package gitpb

// 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_GOSRC} is set
func (all *Repos) ConfigSave() error {
	if os.Getenv("FORGE_GOSRC") == "" {
		homeDir, _ := os.UserHomeDir()
		fullpath := filepath.Join(homeDir, ".config/forge")
		os.Setenv("FORGE_GOSRC", fullpath)
	}
	if all == nil {
		log.Warn("gitpb all == nil")
		return errors.New("gitpb.ConfigSave() all == nil")
	}

	data, err := all.Marshal()
	if err != nil {
		log.Info("gitpb proto.Marshal() failed len", len(data), err)
		return err
	}
	log.Info("gitpb.ConfigSave() repos.Marshal() worked len", len(data))
	configWrite("repos.pb", data)
	return nil
}

// load the ~/.config/forge/ files
func (all *Repos) ConfigLoad() error {
	if os.Getenv("FORGE_GOSRC") == "" {
		homeDir, _ := os.UserHomeDir()
		fullpath := filepath.Join(homeDir, ".config/forge")
		os.Setenv("FORGE_GOSRC", fullpath)
	}
	var data []byte
	var err error

	if data, err = loadFile("repos.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?
			log.Warn("gitpb.ConfigLoad() repos.pb is empty")
			return errors.New("gitpb.ConfigLoad() repos.pb is empty")
		}
		if all.Repos == nil {
			log.Warn("gitpb.ConfigLoad() all.Repos == nil")
		} else {
			log.Warn("gitpb.ConfigLoad() all.Repos.Len()", all.Len())
		}
		if err = all.Unmarshal(data); err != nil {
			log.Warn("gitpb.ConfigLoad() failed", err)
			if all.Repos == nil {
				log.Warn("gitpb.ConfigLoad() all.Repos == nil")
			} else {
				log.Warn("gitpb.ConfigLoad() all.Repos.Len()", all.Len())
				log.Warn("gitpb.ConfigLoad() trying to resave the file")
				all.ConfigSave()
			}
			return err
		}
		log.Info("gitpb.Init()", len(all.Repos), "repos in ~/.config/forge/repos.pb")
		return nil
	}
	return nil
}

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