// Copyright 2016-2023, Pulumi Corporation.
//
// 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 pulumix

import (
	"context"

	"github.com/pulumi/pulumi/sdk/v3/go/internal"
)

// FlattenContext unpacks an Output stored inside another input,
// returning an output containing the underlying value.
func FlattenContext[A any, I Input[A]](ctx context.Context, i Input[I]) Output[A] {
	outputOutputA := i.ToOutput(ctx)
	stateOutputOutputA := internal.GetOutputState(outputOutputA)

	stateA := internal.NewOutputState(
		internal.OutputJoinGroup(stateOutputOutputA),
		typeOf[A](),
		internal.OutputDependencies(stateOutputOutputA)...,
	)
	go func() {
		var outputA I
		var a A

		applier := newApplyNState[A](stateA)
		applyNStep(ctx, &applier, outputOutputA, &outputA)
		applyNStep(ctx, &applier, outputA.ToOutput(ctx), &a)

		if applier.ok {
			applier.finish(a, nil /* err */)
		}
	}()

	return Output[A]{OutputState: stateA}
}

// Flatten unpacks the Output stored inside another input,
// returning an output containing the underlying value.
//
// This is a variant of FlattenContext
// that uses the background context.
func Flatten[A any, I Input[A]](i Input[I]) Output[A] {
	return FlattenContext[A, I](context.Background(), i)
}

// All combines multiple inputs into a single output
// that produces a list of all the input values.
func All(args ...Input[any]) Output[[]any] {
	return Array[any](args).ToOutput(context.Background())
}