forgepb/config.go

package forgepb

// functions to import and export the protobuf
// data to and from config files

import (
	"errors"
	"os"
	"path/filepath"
	"time"

	"go.wit.com/log"
)

func (f *Forge) ConfigSave() error {
	var err error
	// backup the current config files
	if e := backupConfig(); e != nil {
		log.Info("forge.BackupConfig() error", e)
		err = e
		// continue here? notsure. could be bad either way
		// out of disk space?
	}
	if f.Config != nil {
		if e := f.Config.ConfigSave(); e != nil {
			log.Info("forge.Config.ConfigSave() error", e)
			err = e
		}
	}
	if f.Repos != nil {
		if e := f.Repos.ConfigSave(); e != nil {
			log.Info("forge.Repos.ConfigSave() error", e)
			err = e
		}
	}
	return err
}

// write to ~/.config/forge/ unless ENV{FORGE_CONFIG} is set
func (f *ForgeConfigs) ConfigSave() error {
	data, err := f.Marshal()
	if err != nil {
		log.Info("proto.Marshal() failed len", len(data), err)
		return err
	}
	log.Info("forgepb.ConfigSave() proto.Marshal() worked len", len(data))
	configWrite("forge.pb", data)

	s := f.FormatTEXT()
	configWrite("forge.text", []byte(s))

	s = f.FormatJSON()
	configWrite("forge.json", []byte(s))

	return nil
}

// load the ~/.config/forge/ files
func (c *ForgeConfigs) ConfigLoad() error {
	if os.Getenv("FORGE_CONFIG") == "" {
		homeDir, _ := os.UserHomeDir()
		fullpath := filepath.Join(homeDir, ".config/forge")
		os.Setenv("FORGE_CONFIG", fullpath)
	}
	// var data []byte
	// var err error
	if c == nil {
		// can't safely do c = new(ForgeConfig) if c is in a struct from the caller. notsure why
		return errors.New("It's not safe to run ConfigLoad() on a nil")
	}

	if data, err := loadFile("forge.pb"); err == nil {
		if data != nil {
			if len(data) != 0 {
				if err = c.Unmarshal(data); err == nil {
					log.Info("forge.ConfigLoad()", len(c.ForgeConfigs), "entries in ~/.config/forge")
					return nil
				}
			}
		}
	}
	log.Warn("broken forge.pb config file")

	// forge.db doesn't exist. try forge.text
	// this lets the user hand edit the config
	if data, err := loadFile("forge.text"); err == nil {
		if data != nil {
			// this means the forge.text file exists and was read
			if len(data) != 0 {
				if err = c.UnmarshalTEXT(data); err != nil {
					log.Info("forge.ConfigLoad()", len(c.ForgeConfigs), "entries in ~/.config/forge")
					// forge.pb file was broken. save on load right away
					log.Info("attempting forge.ConfigSave()")
					c.ConfigSave()
					return nil
				}
				// todo: error out if the file is empty?
			}
		}
	}

	// forge.text doesn't exist. try forge.json
	// this lets the user hand edit the config
	if data, err := loadFile("forge.json"); err != nil {
		if data != nil {
			// this means the forge.json file exists and was read
			if len(data) != 0 {
				if err = c.UnmarshalJSON(data); err == nil {
					log.Info("forge.ConfigLoad()", len(c.ForgeConfigs), "entries in ~/.config/forge")
					// forge.pb file was broken. save on load right away
					log.Info("attempting forge.ConfigSave()")
					c.ConfigSave()
					return nil
				}
			}
		}
	}

	cpath := filepath.Join(os.Getenv("FORGE_CONFIG"), ".")
	if _, err := os.Stat(cpath); err == nil {
		log.Info("Something has gone wrong. Your", os.Getenv("FORGE_CONFIG"), "directory exists")
		log.Info("However, the config files could not be loaded")
		time.Sleep(2 * time.Second)
		os.Exit(-1)
		// return errors.New("config files can not be loaded from" + os.Getenv("FORGE_CONFIG"))
	}

	// first time user. make a template config file
	c.sampleConfig()

	return nil
}

func loadFile(filename string) ([]byte, error) {
	fullname := filepath.Join(os.Getenv("FORGE_CONFIG"), filename)
	data, err := os.ReadFile(fullname)
	if errors.Is(err, os.ErrNotExist) {
		// if file does not exist, just return nil. this
		// will cause ConfigLoad() to try the next config file like "forge.text"
		// because the user might want to edit the .config by hand
		return nil, nil
	}
	if err != nil {
		// log.Info("open config file :", err)
		return nil, err
	}
	return data, nil
}

func configWrite(filename string, data []byte) error {
	fullname := filepath.Join(os.Getenv("FORGE_CONFIG"), filename)

	cfgfile, err := os.OpenFile(fullname, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
	defer cfgfile.Close()
	if err != nil {
		log.Warn("open config file :", err)
		return err
	}
	if filename == "forge.text" {
		// add header
		cfgfile.Write([]byte("# this file is automatically re-generated from forge.pb, however,\n"))
		cfgfile.Write([]byte("# if you want to edit it by hand, you can:\n"))
		cfgfile.Write([]byte("# stop forge; remove forge.pb; edit forge.text; start forge\n"))
		cfgfile.Write([]byte("# this will cause the default behavior to fallback to parsing this file for the config\n"))
		cfgfile.Write([]byte("\n"))
		cfgfile.Write([]byte("# this file is intended to be used to customize settings on what\n"))
		cfgfile.Write([]byte("# git repos you have write access to. That is, where you can run 'git push'\n"))
	}
	cfgfile.Write(data)
	return nil
}