package ssh

import (
	"errors"
	"os"
	"testing"

	"github.com/pkg/sftp"
)

func TestRenamePromotedFileUsesPlainRenameWithoutOverwrite(t *testing.T) {
	client := &recordingRenamer{}
	if err := renamePromotedFile(client, "temp", "index.html", false); err != nil {
		t.Fatalf("renamePromotedFile() error = %v", err)
	}
	if got, want := client.calls, []string{"rename temp index.html"}; !equalStrings(got, want) {
		t.Fatalf("calls = %q, want %q", got, want)
	}
}

func TestRenamePromotedFileUsesPosixRenameForOverwrite(t *testing.T) {
	client := &recordingRenamer{}
	if err := renamePromotedFile(client, "temp", "index.html", true); err != nil {
		t.Fatalf("renamePromotedFile() error = %v", err)
	}
	if got, want := client.calls, []string{"posix temp index.html"}; !equalStrings(got, want) {
		t.Fatalf("calls = %q, want %q", got, want)
	}
}

func TestRenamePromotedFileFallsBackWhenReplaceRenameUnsupported(t *testing.T) {
	for _, err := range []error{
		sftp.ErrSSHFxOpUnsupported,
		sftp.ErrSSHFxFailure,
		&sftp.StatusError{Code: uint32(sftp.ErrSSHFxOpUnsupported)},
		&sftp.StatusError{Code: uint32(sftp.ErrSSHFxFailure)},
	} {
		t.Run(err.Error(), func(t *testing.T) {
			client := &recordingRenamer{posixErr: err}
			if err := renamePromotedFile(client, "temp", "index.html", true); err != nil {
				t.Fatalf("renamePromotedFile() error = %v", err)
			}
			want := []string{"posix temp index.html", "remove index.html", "rename temp index.html"}
			if got := client.calls; !equalStrings(got, want) {
				t.Fatalf("calls = %q, want %q", got, want)
			}
		})
	}
}

func TestRenamePromotedFileIgnoresMissingTargetDuringFallback(t *testing.T) {
	client := &recordingRenamer{
		posixErr: sftp.ErrSSHFxOpUnsupported,
		removeErr: &os.PathError{
			Op:   "remove",
			Path: "index.html",
			Err:  os.ErrNotExist,
		},
	}
	if err := renamePromotedFile(client, "temp", "index.html", true); err != nil {
		t.Fatalf("renamePromotedFile() error = %v", err)
	}
	want := []string{"posix temp index.html", "remove index.html", "rename temp index.html"}
	if got := client.calls; !equalStrings(got, want) {
		t.Fatalf("calls = %q, want %q", got, want)
	}
}

func TestRenamePromotedFileDoesNotFallbackForPermissionError(t *testing.T) {
	client := &recordingRenamer{posixErr: sftp.ErrSSHFxPermissionDenied}
	if err := renamePromotedFile(client, "temp", "index.html", true); !errors.Is(err, sftp.ErrSSHFxPermissionDenied) {
		t.Fatalf("renamePromotedFile() error = %v, want permission denied", err)
	}
	if got, want := client.calls, []string{"posix temp index.html"}; !equalStrings(got, want) {
		t.Fatalf("calls = %q, want %q", got, want)
	}
}

func TestRenamePromotedFileReturnsRemoveFallbackError(t *testing.T) {
	client := &recordingRenamer{
		posixErr:  sftp.ErrSSHFxOpUnsupported,
		removeErr: sftp.ErrSSHFxPermissionDenied,
	}
	if err := renamePromotedFile(client, "temp", "index.html", true); !errors.Is(err, sftp.ErrSSHFxPermissionDenied) {
		t.Fatalf("renamePromotedFile() error = %v, want permission denied", err)
	}
	want := []string{"posix temp index.html", "remove index.html"}
	if got := client.calls; !equalStrings(got, want) {
		t.Fatalf("calls = %q, want %q", got, want)
	}
}

type recordingRenamer struct {
	calls     []string
	posixErr  error
	renameErr error
	removeErr error
}

func (r *recordingRenamer) PosixRename(oldname, newname string) error {
	r.calls = append(r.calls, "posix "+oldname+" "+newname)
	return r.posixErr
}

func (r *recordingRenamer) Rename(oldname, newname string) error {
	r.calls = append(r.calls, "rename "+oldname+" "+newname)
	return r.renameErr
}

func (r *recordingRenamer) Remove(path string) error {
	r.calls = append(r.calls, "remove "+path)
	return r.removeErr
}

func equalStrings(a, b []string) bool {
	if len(a) != len(b) {
		return false
	}
	for index := range a {
		if a[index] != b[index] {
			return false
		}
	}
	return true
}