// This file is part of Deja-vu.
//
// Deja-vu is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Deja-vu is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// See the GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Deja-vu. If not, see <https://www.gnu.org/licenses/>.
//

use core::{
    action::Action,
    components::{
        footer::Footer, fps::FpsCounter, left::Left, popup, right::Right, state::StatefulList,
        title::Title, Component,
    },
    config::Config,
    line::{get_disk_description_right, get_part_description, DVLine},
    state::{CloneSettings, Mode},
    system::{
        boot, cpu::get_cpu_name, disk::PartitionTableType, diskpart::build_dest_format_script,
        drivers,
    },
    tasks::{Task, Tasks},
    tui::{Event, Tui},
};
use std::{
    env,
    iter::zip,
    sync::{Arc, Mutex},
};

use color_eyre::Result;
use ratatui::{
    crossterm::event::KeyEvent,
    layout::{Constraint, Direction, Layout},
    prelude::Rect,
    style::Color,
};
use tokio::sync::mpsc;
use tracing::{debug, info};

pub struct App {
    // TUI
    action_rx: mpsc::UnboundedReceiver<Action>,
    action_tx: mpsc::UnboundedSender<Action>,
    components: Vec<Box<dyn Component>>,
    config: Config,
    frame_rate: f64,
    last_tick_key_events: Vec<KeyEvent>,
    should_quit: bool,
    should_suspend: bool,
    tick_rate: f64,
    // App
    clone: CloneSettings,
    cur_mode: Mode,
    list: StatefulList<usize>,
    prev_mode: Mode,
    selections: Vec<Option<usize>>,
    tasks: Tasks,
}

impl App {
    pub fn new(tick_rate: f64, frame_rate: f64) -> Result<Self> {
        let (action_tx, action_rx) = mpsc::unbounded_channel();
        let disk_list_arc = Arc::new(Mutex::new(Vec::new()));
        let mut tasks = Tasks::new(action_tx.clone(), disk_list_arc.clone());
        tasks.add(Task::ScanDisks);
        Ok(Self {
            // TUI
            action_rx,
            action_tx,
            components: vec![
                Box::new(Title::new()),
                Box::new(FpsCounter::new()),
                Box::new(Left::new()),
                Box::new(Right::new()),
                Box::new(Footer::new()),
                Box::new(popup::Popup::new()),
            ],
            config: Config::new()?,
            frame_rate,
            last_tick_key_events: Vec::new(),
            should_quit: false,
            should_suspend: false,
            tick_rate,
            // App
            clone: CloneSettings::new(disk_list_arc),
            cur_mode: Mode::ScanDisks,
            list: StatefulList::default(),
            prev_mode: Mode::ScanDisks,
            selections: vec![None, None],
            tasks,
        })
    }

    pub fn prev_mode(&mut self) -> Option<Mode> {
        let new_mode = match self.cur_mode {
            Mode::Failed => Some(Mode::Failed),
            Mode::Done => Some(Mode::Done),
            Mode::SelectParts => Some(Mode::SelectParts),
            Mode::Confirm => Some(Mode::SelectTableType),
            Mode::SelectTableType => Some(Mode::SelectDisks),
            Mode::SelectDisks => Some(Mode::ScanDisks),
            //
            Mode::InstallDrivers
            | Mode::ScanDisks
            | Mode::PreClone
            | Mode::Clone
            | Mode::PostClone => None,
        };
        new_mode
    }

    pub fn next_mode(&mut self) -> Option<Mode> {
        let new_mode = match self.cur_mode {
            Mode::InstallDrivers => Mode::ScanDisks,
            Mode::ScanDisks => Mode::SelectDisks,
            Mode::SelectDisks => Mode::SelectTableType,
            Mode::SelectTableType => Mode::Confirm,
            Mode::Confirm => Mode::PreClone,
            Mode::PreClone => Mode::Clone,
            Mode::Clone => Mode::SelectParts,
            Mode::SelectParts => Mode::PostClone,
            Mode::PostClone | Mode::Done => Mode::Done,
            Mode::Failed => Mode::Failed,
        };

        if new_mode == self.cur_mode {
            // No mode change needed
            None
        } else {
            Some(new_mode)
        }
    }

    pub fn set_mode(&mut self, new_mode: Mode) -> Result<()> {
        info!("Setting mode to {new_mode:?}");
        self.cur_mode = new_mode;
        match new_mode {
            Mode::InstallDrivers => self.clone.scan_drivers(),
            Mode::ScanDisks => {
                self.prev_mode = self.cur_mode;
                if self.tasks.idle() {
                    self.tasks.add(Task::ScanDisks);
                }
                self.action_tx.send(Action::DisplayPopup(
                    popup::Type::Info,
                    String::from("Scanning Disks..."),
                ))?;
            }
            Mode::PreClone => {
                self.action_tx.send(Action::DisplayPopup(
                    popup::Type::Info,
                    String::from("Formatting destination disk"),
                ))?;

                // Build Diskpart script to format destination disk
                let disk_list = self.clone.disk_list.lock().unwrap();
                if let Some(disk_index) = self.clone.disk_index_dest {
                    if let Some(disk) = disk_list.get(disk_index) {
                        let table_type = self.clone.table_type.clone().unwrap();
                        let diskpart_script = build_dest_format_script(disk.id, &table_type);
                        self.tasks.add(Task::Diskpart(diskpart_script));
                    }
                }
            }
            Mode::Clone => {
                self.action_tx.send(Action::DisplayPopup(
                    popup::Type::Info,
                    String::from("Running Clone Tool"),
                ))?;
                self.tasks.add(Task::Command(
                    self.config.clone_app_path.clone(),
                    Vec::new(),
                ));
                if let Some(dest_index) = self.clone.disk_index_dest {
                    self.tasks.add(Task::UpdateDestDisk(dest_index));
                }
            }
            Mode::PostClone => {
                self.action_tx.send(Action::DisplayPopup(
                    popup::Type::Info,
                    String::from("Updating boot configuration"),
                ))?;

                // Get System32 path
                let system32 = if cfg!(windows) {
                    if let Ok(path) = env::var("SYSTEMROOT") {
                        format!("{path}/System32")
                    } else {
                        self.action_tx.send(Action::Error(String::from(
                            "ERROR\n\n\nFailed to find SYSTEMROOT",
                        )))?;
                        return Ok(());
                    }
                } else {
                    String::from(".")
                };

                // Add actions
                let disk_list = self.clone.disk_list.lock().unwrap();
                if let Some(disk_index) = self.clone.disk_index_dest {
                    if let Some(disk) = disk_list.get(disk_index) {
                        let table_type = self.clone.table_type.clone().unwrap();
                        let letter_boot = disk.get_part_letter(self.clone.part_index_boot.unwrap());
                        let letter_os = disk.get_part_letter(self.clone.part_index_os.unwrap());

                        // Safety check
                        if letter_boot.is_empty() || letter_os.is_empty() {
                            self.action_tx.send(Action::Error(String::from(
                                "ERROR\n\n\nFailed to get drive letters for the destination",
                            )))?;
                            return Ok(());
                        }

                        // Create boot files
                        for task in
                            boot::configure_disk(&letter_boot, &letter_os, &system32, table_type)
                        {
                            self.tasks.add(task);
                        }

                        // Inject driver(s) (if selected)
                        if let Some(driver) = &self.clone.driver {
                            if let Ok(task) = boot::inject_driver(driver, &letter_os, &system32) {
                                self.tasks.add(task);
                            } else {
                                self.action_tx.send(Action::Error(format!(
                                    "Failed to inject driver:\n{}",
                                    driver.name
                                )))?;
                            }
                        }
                    }
                }
            }
            Mode::Done => {
                self.action_tx.send(Action::DisplayPopup(
                    popup::Type::Success,
                    String::from("COMPLETE\n\n\nThank you for using this tool!"),
                ))?;
            }
            _ => {}
        }
        Ok(())
    }

    pub async fn run(&mut self) -> Result<()> {
        let mut tui = Tui::new()?
            // .mouse(true) // uncomment this line to enable mouse support
            .tick_rate(self.tick_rate)
            .frame_rate(self.frame_rate);
        tui.enter()?;

        for component in &mut self.components {
            component.register_action_handler(self.action_tx.clone())?;
        }
        for component in &mut self.components {
            component.register_config_handler(self.config.clone())?;
        }
        for component in &mut self.components {
            component.init(tui.size()?)?;
        }

        let action_tx = self.action_tx.clone();
        loop {
            self.handle_events(&mut tui).await?;
            self.handle_actions(&mut tui)?;
            if self.should_suspend {
                tui.suspend()?;
                action_tx.send(Action::Resume)?;
                action_tx.send(Action::ClearScreen)?;
                // tui.mouse(true);
                tui.enter()?;
            } else if self.should_quit {
                tui.stop()?;
                break;
            }
        }
        tui.exit()?;
        Ok(())
    }

    async fn handle_events(&mut self, tui: &mut Tui) -> Result<()> {
        let Some(event) = tui.next_event().await else {
            return Ok(());
        };
        let action_tx = self.action_tx.clone();
        match event {
            Event::Quit => action_tx.send(Action::Quit)?,
            Event::Tick => action_tx.send(Action::Tick)?,
            Event::Render => action_tx.send(Action::Render)?,
            Event::Resize(x, y) => action_tx.send(Action::Resize(x, y))?,
            Event::Key(key) => self.handle_key_event(key)?,
            _ => {}
        }
        for component in &mut self.components {
            if let Some(action) = component.handle_events(Some(event.clone()))? {
                action_tx.send(action)?;
            }
        }
        Ok(())
    }

    fn handle_key_event(&mut self, key: KeyEvent) -> Result<()> {
        let action_tx = self.action_tx.clone();
        let Some(keymap) = self.config.keybindings.get(&self.cur_mode) else {
            return Ok(());
        };
        if let Some(action) = keymap.get(&vec![key]) {
            info!("Got action: {action:?}");
            action_tx.send(action.clone())?;
        } else {
            // If the key was not handled as a single key action,
            // then consider it for multi-key combinations.
            self.last_tick_key_events.push(key);

            // Check for multi-key combinations
            if let Some(action) = keymap.get(&self.last_tick_key_events) {
                info!("Got action: {action:?}");
                action_tx.send(action.clone())?;
            }
        }
        Ok(())
    }

    fn handle_actions(&mut self, tui: &mut Tui) -> Result<()> {
        while let Ok(action) = self.action_rx.try_recv() {
            if action != Action::Tick && action != Action::Render {
                debug!("{action:?}");
            }
            match action {
                Action::Tick => {
                    self.last_tick_key_events.drain(..);
                    match self.cur_mode {
                        Mode::ScanDisks | Mode::PreClone | Mode::Clone | Mode::PostClone => {
                            // Check background task
                            self.tasks.poll()?; // Once all are complete Action::NextScreen is sent
                        }
                        _ => {}
                    }
                }
                Action::Quit => self.should_quit = true,
                Action::Suspend => self.should_suspend = true,
                Action::Resume => self.should_suspend = false,
                Action::ClearScreen => tui.terminal.clear()?,
                Action::KeyUp => self.list.previous(),
                Action::KeyDown => self.list.next(),
                Action::Error(ref msg) => {
                    self.action_tx
                        .send(Action::DisplayPopup(popup::Type::Error, msg.clone()))?;
                    self.action_tx.send(Action::SetMode(Mode::Failed))?;
                }
                Action::InstallDriver => {
                    self.action_tx.send(Action::SetMode(Mode::InstallDrivers))?;
                }
                Action::Process => match self.cur_mode {
                    Mode::Confirm => {
                        self.action_tx.send(Action::NextScreen)?;
                    }
                    _ => {}
                },
                Action::Resize(w, h) => self.handle_resize(tui, w, h)?,
                Action::Render => self.render(tui)?,
                Action::PrevScreen => {
                    if let Some(new_mode) = self.prev_mode() {
                        self.prev_mode = new_mode;
                        self.cur_mode = new_mode;
                        self.action_tx.send(Action::SetMode(new_mode))?;
                    }
                }
                Action::NextScreen => match self.next_mode() {
                    None => {}
                    Some(next) => {
                        self.prev_mode = self.cur_mode;
                        self.cur_mode = next;
                        self.action_tx.send(Action::DismissPopup)?;
                        self.action_tx.send(Action::SetMode(next))?;
                    }
                },
                Action::ScanDisks => self.action_tx.send(Action::SetMode(Mode::ScanDisks))?,
                Action::Select(one, two) => {
                    match self.cur_mode {
                        Mode::InstallDrivers => {
                            if let Some(index) = one {
                                if let Some(driver) = self.clone.driver_list.get(index).cloned() {
                                    drivers::load(&driver.inf_paths);
                                    self.clone.driver = Some(driver);
                                }
                            }
                        }
                        Mode::SelectDisks => {
                            self.clone.disk_index_source = one;
                            self.clone.disk_index_dest = two;
                        }
                        Mode::SelectParts => {
                            self.clone.part_index_boot = one;
                            self.clone.part_index_os = two;
                        }
                        Mode::SelectTableType => {
                            self.clone.table_type = {
                                if let Some(index) = one {
                                    match index {
                                        0 => Some(PartitionTableType::Guid),
                                        1 => Some(PartitionTableType::Legacy),
                                        index => {
                                            panic!("Failed to select PartitionTableType: {}", index)
                                        }
                                    }
                                } else {
                                    None
                                }
                            }
                        }
                        _ => {}
                    }
                    self.selections[0] = one;
                    self.selections[1] = two;
                }
                Action::SetMode(new_mode) => {
                    self.set_mode(new_mode)?;
                    self.action_tx
                        .send(Action::UpdateFooter(build_footer_string(self.cur_mode)))?;
                    let (title, labels, items, select_one) = build_left_items(self, self.cur_mode);
                    self.action_tx
                        .send(Action::UpdateLeft(title, labels, items, select_one))?;
                    let (labels, start, items) = build_right_items(self, self.cur_mode);
                    self.action_tx
                        .send(Action::UpdateRight(labels, start, items))?;
                    match new_mode {
                        // Mode::InstallDrivers | Mode::SelectDisks => {
                        //     self.action_tx.send(Action::Select(None, None))?
                        // }
                        Mode::SelectTableType | Mode::Confirm => {
                            // Select source/dest disks
                            self.action_tx.send(Action::SelectRight(
                                self.clone.disk_index_source,
                                self.clone.disk_index_dest,
                            ))?;
                        }
                        Mode::SelectParts => {
                            // Select first partition as boot partition
                            self.action_tx.send(Action::Select(Some(0), None))?;

                            // Highlight 2nd or 3rd partition as OS partition
                            let index = if let Some(table_type) = &self.clone.table_type {
                                match table_type {
                                    PartitionTableType::Guid => 2,
                                    PartitionTableType::Legacy => 1,
                                }
                            } else {
                                1
                            };
                            self.action_tx.send(Action::Highlight(index))?;
                        }
                        _ => {}
                    };
                }
                _ => {}
            }
            for component in &mut self.components {
                if let Some(action) = component.update(action.clone())? {
                    self.action_tx.send(action)?;
                };
            }
        }
        Ok(())
    }

    fn handle_resize(&mut self, tui: &mut Tui, w: u16, h: u16) -> Result<()> {
        tui.resize(Rect::new(0, 0, w, h))?;
        self.render(tui)?;
        Ok(())
    }

    fn render(&mut self, tui: &mut Tui) -> Result<()> {
        tui.draw(|frame| {
            if let [header, _body, footer, left, right, popup] = get_chunks(frame.area())[..] {
                let component_areas = vec![
                    header, // Title Bar
                    header, // FPS Counter
                    left, right, footer, popup,
                ];
                for (component, area) in zip(self.components.iter_mut(), component_areas) {
                    if let Err(err) = component.draw(frame, area) {
                        let _ = self
                            .action_tx
                            .send(Action::Error(format!("Failed to draw: {err:?}")));
                    }
                }
            };
        })?;
        Ok(())
    }
}

fn centered_rect(percent_x: u16, percent_y: u16, r: Rect) -> Rect {
    // Cut the given rectangle into three vertical pieces
    let popup_layout = Layout::default()
        .direction(Direction::Vertical)
        .constraints([
            Constraint::Percentage((100 - percent_y) / 2),
            Constraint::Percentage(percent_y),
            Constraint::Percentage((100 - percent_y) / 2),
        ])
        .split(r);

    // Then cut the middle vertical piece into three width-wise pieces
    Layout::default()
        .direction(Direction::Horizontal)
        .constraints([
            Constraint::Percentage((100 - percent_x) / 2),
            Constraint::Percentage(percent_x),
            Constraint::Percentage((100 - percent_x) / 2),
        ])
        .split(popup_layout[1])[1] // Return the middle chunk
}

fn get_chunks(r: Rect) -> Vec<Rect> {
    let mut chunks: Vec<Rect> = Vec::with_capacity(6);

    // Main sections
    chunks.extend(
        Layout::default()
            .direction(Direction::Vertical)
            .constraints([
                Constraint::Length(3),
                Constraint::Min(1),
                Constraint::Length(3),
            ])
            .split(r)
            .to_vec(),
    );

    // Left/Right
    chunks.extend(
        Layout::default()
            .direction(Direction::Horizontal)
            .constraints([Constraint::Percentage(50), Constraint::Percentage(50)])
            .split(centered_rect(90, 90, chunks[1]))
            .to_vec(),
    );

    // Popup
    chunks.push(centered_rect(60, 25, r));

    // Done
    chunks
}

fn build_footer_string(cur_mode: Mode) -> String {
    match cur_mode {
        Mode::ScanDisks | Mode::PreClone | Mode::Clone | Mode::PostClone => {
            String::from("(q) to quit")
        }
        Mode::SelectParts => String::from("(Enter) to select / (s) to start over / (q) to quit"),
        Mode::SelectDisks => String::from(
            "(Enter) to select / / (i) to install driver / (r) to rescan / (q) to quit",
        ),
        Mode::SelectTableType => String::from("(Enter) to select / (b) to go back / (q) to quit"),
        Mode::Confirm => String::from("(Enter) to confirm / (b) to go back / (q) to quit"),
        Mode::Done | Mode::Failed | Mode::InstallDrivers => String::from("(Enter) or (q) to quit"),
    }
}
fn build_left_items(app: &App, cur_mode: Mode) -> (String, Vec<String>, Vec<String>, bool) {
    let title: String;
    let mut items = Vec::new();
    let mut labels: Vec<String> = Vec::new();
    let mut select_one = false;
    match cur_mode {
        Mode::InstallDrivers => {
            title = String::from("Install Drivers");
            select_one = true;
            app.clone
                .driver_list
                .iter()
                .for_each(|driver| items.push(driver.to_string()));
        }
        Mode::SelectDisks => {
            title = String::from("Select Source and Destination Disks");
            labels.push(String::from("source"));
            labels.push(String::from("dest"));
            let disk_list = app.clone.disk_list.lock().unwrap();
            disk_list
                .iter()
                .for_each(|disk| items.push(disk.description.to_string()));
        }
        Mode::SelectTableType => {
            title = String::from("Select Partition Table Type");
            select_one = true;
            items.push(format!("{}", PartitionTableType::Guid));
            items.push(format!("{}", PartitionTableType::Legacy));
        }
        Mode::Confirm => {
            title = String::from("Confirm Selections");
        }
        Mode::PreClone | Mode::Clone | Mode::PostClone | Mode::ScanDisks => {
            title = String::from("Processing");
        }
        Mode::SelectParts => {
            title = String::from("Select Boot and OS Partitions");
            labels.push(String::from("boot"));
            labels.push(String::from("os"));
            let disk_list = app.clone.disk_list.lock().unwrap();
            if let Some(index) = app.clone.disk_index_dest {
                if let Some(disk) = disk_list.get(index) {
                    disk.get_parts().iter().for_each(|part| {
                        items.push(part.to_string());
                    });
                }
            }
        }
        Mode::Done | Mode::Failed => title = String::from("Done"),
    };
    (title, labels, items, select_one)
}

fn build_right_items(app: &App, cur_mode: Mode) -> (Vec<Vec<DVLine>>, usize, Vec<Vec<DVLine>>) {
    let mut items = Vec::new();
    let mut labels: Vec<Vec<DVLine>> = Vec::new();
    let mut start_index = 0;
    match cur_mode {
        Mode::InstallDrivers => {
            items.push(vec![DVLine {
                line_parts: vec![String::from("CPU")],
                line_colors: vec![Color::Cyan],
            }]);
            items.push(vec![DVLine {
                line_parts: vec![get_cpu_name()],
                line_colors: vec![Color::Reset],
            }]);
            start_index = 2;
        }
        Mode::SelectDisks | Mode::SelectTableType | Mode::Confirm => {
            // Labels
            labels.push(vec![DVLine {
                line_parts: vec![String::from("Source")],
                line_colors: vec![Color::Cyan],
            }]);
            let dest_dv_line = DVLine {
                line_parts: vec![
                    String::from("Dest"),
                    String::from("  (WARNING: ALL DATA WILL BE DELETED!)"),
                ],
                line_colors: vec![Color::Cyan, Color::Red],
            };
            if let Some(table_type) = &app.clone.table_type {
                // Show table type
                let type_str = match table_type {
                    PartitionTableType::Guid => "GPT",
                    PartitionTableType::Legacy => "MBR",
                };
                labels.push(vec![
                    dest_dv_line,
                    DVLine {
                        line_parts: vec![format!("      (Will be formatted {type_str})")],
                        line_colors: vec![Color::Yellow],
                    },
                ]);
            } else {
                labels.push(vec![dest_dv_line]);
            }
            let disk_list = app.clone.disk_list.lock().unwrap();
            disk_list
                .iter()
                .for_each(|disk| items.push(get_disk_description_right(&disk)));
        }
        Mode::SelectParts => {
            vec!["Boot", "OS"].iter().for_each(|s| {
                labels.push(vec![DVLine {
                    line_parts: vec![String::from(*s)],
                    line_colors: vec![Color::Cyan],
                }])
            });
            if let Some(index) = app.clone.disk_index_dest {
                start_index = 1;
                let disk_list = app.clone.disk_list.lock().unwrap();
                if let Some(disk) = disk_list.get(index) {
                    // Disk Details
                    items.push(get_disk_description_right(&disk));

                    // Partition Details
                    disk.parts
                        .iter()
                        .for_each(|part| items.push(get_part_description(&part)));
                }
            }
        }
        _ => {}
    }
    (labels, start_index, items)
}