package utils

import (
	"errors"
	"net/url"
	"os"
	"slices"
	"strings"
	"tinyauth/internal/constants"
	"tinyauth/internal/types"

	"github.com/rs/zerolog/log"
)

// Parses a list of comma separated users in a struct
func ParseUsers(users string) (types.Users, error) {
	log.Debug().Msg("Parsing users")

	// Create a new users struct
	var usersParsed types.Users

	// Split the users by comma
	userList := strings.Split(users, ",")

	// Check if there are any users
	if len(userList) == 0 {
		return types.Users{}, errors.New("invalid user format")
	}

	// Loop through the users and split them by colon
	for _, user := range userList {
		// Split the user by colon
		userSplit := strings.Split(user, ":")

		// Check if the user is in the correct format
		if len(userSplit) != 2 {
			return types.Users{}, errors.New("invalid user format")
		}

		// Append the user to the users struct
		usersParsed = append(usersParsed, types.User{
			Username: userSplit[0],
			Password: userSplit[1],
		})
	}

	log.Debug().Msg("Parsed users")

	// Return the users struct
	return usersParsed, nil
}

// Root url parses parses a hostname and returns the root domain (e.g. sub1.sub2.domain.com -> sub2.domain.com)
func GetRootURL(urlSrc string) (string, error) {
	// Make sure the url is valid
	urlParsed, parseErr := url.Parse(urlSrc)

	// Check if there was an error
	if parseErr != nil {
		return "", parseErr
	}

	// Split the hostname by period
	urlSplitted := strings.Split(urlParsed.Hostname(), ".")

	// Get the last part of the url
	urlFinal := strings.Join(urlSplitted[1:], ".")

	// Return the root domain
	return urlFinal, nil
}

// Reads a file and returns the contents
func ReadFile(file string) (string, error) {
	// Check if the file exists
	_, statErr := os.Stat(file)

	// Check if there was an error
	if statErr != nil {
		return "", statErr
	}

	// Read the file
	data, readErr := os.ReadFile(file)

	// Check if there was an error
	if readErr != nil {
		return "", readErr
	}

	// Return the file contents
	return string(data), nil
}

// Parses a file into a comma separated list of users
func ParseFileToLine(content string) string {
	// Split the content by newline
	lines := strings.Split(content, "\n")

	// Create a list of users
	users := make([]string, 0)

	// Loop through the lines, trimming the whitespace and appending to the users list
	for _, line := range lines {
		if strings.TrimSpace(line) == "" {
			continue
		}

		users = append(users, strings.TrimSpace(line))
	}

	// Return the users as a comma separated string
	return strings.Join(users, ",")
}

// Get the secret from the config or file
func GetSecret(conf string, file string) string {
	// If neither the config or file is set, return an empty string
	if conf == "" && file == "" {
		return ""
	}

	// If the config is set, return the config (environment variable)
	if conf != "" {
		return conf
	}

	// If the file is set, read the file
	contents, err := ReadFile(file)

	// Check if there was an error
	if err != nil {
		return ""
	}

	// Return the contents of the file
	return contents
}

// Get the users from the config or file
func GetUsers(conf string, file string) (types.Users, error) {
	// Create a string to store the users
	var users string

	// If neither the config or file is set, return an empty users struct
	if conf == "" && file == "" {
		return types.Users{}, nil
	}

	// If the config (environment) is set, append the users to the users string
	if conf != "" {
		log.Debug().Msg("Using users from config")
		users += conf
	}

	// If the file is set, read the file and append the users to the users string
	if file != "" {
		// Read the file
		fileContents, fileErr := ReadFile(file)

		// If there isn't an error we can append the users to the users string
		if fileErr == nil {
			log.Debug().Msg("Using users from file")

			// Append the users to the users string
			if users != "" {
				users += ","
			}

			// Parse the file contents into a comma separated list of users
			users += ParseFileToLine(fileContents)
		}
	}

	// Return the parsed users
	return ParseUsers(users)
}

// Parse the docker labels to the tinyauth labels struct
func GetTinyauthLabels(labels map[string]string) types.TinyauthLabels {
	// Create a new tinyauth labels struct
	var tinyauthLabels types.TinyauthLabels

	// Loop through the labels
	for label, value := range labels {

		// Check if the label is in the tinyauth labels
		if slices.Contains(constants.TinyauthLabels, label) {

			log.Debug().Str("label", label).Msg("Found label")

			// Add the label value to the tinyauth labels struct
			switch label {
			case "tinyauth.oauth.whitelist":
				tinyauthLabels.OAuthWhitelist = strings.Split(value, ",")
			case "tinyauth.users":
				tinyauthLabels.Users = strings.Split(value, ",")
			}
		}
	}

	// Return the tinyauth labels
	return tinyauthLabels
}

// Check if any of the OAuth providers are configured based on the client id and secret
func OAuthConfigured(config types.Config) bool {
	return (config.GithubClientId != "" && config.GithubClientSecret != "") || (config.GoogleClientId != "" && config.GoogleClientSecret != "") || (config.GenericClientId != "" && config.GenericClientSecret != "") || (config.TailscaleClientId != "" && config.TailscaleClientSecret != "")
}

// Filter helper function
func Filter[T any](slice []T, test func(T) bool) (res []T) {
	for _, value := range slice {
		if test(value) {
			res = append(res, value)
		}
	}
	return res
}