package zfsadm

import (
	"context"
	"errors"
	"strings"
	"testing"
)

func TestValidators(t *testing.T) {
	for _, s := range []string{"media", "media/video", "a.b_c:d-e", "x/y/z"} {
		if err := ValidateRelName(s); err != nil {
			t.Errorf("%q rejected: %v", s, err)
		}
	}
	for _, s := range []string{"", "/media", "media/", "a//b", "..", "a/../b", ".", "-x", "a/-b", "a b", "a;b", "a/b\n", strings.Repeat("x", 201)} {
		if ValidateRelName(s) == nil {
			t.Errorf("%q accepted", s)
		}
	}
	for _, s := range []string{"", "100G", "1.5T", "512M", "10k", "42"} {
		if ValidateSize(s) != nil {
			t.Errorf("size %q rejected", s)
		}
	}
	for _, s := range []string{"10 G", "10GB", "G", "-1G", "1e3"} {
		if ValidateSize(s) == nil {
			t.Errorf("size %q accepted", s)
		}
	}
	if ValidateCompression("gzip") == nil || ValidateCompression("lz4") != nil || ValidateCompression("") != nil {
		t.Error("compression validation")
	}
	if ValidateOwner("ansible") == nil || ValidateOwner("1000:1000") != nil || ValidateOwner("") != nil {
		t.Error("owner validation")
	}
}

// fake records calls and answers by command prefix.
type fake struct {
	calls []string
	reply map[string]string
	fail  map[string]string
}

func (f *fake) run(_ context.Context, name string, args ...string) (string, error) {
	c := name + " " + strings.Join(args, " ")
	f.calls = append(f.calls, c)
	for k, v := range f.fail {
		if strings.HasPrefix(c, k) {
			return v, errors.New(v)
		}
	}
	for k, v := range f.reply {
		if strings.HasPrefix(c, k) {
			return v, nil
		}
	}
	return "", nil
}

func TestCreate(t *testing.T) {
	f := &fake{reply: map[string]string{"zfs get": "/tank/media"}}
	a := New(f.run)
	if err := a.Create("tank/media", CreateOpts{Compression: "lz4", Quota: "100G", Owner: "1000:1000"}); err != nil {
		t.Fatal(err)
	}
	want := []string{
		"zfs create -p -o compression=lz4 -o quota=100G tank/media",
		"zfs get -H -o value mountpoint tank/media",
		"chown 1000:1000 /tank/media",
	}
	if strings.Join(f.calls, "\n") != strings.Join(want, "\n") {
		t.Errorf("calls:\n%s\nwant:\n%s", strings.Join(f.calls, "\n"), strings.Join(want, "\n"))
	}

	// no owner, inherit everything
	f = &fake{}
	a = New(f.run)
	if err := a.Create("tank/x", CreateOpts{}); err != nil {
		t.Fatal(err)
	}
	if len(f.calls) != 1 || f.calls[0] != "zfs create -p tank/x" {
		t.Errorf("calls = %v", f.calls)
	}

	// invalid input never reaches the runner
	f = &fake{}
	a = New(f.run)
	if err := a.Create("tank/../x", CreateOpts{}); err == nil || len(f.calls) != 0 {
		t.Errorf("bad name: err=%v calls=%v", err, f.calls)
	}
	if err := a.Create("tank/x", CreateOpts{Quota: "lots"}); err == nil || len(f.calls) != 0 {
		t.Errorf("bad quota: err=%v calls=%v", err, f.calls)
	}

	// zfs error is surfaced verbatim
	f = &fake{fail: map[string]string{"zfs create": "cannot create 'tank/x': out of space"}}
	a = New(f.run)
	if err := a.Create("tank/x", CreateOpts{}); err == nil || !strings.Contains(err.Error(), "out of space") {
		t.Errorf("err = %v", err)
	}

	// unmounted dataset: created but chown skipped, reported
	f = &fake{reply: map[string]string{"zfs get": "none"}}
	a = New(f.run)
	err := a.Create("tank/x", CreateOpts{Owner: "1000:1000"})
	if err == nil || !strings.Contains(err.Error(), "chown skipped") {
		t.Errorf("err = %v", err)
	}
	for _, c := range f.calls {
		if strings.HasPrefix(c, "chown") {
			t.Errorf("chown must not run: %v", f.calls)
		}
	}
}

func TestDestroyEmpty(t *testing.T) {
	ok := map[string]string{"zfs list -Hp -r -t filesystem": "tank/x\t98304", "zfs list -H -t snapshot": ""}
	f := &fake{reply: ok}
	a := New(f.run)
	if err := a.DestroyEmpty("tank/x"); err != nil {
		t.Fatal(err)
	}
	if f.calls[len(f.calls)-1] != "zfs destroy tank/x" {
		t.Errorf("calls = %v", f.calls)
	}

	cases := map[string]map[string]string{
		"children":  {"zfs list -Hp -r -t filesystem": "tank/x\t98304\ntank/x/y\t98304", "zfs list -H -t snapshot": ""},
		"not empty": {"zfs list -Hp -r -t filesystem": "tank/x\t5000000", "zfs list -H -t snapshot": ""},
		"snapshots": {"zfs list -Hp -r -t filesystem": "tank/x\t98304", "zfs list -H -t snapshot": "tank/x@s1"},
	}
	for name, reply := range cases {
		f := &fake{reply: reply}
		a := New(f.run)
		err := a.DestroyEmpty("tank/x")
		if err == nil {
			t.Errorf("%s: destroyed", name)
		}
		for _, c := range f.calls {
			if strings.HasPrefix(c, "zfs destroy") {
				t.Errorf("%s: destroy ran", name)
			}
		}
	}

	f = &fake{reply: ok}
	a = New(f.run)
	if err := a.DestroyEmpty("tank"); err == nil || len(f.calls) != 0 {
		t.Errorf("pool root: err=%v calls=%v", err, f.calls)
	}
}