/*
   Copyright 2014 CoreOS, Inc.

   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 system

import (
	"fmt"
	"io/ioutil"
	"os"
	"path"
	"testing"

	"github.com/coreos/coreos-cloudinit/config"
)

func TestPlaceUnit(t *testing.T) {
	tests := []config.Unit{
		{
			Name:    "50-eth0.network",
			Runtime: true,
			Content: "[Match]\nName=eth47\n\n[Network]\nAddress=10.209.171.177/19\n",
		},
		{
			Name:    "media-state.mount",
			Content: "[Mount]\nWhat=/dev/sdb1\nWhere=/media/state\n",
		},
	}

	for _, tt := range tests {
		dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
		if err != nil {
			panic(fmt.Sprintf("Unable to create tempdir: %v", err))
		}

		u := Unit{tt}
		sd := &systemd{dir}

		if err := sd.PlaceUnit(u); err != nil {
			t.Fatalf("PlaceUnit(): bad error (%+v): want nil, got %s", tt, err)
		}

		fi, err := os.Stat(u.Destination(dir))
		if err != nil {
			t.Fatalf("Stat(): bad error (%+v): want nil, got %s", tt, err)
		}

		if mode := fi.Mode(); mode != os.FileMode(0644) {
			t.Errorf("bad filemode (%+v): want %v, got %v", tt, os.FileMode(0644), mode)
		}

		c, err := ioutil.ReadFile(u.Destination(dir))
		if err != nil {
			t.Fatalf("ReadFile(): bad error (%+v): want nil, got %s", tt, err)
		}

		if string(c) != tt.Content {
			t.Errorf("bad contents (%+v): want %q, got %q", tt, tt.Content, string(c))
		}

		os.RemoveAll(dir)
	}
}

func TestPlaceUnitDropIn(t *testing.T) {
	tests := []config.Unit{
		{
			Name:    "false.service",
			Runtime: true,
			DropIns: []config.UnitDropIn{
				{
					Name:    "00-true.conf",
					Content: "[Service]\nExecStart=\nExecStart=/usr/bin/true\n",
				},
			},
		},
		{
			Name: "true.service",
			DropIns: []config.UnitDropIn{
				{
					Name:    "00-false.conf",
					Content: "[Service]\nExecStart=\nExecStart=/usr/bin/false\n",
				},
			},
		},
	}

	for _, tt := range tests {
		dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
		if err != nil {
			panic(fmt.Sprintf("Unable to create tempdir: %v", err))
		}

		u := Unit{tt}
		sd := &systemd{dir}

		if err := sd.PlaceUnitDropIn(u, u.DropIns[0]); err != nil {
			t.Fatalf("PlaceUnit(): bad error (%+v): want nil, got %s", tt, err)
		}

		fi, err := os.Stat(u.DropInDestination(dir, u.DropIns[0]))
		if err != nil {
			t.Fatalf("Stat(): bad error (%+v): want nil, got %s", tt, err)
		}

		if mode := fi.Mode(); mode != os.FileMode(0644) {
			t.Errorf("bad filemode (%+v): want %v, got %v", tt, os.FileMode(0644), mode)
		}

		c, err := ioutil.ReadFile(u.DropInDestination(dir, u.DropIns[0]))
		if err != nil {
			t.Fatalf("ReadFile(): bad error (%+v): want nil, got %s", tt, err)
		}

		if string(c) != u.DropIns[0].Content {
			t.Errorf("bad contents (%+v): want %q, got %q", tt, u.DropIns[0].Content, string(c))
		}

		os.RemoveAll(dir)
	}
}

func TestMachineID(t *testing.T) {
	dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
	if err != nil {
		t.Fatalf("Unable to create tempdir: %v", err)
	}
	defer os.RemoveAll(dir)

	os.Mkdir(path.Join(dir, "etc"), os.FileMode(0755))
	ioutil.WriteFile(path.Join(dir, "etc", "machine-id"), []byte("node007\n"), os.FileMode(0444))

	if MachineID(dir) != "node007" {
		t.Fatalf("File has incorrect contents")
	}
}

func TestMaskUnit(t *testing.T) {
	dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
	if err != nil {
		t.Fatalf("Unable to create tempdir: %v", err)
	}
	defer os.RemoveAll(dir)

	sd := &systemd{dir}

	// Ensure mask works with units that do not currently exist
	uf := Unit{config.Unit{Name: "foo.service"}}
	if err := sd.MaskUnit(uf); err != nil {
		t.Fatalf("Unable to mask new unit: %v", err)
	}
	fooPath := path.Join(dir, "etc", "systemd", "system", "foo.service")
	fooTgt, err := os.Readlink(fooPath)
	if err != nil {
		t.Fatal("Unable to read link", err)
	}
	if fooTgt != "/dev/null" {
		t.Fatal("unit not masked, got unit target", fooTgt)
	}

	// Ensure mask works with unit files that already exist
	ub := Unit{config.Unit{Name: "bar.service"}}
	barPath := path.Join(dir, "etc", "systemd", "system", "bar.service")
	if _, err := os.Create(barPath); err != nil {
		t.Fatalf("Error creating new unit file: %v", err)
	}
	if err := sd.MaskUnit(ub); err != nil {
		t.Fatalf("Unable to mask existing unit: %v", err)
	}
	barTgt, err := os.Readlink(barPath)
	if err != nil {
		t.Fatal("Unable to read link", err)
	}
	if barTgt != "/dev/null" {
		t.Fatal("unit not masked, got unit target", barTgt)
	}
}

func TestUnmaskUnit(t *testing.T) {
	dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
	if err != nil {
		t.Fatalf("Unable to create tempdir: %v", err)
	}
	defer os.RemoveAll(dir)

	sd := &systemd{dir}

	nilUnit := Unit{config.Unit{Name: "null.service"}}
	if err := sd.UnmaskUnit(nilUnit); err != nil {
		t.Errorf("unexpected error from unmasking nonexistent unit: %v", err)
	}

	uf := Unit{config.Unit{Name: "foo.service", Content: "[Service]\nExecStart=/bin/true"}}
	dst := uf.Destination(dir)
	if err := os.MkdirAll(path.Dir(dst), os.FileMode(0755)); err != nil {
		t.Fatalf("Unable to create unit directory: %v", err)
	}
	if _, err := os.Create(dst); err != nil {
		t.Fatalf("Unable to write unit file: %v", err)
	}

	if err := ioutil.WriteFile(dst, []byte(uf.Content), 700); err != nil {
		t.Fatalf("Unable to write unit file: %v", err)
	}
	if err := sd.UnmaskUnit(uf); err != nil {
		t.Errorf("unmask of non-empty unit returned unexpected error: %v", err)
	}
	got, _ := ioutil.ReadFile(dst)
	if string(got) != uf.Content {
		t.Errorf("unmask of non-empty unit mutated unit contents unexpectedly")
	}

	ub := Unit{config.Unit{Name: "bar.service"}}
	dst = ub.Destination(dir)
	if err := os.Symlink("/dev/null", dst); err != nil {
		t.Fatalf("Unable to create masked unit: %v", err)
	}
	if err := sd.UnmaskUnit(ub); err != nil {
		t.Errorf("unmask of unit returned unexpected error: %v", err)
	}
	if _, err := os.Stat(dst); !os.IsNotExist(err) {
		t.Errorf("expected %s to not exist after unmask, but got err: %s", dst, err)
	}
}

func TestNullOrEmpty(t *testing.T) {
	dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
	if err != nil {
		t.Fatalf("Unable to create tempdir: %v", err)
	}
	defer os.RemoveAll(dir)

	non := path.Join(dir, "does_not_exist")
	ne, err := nullOrEmpty(non)
	if !os.IsNotExist(err) {
		t.Errorf("nullOrEmpty on nonexistent file returned bad error: %v", err)
	}
	if ne {
		t.Errorf("nullOrEmpty returned true unxpectedly")
	}

	regEmpty := path.Join(dir, "regular_empty_file")
	_, err = os.Create(regEmpty)
	if err != nil {
		t.Fatalf("Unable to create tempfile: %v", err)
	}
	gotNe, gotErr := nullOrEmpty(regEmpty)
	if !gotNe || gotErr != nil {
		t.Errorf("nullOrEmpty of regular empty file returned %t, %v - want true, nil", gotNe, gotErr)
	}

	reg := path.Join(dir, "regular_file")
	if err := ioutil.WriteFile(reg, []byte("asdf"), 700); err != nil {
		t.Fatalf("Unable to create tempfile: %v", err)
	}
	gotNe, gotErr = nullOrEmpty(reg)
	if gotNe || gotErr != nil {
		t.Errorf("nullOrEmpty of regular file returned %t, %v - want false, nil", gotNe, gotErr)
	}

	null := path.Join(dir, "null")
	if err := os.Symlink(os.DevNull, null); err != nil {
		t.Fatalf("Unable to create /dev/null link: %s", err)
	}
	gotNe, gotErr = nullOrEmpty(null)
	if !gotNe || gotErr != nil {
		t.Errorf("nullOrEmpty of null symlink returned %t, %v - want true, nil", gotNe, gotErr)
	}

}