mail

type Address struct {
	Name  string
	Email string
}

type Attachment struct {
	ID       string
	Filename string
	MimeType string
	Size     int64
}

type Draft struct {
	To      []Address
	Cc      []Address
	Bcc     []Address
	Subject string
	Body    string

	ThreadID   string
	InReplyTo  string
	References string
}

type Label struct {
	ID     string
	Name   string
	Unread int
	Total  int
	Kind   LabelKind
}

type LabelDelta struct {
	Add    []string
	Remove []string
}

type LabelKind int

type Message struct {
	ID       string
	ThreadID string

	From Address
	To   []Address
	Cc   []Address
	Bcc  []Address

	Subject string
	Date    time.Time

	// Body is plain text. HTML-only mail is converted at the provider boundary
	// so that no part of the UI needs an HTML renderer, and so remote images
	// are never fetched.
	Body        string
	Attachments []Attachment

	Labels []string
	Unread bool

	// MessageID and References carry the RFC 5322 headers needed to thread a
	// reply correctly.
	MessageID  string
	References string
}

type Provider interface {
	// Name identifies the service for display, e.g. "Gmail".
	Name() string

	// Account returns the authenticated address.
	Account() string

	// Labels lists all mailboxes and tags.
	Labels(ctx context.Context) ([]Label, error)

	// Threads returns one page of conversation summaries.
	Threads(ctx context.Context, q ThreadQuery) (ThreadPage, error)

	// Thread returns every message in a conversation, oldest first.
	Thread(ctx context.Context, id string) ([]Message, error)

	// Attachment fetches attachment content on demand.
	Attachment(ctx context.Context, msgID, attachmentID string) ([]byte, error)

	// Modify applies a label delta to whole threads.
	Modify(ctx context.Context, threadIDs []string, add, remove []string) error

	// Send delivers a draft.
	Send(ctx context.Context, d Draft) error
}

type Thread struct {
	ID           string
	Subject      string
	Snippet      string
	Participants []Address
	Date         time.Time
	MessageCount int

	Labels         []string
	Unread         bool
	Starred        bool
	HasAttachments bool
}

type ThreadPage struct {
	Threads       []Thread
	NextPageToken string
}

type ThreadQuery struct {
	LabelID   string
	Search    string
	PageToken string
	Limit     int
}