// Copyright 2024 The Ebitengine Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package shaderprecomp

import (
	"io"

	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/metal"
	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
	"github.com/hajimehoshi/ebiten/v2/internal/shaderir/msl"
)

// CompileToMSL compiles the shader source to Metal Shader Language, and writes the result to w.
//
// CompileToMSL is concurrent-safe.
func CompileToMSL(w io.Writer, source *ShaderSource) error {
	ir, err := graphics.CompileShader(source.source)
	if err != nil {
		return err
	}
	if _, err = w.Write([]byte(msl.Compile(ir))); err != nil {
		return err
	}
	return nil
}

// RegisterMetalLibrary registers a precompiled Metal library for a shader source.
// library must be the content of a .metallib file.
// For more details, see https://developer.apple.com/documentation/metal/shader_libraries/building_a_shader_library_by_precompiling_source_files.
//
// RegisterMetalLibrary is concurrent-safe.
func RegisterMetalLibrary(source *ShaderSource, library []byte) {
	metal.RegisterPrecompiledLibrary(shaderir.SourceHash(source.ID()), library)
}