#![allow(clippy::if_same_then_else)]

use crate::{color::*, math::*, types::*};

#[derive(Clone, Copy, Debug, Serialize)]
pub struct Style {
    /// Horizontal and vertical padding within a window frame.
    pub window_padding: Vec2,

    /// Button size is text size plus this on each side
    pub button_padding: Vec2,

    /// Horizontal and vertical spacing between widgets
    pub item_spacing: Vec2,

    /// Indent collapsing regions etc by this much.
    pub indent: f32,

    /// Anything clickable is (at least) this wide.
    pub clickable_diameter: f32,

    /// Checkboxes, radio button and collapsing headers have an icon at the start.
    /// The text starts after this many pixels.
    pub start_icon_width: f32,

    // -----------------------------------------------
    // Purely visual:
    /// For stuff like check marks in check boxes.
    pub line_width: f32,

    pub cursor_blink_hz: f32,
    pub text_cursor_width: f32,

    // TODO: add ability to disable animations!
    /// How many seconds a typical animation should last
    pub animation_time: f32,

    pub window: Window,

    /// Allow child widgets to be just on the border and still have an outline with some thickness
    pub clip_rect_margin: f32,

    // -----------------------------------------------
    // Debug rendering:
    pub debug_regions: bool,
}

#[derive(Clone, Copy, Debug, Serialize)]
pub struct Window {
    pub corner_radius: f32,
}

impl Default for Style {
    fn default() -> Self {
        Style {
            window_padding: vec2(6.0, 6.0),
            button_padding: vec2(5.0, 3.0),
            item_spacing: vec2(8.0, 4.0),
            indent: 21.0,
            clickable_diameter: 22.0,
            start_icon_width: 16.0,
            line_width: 1.0,
            cursor_blink_hz: 1.0,
            text_cursor_width: 2.0,
            animation_time: 1.0 / 20.0,
            window: Window::default(),
            clip_rect_margin: 3.0,
            debug_regions: false,
        }
    }
}

impl Default for Window {
    fn default() -> Self {
        Window {
            corner_radius: 10.0,
        }
    }
}

impl Style {
    /// e.g. the background of the slider
    pub fn background_fill_color(&self) -> Color {
        gray(34, 250)
    }

    pub fn text_color(&self) -> Color {
        gray(255, 200)
    }

    /// Fill color of the interactive part of a component (button, slider grab, checkbox, ...)
    pub fn interact_fill_color(&self, interact: &InteractInfo) -> Option<Color> {
        if interact.active {
            Some(srgba(120, 120, 200, 255))
        } else if interact.hovered {
            Some(srgba(100, 100, 150, 255))
        } else {
            Some(srgba(60, 60, 80, 255))
        }
    }

    /// Stroke and text color of the interactive part of a component (button, slider grab, checkbox, ...)
    pub fn interact_stroke_color(&self, interact: &InteractInfo) -> Color {
        if interact.active {
            gray(255, 255)
        } else if interact.hovered {
            gray(255, 255)
        } else {
            gray(220, 255) // Mustn't look grayed out!
        }
    }

    /// For lines etc
    pub fn interact_stroke_width(&self, interact: &InteractInfo) -> f32 {
        if interact.active {
            2.0
        } else if interact.hovered {
            1.5
        } else {
            1.0
        }
    }

    /// For rectangles
    pub fn interact_outline(&self, interact: &InteractInfo) -> Option<Outline> {
        if interact.active {
            Some(Outline::new(
                self.interact_stroke_width(interact),
                self.interact_stroke_color(interact),
            ))
        } else if interact.hovered {
            None
        } else {
            None
        }
    }

    /// Buttons etc
    pub fn interact_corner_radius(&self, interact: &InteractInfo) -> f32 {
        if interact.active {
            5.0
        } else if interact.hovered {
            5.0
        } else {
            0.0
        }
    }

    /// Returns small icon rectangle and big icon rectangle
    pub fn icon_rectangles(&self, rect: &Rect) -> (Rect, Rect) {
        let box_side = self.start_icon_width;
        let big_icon_rect = Rect::from_center_size(
            pos2(rect.left() + box_side / 2.0, rect.center().y),
            vec2(box_side, box_side),
        );

        let small_icon_rect = Rect::from_center_size(big_icon_rect.center(), vec2(10.0, 10.0));

        (small_icon_rect, big_icon_rect)
    }
}

impl Style {
    #[rustfmt::skip]
    pub fn ui(&mut self, region: &mut crate::Region) {
        use crate::{widgets::*, *};
        if region.add(Button::new("Reset style")).clicked {
            *self = Default::default();
        }


        region.add(Slider::f32(&mut self.item_spacing.x,     0.0..=10.0).text("item_spacing.x").precision(0));
        region.add(Slider::f32(&mut self.item_spacing.y,     0.0..=10.0).text("item_spacing.y").precision(0));
        region.add(Slider::f32(&mut self.window_padding.x,   0.0..=10.0).text("window_padding.x").precision(0));
        region.add(Slider::f32(&mut self.window_padding.y,   0.0..=10.0).text("window_padding.y").precision(0));
        region.add(Slider::f32(&mut self.indent,             0.0..=100.0).text("indent").precision(0));
        region.add(Slider::f32(&mut self.button_padding.x,   0.0..=20.0).text("button_padding.x").precision(0));
        region.add(Slider::f32(&mut self.button_padding.y,   0.0..=20.0).text("button_padding.y").precision(0));
        region.add(Slider::f32(&mut self.clickable_diameter, 0.0..=60.0).text("clickable_diameter").precision(0));
        region.add(Slider::f32(&mut self.start_icon_width,   0.0..=60.0).text("start_icon_width").precision(0));
        region.add(Slider::f32(&mut self.line_width,         0.0..=10.0).text("line_width").precision(0));
        region.add(Slider::f32(&mut self.animation_time,     0.0..=1.0).text("animation_time").precision(2));


        // TODO: region.section("Heading", |ui| ui.add(contents))
        region.add(Separator::new());
        region.add(label!("Debug:").text_style(TextStyle::Heading));
        region.add(Checkbox::new(&mut self.debug_regions, "debug_regions"));
    }
}