// Copyright (c) 2025-2026 Probo Inc <hello@getprobo.com>.
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.

package probod

import (
	"encoding/base64"
	"fmt"
)

type AuthConfig struct {
	Cookie                              CookieConfig       `json:"cookie"`
	Password                            PasswordConfig     `json:"password"`
	DisableSignup                       bool               `json:"disable-signup"`
	InvitationConfirmationTokenValidity int                `json:"invitation-confirmation-token-validity"`
	PasswordResetTokenValidity          int                `json:"password-reset-token-validity"`
	MagicLinkTokenValidity              int                `json:"magic-link-token-validity"`
	SAML                                SAMLConfig         `json:"saml"`
	Google                              OIDCProviderConfig `json:"google"`
	Microsoft                           OIDCProviderConfig `json:"microsoft"`
	OAuth2Server                        OAuth2ServerConfig `json:"oauth2-server"`
}

type OAuth2ServerConfig struct {
	SigningKeys               []OAuth2SigningKeyConfig `json:"signing-keys"`
	AccessTokenDuration       int                      `json:"access-token-duration"`
	RefreshTokenDuration      int                      `json:"refresh-token-duration"`
	AuthorizationCodeDuration int                      `json:"authorization-code-duration"`
	DeviceCodeDuration        int                      `json:"device-code-duration"`
}

type OAuth2SigningKeyConfig struct {
	PrivateKey string `json:"private-key"`
	KID        string `json:"kid"`
	Active     bool   `json:"active"`
}

type CookieConfig struct {
	Domain   string `json:"domain"`
	Secret   string `json:"secret"`
	Duration int    `json:"duration"`
	Name     string `json:"name"`
	Secure   bool   `json:"secure"`
}

type PasswordConfig struct {
	Iterations int    `json:"iterations"`
	Pepper     string `json:"pepper"`
}

func (c AuthConfig) GetPepperBytes() ([]byte, error) {
	if c.Password.Pepper == "" {
		return nil, fmt.Errorf("pepper cannot be empty")
	}

	if decoded, err := base64.StdEncoding.DecodeString(c.Password.Pepper); err == nil {
		if len(decoded) < 32 {
			return nil, fmt.Errorf("decoded pepper must be at least 32 bytes long")
		}
		return decoded, nil
	}

	if len(c.Password.Pepper) < 32 {
		return nil, fmt.Errorf("pepper must be at least 32 bytes long")
	}

	return []byte(c.Password.Pepper), nil
}

func (c AuthConfig) GetCookieSecretBytes() ([]byte, error) {
	if c.Cookie.Secret == "" {
		return nil, fmt.Errorf("cookie secret cannot be empty")
	}

	if decoded, err := base64.StdEncoding.DecodeString(c.Cookie.Secret); err == nil {
		if len(decoded) < 32 {
			return nil, fmt.Errorf("decoded cookie secret must be at least 32 bytes long")
		}
		return decoded, nil
	}

	if len(c.Cookie.Secret) < 32 {
		return nil, fmt.Errorf("cookie secret must be at least 32 bytes long")
	}

	return []byte(c.Cookie.Secret), nil
}