 0.0;
        let previous_cpu = stats.precpu_stats.cpu_usage.total_usage;
        let cpu_delta = stats.cpu_stats.cpu_usage.total_usage as f64 - previous_cpu as f64;

        if let (Some(cpu_stats_usage), Some(precpu_stats_usage)) = (
            stats.cpu_stats.system_cpu_usage,
            stats.precpu_stats.system_cpu_usage,
        ) {
            let system_delta = (cpu_stats_usage - precpu_stats_usage) as f64;
            let online_cpus = stats.cpu_stats.online_cpus.unwrap_or_else(|| {
                stats
                    .cpu_stats
                    .cpu_usage
                    .percpu_usage
                    .clone()
                    .unwrap_or_default()
                    .len() as u64
            }) as f64;
            if system_delta > 0.0 && cpu_delta > 0.0 {
                cpu_percentage = (cpu_delta / system_delta) * online_cpus * 100.0;
            }
        }
        cpu_percentage
    }

    /// Get a single docker stat in order to update mem and cpu usage
    /// don't take &self, so that can tokio::spawn into it's own thread
    /// remove if from spawns hashmap when complete
    async fn update_container_stat(
        docker: Arc<Docker>,
        id: String,
        app_data: Arc<Mutex<AppData>>,
        is_running: bool,
        spawns: Arc<Mutex<HashMap<SpawnId, JoinHandle<()>>>>,
    ) {
        let mut stream = docker
            .stats(
                &id,
                Some(StatsOptions {
                    stream: false,
                    one_shot: !is_running,
                }),
            )
            .take(1);

        while let Some(Ok(stats)) = stream.next().await {
            let mem_stat = stats.memory_stats.usage.unwrap_or(0);
            let mem_limit = stats.memory_stats.limit.unwrap_or(0);

            let some_key = if let Some(networks) = &stats.networks {
                networks.keys().next().map(|x| x.to_owned())
            } else {
                None
            };

            let cpu_stats = Self::calculate_usage(&stats);

            let no_bytes = (0, 0);
            let (rx, tx) = if let Some(key) = some_key {
                match stats.networks.unwrap_or_default().get(&key) {
                    Some(data) => (data.rx_bytes.to_owned(), data.tx_bytes.to_owned()),
                    None => no_bytes,
                }
            } else {
                no_bytes
            };

            if is_running {
                app_data.lock().update_stats(
                    id.clone(),
                    Some(cpu_stats),
                    Some(mem_stat),
                    mem_limit,
                    rx,
                    tx,
                );
            } else {
                app_data
                    .lock()
                    .update_stats(id.clone(), None, None, mem_limit, rx, tx);
            }
            let key = SpawnId::Stats(id.to_owned());
            spawns.lock().remove(&key);
        }
    }

    /// Update all stats, spawn each container into own tokio::spawn thread
    async fn update_all_container_stats(&mut self, all_ids: &[(bool, String)]) {
        for (is_running, id) in all_ids.iter() {
            let docker = Arc::clone(&self.docker);
            let app_data = Arc::clone(&self.app_data);
            let spawns = Arc::clone(&self.spawns);
            let is_running = *is_running;
            let id = id.to_owned();

            let key = SpawnId::Stats(id.to_owned());
            let spawn_contains_id = spawns.lock().contains_key(&key);
            let s = tokio::spawn(Self::update_container_stat(
                docker,
                id.to_owned(),
                app_data,
                is_running,
                spawns,
            ));
            if !spawn_contains_id {
                self.spawns.lock().insert(key, s);
            }
        }
    }

    /// Get all current containers, handle into ContainerItem in the app_data struct rather than here
    /// Just make sure that items sent are guaranteed to have an id
    pub async fn update_all_containers(&mut self) -> Vec<(bool, String)> {
        let containers = self
            .docker
            .list_containers(Some(ListContainersOptions::<String> {
                all: true,
                ..Default::default()
            }))
            .await
            .unwrap_or_default();

        let mut output = vec![];
        // iter over containers, to only send ones which have an id, as use id for identification throughout!
        containers
            .iter()
            .filter(|i| i.id.is_some())
            .for_each(|c| output.push(c.to_owned()));

        self.app_data.lock().update_containers(&output);

        let current_sort = self.app_data.lock().get_sorted();
        self.app_data.lock().set_sorted(current_sort);

        output
            .iter()
            .filter_map(|i| {
                i.id.as_ref().map(|id| {
                    (
                        i.state.as_ref().unwrap_or(&String::new()) == "running",
                        id.to_owned(),
                    )
                })
            })
            .collect::<Vec<_>>()
    }

    /// Update single container logs
    /// don't take &self, so that can tokio::spawn into it's own thread
    /// remove if from spawns hashmap when complete
    async fn update_log(
        docker: Arc<Docker>,
        id: String,
        timestamps: bool,
        since: i64,
        app_data: Arc<Mutex<AppData>>,
        spawns: Arc<Mutex<HashMap<SpawnId, JoinHandle<()>>>>,
    ) {
        let options = Some(LogsOptions::<String> {
            stdout: true,
            timestamps,
            since,
            ..Default::default()
        });

        let mut logs = docker.logs(&id, options);

        let mut output = vec![];

        while let Some(value) = logs.next().await {
            if let Ok(data) = value {
                let log_string = data.to_string();
                if !log_string.trim().is_empty() {
                    output.push(log_string);
                }
            }
        }
        let key = SpawnId::Log(id.to_owned());
        spawns.lock().remove(&key);
        app_data.lock().update_log_by_id(output, id.to_owned());
    }

    /// Update all logs, spawn each container into own tokio::spawn thread
    async fn init_all_logs(&mut self, all_ids: &[(bool, String)]) {
        for (_, id) in all_ids.iter() {
            let docker = Arc::clone(&self.docker);
            let timestamps = self.timestamps;
            let id = id.to_owned();
            let app_data = Arc::clone(&self.app_data);
            let spawns = Arc::clone(&self.spawns);
            let key = SpawnId::Log(id.to_owned());
            let s = tokio::spawn(Self::update_log(
                docker, id, timestamps, 0, app_data, spawns,
            ));

            self.spawns.lock().insert(key, s);
        }
    }

    async fn update_everything(&mut self) {
        let all_ids = self.update_all_containers().await;
        let optional_index = self.app_data.lock().get_selected_log_index();
        if let Some(index) = optional_index {
            let id = self.app_data.lock().containers.items[index].id.to_owned();

            let key = SpawnId::Log(id.to_owned());
            let running = self.spawns.lock().contains_key(&key);

            if !running {
                let since = self.app_data.lock().containers.items[index].last_updated as i64;
                let docker = Arc::clone(&self.docker);
                let timestamps = self.timestamps;

                let app_data = Arc::clone(&self.app_data);
                let spawns = Arc::clone(&self.spawns);
                let s = tokio::spawn(Self::update_log(
                    docker, id, timestamps, since, app_data, spawns,
                ));
                self.spawns.lock().insert(key, s);
            }
        };

        self.update_all_container_stats(&all_ids).await;
    }

    /// Animate the loading icon
    async fn loading_spin(&mut self) -> JoinHandle<()> {
        let gui_state = Arc::clone(&self.gui_state);
        tokio::spawn(async move {
            loop {
                tokio::time::sleep(std::time::Duration::from_millis(100)).await;
                gui_state.lock().next_loading();
            }
        })
    }

    /// Stop the loading_spin function, and reset gui loading status
    fn stop_loading_spin(&mut self, handle: JoinHandle<()>) {
        handle.abort();
        self.gui_state.lock().reset_loading();
    }

    // Initialize docker container data, before any messages are received
    async fn initialise_container_data(&mut self) {
        let loading_spin = self.loading_spin().await;

        let all_ids = self.update_all_containers().await;
        self.update_all_container_stats(&all_ids).await;

        // Maybe only do a single one at first?
        self.init_all_logs(&all_ids).await;

        if all_ids.is_empty() {
            self.initialised = true;
        }

        // wait until all logs have initialised
        while !self.initialised {
            tokio::time::sleep(std::time::Duration::from_millis(100)).await;
            self.initialised = self.app_data.lock().initialised(&all_ids);
        }
        self.app_data.lock().init = true;
        self.stop_loading_spin(loading_spin);
    }

    /// Handle incoming messages, container controls & all container information update
    async fn message_handler(&mut self) {
        while let Some(message) = self.receiver.recv().await {
            let docker = Arc::clone(&self.docker);
            let app_data = Arc::clone(&self.app_data);
            match message {
                DockerMessage::Pause(id) => {
                    let loading_spin = self.loading_spin().await;
                    docker.pause_container(&id).await.unwrap_or_else(|_| {
                        app_data
                            .lock()
                            .set_error(AppError::DockerCommand(DockerControls::Pause))
                    });
                    self.stop_loading_spin(loading_spin);
                }
                DockerMessage::Restart(id) => {
                    let loading_spin = self.loading_spin().await;
                    docker
                        .restart_container(&id, None)
                        .await
                        .unwrap_or_else(|_| {
                            app_data
                                .lock()
                                .set_error(AppError::DockerCommand(DockerControls::Restart))
                        });
                    self.stop_loading_spin(loading_spin);
                }
                DockerMessage::Start(id) => {
                    let loading_spin = self.loading_spin().await;
                    docker
                        .start_container(&id, None::<StartContainerOptions<String>>)
                        .await
                        .unwrap_or_else(|_| {
                            app_data
                                .lock()
                                .set_error(AppError::DockerCommand(DockerControls::Start))
                        });
                    self.stop_loading_spin(loading_spin);
                }
                DockerMessage::Stop(id) => {
                    let loading_spin = self.loading_spin().await;
                    docker.stop_container(&id, None).await.unwrap_or_else(|_| {
                        app_data
                            .lock()
                            .set_error(AppError::DockerCommand(DockerControls::Stop))
                    });
                    self.stop_loading_spin(loading_spin);
                }
                DockerMessage::Unpause(id) => {
                    let loading_spin = self.loading_spin().await;
                    docker.unpause_container(&id).await.unwrap_or_else(|_| {
                        app_data
                            .lock()
                            .set_error(AppError::DockerCommand(DockerControls::Unpause))
                    });
                    self.stop_loading_spin(loading_spin);
                    self.update_everything().await
                }
                DockerMessage::Update => self.update_everything().await,
                DockerMessage::Quit => {
                    self.spawns
                        .lock()
                        .values()
                        .into_iter()
                        .for_each(|i| i.abort());
                    self.is_running.store(false, Ordering::SeqCst);
                }
            }
        }
    }

    /// Initialise self, and start the message receiving loop
    pub async fn init(
        args: CliArgs,
        app_data: Arc<Mutex<AppData>>,
        docker: Arc<Docker>,
        gui_state: Arc<Mutex<GuiState>>,
        receiver: Receiver<DockerMessage>,
        is_running: Arc<AtomicBool>,
    ) {
        if app_data.lock().get_error().is_none() {
            let mut inner = Self {
                app_data,
                docker,
                gui_state,
                initialised: false,
                receiver,
                spawns: Arc::new(Mutex::new(HashMap::new())),
                timestamps: args.timestamp,
                is_running,
            };
            inner.initialise_container_data().await;

            inner.message_handler().await;
        }
    }
}

// tests, use redis-test container, check logs exists, and selector of logs, and that it increases, and matches end, when you run restart on the docker containers