use crate::ffi::{ExternPointer, IdentifiablePointer, OwnedPtr};
use crate::static_data::{Ability, AbilityImpl, EffectParameter};
use crate::StringKey;
use std::ffi::{c_char, CStr, CString};
use std::ptr::drop_in_place;
use std::sync::Arc;

/// Instantiates a new ability.
#[no_mangle]
unsafe extern "C" fn ability_new(
    name: *const c_char,
    effect: *const c_char,
    parameters: *const OwnedPtr<EffectParameter>,
    parameters_length: usize,
) -> IdentifiablePointer<Arc<dyn Ability>> {
    let parameters = std::slice::from_raw_parts(parameters, parameters_length);
    let mut parameters_vec: Vec<EffectParameter> = Vec::with_capacity(parameters_length);
    for parameter in parameters {
        parameters_vec.push(*Box::from_raw(*parameter));
    }

    let name: StringKey = CStr::from_ptr(name).to_str().unwrap().into();
    let effect: StringKey = CStr::from_ptr(effect).to_str().unwrap().into();

    let arc: Arc<dyn Ability> = Arc::new(AbilityImpl::new(&name, &effect, parameters_vec));
    arc.into()
}

/// Drops a reference counted ability.
#[no_mangle]
unsafe extern "C" fn ability_drop(ptr: OwnedPtr<Arc<dyn Ability>>) {
    drop_in_place(ptr)
}

/// The name of the ability.
#[no_mangle]
unsafe extern "C" fn ability_name(ptr: ExternPointer<Arc<dyn Ability>>) -> OwnedPtr<c_char> {
    CString::new(ptr.as_ref().name().str()).unwrap().into_raw()
}

/// The name of the script effect of the ability.
#[no_mangle]
unsafe extern "C" fn ability_effect(ptr: ExternPointer<Arc<dyn Ability>>) -> OwnedPtr<c_char> {
    CString::new(ptr.as_ref().effect().str()).unwrap().into_raw()
}

/// The length of the parameters for the script effect of the ability.
#[no_mangle]
unsafe extern "C" fn ability_parameter_length(ptr: ExternPointer<Arc<dyn Ability>>) -> usize {
    ptr.as_ref().parameters().len()
}

/// Gets a parameter for the script effect of the ability.
#[no_mangle]
unsafe extern "C" fn ability_parameter_get(
    ptr: ExternPointer<Arc<dyn Ability>>,
    index: usize,
) -> IdentifiablePointer<EffectParameter> {
    if let Some(p) = ptr.as_ref().parameters().get(index) {
        (p as *const EffectParameter).into()
    } else {
        IdentifiablePointer::none()
    }
}