package main

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

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

	"go.wit.com/log"
	"google.golang.org/protobuf/proto"
)

func (m *Portmaps) ConfigSave() error {
	if m == nil {
		return fmt.Errorf("ConfigSave() nil")
	}
	s := m.FormatTEXT()
	log.Info("proto.Marshal() worked len", len(s))
	configWrite([]byte(s))
	return nil
}

func ConfigLoad() *Portmaps {
	if os.Getenv("CLOUD_HOME") == "" {
		homeDir, _ := os.UserHomeDir()
		fullpath := filepath.Join(homeDir, ".config/cloud")
		os.Setenv("CLOUD_HOME", fullpath)
	}

	var data []byte
	var err error
	if data, err = loadFile("gus.text"); err != nil {
		log.Warn("gus.text failed to load", err)
		// something went wrong loading the file
		return nil
	}

	if data == nil {
		return nil
	}
	p := new(Portmaps)
	if err = p.UnmarshalTEXT(data); err != nil {
		log.Warn("unmarshal failed on gus.text config file", err)
		return nil
	}

	log.Log(INFO, "gus.ConfigLoad() has", p.Len(), "port mappings")
	return p
}

func (m *Portmaps) ConfigLoad() error {
	if m == nil {
		return errors.New("It's not safe to run ConfigLoad() on a nil ?")
	}
	if os.Getenv("CLOUD_HOME") == "" {
		homeDir, _ := os.UserHomeDir()
		fullpath := filepath.Join(homeDir, ".config/cloud")
		os.Setenv("CLOUD_HOME", fullpath)
	}

	var data []byte
	var err error
	if data, err = loadFile("gus.text"); err != nil {
		// something went wrong loading the file
		return err
	}

	if data != nil {
		if err = proto.Unmarshal(data, m); err != nil {
			log.Warn("broken gus.text config file", "gus.text")
			return err
		}
		return nil
	}

	log.Log(INFO, "gus.ConfigLoad() has", m.Len(), "port mappings")
	return nil
}

func loadFile(filename string) ([]byte, error) {
	homeDir, err := os.UserHomeDir()
	p := filepath.Join(homeDir, ".config/cloud")
	fullname := filepath.Join(p, filename)
	data, err := os.ReadFile(fullname)
	if errors.Is(err, os.ErrNotExist) {
		// if file does not exist, just return nil. this
		return nil, nil
	}
	if err != nil {
		// log.Info("open config file :", err)
		return nil, err
	}
	return data, nil
}

func (m *Portmaps) loadFile(fname string) ([]byte, error) {
	fullname := filepath.Join(os.Getenv("CLOUD_HOME"), fname)

	data, err := os.ReadFile(fullname)
	if err != nil {
		// log.Info("open config file :", err)
		return nil, err
	}
	return data, nil
}

func configWrite(data []byte) error {
	homeDir, err := os.UserHomeDir()
	p := filepath.Join(homeDir, ".config/cloud")
	fname := filepath.Join(p, "gus.text")
	cfgfile, err := os.OpenFile(fname, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
	defer cfgfile.Close()
	if err != nil {
		log.Warn("open config file :", err)
		return err
	}
	cfgfile.Write(data)
	return nil
}

func (m *Portmaps) configWrite(fname string, data []byte) error {
	fullname := filepath.Join(os.Getenv("CLOUD_HOME"), fname)

	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
	}
	cfgfile.Write(data)
	return nil
}