package ckconfig

import (
	"context"
	"errors"
	"io"
	"testing"

	commandkit "gitea.maximumdirect.net/eric/CommandKit"
)

func TestBufferedReportCancellationBeforeDelivery(t *testing.T) {
	for _, quiet := range []bool{false, true} {
		t.Run(map[bool]string{false: "ordinary", true: "quiet"}[quiet], func(t *testing.T) {
			ctx, cancel := context.WithCancel(context.Background())
			defer cancel()
			prepared := false
			app := newConfigTestApp(t, commandkit.NewCommand(commandkit.CommandSpec[struct{}]{
				Name: "report",
				Run: func(invocation commandkit.Invocation, _ struct{}) commandkit.Outcome {
					return renderPreparedConfigReport(invocation, commandkit.Explanation{Message: "selected context"}, func() ([]byte, error) {
						prepared = true
						cancel()
						return []byte("prepared report"), nil
					})
				},
			}))
			args := []string{"report"}
			if quiet {
				args = append(args, "--quiet")
			}
			writes := 0
			got := app.Execute(ctx, args, commandkit.Streams{Out: reportWriteFunc(func(p []byte) (int, error) {
				writes++
				return len(p), nil
			})})
			if !prepared || writes != 0 || got.Status != 1 || !errors.Is(got.Cause, context.Canceled) || got.Explanation.Message != "selected context" {
				t.Fatalf("prepared=%t writes=%d outcome=%#v", prepared, writes, got)
			}
			if got.Presentation.Output.RenderError != nil || got.Presentation.Output.WriteError != nil {
				t.Fatalf("cancellation became a presentation failure: %#v", got.Presentation.Output)
			}
		})
	}
}

type reportWriteFunc func([]byte) (int, error)

func (write reportWriteFunc) Write(p []byte) (int, error) { return write(p) }

func TestBufferedReportDoesNotRejectCancellationAfterDeliveryStarts(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	app := newConfigTestApp(t, commandkit.NewCommand(commandkit.CommandSpec[struct{}]{
		Name: "report",
		Run: func(invocation commandkit.Invocation, _ struct{}) commandkit.Outcome {
			return renderPreparedConfigReport(invocation, commandkit.Explanation{}, func() ([]byte, error) {
				return []byte("report"), nil
			})
		},
	}))
	got := app.Execute(ctx, []string{"report"}, commandkit.Streams{Out: reportWriteFunc(func(p []byte) (int, error) {
		cancel()
		return io.Discard.Write(p)
	})})
	if got.Status != 0 || got.Cause != nil {
		t.Fatalf("post-delivery cancellation changed the operation outcome: %#v", got)
	}
}