package credentials

import (
	"bufio"
	"encoding/json"
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"golang.org/x/term"
)

type (
	credential struct {
		Username string `json:"username"`
		Password string `json:"password"`
	}

	credentialsStore struct {
		Store map[string]credential `json:"store"`
	}
)

var (
	datastorePath string
)

func init() {
	roaming, err := os.UserConfigDir()
	if err != nil {
		panic("failed to get user config path: " + err.Error())
	}
	datastorePath = filepath.Join(roaming, "cloudsave")
}

func Read(server string) (string, string, error) {
	var err error
	store, err := load()
	if err == nil {
		if c, ok := store[server]; ok {
			return c.Username, c.Password, nil
		}
	}

	fmt.Print("Enter username: ")
	reader := bufio.NewReader(os.Stdin)
	username, _ := reader.ReadString('\n')
	username = strings.TrimSpace(username)

	fmt.Printf("password for %s: ", username)
	password, err := term.ReadPassword(int(os.Stdin.Fd()))
	if err != nil {
		return "", "", err
	}
	fmt.Println()

	return username, string(password), nil
}

func Login(username, password, server string) error {
	store, err := load()
	if err != nil {
		return err
	}

	store[server] = credential{
		Username: username,
		Password: password,
	}

	return save(store)
}

func Logout(server string) error {
	store, err := load()
	if err != nil {
		return err
	}

	delete(store, server)

	return save(store)
}

func save(store map[string]credential) error {
	c := credentialsStore{
		Store: store,
	}

	f, err := os.OpenFile(filepath.Clean(filepath.Join(datastorePath, "credential.json")), os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0600)
	if err != nil {
		return fmt.Errorf("failed to open datastore: %w", err)
	}
	defer f.Close()

	e := json.NewEncoder(f)
	if err := e.Encode(c); err != nil {
		return fmt.Errorf("failed to encode data: %w", err)
	}

	return nil
}

func load() (map[string]credential, error) {
	f, err := os.OpenFile(filepath.Clean(filepath.Join(datastorePath, "credential.json")), os.O_RDONLY, 0)
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			return make(map[string]credential), nil
		}
		return nil, fmt.Errorf("failed to open datastore: %w", err)
	}
	defer f.Close()

	var c credentialsStore
	d := json.NewDecoder(f)
	if err := d.Decode(&c); err != nil {
		return nil, fmt.Errorf("failed to decode data: %w", err)
	}

	return c.Store, nil
}