use crate::{
    align::{horizontal, vertical, Alignment, HorizontalAlignment, VerticalAlignment},
    layout::linear::{
        secondary_alignment::SecondaryAlignment,
        spacing::{ElementSpacing, Tight},
    },
    View,
};
use embedded_graphics::{
    prelude::{Point, Size},
    primitives::Rectangle,
};

/// Helper trait that describes a linear layout orientation.
pub trait Orientation: Copy + Clone {
    /// Secondary alignment that will be applied to all the views
    type Secondary: SecondaryAlignment + Alignment;

    /// Destructure `Size` into `(primary_size, secondary_size)`
    fn destructure_size(size: Size) -> (u32, u32);

    /// Create a `Size` from primary and secondary size values
    fn create_size(primary: u32, secondary: u32) -> Size;

    /// Computes translation for the next view.
    fn compute_offset(
        &self,
        bounds: Rectangle,
        size: Size,
        previous: Rectangle,
        n: usize,
        count: usize,
    ) -> Point;

    /// Place view
    #[inline]
    fn place(
        &self,
        view: &mut dyn View,
        size: Size,
        previous: Rectangle,
        n: usize,
        count: usize,
    ) -> Rectangle {
        let offset = self.compute_offset(view.bounds(), size, previous, n, count);
        view.translate_impl(offset);
        view.bounds()
    }
}

/// Horizontal layout direction
#[derive(Copy, Clone)]
pub struct Horizontal<Secondary, Spacing = Tight>
where
    Secondary: SecondaryAlignment + VerticalAlignment,
    Spacing: ElementSpacing,
{
    pub(crate) secondary: Secondary,
    pub(crate) spacing: Spacing,
}

impl<Secondary, Spacing> Horizontal<Secondary, Spacing>
where
    Secondary: SecondaryAlignment + VerticalAlignment,
    Spacing: ElementSpacing,
{
    /// Change secondary alignment
    #[inline]
    pub fn with_secondary_alignment<Sec: SecondaryAlignment + VerticalAlignment>(
        self,
        secondary: Sec,
    ) -> Horizontal<Sec, Spacing> {
        Horizontal {
            secondary,
            spacing: self.spacing,
        }
    }

    /// Change element spacing
    #[inline]
    pub fn with_spacing<ElSpacing: ElementSpacing>(
        self,
        spacing: ElSpacing,
    ) -> Horizontal<Secondary, ElSpacing> {
        Horizontal {
            secondary: self.secondary,
            spacing,
        }
    }
}

impl Default for Horizontal<vertical::Bottom, Tight> {
    #[inline]
    fn default() -> Self {
        Self {
            secondary: vertical::Bottom,
            spacing: Tight,
        }
    }
}

impl<Secondary, Spacing> Orientation for Horizontal<Secondary, Spacing>
where
    Secondary: SecondaryAlignment + VerticalAlignment,
    Spacing: ElementSpacing,
{
    type Secondary = Secondary;

    #[inline]
    fn destructure_size(size: Size) -> (u32, u32) {
        (size.width, size.height)
    }

    #[inline]
    fn create_size(primary: u32, secondary: u32) -> Size {
        Size::new(primary, secondary)
    }

    #[inline]
    fn compute_offset(
        &self,
        bounds: Rectangle,
        size: Size,
        previous: Rectangle,
        n: usize,
        count: usize,
    ) -> Point {
        let (primary_size, _) = Self::destructure_size(size);

        if n == 0 {
            Point::new(
                self.spacing
                    .align(horizontal::Left, bounds, previous, n, count, primary_size),
                Secondary::First::default().align(bounds, previous),
            )
        } else {
            Point::new(
                self.spacing.align(
                    horizontal::LeftToRight,
                    bounds,
                    previous,
                    n,
                    count,
                    primary_size,
                ),
                Secondary::default().align(bounds, previous),
            )
        }
    }
}

/// Vertical layout direction
#[derive(Copy, Clone)]
pub struct Vertical<Secondary, Spacing = Tight>
where
    Secondary: SecondaryAlignment + HorizontalAlignment,
    Spacing: ElementSpacing,
{
    pub(crate) secondary: Secondary,
    pub(crate) spacing: Spacing,
}

impl Default for Vertical<horizontal::Left, Tight> {
    #[inline]
    fn default() -> Self {
        Self {
            secondary: horizontal::Left,
            spacing: Tight,
        }
    }
}

impl<Secondary, Spacing> Vertical<Secondary, Spacing>
where
    Secondary: SecondaryAlignment + HorizontalAlignment,
    Spacing: ElementSpacing,
{
    /// Change secondary alignment
    #[inline]
    pub fn with_secondary_alignment<Sec: SecondaryAlignment + HorizontalAlignment>(
        self,
        secondary: Sec,
    ) -> Vertical<Sec, Spacing> {
        Vertical {
            secondary,
            spacing: self.spacing,
        }
    }

    /// Change element spacing
    #[inline]
    pub fn with_spacing<ElSpacing: ElementSpacing>(
        self,
        spacing: ElSpacing,
    ) -> Vertical<Secondary, ElSpacing> {
        Vertical {
            secondary: self.secondary,
            spacing,
        }
    }
}

impl<Secondary, Spacing> Orientation for Vertical<Secondary, Spacing>
where
    Secondary: SecondaryAlignment + HorizontalAlignment,
    Spacing: ElementSpacing,
{
    type Secondary = Secondary;

    #[inline]
    fn destructure_size(size: Size) -> (u32, u32) {
        (size.height, size.width)
    }

    #[inline]
    fn create_size(primary: u32, secondary: u32) -> Size {
        Size::new(secondary, primary)
    }

    #[inline]
    fn compute_offset(
        &self,
        bounds: Rectangle,
        size: Size,
        previous: Rectangle,
        n: usize,
        count: usize,
    ) -> Point {
        let (primary_size, _) = Self::destructure_size(size);

        if n == 0 {
            Point::new(
                Secondary::First::default().align(bounds, previous),
                self.spacing
                    .align(vertical::Top, bounds, previous, n, count, primary_size),
            )
        } else {
            Point::new(
                Secondary::default().align(bounds, previous),
                self.spacing.align(
                    vertical::TopToBottom,
                    bounds,
                    previous,
                    n,
                    count,
                    primary_size,
                ),
            )
        }
    }
}