use std::{

    collections::hash_map::HashMap,

    borrow::Borrow,

    mem::replace

};

use serde::{Deserialize};

use serde_derive::{Deserialize};

use serde_yaml;

use integral_geometry::{Point, Size, Rect};

use landgen::{

    outline_template::OutlineTemplate

};

use rand::{thread_rng, Rng};

#[derive(Deserialize)]

struct PointDesc {

    x: u32,

    y: u32

}

#[derive(Deserialize)]

struct RectDesc {

    x: u32,

    y: u32,

    w: u32,

    h: u32

}

#[derive(Deserialize)]

struct TemplateDesc {

    width: usize,

    height: usize,

    can_flip: bool,

    can_invert: bool,

    can_mirror: bool,

    is_negative: bool,

    put_girders: bool,

    max_hedgehogs: u8,

    outline_points: Vec<Vec<RectDesc>>,

    fill_points: Vec<PointDesc>

}

#[derive(Deserialize)]

struct TemplateCollectionDesc {

    templates: Vec<TemplateDesc>,

    template_types: HashMap<String, Vec<usize>>

}

impl From<&TemplateDesc> for OutlineTemplate {

    fn from(desc: &TemplateDesc) -> Self {

        OutlineTemplate {

            islands: desc.outline_points.iter()

                .map(|v| v.iter()

                    .collect())

                .collect(),

            fill_points: desc.fill_points.iter()

                .map(|p| Point::new(p.x as i32, p.y as i32))

                .collect(),

            size: Size::new(desc.width, desc.height),

            can_flip: desc.can_flip,

            can_invert: desc.can_invert,

            can_mirror: desc.can_mirror,

            is_negative: desc.is_negative

        }

    }

}

#[derive(PartialEq, Eq, Hash, Clone, Debug)]

struct TemplateType(String);

impl Borrow<str> for TemplateType {

    fn borrow(&self) -> &str {

        self.0.as_str()

    }

}

#[derive(Debug)]

pub struct MapGenerator {

    pub(crate) templates: HashMap<TemplateType, Vec<OutlineTemplate>>

}

impl MapGenerator {

    pub fn new() -> Self {

        Self { templates: HashMap::new() }

    }

    pub fn import_yaml_templates(&mut self, text: &str) {

        let mut desc: TemplateCollectionDesc = serde_yaml::from_str(text).unwrap();

        let templates = replace(&mut desc.templates, vec![]);

        self.templates = desc.template_types.into_iter()

            .map(|(size, indices)|

                (TemplateType(size), indices.iter()

                    .map(|i| (&templates[*i]).into())

                    .collect()))

            .collect();

    }

    pub fn get_template(&self, template_type: &str) -> Option<&OutlineTemplate> {

        self.templates.get(template_type).and_then(|t| thread_rng().choose(t))

    }

}

#[cfg(test)]

mod tests {

    use crate::{

        MapGenerator,

        TemplateType

    };

    #[test]

    fn simple_load() {

        let text = r#"

# comment

templates:

  -

    width: 3072

    height: 1424

    can_flip: false

    can_invert: false

    can_mirror: true

    is_negative: false

    put_girders: true

    max_hedgehogs: 18

    outline_points:

      -

        - {x: 748, y: 1424, w: 1, h: 1}

        - {x: 636, y: 1252, w: 208, h: 72}

        - {x: 898, y: 1110, w: 308, h: 60}

        - {x: 1128, y: 1252, w: 434, h: 40}

        - {x: 1574, y: 1112, w: 332, h: 40}

        - {x: 1802, y: 1238, w: 226, h: 36}

        - {x: 1930, y: 1424, w: 1, h: 1}

    fill_points:

      - {x: 1023, y: 0}

      - {x: 1023, y: 0}

template_types:

    test: [0]

"#;

        let mut generator = MapGenerator::new();

        generator.import_yaml_templates(&text);

        assert!(generator.templates.contains_key(&TemplateType("test".to_string())));

        let template = generator.get_template("test").unwrap();

        assert_eq!(template.islands[0].len(), 7);

    }

}