// 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 color_eyre::Result;
use ratatui::{
    Frame,
    layout::Rect,
    widgets::{Block, Clear, Padding, Paragraph, Wrap},
};
use tokio::sync::mpsc::UnboundedSender;

use core::{
    action::Action,
    components::{Component, state::StatefulList},
    config::Config,
    state::Mode,
};
use std::{
    cmp::min,
    sync::{Arc, Mutex},
};

use crate::diags::DiagGroup;

#[derive(Default, Debug, Clone)]
pub struct LogView {
    command_tx: Option<UnboundedSender<Action>>,
    config: Config,
    line_index: u16,
    list: StatefulList<String>,
    mode: Mode,
    diag_groups: Arc<Mutex<Vec<DiagGroup>>>,
}

impl LogView {
    #[must_use]
    pub fn new(diag_groups: Arc<Mutex<Vec<DiagGroup>>>) -> Self {
        LogView {
            diag_groups,
            ..Default::default()
        }
    }
}

impl Component for LogView {
    fn register_action_handler(&mut self, tx: UnboundedSender<Action>) -> Result<()> {
        self.command_tx = Some(tx);
        Ok(())
    }

    fn register_config_handler(&mut self, config: Config) -> Result<()> {
        self.config = config;
        Ok(())
    }

    fn update(&mut self, action: Action) -> Result<Option<Action>> {
        match action {
            Action::KeyUp => {
                if self.mode == Mode::LogView {
                    if self.line_index > 0 {
                        self.line_index = self.line_index - 1;
                    }
                } else {
                    self.list.previous();
                }
            }
            Action::KeyDown => {
                if self.mode == Mode::LogView {
                    let new_index = self.line_index + 1;
                    if let Some(log_text) = self.list.get_selected() {
                        let lines: Vec<&str> = log_text.split('\n').collect();
                        if new_index as usize > lines.len() {
                            self.line_index = lines.len() as u16;
                        } else {
                            self.line_index = new_index;
                        }
                    }
                } else {
                    self.list.next();
                }
            }
            Action::KeyPageUp => {
                if self.mode == Mode::LogView {
                    if self.line_index > 10 {
                        self.line_index -= 10;
                    } else {
                        self.line_index = 0;
                    }
                }
            }
            Action::KeyPageDown => {
                if self.mode == Mode::LogView {
                    let new_index = self.line_index + 10;
                    if let Some(log_text) = self.list.get_selected() {
                        let lines: Vec<&str> = log_text.split('\n').collect();
                        let new_index: u16 = min((lines.len() - 3) as u16, new_index);
                        self.line_index = new_index;
                    }
                }
            }
            Action::KeyHome => {
                if self.mode == Mode::LogView {
                    self.line_index = 0;
                }
            }
            Action::KeyEnd => {
                if self.mode == Mode::LogView {
                    if let Some(log_text) = self.list.get_selected() {
                        let lines: Vec<&str> = log_text.split('\n').collect();
                        self.line_index = (lines.len() - 3) as u16;
                    }
                }
            }
            Action::Process => {
                if self.mode == Mode::LogView {
                    if let Some(command_tx) = self.command_tx.clone() {
                        command_tx.send(Action::SetMode(Mode::BootDiags))?;
                    }
                }
            }
            Action::SetMode(new_mode) => {
                self.line_index = 0;
                self.mode = new_mode;
                if self.mode == Mode::BootDiags {
                    self.list.clear_items();
                    if let Ok(diag_groups) = self.diag_groups.lock() {
                        let raw_logs = diag_groups
                            .iter()
                            .map(|group| group.get_logs_raw())
                            .collect();
                        self.list.set_items(raw_logs);
                    }
                }
            }
            _ => {}
        };
        Ok(None)
    }

    fn draw(&mut self, frame: &mut Frame, rect: Rect) -> Result<()> {
        if self.mode != Mode::LogView {
            return Ok(());
        }

        if let Some(log_text) = self.list.get_selected() {
            let paragraph = Paragraph::new(log_text)
                .wrap(Wrap { trim: true })
                .scroll((self.line_index, 0))
                .block(Block::bordered().padding(Padding::horizontal(1)));
            frame.render_widget(Clear, rect);
            frame.render_widget(paragraph, rect);
        }

        Ok(())
    }
}