formats/config: Added encoder/decoder for git config files. (#97)

* WIP: Add config format parser.

* add decoder based on gcfg.

Portions of code taken from:
https://github.com/go-gcfg/gcfg/blob/5b9f94ee80b2331c3982477bd84be8edd857df33/read.go

* add git config encoder and config methods.

* use format/config in storage/filesystem for read

* use format/config in storage/filesystem to write

* formats/config: improve docs.

* formats/config: improve tests.

* formats/config: use our fork of gcfg; improve api.

* formats/config: improve api.

* storage/filesystem: fix gofmt

* formats/config: use NoSubsection constant.

* formats/config: add doc.go

* formats/config: requested sytle changes.

* formats/config: do not use *_test packages.

1 files changed, 96 insertions, 0 deletions

diff --git a/formats/config/common.go b/formats/config/common.go
new file mode 100644
index 0000000..e7292e9
--- /dev/null
+++ b/formats/config/common.go
@@ -0,0 +1,96 @@
+package config
+
+// New creates a new config instance.
+func New() *Config {
+	return &Config{}
+}
+
+type Config struct {
+	Comment  *Comment
+	Sections Sections
+	Includes Includes
+}
+
+type Includes []*Include
+
+// A reference to a included configuration.
+type Include struct {
+	Path   string
+	Config *Config
+}
+
+type Comment string
+
+const (
+	NoSubsection = ""
+)
+
+func (c *Config) Section(name string) *Section {
+	for i := len(c.Sections) - 1; i >= 0; i-- {
+		s := c.Sections[i]
+		if s.IsName(name) {
+			return s
+		}
+	}
+	s := &Section{Name: name}
+	c.Sections = append(c.Sections, s)
+	return s
+}
+
+// AddOption is a convenience method to add an option to a given
+// section and subsection.
+//
+// Use the NoSubsection constant for the subsection argument
+// if no subsection is wanted.
+func (s *Config) AddOption(section string, subsection string, key string, value string) *Config {
+	if subsection == "" {
+		s.Section(section).AddOption(key, value)
+	} else {
+		s.Section(section).Subsection(subsection).AddOption(key, value)
+	}
+
+	return s
+}
+
+// SetOption is a convenience method to set an option to a given
+// section and subsection.
+//
+// Use the NoSubsection constant for the subsection argument
+// if no subsection is wanted.
+func (s *Config) SetOption(section string, subsection string, key string, value string) *Config {
+	if subsection == "" {
+		s.Section(section).SetOption(key, value)
+	} else {
+		s.Section(section).Subsection(subsection).SetOption(key, value)
+	}
+
+	return s
+}
+
+func (c *Config) RemoveSection(name string) *Config {
+	result := Sections{}
+	for _, s := range c.Sections {
+		if !s.IsName(name) {
+			result = append(result, s)
+		}
+	}
+
+	c.Sections = result
+	return c
+}
+
+func (c *Config) RemoveSubsection(section string, subsection string) *Config {
+	for _, s := range c.Sections {
+		if s.IsName(section) {
+			result := Subsections{}
+			for _, ss := range s.Subsections {
+				if !ss.IsName(subsection) {
+					result = append(result, ss)
+				}
+			}
+			s.Subsections = result
+		}
+	}
+
+	return c
+}