package backend

import (
	"strings"
	"testing"

	"github.com/emersion/go-imap/v2"
)

func TestSanitizeIMAPFlagsDropsRecentAndWildcard(t *testing.T) {
	got := sanitizeIMAPFlags([]imap.Flag{imap.FlagSeen, imap.Flag(`\Recent`), imap.FlagWildcard, imap.FlagAnswered})
	if len(got) != 2 || got[0] != imap.FlagSeen || got[1] != imap.FlagAnswered {
		t.Fatalf("sanitizeIMAPFlags returned %#v", got)
	}
}

func TestMessageIDFallsBackToBodyHash(t *testing.T) {
	body := []byte("From: a@example.com\r\nSubject: Test\r\n\r\nBody")
	id := messageID(body)
	if !strings.HasPrefix(id, "sha256:") {
		t.Fatalf("expected sha256 fallback, got %q", id)
	}
	if id != messageID(body) {
		t.Fatal("messageID hash fallback is not stable")
	}
}

func TestBodySHA256IsStableAcrossMboxNormalization(t *testing.T) {
	raw := []byte("From: a@example.com\r\nSubject: Test\r\n\r\nFirst\r\nFrom escaped\r\n\r\n")
	record := mboxRecord(RawMessage{Body: raw})
	parts := splitMboxRecordsWithOffsets(record)
	if len(parts) != 1 {
		t.Fatalf("mbox parts=%d, want 1", len(parts))
	}
	if got, want := bodySHA256(parts[0].Message), bodySHA256(raw); got != want {
		t.Fatalf("mbox hash=%s, raw hash=%s", got, want)
	}
}

func TestIdentityUsesMessageIDAndBodyHash(t *testing.T) {
	first := identityForRawMessage(RawMessage{MessageID: "<same@example.com>", Body: []byte("Message-ID: <same@example.com>\r\n\r\nfirst")})
	second := identityForRawMessage(RawMessage{MessageID: "<same@example.com>", Body: []byte("Message-ID: <same@example.com>\r\n\r\nsecond")})
	if first.MessageID != second.MessageID {
		t.Fatalf("message IDs differ: %#v %#v", first, second)
	}
	if first.BodySHA256 == second.BodySHA256 {
		t.Fatalf("different bodies have same identity hash: %#v %#v", first, second)
	}
}

func TestIdentityWithoutMessageIDKeepsLegacyRawHash(t *testing.T) {
	body := []byte("From: a@example.com\r\n\r\nbody")
	identity := identityForRawMessage(RawMessage{MessageID: messageID(body), Body: body})
	if identity.MessageID != "" || identity.BodySHA256 == "" || !strings.HasPrefix(identity.LegacyMessageID, "sha256:") {
		t.Fatalf("unexpected identity: %#v", identity)
	}
}