use std::process::Command;
use crossterm::event::{Event, KeyCode, KeyEvent, KeyModifiers};
use crate::state::{AppState, TimeItem};

pub struct App {
    pub state: AppState,
}

impl App {
    pub fn new() -> anyhow::Result<Self> {
        Ok(Self {
            state: AppState::load()?,
        })
    }

    pub fn handle_event(&mut self, event: Event) -> anyhow::Result<bool> {
        match event {
            Event::Key(KeyEvent {
                code,
                modifiers,
                ..
            }) => match (code, modifiers) {
                (KeyCode::Char('q'), _) => return Ok(true),
                (KeyCode::Char('j'), _) | (KeyCode::Down, _) => self.move_selection(1),
                (KeyCode::Char('k'), _) | (KeyCode::Up, _) => self.move_selection(-1),
                (KeyCode::Char('h'), _) | (KeyCode::Left, _) => self.change_pane(-1),
                (KeyCode::Char('l'), _) | (KeyCode::Right, _) => self.change_pane(1),
                (KeyCode::Enter, _) => self.toggle_current_item()?,
                (KeyCode::Char('e'), KeyModifiers::CONTROL) => self.edit_config()?,
                _ => {}
            },
            _ => {}
        }
        Ok(false)
    }

    fn move_selection(&mut self, delta: i32) {
        let items_len = match self.state.current_pane {
            0 => self.state.permanent_items.len(),
            1 => self.state.recurring_items.len(),
            2 => self.state.recent_items.len(),
            _ => return,
        };

        if items_len == 0 {
            return;
        }

        let current = self.state.selected_indices[self.state.current_pane] as i32;
        let new_index = (current + delta).rem_euclid(items_len as i32) as usize;
        self.state.selected_indices[self.state.current_pane] = new_index;
    }

    fn change_pane(&mut self, delta: i32) {
        self.state.current_pane = ((self.state.current_pane as i32 + delta).rem_euclid(3)) as usize;
    }

    fn get_current_item(&self) -> Option<TimeItem> {
        let items = match self.state.current_pane {
            0 => &self.state.permanent_items,
            1 => &self.state.recurring_items,
            2 => &self.state.recent_items,
            _ => return None,
        };

        let index = self.state.selected_indices[self.state.current_pane];
        items.get(index).cloned()
    }

    fn toggle_current_item(&mut self) -> anyhow::Result<()> {
        if let Some(item) = self.get_current_item() {
            if self.state.active_timer.as_ref().map(|(active, _)| active.name == item.name).unwrap_or(false) {
                self.state.stop_timer()?;
            } else {
                self.state.start_timer(item)?;
            }
            self.state.save()?;
        }
        Ok(())
    }

    fn edit_config(&self) -> anyhow::Result<()> {
        let editor = std::env::var("EDITOR").unwrap_or_else(|_| "vi".to_string());
        let config_path = AppState::config_file()?;
        
        if !config_path.exists() {
            std::fs::write(&config_path, "# WAT Configuration\n# Add your permanent items here\n\npermanent_items:\n  - name: Daily Standup\n    tags: [daily, meeting]\n")?;
        }

        Command::new(editor)
            .arg(&config_path)
            .spawn()?
            .wait()?;

        // Reload configuration
        if config_path.exists() {
            let contents = std::fs::read_to_string(config_path)?;
            let config: serde_yaml::Value = serde_yaml::from_str(&contents)?;
            
            if let Some(items) = config["permanent_items"].as_sequence() {
                // Clear existing permanent items
                self.state.permanent_items.clear();
                
                // Add new items from config
                for item in items {
                    if let (Some(name), Some(tags)) = (
                        item["name"].as_str(),
                        item["tags"].as_sequence()
                    ) {
                        let tags = tags
                            .iter()
                            .filter_map(|t| t.as_str())
                            .map(String::from)
                            .collect();
                            
                        self.state.permanent_items.push(TimeItem {
                            name: name.to_string(),
                            tags,
                            last_used: None,
                        });
                    }
                }
            }
        }

        Ok(())
    }
}