// config.go

//

// This file implements the configuration part for when you need the API

// key to modify things in the Mastodon configuration and manage measurements.

package gondole

import (

	"fmt"

	"io/ioutil"

	"log"

	"os"

	"path/filepath"

	"github.com/naoina/toml"

)

/*

Assume the application is registered if $HOME/.config/<gondole>/config.toml already exist

We will store the per-instance token into $HOME/.config/<gondole>/<site>.token

*/

const (

	DefaultName = "config.toml"

)

var (

	baseDir = filepath.Join(os.Getenv("HOME"),

		".config",

		"gondole",

	)

)

// Config holds our parameters

type Server struct {

	ID          string

	Name        string

	BearerToken string

}

type Config struct {

	Default string

}

func loadGlobal(file string) (c *Config, err error) {

	log.Printf("file=%s", file)

	// Check if there is any config file

	_, err = os.Stat(file)

	if err != nil {

		return

	}

	log.Printf("file=%s, found it", file)

	// Read it

	buf, err := ioutil.ReadFile(file)

	if err != nil {

		return c, fmt.Errorf("Can not read %s", file)

	}

	cnf := Config{}

	err = toml.Unmarshal(buf, &cnf)

	if err != nil {

		return c, fmt.Errorf("Error parsing toml %s: %v", file, err)

	}

	c = &cnf

	return

}

func loadInstance(name string) (s *Server, err error) {

	// Load instance-specific file

	file := filepath.Join(baseDir, name+".token")

	log.Printf("instance is %s", file)

	// Check if there is any config file

	if _, err = os.Stat(file); err == nil {

		// Read it

		buf, err := ioutil.ReadFile(file)

		if err != nil {

			return s, fmt.Errorf("Can not read %s", file)

		}

		sc := Server{}

		err = toml.Unmarshal(buf, &sc)

		if err != nil {

			return s, fmt.Errorf("Error parsing toml %s: %v", file, err)

		}

		s = &sc

	}

	return

}

func GetInstanceList() (list []string) {

	list, err := filepath.Glob(filepath.Join(baseDir, "*.token"))

	log.Printf("basedir=%s", filepath.Join(baseDir, "*.token"))

	if err != nil {

		log.Printf("warning, no *.token files in %s", baseDir)

		list = nil

	}

	log.Printf("list=%v", list)

	return

}

// LoadConfig reads a file as a TOML document and return the structure

func LoadConfig(name string) (s *Server, err error) {

	// Load global file

	gFile := filepath.Join(baseDir, DefaultName)

	log.Printf("global is %s", gFile)

	c, err := loadGlobal(gFile)

	if err != nil {

		return

	}

	if name == "" {

		s, err = loadInstance(c.Default)

	} else {

		s, err = loadInstance(name)

	}

	return s, err

}

func (c *Config) Write() (err error) {

	if err = os.MkdirAll(baseDir, 0700); err != nil {

		log.Fatalf("error creating configuration directory: %s", baseDir)

	}

	var sc []byte

	if sc, err = toml.Marshal(*c); err != nil {

		log.Fatalf("error saving configuration")

	}

	err = ioutil.WriteFile(filepath.Join(baseDir, DefaultName), sc, 0600)

	return

}

func (s *Server) WriteToken(instance string) (err error) {

	if err = os.MkdirAll(baseDir, 0700); err != nil {

		log.Fatalf("error creating configuration directory: %s", baseDir)

	}

	var sc []byte

	if sc, err = toml.Marshal(s); err != nil {

		log.Fatalf("error saving configuration")

	}

	full := instance + ".token"

	err = ioutil.WriteFile(filepath.Join(baseDir, full), sc, 0600)

	return

}