oxwm

use super::{GapConfig, Layout, WindowGeometry};

use x11rb::protocol::xproto::Window;

pub struct GridLayout;

impl Layout for GridLayout {

    fn name(&self) -> &'static str {

        super::LayoutType::Grid.as_str()

    }

    fn symbol(&self) -> &'static str {

        "[#]"

    }

    fn arrange(

        &self,

        windows: &[Window],

        screen_width: u32,

        screen_height: u32,

        gaps: &GapConfig,

    ) -> Vec<WindowGeometry> {

        let window_count = windows.len();

        if window_count == 0 {

            return Vec::new();

        }

        if window_count == 1 {

            let x = gaps.outer_horizontal as i32;

            let y = gaps.outer_vertical as i32;

            let width = screen_width.saturating_sub(2 * gaps.outer_horizontal);

            let height = screen_height.saturating_sub(2 * gaps.outer_vertical);

            return vec![WindowGeometry {

                x_coordinate: x,

                y_coordinate: y,

                width,

                height,

            }];

        }

        let cols = (window_count as f64).sqrt().ceil() as usize;

        let rows = (window_count as f64 / cols as f64).ceil() as usize;

        let mut geometries = Vec::new();

        let total_horizontal_gaps =

            gaps.outer_horizontal * 2 + gaps.inner_horizontal * (cols as u32 - 1);

        let total_vertical_gaps = gaps.outer_vertical * 2 + gaps.inner_vertical * (rows as u32 - 1);

        let cell_width = screen_width.saturating_sub(total_horizontal_gaps) / cols as u32;

        let cell_height = screen_height.saturating_sub(total_vertical_gaps) / rows as u32;

        for (index, _window) in windows.iter().enumerate() {

            let row = index / cols;

            let col = index % cols;

            let is_last_row = row == rows - 1;

            let windows_in_last_row = window_count - (rows - 1) * cols;

            let (x, y, width, height) = if is_last_row && windows_in_last_row < cols {

                let last_row_col = index % cols;

                let last_row_cell_width =

                    screen_width.saturating_sub(total_horizontal_gaps.saturating_sub(

                        gaps.inner_horizontal * (cols as u32 - windows_in_last_row as u32),

                    )) / windows_in_last_row as u32;

                let x = gaps.outer_horizontal

                    + last_row_col as u32 * (last_row_cell_width + gaps.inner_horizontal);

                let y = gaps.outer_vertical + row as u32 * (cell_height + gaps.inner_vertical);

                (x as i32, y as i32, last_row_cell_width, cell_height)

            } else {

                let x = gaps.outer_horizontal + col as u32 * (cell_width + gaps.inner_horizontal);

                let y = gaps.outer_vertical + row as u32 * (cell_height + gaps.inner_vertical);

                (x as i32, y as i32, cell_width, cell_height)

            };

            geometries.push(WindowGeometry {

                x_coordinate: x,

                y_coordinate: y,

                width,

                height,

            });

        }

        geometries

    }

}