// Pushrod Widget Library
// Image Widget
//
// 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 crate::render::callbacks::CallbackRegistry;
use crate::render::layout_cache::LayoutContainer;
use crate::render::widget::*;
use crate::render::widget_cache::WidgetContainer;
use crate::render::widget_config::{
    CompassPosition, Config, WidgetConfig, CONFIG_COLOR_BASE, CONFIG_IMAGE_POSITION, CONFIG_SIZE,
};
use crate::render::{make_size, Points, Size};

use sdl2::rect::Rect;
use sdl2::render::{Canvas, Texture, TextureQuery};
use sdl2::video::Window;

use crate::render::texture_cache::TextureCache;
use crate::render::texture_store::TextureStore;
use std::any::Any;
use std::collections::HashMap;

/// This is the storage object for the `ImageWidget`.  It stores the config, properties, callback registry,
/// the image name, and a scale flag.
pub struct ImageWidget {
    config: WidgetConfig,
    system_properties: HashMap<i32, String>,
    callback_registry: CallbackRegistry,
    texture_store: TextureStore,
    image_name: String,
    scaled: bool,
    texture_sizes: Size,
}

/// Creates a new `ImageWidget`, which draws an image in a supported image format for SDL2 at a specific
/// location on the screen.  Requires the name of the image (the full path to the file), the position
/// within the widget (defined as `ImagePosition`), the xywh bounds, and whether or not the image is
/// scaled within the bounds of the `Widget`.
impl ImageWidget {
    /// Creates a new instance of the `ImageWidget` object.  Requires an image name (full path of the file),
    /// image position (defined in `ImagePosition`), the `xywh` bounds of the `Widget`, and a scale flag.
    /// If `scaled` is set to `true`, the image will be scaled within the `Widget` bounds, and the
    /// `ImagePosition` will be ignored.  Likewise, if set to `false`, the image will be displayed for
    /// the size of the image, and will be placed in the bounds of the `Widget` based on the position
    /// specified in the `ImagePosition`.
    pub fn new(image_name: String, points: Points, size: Size, scaled: bool) -> Self {
        Self {
            config: WidgetConfig::new(points, size),
            system_properties: HashMap::new(),
            callback_registry: CallbackRegistry::new(),
            texture_store: TextureStore::default(),
            image_name,
            scaled,
            texture_sizes: make_size(0, 0),
        }
    }

    /// Returns the size of the texture.
    pub fn get_texture_size(&self) -> Size {
        self.texture_sizes.clone()
    }
}

/// This is the `Widget` implementation of the `ImageWidget`.  Image is rendered onto a 3D texture, then
/// copied to the canvas after rendering.
impl Widget for ImageWidget {
    fn draw(&mut self, c: &mut Canvas<Window>, t: &mut TextureCache) -> Option<&Texture> {
        if self.get_config().invalidated() {
            let bounds = self.get_config().get_size(CONFIG_SIZE);

            self.texture_store
                .create_or_resize_texture(c, bounds[0] as u32, bounds[1] as u32);

            let base_color = self.get_color(CONFIG_COLOR_BASE);
            let image_texture = t.get_image(c, self.image_name.clone());
            let widget_w = self.get_size(CONFIG_SIZE)[0] as i32;
            let widget_h = self.get_size(CONFIG_SIZE)[1] as i32;
            let TextureQuery { width, height, .. } = image_texture.query();
            let scaled = self.scaled;

            self.texture_sizes = make_size(width, height);

            let texture_x = match self.get_compass(CONFIG_IMAGE_POSITION) {
                CompassPosition::NW | CompassPosition::W | CompassPosition::SW => 0,

                CompassPosition::N | CompassPosition::Center | CompassPosition::S => {
                    (widget_w - width as i32) / 2
                }

                CompassPosition::NE | CompassPosition::E | CompassPosition::SE => {
                    widget_w - width as i32
                }
            };

            let texture_y = match self.get_compass(CONFIG_IMAGE_POSITION) {
                CompassPosition::NW | CompassPosition::N | CompassPosition::NE => 0,

                CompassPosition::W | CompassPosition::Center | CompassPosition::E => {
                    (widget_h - height as i32) / 2
                }

                CompassPosition::SW | CompassPosition::S | CompassPosition::SE => {
                    widget_h - height as i32
                }
            };

            c.with_texture_canvas(self.texture_store.get_mut_ref(), |texture| {
                texture.set_draw_color(base_color);
                texture.clear();

                if !scaled {
                    texture
                        .copy(
                            image_texture,
                            None,
                            Rect::new(texture_x, texture_y, width, height),
                        )
                        .unwrap();
                } else {
                    texture
                        .copy(
                            image_texture,
                            None,
                            Rect::new(0, 0, widget_w as u32, widget_h as u32),
                        )
                        .unwrap();
                }
            })
            .unwrap();
        }

        self.texture_store.get_optional_ref()
    }

    /// Responds to a screen redraw only if the `CONFIG_IMAGE_POSITION` key was changed.
    fn on_config_changed(&mut self, _k: u8, _v: Config) {
        if _k == CONFIG_IMAGE_POSITION {
            self.get_config().set_invalidated(true);
        }
    }

    default_widget_functions!();
    default_widget_properties!();
    default_widget_callbacks!();
}