// Box Widget
// Extensible widget for the widget library - handles drawing a box with a border and a fill color
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use opengl_graphics::GlGraphics;
use piston_window::*;

use std::cell::RefCell;
use std::collections::HashMap;

use crate::core::point::*;
use crate::widget::widget::*;

/// This is the `BoxWidget`, which contains a top-level widget for display, overriding the
/// draw method to draw the base widget and the border for this box.
pub struct BoxWidget {
    config: RefCell<HashMap<u8, WidgetConfig>>,
    base_widget: BaseWidget,
}

/// Implementation of the constructor for the `BaseWidget`.  Creates a new base widget
/// that can be positioned anywhere on the screen.
impl BoxWidget {
    pub fn new() -> Self {
        Self {
            config: RefCell::new(HashMap::new()),
            base_widget: BaseWidget::new(),
        }
    }

    /// Sets the border color for this widget.
    pub fn set_border_color(&mut self, color: types::Color) {
        self.set_config(
            CONFIG_COLOR_BORDER,
            WidgetConfig::BorderColor { color },
        );
        self.invalidate();
    }

    /// Retrieves the border color of this widget.
    /// Defaults to black color `[0.0, 0.0, 0.0, 1.0]` if not set.
    pub fn get_border_color(&mut self) -> types::Color {
        if self
            .get_config()
            .borrow()
            .contains_key(&CONFIG_COLOR_BORDER)
        {
            match self.get_config().borrow()[&CONFIG_COLOR_BORDER] {
                WidgetConfig::BorderColor { color } => color,
                _ => [0.0, 0.0, 0.0, 1.0],
            }
        } else {
            [0.0, 0.0, 0.0, 1.0]
        }
    }

    /// Sets the thickness of the border for this widget.
    pub fn set_border_thickness(&mut self, thickness: u8) {
        self.set_config(
            CONFIG_BORDER_WIDTH,
            WidgetConfig::BorderWidth { thickness },
        );
        self.invalidate();
    }

    /// Retrieves the border thickness of this widget.
    /// Defaults to 1 if not set.
    pub fn get_border_thickness(&mut self) -> u8 {
        if self
            .get_config()
            .borrow()
            .contains_key(&CONFIG_BORDER_WIDTH)
        {
            match self.get_config().borrow()[&CONFIG_BORDER_WIDTH] {
                WidgetConfig::BorderWidth { thickness } => thickness,
                _ => 1,
            }
        } else {
            1
        }
    }

    /// Function to draw a box for the point and size of this box.  Automatically draws the border
    /// along with the width of the border.  This is automatically determined by the origin, so the
    /// box is automatically drawn for the bounds of the `Widget`.
    fn draw_box(&mut self, context: Context, graphics: &mut GlGraphics) {
        let origin: Point = self.get_origin();
        let size: crate::core::point::Size = self.get_size();
        let border: f64 = self.get_border_thickness() as f64;
        let color: types::Color = self.get_border_color();

        // Upper left to upper right
        line(
            color,
            border,
            [
                origin.x as f64,
                origin.y as f64 + border,
                (origin.x + size.w) as f64,
                origin.y as f64 + border,
            ],
            context.transform,
            graphics,
        );

        // Upper left to lower right
        line(
            color,
            border,
            [
                (origin.x + size.w) as f64 - border,
                origin.y as f64 + border,
                (origin.x + size.w) as f64 - border,
                (origin.y + size.h) as f64,
            ],
            context.transform,
            graphics,
        );

        // Upper left to lower left
        line(
            color,
            border,
            [
                origin.x as f64 + border,
                origin.y as f64 + border,
                origin.x as f64 + border,
                (origin.y + size.h) as f64,
            ],
            context.transform,
            graphics,
        );

        // Lower left to lower right
        line(
            color,
            border,
            [
                origin.x as f64,
                (origin.y + size.h) as f64 - border,
                (origin.x + size.w) as f64,
                (origin.y + size.h) as f64 - border,
            ],
            context.transform,
            graphics,
        );
    }
}

/// Implementation of the `BoxWidget` object with the `Widget` traits implemented.
/// This implementation is similar to the `BaseWidget`, but incorporates a drawable box inside
/// the widget.  Base widget is the `BaseWidget`.
///
/// This is basically just a box with a fill color.  Use this to draw other things like buttons,
/// text widgets, and so on, if you need anything with a drawable border.
///
/// Example usage:
/// ```no_run
/// # use piston_window::*;
/// # use pushrod::core::point::*;
/// # use pushrod::core::window::*;
/// # use pushrod::widget::widget::*;
/// # use pushrod::widget::box_widget::*;
/// # fn main() {
/// #   let opengl = OpenGL::V3_2;
/// #   let mut pushrod_window: PushrodWindow = PushrodWindow::new(
/// #       WindowSettings::new("Pushrod Window", [640, 480])
/// #           .opengl(opengl)
/// #           .build()
/// #           .unwrap_or_else(|error| panic!("Failed to build PistonWindow: {}", error)),
/// #   );
/// #
///    let mut box_widget = BoxWidget::new();
///
///    box_widget.set_origin(Point { x: 100, y: 100 });
///    box_widget.set_size(pushrod::core::point::Size { w: 200, h: 200 });
///    box_widget.set_color([0.5, 0.5, 0.5, 1.0]);
///    box_widget.set_border_color([0.0, 0.0, 0.0, 1.0]);
///    box_widget.set_border_thickness(3);
/// # }
/// ```
impl Widget for BoxWidget {
    fn get_config(&mut self) -> &RefCell<HashMap<u8, WidgetConfig>> {
        &self.config
    }

    /// Sets the `Point` of origin for this widget and the base widget.  Invalidates the widget afterward.
    fn set_origin(&mut self, point: Point) {
        self.set_config(
            CONFIG_ORIGIN,
            WidgetConfig::Origin {
                point: point.clone(),
            },
        );
        self.base_widget.set_origin(point.clone());
        self.invalidate();
    }

    /// Sets the `Size` for this widget and the base widget.  Invalidates the widget afterward.
    fn set_size(&mut self, size: crate::core::point::Size) {
        self.set_config(
            CONFIG_SIZE,
            WidgetConfig::Size { size: size.clone() },
        );
        self.base_widget.set_size(size.clone());
        self.invalidate();
    }

    /// Sets the color for this widget.  Invalidates the widget afterward.
    fn set_color(&mut self, color: types::Color) {
        self.set_config(CONFIG_COLOR, WidgetConfig::Color { color });
        self.base_widget.set_color(color);
        self.invalidate();
    }

    /// Retrieves the color of this widget.
    /// Defaults to white color `[1.0; 4]` if not set.
    fn get_color(&mut self) -> types::Color {
        self.base_widget.get_color()
    }

    fn mouse_entered(&mut self, widget_id: i32) {
        eprintln!("[Box] Mouse entered: id={}", widget_id);
    }

    fn mouse_exited(&mut self, widget_id: i32) {
        eprintln!("[Box] Mouse exited: id={}", widget_id);
    }

    fn mouse_scrolled(&mut self, widget_id: i32, point: Point) {
        eprintln!(
            "[Box] Mouse scrolled: x={} y={}: id={}",
            point.x, point.y, widget_id
        );
    }

    /// Draws the contents of the widget in this order:
    ///
    /// - Base widget first
    /// - Box graphic for the specified width
    fn draw(&mut self, context: Context, graphics: &mut GlGraphics) {
        // Paint the base widget first.  Forcing a draw() call here will ignore invalidation.
        // Invalidation is controlled by the top level widget (this box).
        self.base_widget.draw(context, graphics);

        // Paint the box.
        self.draw_box(context, graphics);

        // Then clear invalidation.
        self.clear_invalidate();
    }
}