use crate::vec2::Vec2;
use crate::{HexMap, Rect, Tileset};
use std::fs;
use std::fs::File;
use std::rc::Rc;

//todo: make dynamically different bitdepths
pub struct Image {
    data: Vec<u8>,
    size: Vec2<i32>,
}

impl Image {
    pub fn new(size: Vec2<i32>) -> Self {
        Image {
            data: vec![0u8; size.size()],
            size,
        }
    }

    pub fn load(path: &str) -> Rc<Self> {
        Self::load_data(fs::read(path).unwrap().as_slice())
    }

    pub fn load_data(data: &[u8]) -> Rc<Self> {
        let mut options = gif::DecodeOptions::new();
        options.set_color_output(gif::ColorOutput::Indexed);
        let mut decoder = options.read_info(data).unwrap();

        let x = decoder.width();
        let y = decoder.height();

        let mut data = vec![0u8; (x * y) as usize];
        decoder.next_frame_info().unwrap();
        decoder.read_into_buffer(&mut data).unwrap();
        Image {
            data,
            size: Vec2 {
                x: x as i32,
                y: y as i32,
            },
        }
        .into()
    }

    pub fn clear(&mut self) {
        self.fill(0);
    }

    pub fn data_mut(&mut self) -> &mut [u8] {
        self.data.as_mut_slice()
    }

    pub fn data(&mut self) -> &[u8] {
        self.data.as_slice()
    }

    pub fn draw_hexmap(&mut self, pos: Vec2<i32>, hexmap: &HexMap) {
        for i in hexmap.size().to_rect().iter() {
            if i.x % 1 == 0 {
                hexmap.draw_tile_to_image(self, i, pos);
            }
        }
    }

    pub fn draw_image(&mut self, pos: Vec2<i32>, image: &Image) {
        self.draw_image_partial(
            pos,
            image,
            Rect {
                pos: Vec2::zero(),
                size: image.size,
            },
        );
    }

    pub fn draw_image_partial(&mut self, pos: Vec2<i32>, image: &Image, src_rect: Rect<i32>) {
        //todo: write proper implementation later
        for i in Vec2::zero().iter_to(src_rect.size) {
            //todo: implement better(very stupid to do per pixel)
            if self.size.to_rect().contains(i + pos) {
                let p = image.get_pixel(i + src_rect.pos);
                if p > 0 {
                    self.set_pixel(i + pos, p);
                }
            }
        }
    }

    pub fn draw_line(&mut self, pos1: Vec2<i32>, pos2: Vec2<i32>, color: u8) {
        let (x1, y1, x2, y2) = (pos1.x, pos1.y, pos2.x, pos2.y);

        let mut x = x1 as f32;
        let mut y = y1 as f32;
        let xdiff = (x2 - x1) as f32;
        let ydiff = (y2 - y1) as f32;
        let step = if xdiff.abs() > ydiff.abs() {
            xdiff.abs()
        } else {
            ydiff.abs()
        };
        let xs = xdiff / step;
        let ys = ydiff / step;
        for _ in 1..=(step as i32) {
            self.set_pixel(
                Vec2 {
                    x: x as i32,
                    y: y as i32,
                },
                color,
            );
            x += xs;
            y += ys;
        }
    }

    pub fn draw_string(&mut self, pos: Vec2<i32>, str: &str, font: &Tileset) {
        assert!(str.is_ascii());
        let array = str.as_bytes();
        for i in 0..array.len() {
            self.draw_image(
                Vec2 {
                    x: pos.x + font.tile_size().x * i as i32,
                    y: pos.y,
                },
                font.get(array[i] as i32),
            );
        }
    }

    pub fn fill(&mut self, color: u8) {
        self.data.fill(color);
    }

    pub fn fill_rect(&mut self, rect: Rect<i32>, color: u8) {
        for pos in rect.iter() {
            self.set_pixel(pos, color);
        }
    }

    pub fn get_pixel(&self, pos: Vec2<i32>) -> u8 {
        self.data[(pos.x + self.size.x * pos.y) as usize]
    }

    pub fn set_pixel(&mut self, pos: Vec2<i32>, color: u8) {
        self.data[(pos.x + self.size.x * pos.y) as usize] = color;
    }

    pub fn size(&self) -> Vec2<i32> {
        self.size
    }
}