/** Minimal Gmail message metadata from list endpoint */
export interface GmailMessageRef {
  id: string;
  threadId: string;
}

/** Gmail message list response */
export interface GmailMessageListResponse {
  messages?: GmailMessageRef[];
  nextPageToken?: string;
  resultSizeEstimate?: number;
}

/** A single header key-value pair */
export interface GmailHeader {
  name: string;
  value: string;
}

/** Message payload part (recursive for multipart) */
export interface GmailMessagePart {
  partId?: string;
  mimeType?: string;
  filename?: string;
  headers?: GmailHeader[];
  body?: {
    attachmentId?: string;
    size?: number;
    data?: string; // base64url-encoded
  };
  parts?: GmailMessagePart[];
}

/** Full Gmail message */
export interface GmailMessage {
  id: string;
  threadId: string;
  labelIds?: string[];
  snippet?: string;
  historyId?: string;
  internalDate?: string;
  payload?: GmailMessagePart;
  sizeEstimate?: number;
  raw?: string;
}

/** Gmail thread response */
export interface GmailThread {
  id: string;
  historyId?: string;
  messages?: GmailMessage[];
}

/** Gmail label */
export interface GmailLabel {
  id: string;
  name: string;
  type?: "system" | "user";
  messageListVisibility?: "show" | "hide";
  labelListVisibility?: "labelShow" | "labelShowIfUnread" | "labelHide";
  messagesTotal?: number;
  messagesUnread?: number;
  threadsTotal?: number;
  threadsUnread?: number;
  color?: {
    textColor?: string;
    backgroundColor?: string;
  };
}

/** Gmail labels list response */
export interface GmailLabelsListResponse {
  labels?: GmailLabel[];
}

/** Gmail profile response */
export interface GmailProfile {
  emailAddress: string;
  messagesTotal?: number;
  threadsTotal?: number;
  historyId?: string;
}

/** Gmail draft response */
export interface GmailDraft {
  id: string;
  message?: GmailMessage;
}

/** Modify request body */
export interface GmailModifyRequest {
  addLabelIds?: string[];
  removeLabelIds?: string[];
}

/** Message format for GET requests */
export type GmailMessageFormat = "minimal" | "full" | "raw" | "metadata";