package adapter

// Role is the strongly typed identity role the channel layer assigns to a
// message sender. It is derived from channel-level actor metadata (login state,
// account binding, group membership) by the strategy engine, never from prompt
// text. This is a project red line: identity resolution must not rely on
// natural-language hints.
type Role string

const (
	// RoleOwner is the bound owner/primary account. 只有渠道层的白名单判主可以赋这个角色
	// （owner.yaml 账号白名单 + 每渠道 adminIds[]，裁决 06.4.2）：适配器**不得**从平台字段
	// （如 OneBot 的 sender.role=owner）直接上报它——群主/群管理员都上报 RoleMember。
	RoleOwner Role = "owner"
	// RoleMember is a non-owner participant (for example a stranger in a group).
	RoleMember Role = "member"
	// RoleSystem is a system/synthetic sender (platform notice, bot).
	RoleSystem Role = "system"
	// RoleUnknown is a sender whose identity could not be determined.
	RoleUnknown Role = "unknown"
)

// Valid reports whether r is one of the known roles.
func (r Role) Valid() bool {
	switch r {
	case RoleOwner, RoleMember, RoleSystem, RoleUnknown:
		return true
	default:
		return false
	}
}

// Actor is the strongly typed identity metadata attached to a message sender.
// The channel layer derives it from channel telemetry (login session, account
// binding, group membership) rather than from the message's free-text sender
// name. Owner detection and group isolation read this field, not prompt text.
type Actor struct {
	// Role is the resolved identity role.
	Role Role
	// UserID is the stable platform user identifier.
	UserID string
	// DisplayName is the human-readable sender name, used for display only.
	DisplayName string
	// IsGroup is true when the actor represents a group/room conversation
	// rather than a single user.
	IsGroup bool
	// GroupID is the group identifier, set when IsGroup is true.
	GroupID string
	// GroupName is the human-readable group name, used for display only.
	GroupName string
}

// IsOwner reports whether the actor is the bound owner account.
func (a Actor) IsOwner() bool { return a.Role == RoleOwner }

// IsGroupChat reports whether the actor represents a group conversation.
func (a Actor) IsGroupChat() bool { return a.IsGroup }

// IsSystem reports whether the actor is a system/synthetic sender.
func (a Actor) IsSystem() bool { return a.Role == RoleSystem }

// IsUnknown reports whether the actor's role could not be determined.
func (a Actor) IsUnknown() bool { return a.Role == RoleUnknown }

// Resolve is a pure helper that infers IsGroup and the group identity from the
// GroupID when the channel layer has not set them explicitly, so adapters can
// populate a minimal Actor and still get correct group flags.
func (a Actor) Resolve() Actor {
	if a.GroupID != "" {
		a.IsGroup = true
	}
	return a
}