config.go

package config

import (
	"bytes"
	"io"
	"os"
	"path/filepath"
	"strings"

	"github.com/cloudway/platform/pkg/conf"
)

type Config struct {
	filename string
	cfg      *conf.ConfigFile
}

// Create a new configuration.
func New(filename string) *Config {
	return &Config{filename: filename, cfg: conf.NewConfigFile()}
}

// Open Configuration file from the give file name.
func Open(filename string) (*Config, error) {
	cfg, err := conf.ReadConfigFile(filename)
	return &Config{
		filename: filename,
		cfg:      cfg,
	}, err
}

// Save configurations to file.
func (c *Config) Save() (err error) {
	if err := os.MkdirAll(filepath.Dir(c.filename), 0750); err != nil {
		return err
	}

	var file *os.File
	if file, err = os.Create(c.filename); err != nil {
		return err
	}
	defer file.Close()

	if err = c.writeSection(file, conf.DefaultSection); err != nil {
		return err
	}
	for _, section := range c.GetSections() {
		if section != conf.DefaultSection {
			if err = c.writeSection(file, section); err != nil {
				return err
			}
		}
	}
	return nil
}

func (c *Config) writeSection(w io.Writer, section string) (err error) {
	options := c.GetSection(section)
	if len(options) == 0 {
		return
	}

	buf := bytes.Buffer{}

	if section != conf.DefaultSection {
		buf.WriteString("[" + section + "]\n")
	}
	for key, value := range options {
		buf.WriteString(key + " = " + value + "\n")
	}
	buf.WriteString("\n")

	_, err = buf.WriteTo(w)
	return err
}

// Get a configuration value as string.
func (c *Config) Get(key string) string {
	return c.GetOrDefault(key, "")
}

// GetOrDefault get a configuration value, if no such value configured then
// the default value is returned.
func (c *Config) GetOrDefault(key, deflt string) string {
	if c.cfg != nil {
		section := conf.DefaultSection
		parts := strings.SplitN(key, ".", 2)
		if len(parts) == 2 {
			section, key = parts[0], parts[1]
		}
		if value, err := c.cfg.GetString(section, key); err == nil {
			return value
		}
	}
	return deflt
}

// Set a configuration of the given key to the given value.
func (c *Config) Set(key, value string) {
	if c.cfg == nil {
		c.cfg = conf.NewConfigFile()
	}

	section := conf.DefaultSection
	parts := strings.SplitN(key, ".", 2)
	if len(parts) == 2 {
		section, key = parts[0], parts[1]
	}
	c.cfg.AddOption(section, key, value)
}

// Remove a key from configuration.
func (c *Config) Remove(key string) {
	if c.cfg == nil {
		return
	}

	section := conf.DefaultSection
	parts := strings.SplitN(key, ".", 2)
	if len(parts) == 2 {
		section, key = parts[0], parts[1]
	}
	c.cfg.RemoveOption(section, key)
}

// GetSections returns the list of sections in the configuration.
func (c *Config) GetSections() []string {
	if c.cfg == nil {
		return make([]string, 0)
	} else {
		return c.cfg.GetSections()
	}
}

// GetSection get a section in the configuration file.
func (c *Config) GetSection(section string) map[string]string {
	result := make(map[string]string)

	if c.cfg == nil {
		return result
	}

	options, err := c.cfg.GetOptions(section)
	if err != nil {
		return result
	}

	for _, opt := range options {
		value, err := c.cfg.GetString(section, opt)
		if err == nil {
			result[opt] = value
		}
	}

	return result
}

// RemoveSection remove a section from configuration.
func (c *Config) RemoveSection(section string) {
	if c.cfg != nil {
		c.cfg.RemoveSection(section)
	}
}

// GetFrom get a configuration value from the given section.
func (c *Config) GetOption(section, key string) (value string) {
	if c.cfg != nil {
		value, _ = c.cfg.GetString(section, key)
	}
	return value
}

// AddOption add a configuration value into the given section.
func (c *Config) AddOption(section, key, value string) {
	if c.cfg == nil {
		c.cfg = conf.NewConfigFile()
	}
	c.cfg.AddOption(section, key, value)
}

// RemoveFrom removes a configuration value from the given section.
func (c *Config) RemoveOption(section, key string) {
	if c.cfg != nil {
		c.cfg.RemoveOption(section, key)
	}
}