use crate::utils::color_gradient::Color;
use alloc::{
    slice::{Iter, IterMut},
    vec::{IntoIter, Vec},
};
use core::ops::{Index, IndexMut};
#[cfg(feature = "images")]
use std::path::Path;

const RASTER_MAX_WIDTH: u16 = 32_767;
const RASTER_MAX_HEIGHT: u16 = 32_767;

pub struct NoiseImage {
    size: (usize, usize),
    border_color: Color,
    map: Vec<Color>,
}

impl NoiseImage {
    pub fn new(width: usize, height: usize) -> Self {
        Self::initialize().set_size(width, height)
    }

    pub fn iter(&self) -> Iter<'_, Color> {
        self.map.iter()
    }

    pub fn iter_mut(&mut self) -> IterMut<'_, Color> {
        self.map.iter_mut()
    }

    pub fn set_size(self, width: usize, height: usize) -> Self {
        // Check for invalid width or height.
        assert!(width < RASTER_MAX_WIDTH as usize);
        assert!(height < RASTER_MAX_HEIGHT as usize);

        if width == 0 || height == 0 {
            // An empty noise image was specified. Return a new blank, empty map.
            Self::initialize()
        } else {
            // New noise map size specified. Allocate a new Vec unless the current Vec is large
            // enough.
            let map_size = width * height;
            if self.map.capacity() < map_size {
                // New size is too big for the current Vec. Create a new Vec with a large enough
                // capacity now so we're not reallocating when filling the map.
                Self {
                    map: vec![[0; 4]; map_size],
                    size: (width, height),
                    ..self
                }
            } else {
                // Vec capacity is already big enough, so leave it alone and just change the set size.
                Self {
                    size: (width, height),
                    ..self
                }
            }
        }
    }

    pub fn set_border_color(self, color: Color) -> Self {
        Self {
            border_color: color,
            ..self
        }
    }

    pub fn set_value(&mut self, x: usize, y: usize, value: Color) {
        let (width, height) = self.size;

        if x < width && y < height {
            self.map[x + y * width] = value;
        } else {
            // eprintln!("input point out of bounds")
        }
    }

    pub fn size(&self) -> (usize, usize) {
        self.size
    }

    pub fn border_color(&self) -> Color {
        self.border_color
    }

    pub fn get_value(&self, x: usize, y: usize) -> Color {
        let (width, height) = self.size;

        if x < width && y < height {
            self.map[x + y * width]
        } else {
            self.border_color
        }
    }

    fn initialize() -> Self {
        Self {
            size: (0, 0),
            border_color: [0; 4],
            map: Vec::new(),
        }
    }

    #[cfg(feature = "images")]
    pub fn write_to_file(&self, filename: &Path) {
        // collect the values from the map vector into an array
        let (width, height) = self.size;
        let mut result = Vec::with_capacity(width * height);

        for i in &self.map {
            for j in i.iter() {
                result.push(*j);
            }
        }

        let _ = image::save_buffer(
            filename,
            &result,
            self.size.0 as u32,
            self.size.1 as u32,
            image::ColorType::Rgba8,
        );

        println!("\nFinished generating {}", filename.to_string_lossy());
    }
}

impl Default for NoiseImage {
    fn default() -> Self {
        Self::initialize()
    }
}

impl Index<(usize, usize)> for NoiseImage {
    type Output = Color;

    fn index(&self, (x, y): (usize, usize)) -> &Self::Output {
        let (width, height) = self.size;
        if x < width && y < height {
            &self.map[x + y * width]
        } else {
            &self.border_color
        }
    }
}

impl IndexMut<(usize, usize)> for NoiseImage {
    fn index_mut(&mut self, (x, y): (usize, usize)) -> &mut Self::Output {
        let (width, height) = self.size;
        if x < width && y < height {
            &mut self.map[x + y * width]
        } else {
            panic!(
                "index ({}, {}) out of bounds for NoiseImage of size ({}, {})",
                x, y, width, height
            )
        }
    }
}

impl IntoIterator for NoiseImage {
    type Item = Color;

    type IntoIter = IntoIter<Color>;

    fn into_iter(self) -> Self::IntoIter {
        self.map.into_iter()
    }
}

impl<'a> IntoIterator for &'a NoiseImage {
    type Item = &'a Color;

    type IntoIter = Iter<'a, Color>;

    fn into_iter(self) -> Self::IntoIter {
        self.iter()
    }
}

impl<'a> IntoIterator for &'a mut NoiseImage {
    type Item = &'a mut Color;

    type IntoIter = IterMut<'a, Color>;

    fn into_iter(self) -> Self::IntoIter {
        self.iter_mut()
    }
}