use futures::{future::join_all, stream::FuturesUnordered, StreamExt};
use once_cell::sync::OnceCell;
use paris::info;
use serde::{Deserialize, Serialize};
use serde_json::value::Index;
use std::{collections::HashMap, iter::Map, sync::Arc, thread, time::Duration};
use tauri::async_runtime::RwLock;
use tokio::{
    join,
    sync::mpsc,
    task,
    time::{sleep, Instant},
};
use tracing::warn;

use crate::{
    picker::{
        config::DisplayConfig, display_picker::DisplayPicker, led_color::LedColor, manager::Picker,
        screenshot::Screenshot,
    },
    rpc,
};

#[derive(Debug, Serialize, Deserialize)]
pub enum AmbientLightMode {
    None,
    Follow,
    Flowing,
}

pub struct CoreManager {
    ambient_light_mode: Arc<RwLock<AmbientLightMode>>,
}

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

        let core = CORE_MANAGER.get_or_init(|| CoreManager {
            ambient_light_mode: Arc::new(RwLock::new(AmbientLightMode::None)),
        });

        tokio::spawn(async {
            loop {
                core.play_flowing_light().await;
                match core.play_follow().await {
                    Ok(_) => {}
                    Err(error) => {
                        warn!("Can not following displays. {}", error);
                        sleep(Duration::from_millis(1000)).await;
                    }
                };
                sleep(Duration::from_millis(10)).await;
            }
        });
        core
    }

    pub async fn set_ambient_light(&self, target_mode: AmbientLightMode) {
        let mut mode = self.ambient_light_mode.write().await;
        *mode = target_mode;
    }

    pub async fn play_flowing_light(&self) {
        let mut hue = 0f64;
        let step_length = 2.0;
        loop {
            let lock = self.ambient_light_mode.read().await;
            if let AmbientLightMode::Flowing = *lock {
                let mut colors = Vec::<LedColor>::new();
                for i in 0..60 {
                    let color =
                        LedColor::from_hsv((hue + i as f64 * step_length) % 360.0, 1.0, 0.5);
                    colors.push(color);
                }
                hue = (hue + 1.0) % 360.0;
                match rpc::manager::Manager::global()
                    .publish_led_colors(&colors)
                    .await
                {
                    Ok(_) => {}
                    Err(error) => {
                        warn!("publish led colors failed. {}", error);
                    }
                }
            } else {
                break;
            }
            sleep(Duration::from_millis(50)).await;
        }
    }

    pub async fn play_follow(&self) -> anyhow::Result<()> {
        let lock = self.ambient_light_mode.read().await;
        let mut futs = vec![];
        if let AmbientLightMode::Follow = *lock {
            drop(lock);
            let configs = Picker::global().display_configs.lock().await;

            let (tx, mut rx) = mpsc::channel(10);

            for config in configs.to_owned() {
                let tx = tx.clone();
                let fut = tokio::spawn(async move {
                    match Self::follow_display_by_config(config, tx).await {
                        Ok(_) => {}
                        Err(error) => {
                            warn!("following failed. {}", error);
                        }
                    }
                });
                futs.push(fut);
            }

            let configs = configs.clone();

            tokio::spawn(async move {
                let mut global_colors = HashMap::new();
                while let Some(screenshot) = rx.recv().await {
                    let start_at = Instant::now();
                    match screenshot.get_top_colors().await {
                        Ok(colors) => {
                            let start = screenshot.get_top_of_led_start_at().min(screenshot.get_top_of_led_end_at());

                            let colors_len = colors.len();
                            for (index, color) in colors.into_iter().enumerate() {
                                global_colors.insert(index + start, color);
                            }

                            info!("led count: {}, spend: {:?}", global_colors.len(), start_at.elapsed());

                            if global_colors.len() == 60 {
                                let mut colors = vec![];
                                for index in 0..global_colors.len() {
                                    colors.push(*global_colors.get(&index).unwrap());
                                }
                                global_colors = HashMap::new();
                                match rpc::manager::Manager::global()
                                    .publish_led_colors(&colors)
                                    .await
                                {
                                    Ok(_) => {
                                        info!("publish successful",);
                                    }
                                    Err(error) => {
                                        warn!("publish led colors failed. {}", error);
                                    }
                                }
                            }
                        }
                        Err(_) => {}
                    };
                }
            });

            join_all(futs).await;
        } else {
            drop(lock);
            return Ok(());
        }

        Ok(())
    }

    async fn follow_display_by_config(
        config: DisplayConfig,
        tx: mpsc::Sender<Screenshot>,
    ) -> anyhow::Result<()> {
        let mut picker = DisplayPicker::from_config(config)?;
        info!("width: {}", picker.config.display_width);

        loop {
            let start = Instant::now();
            let next_tick = start + Duration::from_millis(16);
            let lock = Self::global().ambient_light_mode.read().await;
            if let AmbientLightMode::Follow = *lock {
                drop(lock);
                let screenshot = picker.take_screenshot()?;
                info!("Take Screenshot Spend: {:?}", start.elapsed());
                tx.send(screenshot).await;
            } else {
                break;
            }
            tokio::time::sleep_until(next_tick).await;
        }

        // // Picker::global().take_screenshots_for_all().await?;
        // // let colors = Picker::global().get_led_strip_colors().await?;

        // // let colors = colors.into_iter().rev().collect();
        Ok(())
    }
}