use crate::app::{state::UnsavedAction, TextEditor};
use eframe::egui::{self, Frame};

pub(crate) fn tab_bar(app: &mut TextEditor, ctx: &egui::Context) {
    let frame = Frame::NONE.fill(ctx.style().visuals.panel_fill);
    let tab_bar = egui::TopBottomPanel::top("tab_bar")
        .frame(frame)
        .show(ctx, |ui| {
            egui::ScrollArea::horizontal()
                .auto_shrink([false, true])
                .scroll_bar_visibility(egui::scroll_area::ScrollBarVisibility::AlwaysHidden)
                .scroll_source(egui::scroll_area::ScrollSource::DRAG)
                .show(ui, |ui| {
                    ui.horizontal(|ui| {
                        let mut tab_to_close_unmodified = None;
                        let mut tab_to_close_modified = None;
                        let mut tab_to_switch = None;
                        let mut add_new_tab = false;

                        let tabs_len = app.tabs.len();
                        let active_tab_index = app.active_tab_index;

                        let tabs_info: Vec<(String, bool)> = app
                            .tabs
                            .iter()
                            .map(|tab| (tab.get_display_title(), tab.is_modified))
                            .collect();

                        for (i, (title, is_modified)) in tabs_info.iter().enumerate() {
                            let is_active = i == active_tab_index;

                            let mut label_text = if is_active {
                                egui::RichText::new(title).strong()
                            } else {
                                egui::RichText::new(title).color(ui.visuals().weak_text_color())
                            };

                            if *is_modified {
                                label_text = label_text.italics();
                            }

                            let tab_response = ui.add(egui::Label::new(label_text).selectable(false).sense(egui::Sense::click()));
                            if tab_response.clicked() {
                                tab_to_switch = Some(i);
                            }

                            if tabs_len > 1 {
                                let visuals = ui.visuals();
                                let close_button = egui::Button::new("×")
                                    .small()
                                    .fill(visuals.panel_fill)
                                    .stroke(egui::Stroke::new(0.0, egui::Color32::from_rgb(0, 0, 0)));
                                let close_response = ui.add(close_button);
                                if close_response.clicked() {
                                    if *is_modified {
                                        tab_to_close_modified = Some(i);
                                    } else {
                                        tab_to_close_unmodified = Some(i);
                                    }
                                }
                            }

                            ui.separator();
                        }

                        let visuals = ui.visuals();
                        let add_button = egui::Button::new("+")
                            .small()
                            .fill(visuals.panel_fill)
                            .stroke(egui::Stroke::new(0.0, egui::Color32::from_rgb(0, 0, 0)));
                        if ui.add(add_button).clicked() {
                            add_new_tab = true;
                        }

                        if let Some(tab_index) = tab_to_switch {
                            app.switch_to_tab(tab_index);
                        }
                        if let Some(tab_index) = tab_to_close_unmodified {
                            app.close_tab(tab_index);
                        }
                        if let Some(tab_index) = tab_to_close_modified {
                            app.switch_to_tab(tab_index);
                            app.pending_unsaved_action = Some(UnsavedAction::CloseTab(tab_index));
                        }
                        if add_new_tab {
                            app.add_new_tab();
                        }
                    });
                });
        });

    app.tab_bar_rect = Some(tab_bar.response.rect);
    
}