//! Implemented interfaces for Rozinante.

use cairo_sys::*;
use gdk_pixbuf_sys::*;
use gdk_sys::*;
use maraiah::{c_str, durandal::{ffi::*, image::*}, rozinante::draw::*};

/// Converts a `Color` to a `f64` triple.
fn flt_color(cr: impl Color) -> (f64, f64, f64)
{
   fn flt_color(n: u16) -> f64 {f64::from(n) / f64::from(u16::max_value())}

   (flt_color(cr.r()), flt_color(cr.g()), flt_color(cr.b()))
}

impl CacheImage for CrImage
{
   fn w(&self) -> Coord {unsafe {gdk_pixbuf_get_width(self.0)  as Coord}}
   fn h(&self) -> Coord {unsafe {gdk_pixbuf_get_height(self.0) as Coord}}
}

impl CrDrawArea
{
   pub const fn new(ctx: *mut cairo_t, w: f64, h: f64) -> Self
   {
      CrDrawArea{ctx, w: w as Coord, h: h as Coord}
   }
}

impl DrawArea for CrDrawArea
{
   type NativeImage = CrImage;

   fn w(&self) -> Coord {self.w}
   fn h(&self) -> Coord {self.h}

   fn clear(&mut self, cr: impl Color)
   {
      self.rect(Rect{x: 0, y: 0, w: self.w(), h: self.h()}, cr);

      let sl = FONT_SLANT_NORMAL;
      let wt = FONT_WEIGHT_NORMAL;

      unsafe {
         cairo_select_font_face(self.ctx, c_str!("Monospace"), sl, wt);
         cairo_set_font_size(self.ctx, 14.0);
         cairo_set_line_width(self.ctx, 1.0);
      }
   }

   fn line_width(&mut self, width: u8)
   {
      let width = f64::from(width);

      unsafe {
         cairo_set_line_width(self.ctx, width);
      }
   }

   fn line(&mut self, p1: Point, p2: Point, cr: impl Color)
   {
      let (r, g, b) = flt_color(cr);

      let x1 = f64::from(p1.0);
      let y1 = f64::from(p1.1);

      let x2 = f64::from(p2.0);
      let y2 = f64::from(p2.1);

      unsafe {
         cairo_set_source_rgb(self.ctx, r, g, b);
         cairo_move_to(self.ctx, x1, y1);
         cairo_line_to(self.ctx, x2, y2);
         cairo_stroke(self.ctx);
      }
   }

   fn rect(&mut self, rect: Rect, cr: impl Color)
   {
      let px = f64::from(rect.x);
      let py = f64::from(rect.y);
      let sx = f64::from(rect.w);
      let sy = f64::from(rect.h);

      let (r, g, b) = flt_color(cr);

      unsafe {
         cairo_set_source_rgb(self.ctx, r, g, b);
         cairo_rectangle(self.ctx, px, py, sx, sy);
         cairo_fill(self.ctx);
      }
   }

   fn text(&mut self, pos: Point, text: &str, cr: impl Color)
   {
      let (r, g, b) = flt_color(cr);

      let x = f64::from(pos.0);
      let y = f64::from(pos.1);

      let text = CString::new(text).unwrap();

      unsafe {
         cairo_set_source_rgb(self.ctx, r, g, b);
         cairo_move_to(self.ctx, x, y);
         cairo_show_text(self.ctx, text.as_ptr());
      }
   }

   fn image(&mut self, pos: Point, im: &Self::NativeImage)
   {
      let x = f64::from(pos.0);
      let y = f64::from(pos.1);

      unsafe {
         gdk_cairo_set_source_pixbuf(self.ctx, im.0, x, y);
         cairo_paint(self.ctx);
      }
   }
}

/// An image for a `CrDrawArea`.
pub struct CrImage(pub *const GdkPixbuf);

/// A `DrawArea` for a Cairo surface.
pub struct CrDrawArea
{
   ctx: *mut cairo_t,
   w:   Coord,
   h:   Coord,
}

// EOF