#[derive(Debug, PartialEq)]
#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
enum Enum {
    First,
    Second,
    Third,
}

/// Shows off one example of each major type of widget.
#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
pub struct WidgetGallery {
    enabled: bool,
    visible: bool,
    boolean: bool,
    radio: Enum,
    scalar: f32,
    string: String,
    color: egui::Color32,
    animate_progress_bar: bool,

    #[cfg(feature = "chrono")]
    #[cfg_attr(feature = "serde", serde(skip))]
    date: Option<chrono::NaiveDate>,

    #[cfg_attr(feature = "serde", serde(skip))]
    texture: Option<egui::TextureHandle>,
}

impl Default for WidgetGallery {
    fn default() -> Self {
        Self {
            enabled: true,
            visible: true,
            boolean: false,
            radio: Enum::First,
            scalar: 42.0,
            string: Default::default(),
            color: egui::Color32::LIGHT_BLUE.linear_multiply(0.5),
            animate_progress_bar: false,
            #[cfg(feature = "chrono")]
            date: None,
            texture: None,
        }
    }
}

impl super::Demo for WidgetGallery {
    fn name(&self) -> &'static str {
        "🗄 Widget Gallery"
    }

    fn show(&mut self, ctx: &egui::Context, open: &mut bool) {
        egui::Window::new(self.name())
            .open(open)
            .resizable(true)
            .default_width(280.0)
            .show(ctx, |ui| {
                use super::View as _;
                self.ui(ui);
            });
    }
}

impl super::View for WidgetGallery {
    fn ui(&mut self, ui: &mut egui::Ui) {
        ui.add_enabled_ui(self.enabled, |ui| {
            ui.set_visible(self.visible);

            egui::Grid::new("my_grid")
                .num_columns(2)
                .spacing([40.0, 4.0])
                .striped(true)
                .show(ui, |ui| {
                    self.gallery_grid_contents(ui);
                });
        });

        ui.separator();

        ui.horizontal(|ui| {
            ui.checkbox(&mut self.visible, "Visible")
                .on_hover_text("Uncheck to hide all the widgets.");
            if self.visible {
                ui.checkbox(&mut self.enabled, "Interactive")
                    .on_hover_text("Uncheck to inspect how the widgets look when disabled.");
            }
        });

        ui.separator();

        ui.vertical_centered(|ui| {
            let tooltip_text = "The full egui documentation.\nYou can also click the different widgets names in the left column.";
            ui.hyperlink("https://docs.rs/egui/").on_hover_text(tooltip_text);
            ui.add(crate::egui_github_link_file!(
                "Source code of the widget gallery"
            ));
        });
    }
}

impl WidgetGallery {
    fn gallery_grid_contents(&mut self, ui: &mut egui::Ui) {
        let Self {
            enabled: _,
            visible: _,
            boolean,
            radio,
            scalar,
            string,
            color,
            animate_progress_bar,
            #[cfg(feature = "chrono")]
            date,
            texture,
        } = self;

        let texture: &egui::TextureHandle = texture.get_or_insert_with(|| {
            ui.ctx()
                .load_texture("example", egui::ColorImage::example(), Default::default())
        });

        ui.add(doc_link_label("Label", "label,heading"));
        ui.label("Welcome to the widget gallery!");
        ui.end_row();

        ui.add(doc_link_label("Hyperlink", "Hyperlink"));
        use egui::special_emojis::GITHUB;
        ui.hyperlink_to(
            format!("{} egui on GitHub", GITHUB),
            "https://github.com/emilk/egui",
        );
        ui.end_row();

        ui.add(doc_link_label("TextEdit", "TextEdit,text_edit"));
        ui.add(egui::TextEdit::singleline(string).hint_text("Write something here"));
        ui.end_row();

        ui.add(doc_link_label("Button", "button"));
        if ui.button("Click me!").clicked() {
            *boolean = !*boolean;
        }
        ui.end_row();

        ui.add(doc_link_label("Link", "link"));
        if ui.link("Click me!").clicked() {
            *boolean = !*boolean;
        }
        ui.end_row();

        ui.add(doc_link_label("Checkbox", "checkbox"));
        ui.checkbox(boolean, "Checkbox");
        ui.end_row();

        ui.add(doc_link_label("RadioButton", "radio"));
        ui.horizontal(|ui| {
            ui.radio_value(radio, Enum::First, "First");
            ui.radio_value(radio, Enum::Second, "Second");
            ui.radio_value(radio, Enum::Third, "Third");
        });
        ui.end_row();

        ui.add(doc_link_label(
            "SelectableLabel",
            "selectable_value,SelectableLabel",
        ));
        ui.horizontal(|ui| {
            ui.selectable_value(radio, Enum::First, "First");
            ui.selectable_value(radio, Enum::Second, "Second");
            ui.selectable_value(radio, Enum::Third, "Third");
        });
        ui.end_row();

        ui.add(doc_link_label("ComboBox", "ComboBox"));

        egui::ComboBox::from_label("Take your pick")
            .selected_text(format!("{:?}", radio))
            .show_ui(ui, |ui| {
                ui.style_mut().wrap = Some(false);
                ui.set_min_width(60.0);
                ui.selectable_value(radio, Enum::First, "First");
                ui.selectable_value(radio, Enum::Second, "Second");
                ui.selectable_value(radio, Enum::Third, "Third");
            });
        ui.end_row();

        ui.add(doc_link_label("Slider", "Slider"));
        ui.add(egui::Slider::new(scalar, 0.0..=360.0).suffix("°"));
        ui.end_row();

        ui.add(doc_link_label("DragValue", "DragValue"));
        ui.add(egui::DragValue::new(scalar).speed(1.0));
        ui.end_row();

        ui.add(doc_link_label("ProgressBar", "ProgressBar"));
        let progress = *scalar / 360.0;
        let progress_bar = egui::ProgressBar::new(progress)
            .show_percentage()
            .animate(*animate_progress_bar);
        *animate_progress_bar = ui
            .add(progress_bar)
            .on_hover_text("The progress bar can be animated!")
            .hovered();
        ui.end_row();

        ui.add(doc_link_label("Color picker", "color_edit"));
        ui.color_edit_button_srgba(color);
        ui.end_row();

        let img_size = 16.0 * texture.size_vec2() / texture.size_vec2().y;

        ui.add(doc_link_label("Image", "Image"));
        ui.image(texture, img_size);
        ui.end_row();

        ui.add(doc_link_label("ImageButton", "ImageButton"));
        if ui.add(egui::ImageButton::new(texture, img_size)).clicked() {
            *boolean = !*boolean;
        }
        ui.end_row();

        #[cfg(feature = "chrono")]
        {
            let date = date.get_or_insert_with(|| chrono::offset::Utc::now().date_naive());
            ui.add(doc_link_label("DatePickerButton", "DatePickerButton"));
            ui.add(egui_extras::DatePickerButton::new(date));
            ui.end_row();
        }

        ui.add(doc_link_label("Separator", "separator"));
        ui.separator();
        ui.end_row();

        ui.add(doc_link_label("CollapsingHeader", "collapsing"));
        ui.collapsing("Click to see what is hidden!", |ui| {
            ui.horizontal_wrapped(|ui| {
                ui.spacing_mut().item_spacing.x = 0.0;
                ui.label("It's a ");
                ui.add(doc_link_label("Spinner", "spinner"));
                ui.add_space(4.0);
                ui.add(egui::Spinner::new());
            });
        });
        ui.end_row();

        ui.add(doc_link_label("Plot", "plot"));
        example_plot(ui);
        ui.end_row();

        ui.hyperlink_to(
            "Custom widget:",
            super::toggle_switch::url_to_file_source_code(),
        );
        ui.add(super::toggle_switch::toggle(boolean)).on_hover_text(
            "It's easy to create your own widgets!\n\
            This toggle switch is just 15 lines of code.",
        );
        ui.end_row();
    }
}

fn example_plot(ui: &mut egui::Ui) -> egui::Response {
    use egui::plot::{Line, PlotPoints};
    let n = 128;
    let line_points: PlotPoints = (0..=n)
        .map(|i| {
            use std::f64::consts::TAU;
            let x = egui::remap(i as f64, 0.0..=n as f64, -TAU..=TAU);
            [x, x.sin()]
        })
        .collect();
    let line = Line::new(line_points);
    egui::plot::Plot::new("example_plot")
        .height(32.0)
        .data_aspect(1.0)
        .show(ui, |plot_ui| plot_ui.line(line))
        .response
}

fn doc_link_label<'a>(title: &'a str, search_term: &'a str) -> impl egui::Widget + 'a {
    let label = format!("{}:", title);
    let url = format!("https://docs.rs/egui?search={}", search_term);
    move |ui: &mut egui::Ui| {
        ui.hyperlink_to(label, url).on_hover_ui(|ui| {
            ui.horizontal_wrapped(|ui| {
                ui.label("Search egui docs for");
                ui.code(search_term);
            });
        })
    }
}