use std::sync::{Arc, LazyLock};

use hashbrown::{HashMap, HashSet};

use crate::static_data::Form;
use crate::static_data::Gender;
use crate::Random;
use crate::StringKey;

/// The data belonging to a Pokemon with certain characteristics.
#[derive(Debug)]
#[cfg_attr(feature = "wasm", derive(unique_type_id_derive::UniqueTypeId))]
pub struct Species {
    /// The national dex identifier of the Pokemon.
    id: u16,
    /// The name of the Pokemon.
    name: StringKey,
    /// The chance between 0.0 and 1.0 that a Pokemon is female.
    gender_rate: f32,
    /// How much experience is required for a level.
    growth_rate: StringKey,
    /// How hard it is to capture a Pokemon. 255 means this will be always caught, 0 means this is
    /// uncatchable.
    capture_rate: u8,
    /// The forms that belong to this Pokemon.
    forms: HashMap<StringKey, Arc<Form>>,
    /// The arbitrary flags that can be set on a Pokemon for script use.
    flags: HashSet<StringKey>,
}

/// A cached String Key to get the default form.
static DEFAULT_KEY: LazyLock<StringKey> = LazyLock::new(|| StringKey::new("default"));

/// Gets the StringKey for "default". Initialises it if it does not exist.
fn get_default_key() -> StringKey {
    DEFAULT_KEY.clone()
}

impl Species {
    /// Creates a new species.
    pub fn new(
        id: u16,
        name: &StringKey,
        gender_rate: f32,
        growth_rate: &StringKey,
        capture_rate: u8,
        default_form: Form,
        flags: HashSet<StringKey>,
    ) -> Species {
        let mut forms = HashMap::with_capacity(1);
        forms.insert_unique_unchecked(get_default_key(), Arc::new(default_form));
        Species {
            id,
            name: name.clone(),
            gender_rate,
            growth_rate: growth_rate.clone(),
            capture_rate,
            forms,
            flags,
        }
    }

    /// The national dex identifier of the Pokemon.
    pub fn id(&self) -> u16 {
        self.id
    }
    /// The name of the Pokemon.
    pub fn name(&self) -> &StringKey {
        &self.name
    }
    /// The chance between 0.0 and 1.0 that a Pokemon is female.
    pub fn gender_rate(&self) -> f32 {
        self.gender_rate
    }
    /// How much experience is required for a level.
    pub fn growth_rate(&self) -> &StringKey {
        &self.growth_rate
    }
    /// How hard it is to capture a Pokemon. 255 means this will be always caught, 0 means this is
    /// uncatchable.
    pub fn capture_rate(&self) -> u8 {
        self.capture_rate
    }
    /// The forms that belong to this Pokemon.
    pub fn forms(&self) -> &HashMap<StringKey, Arc<Form>> {
        &self.forms
    }
    /// The arbitrary flags that can be set on a Pokemon for script use.
    pub fn flags(&self) -> &HashSet<StringKey> {
        &self.flags
    }

    /// Adds a new form to the species.
    pub fn add_form(&mut self, id: StringKey, form: Form) {
        self.forms.insert(id, Arc::new(form));
    }

    /// Gets a form by name.
    pub fn get_form(&self, id: &StringKey) -> Option<&Arc<Form>> {
        self.forms.get(id)
    }

    /// Gets the form the Pokemon will have by default, if no other form is specified.
    pub fn get_default_form(&self) -> &Arc<Form> {
        self.forms.get(&get_default_key()).unwrap()
    }

    /// Gets a random gender.
    pub fn get_random_gender(&self, rand: &mut Random) -> Gender {
        if self.gender_rate < 0.0 {
            Gender::Genderless
        } else if rand.get_float() >= self.gender_rate {
            Gender::Female
        } else {
            Gender::Male
        }
    }

    /// Check whether the Pokemon has a specific flag set.
    pub fn has_flag(&self, key: &StringKey) -> bool {
        self.flags.contains(key)
    }
}