package config

import (
	"errors"
	"log"
	"os"
	"strings"

	"github.com/alecthomas/kong"
	kongtoml "github.com/alecthomas/kong-toml"
	"github.com/pelletier/go-toml"
)

type Config struct {
	Port                string            `toml:"port" short:"p" default:"8080" comment:"The port to listen on for the server."`
	DatabaseFilePath    string            `toml:"database-file-path" short:"d" default:"plm.db" comment:"Path to sqlite database file."`
	DemoDataPath        string            `toml:"demo-data-path" comment:"The path to the sql file to load for demo data."`
	JWTKey              string            `toml:"jwt-key" comment:"The key used to encrypt the generated JWT. Encoded in base64. If empty a random one will be generated on every restart."`
	ImageFolderPath     string            `toml:"image-folder-path" short:"i" default:"img" comment:"Folder where uploaded files will be stored."`
	Limit               int               `toml:"limit" default:"100" comment:"A single API call will return at most this number of records."`
	InventaireUrl       string            `toml:"inventaire-url" default:"https://inventaire.io" comment:"An inventaire.io instance URL."`
	DisableRegistration bool              `toml:"disable-registration" short:"n" default:"false" comment:"Disable new account creation."`
	DemoMode            bool              `toml:"demo-mode" short:"D" default:"false" comment:"Activate demo mode: anyone connecting to the instance will be logged in as a single user."`
	DemoUsername        string            `toml:"demo-username" default:"demo" comment:"Name of the single user used for the demo."`
	AddUser             UserListAsStrings `toml:"add-user" short:"a" comment:"Add an user on startup following htpasswd bcrypt format, example: [\"demo:$2y$10$UHR2646SZo2W.Rhna7bn5eWNLXWJZ/Sa3oLd9RlxlXs57Bwp6isOS\",\"user:$2y$10$3WYUp.VDpzJRywtrxO1s/uWfUIKpTE4yh5B1d2RCef3hvczYbEWTC\"]"`
}

type UserListAsStrings []string

func (u UserListAsStrings) Validate() error {
	for _, s := range u {
		if strings.Count(s, ":") != 1 {
			return errors.New("For adding users, please follow the format [username]:[bcrypt hashed password]")
		}
	}
	return nil
}

func defaultConfig() Config {
	return Config{
		Port:                "8080",
		DatabaseFilePath:    "plm.db",
		DemoDataPath:        "",
		JWTKey:              "",
		ImageFolderPath:     "img",
		Limit:               100,
		InventaireUrl:       "https://inventaire.io",
		DisableRegistration: false,
		DemoMode:            false,
		DemoUsername:        "demo",
		AddUser:             []string{},
	}
}

func LoadConfig(configPath string) Config {
	f, err := os.ReadFile(configPath)

	var cfg Config
	configFileNotExist := false
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			cfg = defaultConfig()
			configFileNotExist = true
		} else {
			log.Fatal(err)
		}
	} else {
		err = toml.Unmarshal(f, &cfg)
		if err != nil {
			panic(err)
		}
	}
	kong.Parse(&cfg, kong.Configuration(kongtoml.Loader, configPath))

	if configFileNotExist {
		b, err := toml.Marshal(cfg)
		if err != nil {
			panic(err)
		}
		err = os.WriteFile(configPath, b, 0666)
		if err != nil {
			log.Fatal(err)
		}
	}

	return cfg
}