package forgepb

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

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

	"go.wit.com/log"
)

// write to ~/.config/forge/ unless ENV{FORGE_HOME} is set
func (m *Repos) ConfigSave() error {
	if os.Getenv("FORGE_HOME") == "" {
		homeDir, _ := os.UserHomeDir()
		fullpath := filepath.Join(homeDir, ".config/forge")
		os.Setenv("FORGE_HOME", fullpath)
	}
	// try to backup the current cluster config files
	if err := backupConfig(); err != nil {
		return err
	}
	data, err := m.Marshal()
	if err != nil {
		log.Info("proto.Marshal() failed len", len(data), err)
		return err
	}
	log.Info("proto.Marshal() worked len", len(data))
	configWrite("forge.pb", data)

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

	s = m.FormatJSON()
	configWrite("forge.json", []byte(s))
	return nil
}

// load the ~/.config/forge/ files
func (c *Repos) ConfigLoad() error {
	if os.Getenv("FORGE_HOME") == "" {
		homeDir, _ := os.UserHomeDir()
		fullpath := filepath.Join(homeDir, ".config/forge")
		os.Setenv("FORGE_HOME", fullpath)
	}
	var data []byte
	var err error
	if c == nil {
		// can't safely do c = new(Repo) 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 {
		// something went wrong loading the file
		return err
	}
	if data != nil {
		// this means the forge.pb file exists and was read
		if len(data) == 0 {
			// todo: error out if the file is empty?
			// try forge.text & forge.json?
		}
		if err = c.Unmarshal(data); err != nil {
			log.Warn("broken forge.pb config file")
			return err
		}
		log.Info("config load found", len(c.Repos), "repos")
		return nil
	}

	// forge.db doesn't exist. try forge.text
	// this lets the user hand edit the config
	if data, err = loadFile("forge.text"); err != nil {
		// something went wrong loading the file
		return err
	}

	if data != nil {
		// this means the forge.text file exists and was read
		if len(data) == 0 {
			// todo: error out if the file is empty?
		}
		if err = c.UnmarshalTEXT(data); err != nil {
			log.Warn("broken forge.text config file")
			return err
		}
		log.Info("config load found", len(c.Repos), "repos")
		return nil
	}

	// forge.text doesn't exist. try forge.json
	// this lets the user hand edit the config
	if data, err = loadFile("forge.json"); err != nil {
		// something went wrong loading the file
		return err
	}

	if data != nil {
		// this means the forge.text file exists and was read
		if len(data) == 0 {
			// todo: error out if the file is empty?
		}
		if err = c.UnmarshalJSON(data); err != nil {
			log.Warn("broken forge.json config file")
			return err
		}
		log.Info("config load found", len(c.Repos), "repos")
		return nil
	}

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

	return nil
}

func loadFile(filename string) ([]byte, error) {
	fullname := filepath.Join(os.Getenv("FORGE_HOME"), 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_HOME"), filename)

	cfgfile, err := os.OpenFile(fullname, os.O_RDWR|os.O_CREATE, 0666)
	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
}