oauth2

type Client interface {
	// ID returns the configured client ID
	ID() snowflake.ID
	// Secret returns the configured client secret
	Secret() string
	// Rest returns the underlying rest.OAuth2
	Rest() rest.OAuth2

	// SessionController returns the configured SessionController
	SessionController() SessionController
	// StateController returns the configured StateController
	StateController() StateController

	// GenerateAuthorizationURL generates an authorization URL with the given redirect URI, permissions, guildID, disableGuildSelect & scopes. State is automatically generated
	GenerateAuthorizationURL(redirectURI string, permissions discord.Permissions, guildID snowflake.ID, disableGuildSelect bool, scopes ...discord.OAuth2Scope) string
	// GenerateAuthorizationURLState generates an authorization URL with the given redirect URI, permissions, guildID, disableGuildSelect & scopes. State is automatically generated & returned
	GenerateAuthorizationURLState(redirectURI string, permissions discord.Permissions, guildID snowflake.ID, disableGuildSelect bool, scopes ...discord.OAuth2Scope) (string, string)

	// StartSession starts a new Session with the given authorization code & state
	StartSession(code string, state string, identifier string, opts ...rest.RequestOpt) (Session, error)
	// RefreshSession refreshes the given Session with the refresh token
	RefreshSession(identifier string, session Session, opts ...rest.RequestOpt) (Session, error)

	// GetUser returns the discord.OAuth2User associated with the given Session. Fields filled in the struct depend on the Session.Scopes
	GetUser(session Session, opts ...rest.RequestOpt) (*discord.OAuth2User, error)
	// GetMember returns the discord.Member associated with the given Session in a specific guild.
	GetMember(session Session, guildID snowflake.ID, opts ...rest.RequestOpt) (*discord.Member, error)
	// GetGuilds returns the discord.OAuth2Guild(s) the user is a member of. This requires the discord.OAuth2ScopeGuilds scope in the Session
	GetGuilds(session Session, opts ...rest.RequestOpt) ([]discord.OAuth2Guild, error)
	// GetConnections returns the discord.Connection(s) the user has connected. This requires the discord.OAuth2ScopeConnections scope in the Session
	GetConnections(session Session, opts ...rest.RequestOpt) ([]discord.Connection, error)
}

type Config struct {
	Logger                    log.Logger
	RestClient                rest.Client
	RestClientConfigOpts      []rest.ConfigOpt
	OAuth2                    rest.OAuth2
	SessionController         SessionController
	StateController           StateController
	StateControllerConfigOpts []StateControllerConfigOpt
}

type ConfigOpt func(config *Config)

type Session interface {
	// AccessToken allows requesting user information
	AccessToken() string

	// RefreshToken allows refreshing the AccessToken
	RefreshToken() string

	// Scopes returns the discord.OAuth2Scope(s) of the Session
	Scopes() []discord.OAuth2Scope

	// TokenType returns the discord.TokenType of the AccessToken
	TokenType() discord.TokenType

	// Expiration returns the time.Time when the AccessToken expires and needs to be refreshed
	Expiration() time.Time

	// Webhook returns the discord.IncomingWebhook when the discord.OAuth2ScopeWebhookIncoming is set
	Webhook() *discord.IncomingWebhook
}

type SessionController interface {
	// GetSession returns the Session for the given identifier or nil if none was found
	GetSession(identifier string) Session

	// CreateSession creates a new Session from the given identifier, access token, refresh token, scope, token type, expiration and webhook
	CreateSession(identifier string, accessToken string, refreshToken string, scopes []discord.OAuth2Scope, tokenType discord.TokenType, expiration time.Time, webhook *discord.IncomingWebhook) Session

	// CreateSessionFromResponse creates a new Session from the given identifier and discord.AccessTokenResponse payload
	CreateSessionFromResponse(identifier string, response discord.AccessTokenResponse) Session
}

type StateController interface {
	// GenerateNewState generates a new random state to be used as a state.
	GenerateNewState(redirectURI string) string

	// ConsumeState validates a state and returns the redirect url or nil if it is invalid.
	ConsumeState(state string) string
}

type StateControllerConfig struct {
	States       map[string]string
	NewStateFunc func() string
	MaxTTL       time.Duration
}

type StateControllerConfigOpt func(config *StateControllerConfig)