WIP: Check and install dependencies

cmd/changelog.go

@@ -20,6 +20,8 @@ import (
 	"os/exec"
 
 	"github.com/gaocegege/maintainer/config"
+	"github.com/gaocegege/maintainer/dep"
+
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 )
@@ -58,6 +60,15 @@ func init() {
 }
 
 func changelogRun() error {
+	isInstalled, err := dep.ChangelogGenerator.IsInstalled()
+	if err != nil {
+		return err
+	}
+	if isInstalled != true {
+		if err = dep.ChangelogGenerator.Install(); err != nil {
+			return err
+		}
+	}
 	token := viper.GetString(config.Token)
 	// Override token in CLI.
 	if *tokenValue != "" {
@@ -68,7 +79,7 @@ func changelogRun() error {
 	// Set STDERR and STDOUT to STDOUT of maintainer.
 	cmd.Stderr = os.Stdout
 	cmd.Stdout = os.Stdout
-	if err := cmd.Run(); err != nil {
+	if err = cmd.Run(); err != nil {
 		return err
 	}
 	return nil

dep/changelog.go

@@ -0,0 +1,50 @@
+// Copyright © 2017 Maintainer Authors
+//
+// 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 dep
+
+import "errors"
+
+const (
+	nameGitHubChangelogGenerator string = "github_changelog_generator"
+)
+
+// GitHubChangelogGenerator is the type for github_changelog_generator.
+// See https://github.com/skywinder/Github-Changelog-Generator.
+type GitHubChangelogGenerator struct {
+	Dependency
+	isInstalled bool
+}
+
+// NewGitHubChangelogGenerator returns a new GitHubChangelogGenerator instance.
+func NewGitHubChangelogGenerator() *GitHubChangelogGenerator {
+	return &GitHubChangelogGenerator{
+		isInstalled: false,
+	}
+}
+
+// Name implements Dependency.Name().
+func (g *GitHubChangelogGenerator) Name() string {
+	return nameGitHubChangelogGenerator
+}
+
+// IsInstalled implements Dependency.IsInstalled().
+func (g *GitHubChangelogGenerator) IsInstalled() (bool, error) {
+	return false, errors.New("Not Implemented")
+}
+
+// Install implements Dependency.Install().
+func (g *GitHubChangelogGenerator) Install() error {
+	return errors.New("Not Implemented")
+}

dep/dependency.go

@@ -0,0 +1,25 @@
+// Copyright © 2017 Maintainer Authors
+//
+// 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 dep
+
+// Dependency is the type for the dependency.
+type Dependency interface {
+	// IsInstalled check where the dependency is installed.
+	IsInstalled() (bool, error)
+	// Install installs the specific dependency and returns error if fails.
+	Install() error
+	// Name return the name of the dependency.
+	Name() string
+}

dep/init.go

@@ -0,0 +1,20 @@
+// Copyright © 2017 Maintainer Authors
+//
+// 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 dep
+
+var (
+	// ChangelogGenerator is the instance for ChangelogGenerator.
+	ChangelogGenerator = NewGitHubChangelogGenerator()
+)