aivi.imap

Types for mailbox syncing, folder summaries, and mail events.

IMAP is the protocol many mail servers use for listing folders and syncing messages. This module defines the shapes an IMAP-backed feature can return. The current stdlib file does not connect to a server on its own.

Current status: this module now names the records used by the built-in IMAP source providers (imap.connect, imap.idle, and imap.fetchBody) while keeping the task alias for background IMAP work.

Import

use aivi.imap (
    ImapError
    ImapAuthFailed
    ImapConnectionFailed
    FolderNotFound
    ImapProtocolError
    SyncState
    ImapFolder
    ImapFlag
    Seen
    Answered
    Flagged
    Draft
    ImapEvent
    NewMessage
    MessageFlagChanged
    FolderChanged
    SyncCompleted
    ImapHeader
    ImapSnapshot
    ImapLiveEvent
    ImapBody
    ImapTask
)

Overview

Type	Purpose
SyncState	Current progress and last error for a sync run
ImapFolder	Folder name plus message counts
ImapFlag	Common message flags
ImapEvent	Events emitted while mail changes
ImapHeader	One synced message header
ImapSnapshot	One mailbox snapshot for one account
ImapLiveEvent	One account-scoped mailbox change event
ImapBody	Full fetched message body
ImapError	Structured connection or sync failures
ImapTask A	Background IMAP work returning A

---

SyncState

type SyncState = {
    lastSyncedAt: Option Int,
    inProgress: Bool,
    error: Option ImapError
}

Tracks the current state of a mailbox sync.

• lastSyncedAt — optional time of the last completed sync
• inProgress — True while a sync is running
• error — the last sync error, if there was one

use aivi.imap (SyncState)

value idleSync : SyncState = {
    lastSyncedAt: None,
    inProgress: False,
    error: None
}

---

ImapFolder

type ImapFolder = {
    name: Text,
    messageCount: Int,
    unreadCount: Int
}

Summary information for one folder.

use aivi.imap (ImapFolder)

value inbox : ImapFolder = {
    name: "INBOX",
    messageCount: 120,
    unreadCount: 4
}

---

ImapFlag

type ImapFlag =
  | Seen
  | Answered
  | Flagged
  | Draft

Common message flags used by mail servers.

• Seen — the message has been read
• Answered — a reply was sent
• Flagged — the message is starred or flagged
• Draft — the message is a draft

---

ImapEvent

type ImapEvent =
  | NewMessage Int
  | MessageFlagChanged Int ImapFlag
  | FolderChanged Text
  | SyncCompleted

Mailbox events you can react to.

• NewMessage Int — a new message arrived, identified by an integer from the backend
• MessageFlagChanged Int ImapFlag — a message flag changed
• FolderChanged Text — a folder changed by name
• SyncCompleted — the current sync run finished

use aivi.imap (
    ImapEvent
    NewMessage
    MessageFlagChanged
    FolderChanged
    SyncCompleted
)

type ImapEvent -> Text
func describeEvent = event => event
 ||> NewMessage _           -> "new message"
 ||> MessageFlagChanged _ _ -> "message flag changed"
 ||> FolderChanged name     -> "folder changed: {name}"
 ||> SyncCompleted          -> "sync completed"

---

ImapHeader

type ImapHeader = {
    uid: Int,
    subject: Text,
    from: Text,
    date: Text,
    messageId: Text,
    flags: List ImapFlag,
    preview: Text,
    rawHeader: Text
}

Best-effort header slice fetched during mailbox sync.

ImapSnapshot

type ImapSnapshot = {
    accountId: Text,
    mailbox: Text,
    highestUid: Option Int,
    messages: List ImapHeader
}

Mailbox snapshot returned by imap.connect.

ImapLiveEvent

type ImapLiveEvent = {
    accountId: Text,
    mailbox: Text,
    event: ImapEvent
}

Account-scoped mailbox change event returned by imap.idle.

ImapBody

type ImapBody = {
    accountId: Text,
    mailbox: Text,
    uid: Int,
    text: Text,
    html: Text,
    raw: Text
}

Fetched body payload returned by imap.fetchBody.

---

ImapError

type ImapError =
  | ImapAuthFailed
  | ImapConnectionFailed Text
  | FolderNotFound Text
  | ImapProtocolError Text

Structured failure reasons for IMAP work.

• ImapAuthFailed — login failed
• ImapConnectionFailed Text — the server could not be reached or the connection dropped
• FolderNotFound Text — a requested folder does not exist
• ImapProtocolError Text — another protocol-level failure occurred

use aivi.imap (
    ImapError
    ImapAuthFailed
    ImapConnectionFailed
    FolderNotFound
    ImapProtocolError
)

type ImapError -> Text
func describeImapError = error => error
 ||> ImapAuthFailed           -> "authentication failed"
 ||> ImapConnectionFailed msg -> "connection failed: {msg}"
 ||> FolderNotFound name      -> "folder not found: {name}"
 ||> ImapProtocolError msg    -> "IMAP protocol error: {msg}"

---

ImapTask

type ImapTask A =
  Task ImapError A

Alias for background IMAP work that either returns A or fails with ImapError.

Source providers

@source imap.connect accounts with {
    mailbox: "INBOX",
    limit: 25,
    refreshOn: syncPulse
}
signal snapshots : Signal (Result ImapError (List ImapSnapshot))

@source imap.idle accounts with {
    mailbox: "INBOX"
}
signal liveEvent : Signal (Result ImapError ImapLiveEvent)

@source imap.fetchBody request
signal body : Signal (Result ImapError ImapBody)