versatiles_image 0.15.2

use crate::{jpeg, png, webp};
use anyhow::Result;
use image::{DynamicImage, GrayAlphaImage, GrayImage, Luma, LumaA, Rgb, RgbImage, Rgba, RgbaImage};
use versatiles_core::types::{Blob, TileFormat};

/// Generate a DynamicImage with RGBA colors
pub fn create_image_rgba() -> DynamicImage {
	DynamicImage::ImageRgba8(RgbaImage::from_fn(256, 256, |x, y| -> Rgba<u8> {
		Rgba([x as u8, (255 - x) as u8, y as u8, (255 - y) as u8])
	}))
}

/// Generate a DynamicImage with RGB colors
pub fn create_image_rgb() -> DynamicImage {
	DynamicImage::ImageRgb8(RgbImage::from_fn(256, 256, |x, y| -> Rgb<u8> {
		Rgb([x as u8, (255 - x) as u8, y as u8])
	}))
}

/// Generate a DynamicImage with grayscale colors
/// Returns a DynamicImage with 256x256 grayscale colors from black to white. Each pixel in the image
/// is a Luma<u8> value.
pub fn create_image_grey() -> DynamicImage {
	DynamicImage::ImageLuma8(GrayImage::from_fn(256, 256, |x, _y| -> Luma<u8> { Luma([x as u8]) }))
}

/// Generate a DynamicImage with grayscale alpha colors
/// Returns a DynamicImage with 256x256 grayscale alpha colors from black to white. Each pixel in the
/// image is a LumaA<u8> value, with the alpha value determined by the y coordinate.
pub fn create_image_greya() -> DynamicImage {
	DynamicImage::ImageLumaA8(GrayAlphaImage::from_fn(256, 256, |x, y| -> LumaA<u8> {
		LumaA([x as u8, y as u8])
	}))
}

/// Compare two DynamicImages for similarity
/// Compares two DynamicImages to ensure that they have the same dimensions and that the maximum
/// difference between the pixel values in each image is less than or equal to a given threshold.
/// # Arguments
/// * `image1` - The first DynamicImage to compare
/// * `image2` - The second DynamicImage to compare
/// * `max_allowed_diff` - The maximum allowed difference between pixel values in the two images
/// # Panics
/// This function will panic if the two images have different dimensions or if the maximum difference
/// between the pixel values in the two images is greater than the specified threshold.
pub fn compare_images(image1: DynamicImage, image2: DynamicImage, max_allowed_diff: u8) {
	assert_eq!(image1.width(), image2.width());
	assert_eq!(image1.height(), image2.height());

	let bytes1 = image1.as_bytes();
	let bytes2 = image2.as_bytes();
	assert_eq!(bytes1.len(), bytes2.len());

	let mut max_diff: u8 = 0;
	for (c1, c2) in bytes1.iter().zip(bytes2) {
		let diff = c1.abs_diff(*c2);
		if diff > max_diff {
			max_diff = diff;
		}
	}

	assert!(
		max_diff <= max_allowed_diff,
		"max_diff ({max_diff}) > max_allowed_diff ({max_allowed_diff})"
	);
}

pub fn image2blob(image: &DynamicImage, format: TileFormat) -> Result<Blob> {
	use TileFormat::*;
	match format {
		AVIF => todo!(),
		BIN => todo!(),
		GEOJSON => todo!(),
		JPG => jpeg::image2blob(image),
		JSON => todo!(),
		PBF => todo!(),
		PNG => png::image2blob(image, true),
		SVG => todo!(),
		TOPOJSON => todo!(),
		WEBP => webp::image2blob(image),
	}
}

pub fn image2blob_fast(image: &DynamicImage, format: TileFormat) -> Result<Blob> {
	use TileFormat::*;
	match format {
		AVIF => todo!(),
		BIN => todo!(),
		GEOJSON => todo!(),
		JPG => jpeg::image2blob(image),
		JSON => todo!(),
		PBF => todo!(),
		PNG => png::image2blob(image, false),
		SVG => todo!(),
		TOPOJSON => todo!(),
		WEBP => webp::image2blob(image),
	}
}