use super::tile_image::{Edge, TileImage};

use super::wavefront_collapse::{CollapseRule, Tile, WavefrontCollapse};

use crate::{LandGenerationParameters, LandGenerator};

use integral_geometry::Size;

use png::Decoder;

use std::collections::HashSet;

use std::fs::File;

use std::io::{BufReader, Result};

use std::path::{Path, PathBuf};

#[derive(Clone)]

pub struct EdgeDescription {

    pub name: String,

    pub reversed: Option<bool>,

    pub symmetrical: Option<bool>,

}

#[derive(Clone)]

pub struct EdgesDescription {

    pub top: EdgeDescription,

    pub right: EdgeDescription,

    pub bottom: EdgeDescription,

    pub left: EdgeDescription,

}

#[derive(Clone)]

pub struct TileDescription {

    pub name: String,

    pub edges: EdgesDescription,

    pub is_negative: Option<bool>,

    pub can_flip: Option<bool>,

    pub can_mirror: Option<bool>,

    pub can_rotate90: Option<bool>,

    pub can_rotate180: Option<bool>,

    pub can_rotate270: Option<bool>,

}

#[derive(Clone)]

pub struct NonStrictEdgesDescription {

    pub top: Option<EdgeDescription>,

    pub right: Option<EdgeDescription>,

    pub bottom: Option<EdgeDescription>,

    pub left: Option<EdgeDescription>,

}

#[derive(Clone)]

pub struct TemplateDescription {

    pub size: Size,

    pub tiles: Vec<TileDescription>,

    pub edges: NonStrictEdgesDescription,

    pub wrap: bool,

}

pub struct WavefrontCollapseLandGenerator {

    pub template: TemplateDescription,

    data_path: PathBuf,

}

impl WavefrontCollapseLandGenerator {

    pub fn new(template: TemplateDescription, data_path: &Path) -> Self {

        Self {

            template,

            data_path: data_path.to_owned(),

        }

    }

    fn load_image_tiles<T: Copy + PartialEq + Default>(

        &self,

        parameters: &LandGenerationParameters<T>,

        tile_description: &TileDescription,

    ) -> Result<Vec<TileImage<T, String>>> {

        let mut result = Vec::new();

        let file = File::open(

            self.data_path

                .join("Tiles")

                .join(&tile_description.name)

                .as_path(),

        )?;

        let decoder = Decoder::new(BufReader::new(file));

        let mut reader = decoder.read_info().unwrap();

        let info = reader.info();

        let mut tiles_image = vec2d::Vec2D::new(

            &Size::new(info.width as usize, info.height as usize),

            parameters.zero,

        );

        let mut buf = vec![0; reader.output_buffer_size()];

        let info = reader.next_frame(&mut buf).unwrap();

        let bytes = &buf[..info.buffer_size()];

        let mut tiles_image_pixels = tiles_image.as_mut_slice().iter_mut();

        let (zero, basic) = if tile_description.is_negative.unwrap_or_default() {

            (parameters.basic(), parameters.zero())

        } else {

            (parameters.zero(), parameters.basic())

        };

        match info.color_type.samples() {

            1 => {

                for line in bytes.chunks_exact(info.line_size) {

                    for value in line.iter() {

                        *tiles_image_pixels

                            .next()

                            .expect("vec2d size matching image dimensions") =

                            if *value == 0 { zero } else { basic };

                    }

                }

            }

            a => {

                for line in bytes.chunks_exact(info.line_size) {

                    for value in line.chunks_exact(a) {

                        print!("{:?},", value);

                        *tiles_image_pixels

                            .next()

                            .expect("vec2d size matching image dimensions") =

                            if value[0] == 0u8 { zero } else { basic };

                    }

                }

            }

        }

        let [top_edge, right_edge, bottom_edge, left_edge]: [Edge<String>; 4] = [

            (&tile_description.edges.top).into(),

            (&tile_description.edges.right).into(),

            (&tile_description.edges.bottom).into(),

            (&tile_description.edges.left).into(),

        ];

        let tile =

            TileImage::<T, String>::new(tiles_image, top_edge, right_edge, bottom_edge, left_edge);

        result.push(tile.clone());

        if tile_description.can_flip.unwrap_or_default() {

            result.push(tile.flipped());

        }

        if tile_description.can_mirror.unwrap_or_default() {

            result.push(tile.mirrored());

        }

        if tile_description.can_flip.unwrap_or_default()

            && tile_description.can_mirror.unwrap_or_default()

        {

            result.push(tile.mirrored().flipped());

        }

        if tile_description.can_rotate90.unwrap_or_default() {

            result.push(tile.rotated90());

        }

        if tile_description.can_rotate180.unwrap_or_default() {

            result.push(tile.rotated180());

        }

        if tile_description.can_rotate270.unwrap_or_default() {

            result.push(tile.rotated270());

        }

        Ok(result)

    }

    pub fn load_template<T: Copy + PartialEq + Default>(

        &self,

        parameters: &LandGenerationParameters<T>,

    ) -> Vec<TileImage<T, String>> {

        let mut result = Vec::new();

        for tile_description in self.template.tiles.iter() {

            if let Ok(mut tiles) = self.load_image_tiles(parameters, tile_description) {

                result.append(&mut tiles);

            } else {

                eprintln!("Failed to load a tile!");

            }

        }

        result

    }

    pub fn build_rules<T: Copy + PartialEq + Default>(

        &self,

        tiles: &[TileImage<T, String>],

    ) -> Vec<CollapseRule> {

        let [grid_top_edge, grid_right_edge, grid_bottom_edge, grid_left_edge]: [Option<

            Edge<String>,

        >; 4] = [

            self.template.edges.top.as_ref(),

            self.template.edges.right.as_ref(),

            self.template.edges.bottom.as_ref(),

            self.template.edges.left.as_ref(),

        ]

        .map(|opt| opt.map(|d| d.into()));

        let mut rules = Vec::<CollapseRule>::new();

        let default_connection = HashSet::from_iter(vec![Tile::Empty].into_iter());

        for (i, tile) in tiles.iter().enumerate() {

            let mut right = default_connection.clone();

            let mut bottom = default_connection.clone();

            let mut left = default_connection.clone();

            let mut top = default_connection.clone();

            // compatibility with grid edges

            if grid_top_edge

                .as_ref()

                .map(|e| e.is_compatible(tile.top_edge()))

                .unwrap_or(true)

            {

                top.insert(Tile::Outside);

            }

            if grid_right_edge

                .as_ref()

                .map(|e| e.is_compatible(tile.right_edge()))

                .unwrap_or(true)

            {

                right.insert(Tile::Outside);

            }

            if grid_bottom_edge

                .as_ref()

                .map(|e| e.is_compatible(tile.bottom_edge()))

                .unwrap_or(true)

            {

                bottom.insert(Tile::Outside);

            }

            if grid_left_edge

                .as_ref()

                .map(|e| e.is_compatible(tile.left_edge()))

                .unwrap_or(true)

            {

                left.insert(Tile::Outside);

            }

            // compatibility with itself

            if tile.left_edge().is_compatible(tile.right_edge()) {

                left.insert(Tile::Numbered(i));

                right.insert(Tile::Numbered(i));

            }

            if tile.top_edge().is_compatible(tile.bottom_edge()) {

                top.insert(Tile::Numbered(i));

                bottom.insert(Tile::Numbered(i));

            }

            // compatibility with previously defined tiles

            for p in 0..i {

                if tiles[p].left_edge().is_compatible(tile.right_edge()) {

                    rules[p].left.insert(Tile::Numbered(i));

                    right.insert(Tile::Numbered(p));

                }

                if tiles[p].right_edge().is_compatible(tile.left_edge()) {

                    rules[p].right.insert(Tile::Numbered(i));

                    left.insert(Tile::Numbered(p));

                }

                if tiles[p].top_edge().is_compatible(tile.bottom_edge()) {

                    rules[p].top.insert(Tile::Numbered(i));

                    bottom.insert(Tile::Numbered(p));

                }

                if tiles[p].bottom_edge().is_compatible(tile.top_edge()) {

                    rules[p].bottom.insert(Tile::Numbered(i));

                    top.insert(Tile::Numbered(p));

                }

            }

            rules.push(CollapseRule {

                tile: Tile::Numbered(i),

                top,

                right,

                bottom,

                left,

            });

        }

        rules

    }

}

impl LandGenerator for WavefrontCollapseLandGenerator {

        &self,

        parameters: &LandGenerationParameters<T>,

    ) -> land2d::Land2D<T> {

        let tiles = self.load_template(parameters);

        let mut wfc = WavefrontCollapse::new(self.template.wrap);

        wfc.set_rules(rules);

        let wfc_size = if let Some(first_tile) = tiles.first() {

            let tile_size = first_tile.size();

            Size::new(

                self.template.size.width / tile_size.width,

                self.template.size.height / tile_size.height,

            )

        } else {

            Size::new(1, 1)

        };

        wfc.generate_map(&wfc_size, |_| {}, random_numbers);

        // render tiles into resulting land array

        let mut result = land2d::Land2D::new(&self.template.size, parameters.zero);

        let offset_y = result.height() - result.play_height();

        let offset_x = (result.width() - result.play_width()) / 2;

        for row in 0..wfc_size.height {

            for column in 0..wfc_size.width {

                if let Some(Tile::Numbered(tile_index)) = wfc.grid().get(row, column) {

                    let tile = &tiles[*tile_index];

                    for tile_row in 0..tile.size().height {

                        for tile_column in 0..tile.size().width {

                            result.map(

                                (row * tile.size().height + tile_row + offset_y) as i32,

                                (column * tile.size().width + tile_column + offset_x) as i32,

                                |p| {

                                    *p =

                                        *tile.get(tile_row, tile_column).unwrap_or(&parameters.zero)

                                },

                            );

                        }

                    }

                }

            }

        }

        result

    }

}

impl From<&EdgeDescription> for Edge<String> {

    fn from(val: &EdgeDescription) -> Self {

        let edge = Edge::new(val.name.clone(), val.symmetrical.unwrap_or_default());

        if val.reversed.unwrap_or_default() {

            edge.reversed()

        } else {

            edge

        }

    }

}