#!/usr/bin/env bash
#
# Copyright (c) 2016 Daniel Kahn Gillmor
#

test_description='thread breakage during reindexing

notmuch uses ghost documents to track messages we have seen references
to but have never seen.  Regardless of the order of delivery, message
deletion, and reindexing, the list of ghost messages for a given
stored corpus should not vary, so that threads can be reassmebled
cleanly.

In practice, we accept a small amount of variation (and therefore
traffic pattern metadata leakage to be stored in the index) for the
sake of efficiency.

This test also embeds some subtests to ensure that indexing actually
works properly and attempted fixes to threading issues do not break
the expected contents of the index.'

. ./test-lib.sh || exit 1

message_a() {
    mkdir -p ${MAIL_DIR}/cur
    cat > ${MAIL_DIR}/cur/a <<EOF
Subject: First message
Message-ID: <a@example.net>
From: Alice <alice@example.net>
To: Bob <bob@example.net>
Date: Thu, 31 Mar 2016 20:10:00 -0400

This is the first message in the thread.
Apple
EOF
}

message_b() {
    mkdir -p ${MAIL_DIR}/cur
    cat > ${MAIL_DIR}/cur/b <<EOF
Subject: Second message
Message-ID: <b@example.net>
In-Reply-To: <a@example.net>
References: <a@example.net>
From: Bob <bob@example.net>
To: Alice <alice@example.net>
Date: Thu, 31 Mar 2016 20:15:00 -0400

This is the second message in the thread.
Banana
EOF
}


test_subject_count() {
    test_begin_subtest "${3:-looking for $2 instance of '$1'}"
    count=$(notmuch count --output=threads "$1")
    test_expect_equal "$count" "$2"
}

test_thread_count() {
    test_begin_subtest "${2:-Expecting $1 thread(s)}"
    count=$(notmuch count --output=threads)
    test_expect_equal "$count" "$1"
}

test_ghost_count() {
    test_begin_subtest "${2:-Expecting $1 ghosts(s)}"
    ghosts=$(../ghost-report ${MAIL_DIR}/.notmuch/xapian)
    test_expect_equal "$ghosts" "$1"
}

notmuch new >/dev/null
pwd
ls -la ${MAIL_DIR}/.notmuch/xapian

test_thread_count 0 'There should be no threads initially'
test_ghost_count 0 'There should be no ghosts initially'

message_a
notmuch new >/dev/null
test_thread_count 1 'One message in: one thread'
test_subject_count apple 1
test_subject_count banana 0
test_ghost_count 0

message_b
notmuch new >/dev/null
test_thread_count 1 'Second message in the same thread: one thread'
test_subject_count apple 1
test_subject_count banana 1
test_ghost_count 0

rm -f ${MAIL_DIR}/cur/a
notmuch new >/dev/null
test_thread_count 1 'First message removed: still only one thread'
test_subject_count apple 0
test_subject_count banana 1
test_begin_subtest 'should be one ghost after first message removed'
test_subtest_known_broken
ghosts=$(../ghost-report ${MAIL_DIR}/.notmuch/xapian)
test_expect_equal "$ghosts" "1"

message_a
notmuch new >/dev/null
# this is known to fail (it shows 2 threads) because no "ghost
# message" was created for message A when it was removed from the
# index, despite message B still pointing to it.
test_begin_subtest 'First message reappears: should return to the same thread'
test_subtest_known_broken
count=$(notmuch count --output=threads)
test_expect_equal "$count" "1"
test_subject_count apple 1
test_subject_count banana 1
test_ghost_count 0

rm -f ${MAIL_DIR}/cur/b
notmuch new >/dev/null
test_thread_count 1 'Removing second message: still only one thread'
test_subject_count apple 1
test_subject_count banana 0
test_ghost_count 0 'No ghosts should remain after deletion of second message'

rm -f ${MAIL_DIR}/cur/a
notmuch new >/dev/null
test_thread_count 0 'All messages gone: no threads'
test_subject_count apple 0
test_subject_count banana 0
test_ghost_count 0

test_done