use std::{path::PathBuf, sync::Arc};

use crossbeam_channel::Receiver;
use egui::mutex::Mutex;
use log::{debug, info};

use crate::{config::{self, ConfigProvider}, mod_builder::ModConfiguration, omori_locator};

#[derive(Clone)]
pub enum UiState {
    Loading,
    KeyRequired(String),
    PickGame(Result<PathBuf, String>, Vec<(PathBuf, u64)>),
    PickPlaytest(Vec<(PathBuf, u64)>),
    Configure(ModConfiguration),
    Error(String)
}

#[derive(Clone)]
pub struct UiStateHolder {
    pub state: Arc<Mutex<UiState>>
}

pub enum UiEvent {
    SetKey(Vec<u8>),
    UsePath(PathBuf),
    UseSteamPath,
    UseConfiguration(ModConfiguration)
}

pub struct AppThread {
    ui_state: UiStateHolder,
    context: egui::Context,
    ui_event_channel: Receiver<UiEvent>,
    decryption_key: Vec<u8>
}

impl AppThread {
    fn commit(&self, s: UiState) {
        let mut state = self.ui_state.state.lock();
        *state = s;
        drop(state);
        self.context.request_repaint();
    }

    fn get_key(&self, reason: String) -> anyhow::Result<Vec<u8>> {
        self.commit(UiState::KeyRequired(reason));
        loop {
            match self.ui_event_channel.recv()? {
                UiEvent::SetKey(key) => {
                    self.commit(UiState::Loading);
                    return Ok(key);
                }
                _ => {}
            }
        }
    }

    fn pick_game(&self, provider: &mut ConfigProvider) -> anyhow::Result<PathBuf> {
        let steam_location = match omori_locator::get_omori_path() {
            Ok(l) => Ok(l),
            Err(e) => Err(String::from(format!("{:#}", e)))
        };

        let location_history = provider.get_game_paths()?;

        self.commit(UiState::PickGame(steam_location.clone(), location_history.clone()));

        loop {
            match self.ui_event_channel.recv()? {
                UiEvent::UsePath(path) => {
                    provider.set_game_path_used(&path)?;
                    self.commit(UiState::Loading);
                    return Ok(path);
                },
                UiEvent::UseSteamPath => {
                    self.commit(UiState::Loading);
                    return Ok(steam_location.expect("The steam location was not set even if the UI told us to use it. This should never happen"));
                }
                _ => {}
            }
        }
    }

    fn pick_playtest(&self, provider: &mut ConfigProvider) -> anyhow::Result<PathBuf> {
        let playtest_history = provider.get_playtest_paths()?;
        self.commit(UiState::PickPlaytest(playtest_history.clone()));

        loop {
            match self.ui_event_channel.recv()? {
                UiEvent::UsePath(path) => {
                    provider.set_playtest_path_used(&path)?;
                    self.commit(UiState::Loading);
                    return Ok(path);
                },
                _ => {}
            }
        }
    }

    fn configure_bundling(&self, provider: &mut ConfigProvider, path: &PathBuf) -> anyhow::Result<ModConfiguration> {
        let configuration = provider.get_configuration_for_playtest(path);
        self.commit(UiState::Configure(configuration));

        loop {
            match self.ui_event_channel.recv()? {
                UiEvent::UseConfiguration(config) => {
                    provider.set_configuration_for_playtest(&path, &config)?;
                    self.commit(UiState::Loading);
                    return Ok(config);
                },
                _ => {}
            }
        }
    }

    pub fn create(state_holder: &UiStateHolder, context: &egui::Context, ui_event_channel: &Receiver<UiEvent>) -> AppThread {
        AppThread {
            ui_state: state_holder.clone(),
            context: context.clone(),
            ui_event_channel: ui_event_channel.clone(),
            decryption_key: Vec::new()
        }
    }

    fn real_main(&mut self) -> anyhow::Result<()> {
        debug!("I am ALIVE! HAHAHAHA!");
        self.commit(UiState::Loading);

        let mut config_provider = config::ConfigProvider::new()?;
        
        self.decryption_key = match config_provider.get_key() {
            Some(key) => key,
            None => match omori_locator::get_omori_key() {
                Ok(key) => key,
                Err(reason) => self.get_key(format!("{:#}", reason))?,
            }
        };
        
        config_provider.set_key(&self.decryption_key)?;

        let game_path = self.pick_game(&mut config_provider)?;
        info!("Will use {:?}", game_path);

        let playtest_path = self.pick_playtest(&mut config_provider)?;
        info!("Playtest {:?}", playtest_path);

        let config = self.configure_bundling(&mut config_provider, &playtest_path)?;
        info!("Config {:?}", config);

        Ok(())
    }

    pub fn main(&mut self) {
        match self.real_main() {
            Ok(_) => {},
            Err(e) => self.commit(UiState::Error(format!("{:#}", e))),
        }
    }
}