// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package asymkey

import (
	"context"
	"fmt"
	"strings"

	"gitea.dev/models/db"
	user_model "gitea.dev/models/user"
	"gitea.dev/modules/setting"
	"gitea.dev/modules/util"
)

// CheckPrincipalKeyString strips spaces and returns an error if the given principal contains newlines
func CheckPrincipalKeyString(ctx context.Context, user *user_model.User, content string) (_ string, err error) {
	if setting.SSH.Disabled {
		return "", db.ErrSSHDisabled{}
	}

	content = strings.TrimSpace(content)
	if strings.ContainsAny(content, "\r\n") {
		return "", util.NewInvalidArgumentErrorf("only a single line with a single principal please")
	}

	// check all the allowed principals, email, username or anything
	// if any matches, return ok
	for _, v := range setting.SSH.AuthorizedPrincipalsAllow {
		switch v {
		case "anything":
			return content, nil
		case "email":
			emails, err := user_model.GetEmailAddresses(ctx, user.ID)
			if err != nil {
				return "", err
			}
			for _, email := range emails {
				if !email.IsActivated {
					continue
				}
				if strings.EqualFold(content, email.LowerEmail) {
					return content, nil
				}
			}

		case "username":
			if content == user.Name {
				return content, nil
			}
		}
	}

	return "", fmt.Errorf("didn't match allowed principals: %s", setting.SSH.AuthorizedPrincipalsAllow)
}
