use cairo::{Context, Error, Extend, Format, ImageSurface, SurfacePattern};

pub const STITCH: [u8; 64] = [
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1,
];

pub const SHINGLES: [u8; 64] = [
    1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0,
    0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1,
];

pub const SHADOW_GRID: [u8; 64] = [
    1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0,
    0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0,
];

pub const WICKER: [u8; 64] = [
    0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0,
    0, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0,
];

/// Creates a cairo surface pattern from pattern data
pub fn create_pattern(
    pattern_data: &[u8; 64],
    foreground: (f64, f64, f64),
    background: (f64, f64, f64),
) -> Result<SurfacePattern, Error> {
    let surface = ImageSurface::create(Format::Rgb24, 8, 8)?;

    {
        let context = Context::new(&surface)?;

        for y in 0_u32..8 {
            for x in 0_u32..8 {
                let value = pattern_data[(y * 8 + x) as usize];
                let (r, g, b) = if value == 0 { foreground } else { background };

                context.set_source_rgb(r, g, b);
                context.rectangle(f64::from(x), f64::from(y), 1.0, 1.0);
                context.fill()?;
            }
        }
    }

    let pattern = SurfacePattern::create(&surface);
    pattern.set_extend(Extend::Repeat);
    Ok(pattern)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_pattern_data_lengths() {
        assert_eq!(STITCH.len(), 64);
        assert_eq!(SHINGLES.len(), 64);
        assert_eq!(SHADOW_GRID.len(), 64);
        assert_eq!(WICKER.len(), 64);
    }

    #[test]
    fn test_pattern_values() {
        for &pixel in &STITCH {
            assert!(pixel == 0 || pixel == 1);
        }
        for &pixel in &SHINGLES {
            assert!(pixel == 0 || pixel == 1);
        }
    }
}