use rand::seq::IteratorRandom;
use rand_distr::{Distribution, Standard};
use strum::IntoEnumIterator;
use strum_macros::{Display, EnumIter};

use crate::{
    skills::{Proficiencies, ToProficiencies},
    stats::{StatBlock, ToStatBlock},
};

#[derive(Debug, PartialEq, Eq, EnumIter, Clone, Copy, Display)]
pub enum Class {
    Guard,
    Knight,
    Brawler,
    Thief,
    Swashbuckler,
    Survivalist,
    Hunter,
    Witch,
    Wizard,
    NPC, // Stubbed in for "no class"
}

impl ToStatBlock for Class {
    fn stat_block(&self) -> StatBlock {
        match self {
            Class::Guard => StatBlock::from((1, 0, 1, 1, 0, 0, 0, 0)),
            Class::Knight => StatBlock::from((1, 0, 0, 1, 0, 0, 0, 1)),
            Class::Brawler => StatBlock::from((1, 1, 1, 0, 0, 0, 0, 0)),
            // -----
            Class::Thief => StatBlock::from((0, 1, 0, 0, 1, 0, 1, 0)),
            Class::Swashbuckler => StatBlock::from((1, 1, 0, 0, 0, 0, 0, 1)),
            // -----
            Class::Survivalist => StatBlock::from((0, 1, 1, 0, 1, 0, 0, 0)),
            Class::Hunter => StatBlock::from((0, 1, 1, 0, 0, 1, 0, 0)),
            // -----
            Class::Witch => StatBlock::from((0, 0, 0, 0, 1, 1, 1, 0)),
            Class::Wizard => StatBlock::from((0, 0, 0, 0, 1, 1, 0, 1)),
            // -----
            Class::NPC => StatBlock::from((0, 0, 0, 0, 0, 0, 0, 0)),
        }
    }
}

impl ToProficiencies for Class {
    fn proficiencies(&self) -> Proficiencies {
        match self {
            Class::Guard => Proficiencies {
                light_armor: true,
                medium_armor: true,
                heavy_armor: true,
                // -----
                // bladed_weapons: true,
                simple_weapons: true,
                pole_weapons: true,
                ..Default::default()
            },
            Class::Knight => Proficiencies {
                light_armor: true,
                medium_armor: true,
                heavy_armor: true,
                // -----
                bladed_weapons: true,
                ..Default::default()
            },
            Class::Brawler => Proficiencies {
                light_armor: true,
                medium_armor: true,
                // -----
                simple_weapons: true,
                blunt_weapons: true,
                thrown_weapons: true,
                ..Default::default()
            },
            Class::Thief => Proficiencies {
                simple_weapons: true,
                thrown_weapons: true,
                ranged_weapons: true,
                ..Default::default()
            },
            Class::Swashbuckler => Proficiencies {
                light_armor: true,
                simple_weapons: true,
                bladed_weapons: true,
                thrown_weapons: true,
                ranged_weapons: true,
                ..Default::default()
            },
            Class::Survivalist => Proficiencies {
                // -----
                simple_weapons: true,
                thrown_weapons: true,
                ..Default::default()
            },
            Class::Hunter => Proficiencies {
                light_armor: true,
                // -----
                simple_weapons: true,
                pole_weapons: true,
                ranged_weapons: true,
                ..Default::default()
            },
            Class::Witch => Proficiencies {
                simple_weapons: true,
                ..Default::default()
            },
            Class::Wizard => Proficiencies::default(),
            Class::NPC => Proficiencies::default(),
        }
    }
}

impl Distribution<Class> for Standard {
    fn sample<R: rand::Rng + ?Sized>(&self, rng: &mut R) -> Class {
        Class::iter().choose(rng).unwrap()
    }
}

#[cfg(test)]
mod class_tests {
    use strum::IntoEnumIterator;

    use crate::{class::Class, stats::ToStatBlock};

    #[test]
    fn stat_sums() {
        for class in Class::iter() {
            let stat_block = class.stat_block();
            if class != Class::NPC {
                assert_eq!(
                    3,
                    stat_block.STR
                        + stat_block.DEX
                        + stat_block.CON
                        + stat_block.STB
                        + stat_block.INT
                        + stat_block.KND
                        + stat_block.CMP
                        + stat_block.CHA
                )
            }
        }
    }

    #[test]
    fn all_unique() {
        for class1 in Class::iter() {
            for class2 in Class::iter() {
                assert!(class1 == class2 || class1.stat_block() != class2.stat_block())
            }
        }
    }
}