use editor::{EditorBlurred, EditorFocused, EditorMode, EditorReleased, Event};
use gpui::MutableAppContext;

use crate::{state::Mode, Vim};

pub fn init(cx: &mut MutableAppContext) {
    cx.subscribe_global(focused).detach();
    cx.subscribe_global(blurred).detach();
    cx.subscribe_global(released).detach();
}

fn focused(EditorFocused(editor): &EditorFocused, cx: &mut MutableAppContext) {
    Vim::update(cx, |vim, cx| {
        if let Some(previously_active_editor) = vim
            .active_editor
            .as_ref()
            .and_then(|editor| editor.upgrade(cx))
        {
            vim.unhook_vim_settings(previously_active_editor, cx);
        }

        vim.active_editor = Some(editor.downgrade());
        vim.editor_subscription = Some(cx.subscribe(editor, |editor, event, cx| match event {
            Event::SelectionsChanged { local: true } => {
                let editor = editor.read(cx);
                if editor.leader_replica_id().is_none() {
                    let newest_empty = editor.selections.newest::<usize>(cx).is_empty();
                    local_selections_changed(newest_empty, cx);
                }
            }
            Event::InputIgnored { text } => {
                Vim::active_editor_input_ignored(text.clone(), cx);
            }
            _ => {}
        }));

        if vim.enabled {
            let editor = editor.read(cx);
            let editor_mode = editor.mode();
            let newest_selection_empty = editor.selections.newest::<usize>(cx).is_empty();

            if editor_mode == EditorMode::Full && !newest_selection_empty {
                vim.switch_mode(Mode::Visual { line: false }, true, cx);
            }
        }

        vim.sync_vim_settings(cx);
    });
}

fn blurred(EditorBlurred(editor): &EditorBlurred, cx: &mut MutableAppContext) {
    Vim::update(cx, |vim, cx| {
        if let Some(previous_editor) = vim.active_editor.clone() {
            if previous_editor == editor.clone() {
                vim.active_editor = None;
            }
        }
        vim.unhook_vim_settings(editor.clone(), cx);
    })
}

fn released(EditorReleased(editor): &EditorReleased, cx: &mut MutableAppContext) {
    cx.update_default_global(|vim: &mut Vim, _| {
        if let Some(previous_editor) = vim.active_editor.clone() {
            if previous_editor == editor.clone() {
                vim.active_editor = None;
            }
        }
    });
}

fn local_selections_changed(newest_empty: bool, cx: &mut MutableAppContext) {
    Vim::update(cx, |vim, cx| {
        if vim.enabled && vim.state.mode == Mode::Normal && !newest_empty {
            vim.switch_mode(Mode::Visual { line: false }, false, cx)
        }
    })
}