// src/pages/login/event.rs
use anyhow::Result;
use crossterm::event::{Event, KeyCode, KeyModifiers};
use canvas::{keymap::KeyEventOutcome, AppMode as CanvasMode};
use crate::{
    state::app::state::AppState,
    pages::login::LoginFormState,
    modes::handlers::event::EventOutcome,
};
use canvas::DataProvider;

/// Handles all Login page-specific events
pub fn handle_login_event(
    event: Event,
    app_state: &mut AppState,
    login_page: &mut LoginFormState,
) -> Result<EventOutcome> {
    if let Event::Key(key_event) = event {
        let key_code = key_event.code;
        let modifiers = key_event.modifiers;

        // From buttons (outside) back into the canvas (ReadOnly) with Up/k from the left-most button
        if login_page.focus_outside_canvas
            && login_page.focused_button_index == 0
                && matches!(key_code, KeyCode::Up | KeyCode::Char('k'))
                && modifiers.is_empty()
        {
            login_page.focus_outside_canvas = false;
            login_page.editor.set_mode(CanvasMode::ReadOnly);
            return Ok(EventOutcome::Ok(String::new()));
        }

        // Focus handoff: inside canvas → buttons
        if !login_page.focus_outside_canvas {
            let last_idx = login_page.editor.data_provider().field_count().saturating_sub(1);
            let at_last = login_page.editor.current_field() >= last_idx;
            if login_page.editor.mode() == CanvasMode::ReadOnly
                && at_last
                && matches!(
                    (key_code, modifiers),
                    (KeyCode::Char('j'), KeyModifiers::NONE) | (KeyCode::Down, _)
                )
            {
                login_page.focus_outside_canvas = true;
                login_page.focused_button_index = 0;
                login_page.editor.set_mode(CanvasMode::ReadOnly);
                return Ok(EventOutcome::Ok("Focus moved to buttons".into()));
            }
        }

        // Forward to canvas if focus is inside
        if !login_page.focus_outside_canvas {
            match login_page.handle_key_event(key_event) {
                KeyEventOutcome::Consumed(Some(msg)) => {
                    return Ok(EventOutcome::Ok(msg));
                }
                KeyEventOutcome::Consumed(None) => {
                    return Ok(EventOutcome::Ok("Login input updated".into()));
                }
                KeyEventOutcome::Pending => {
                    return Ok(EventOutcome::Ok("Waiting for next key...".into()));
                }
                KeyEventOutcome::NotMatched => {
                    // fall through to button handling
                }
            }
        }
    }

    Ok(EventOutcome::Ok(String::new()))
}