Files
LambdaMail/services/protocols/internal/application/usecase/imap_session.go
T
Lucas Rayan 9fa19291d4 #4: implement F2 sub-project 1 - IMAP core (auth, LIST, SELECT, FETCH, STORE)
Adds a real :143 IMAP listener to the Go protocols service: a mailbox
owner authenticates over IMAP (Argon2id against mailboxes.password_hash,
enumeration-resistant per PLAN.md section 14.6), lists folders, selects
INBOX, fetches messages F1's SMTP path already persisted - including real
ENVELOPE/BODY[] built from the actual stored MIME bytes via go-imap/v2's
own ExtractEnvelope/ExtractBodySection helpers, not reconstructed from
denormalized columns - and sets/reads flags via STORE.

- ImapSessionUseCase orchestrates auth, folder listing/selection, message
  querying, and flag mutation against new Postgres repositories (auth,
  folders, message query, flags) and a local-disk blob reader.
- A github.com/emersion/go-imap/v2 (pinned v2.0.0-beta.8) Backend/Session
  implements 7 real methods (Login, List, Select, Unselect, Status, Fetch,
  Store) plus a correct no-op Poll; the other 10 of the interface's 18
  methods (Create/Delete/Rename/Subscribe/Unsubscribe/Append/Idle/Expunge/
  Search/Copy) are explicit stubs returning a clear "not yet implemented"
  IMAP error - SEARCH/EXPUNGE/COPY/MOVE, IDLE/CONDSTORE, mailbox
  management, and APPEND are separate follow-up sub-projects per the
  design doc's agreed ordering with the user.

Verified end-to-end with a real go-imap/v2 imapclient (embedded Postgres,
no Docker needed) driving Login -> Select -> Fetch -> Store -> List
against a message seeded through F1's real SMTP use case, proving true
SMTP-write/IMAP-read interop, not just isolated unit tests.

Built via 8 sequential tasks under subagent-driven development, each
independently reviewed, plus a final whole-branch review. Two real bugs
were found and fixed before merge, both exactly the kind unit tests with
fakes cannot catch:
- Store's UID-set resolution silently no-op'd on dynamic ranges like
  "UID STORE 1:*" (the common "mark all as read" operation) after an
  earlier draft bypassed the folder's real message list; restored to
  resolve against real messages via the same pattern Fetch already used
  correctly, with tests proving both dynamic ranges and non-UID STORE.
- go-imap/v2's server calls Session.Poll() implicitly before the status
  response of nearly every authenticated command (FETCH/STORE/SEARCH/
  APPEND/COPY), not just IDLE as assumed - a hard-stubbed Poll broke every
  real command through this path; fixed to a correct no-op.
- List had zero test coverage despite being committed scope; added unit
  tests for wildcard/delimiter matching plus a real E2E LIST assertion.

Known follow-up, not blocking: a pre-existing test-fixture hygiene gap
(hardcoded content_sha256 blob hashes with no cleanup, shared across
several Postgres integration test files including one new to this
branch) causes local-dev test collisions on repeated runs against a
persistent database - invisible to CI (fresh Postgres per run) but worth
a cleanup pass.
2026-07-23 20:34:48 -03:00

81 lines
2.7 KiB
Go

package usecase
import (
"context"
"errors"
"github.com/alexedwards/argon2id"
"github.com/google/uuid"
"lambdamail/protocols/internal/application/port"
)
// ErrAuthFailed is returned by Login for any credential problem - unknown
// address, wrong password, or (once AuthRepository filters it) an inactive
// mailbox/domain. Deliberately the same error in every case: distinguishing
// them would let a client enumerate valid addresses (PLAN.md section 14.6).
var ErrAuthFailed = errors.New("imap session: authentication failed")
// ErrNoSuchFolder is returned by SelectFolder when the named folder doesn't exist.
var ErrNoSuchFolder = errors.New("imap session: no such folder")
// ImapSessionUseCase implements the read/auth half of PLAN.md section 3's
// HandleImapCommandUseCase (this sub-project's scope: LOGIN, LIST, SELECT,
// FETCH, STORE; SEARCH/EXPUNGE/IDLE/MOVE land in later sub-projects).
type ImapSessionUseCase struct {
auth port.AuthRepository
folders port.ImapFolderRepository
messages port.MessageQueryRepository
flags port.FlagRepository
blobs port.BlobReader
}
func NewImapSessionUseCase(auth port.AuthRepository, folders port.ImapFolderRepository, messages port.MessageQueryRepository, flags port.FlagRepository, blobs port.BlobReader) *ImapSessionUseCase {
return &ImapSessionUseCase{auth: auth, folders: folders, messages: messages, flags: flags, blobs: blobs}
}
func (uc *ImapSessionUseCase) Login(ctx context.Context, address, password string) (string, error) {
rec, err := uc.auth.FindByAddress(ctx, address)
if err != nil {
return "", err
}
if rec == nil {
return "", ErrAuthFailed
}
match, err := argon2id.ComparePasswordAndHash(password, rec.PasswordHash)
if err != nil {
return "", err
}
if !match {
return "", ErrAuthFailed
}
return rec.ID.String(), nil
}
func (uc *ImapSessionUseCase) ListFolders(ctx context.Context, mailboxID string) ([]port.ImapFolderRecord, error) {
return uc.folders.ListFolders(ctx, mailboxID)
}
func (uc *ImapSessionUseCase) SelectFolder(ctx context.Context, mailboxID, name string) (*port.ImapFolderRecord, error) {
rec, err := uc.folders.FindByName(ctx, mailboxID, name)
if err != nil {
return nil, err
}
if rec == nil {
return nil, ErrNoSuchFolder
}
return rec, nil
}
func (uc *ImapSessionUseCase) FetchMessages(ctx context.Context, folderID string) ([]port.MessageRecord, error) {
return uc.messages.ListMessages(ctx, folderID)
}
func (uc *ImapSessionUseCase) ReadBlob(ctx context.Context, blobID uuid.UUID) ([]byte, error) {
return uc.blobs.ReadByID(ctx, blobID)
}
func (uc *ImapSessionUseCase) SetFlags(ctx context.Context, folderID string, uid uint32, op port.FlagOp, flags []string) error {
return uc.flags.SetFlags(ctx, folderID, uid, op, flags)
}