/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

use super::*;
use heck::ToUpperCamelCase;

pub fn pass(namespace: &mut Namespace) -> Result<()> {
    let crate_name = namespace.crate_name.clone();

    // Change `is_async` to `async_data`
    namespace.visit_mut(|callable: &mut Callable| {
        callable.async_data = callable.is_async.then(|| {
            generate_async_data(
                &crate_name,
                callable.return_type.ty.as_ref().map(|ty| &ty.ffi_type),
            )
        });
    });
    namespace.visit_mut(|ffi_func: &mut FfiFunction| {
        ffi_func.async_data = ffi_func
            .is_async
            .then(|| generate_async_data(&crate_name, ffi_func.return_type.ty.as_ref()));
    });
    Ok(())
}

fn generate_async_data(crate_name: &str, ffi_return_type: Option<&FfiTypeNode>) -> AsyncData {
    let return_type_name = match &ffi_return_type.map(|ffi_type| &ffi_type.ty) {
        Some(FfiType::UInt8) => "u8",
        Some(FfiType::Int8) => "i8",
        Some(FfiType::UInt16) => "u16",
        Some(FfiType::Int16) => "i16",
        Some(FfiType::UInt32) => "u32",
        Some(FfiType::Int32) => "i32",
        Some(FfiType::UInt64) => "u64",
        Some(FfiType::Int64) => "i64",
        Some(FfiType::Float32) => "f32",
        Some(FfiType::Float64) => "f64",
        Some(FfiType::Handle(_)) => "u64",
        Some(FfiType::RustBuffer(_)) => "rust_buffer",
        None => "void",
        ty => panic!("Invalid future return type: {ty:?}"),
    };
    let struct_crate_name = match &ffi_return_type.map(|ffi_type| &ffi_type.ty) {
        Some(FfiType::RustBuffer(Some(rust_buffer_crate))) => rust_buffer_crate,
        _ => "",
    };

    AsyncData {
        ffi_rust_future_poll: RustFfiFunctionName(format!(
            "ffi_{crate_name}_rust_future_poll_{return_type_name}"
        )),
        ffi_rust_future_cancel: RustFfiFunctionName(format!(
            "ffi_{crate_name}_rust_future_cancel_{return_type_name}"
        )),
        ffi_rust_future_complete: RustFfiFunctionName(format!(
            "ffi_{crate_name}_rust_future_complete_{return_type_name}"
        )),
        ffi_rust_future_free: RustFfiFunctionName(format!(
            "ffi_{crate_name}_rust_future_free_{return_type_name}"
        )),
        ffi_foreign_future_result: FfiStructName(format!(
            "ForeignFutureResult{struct_crate_name}{}",
            return_type_name.to_upper_camel_case()
        )),
        ffi_foreign_future_complete: FfiFunctionTypeName(format!(
            "ForeignFutureComplete{struct_crate_name}{return_type_name}"
        )),
    }
}