#!/bin/sh
# Test all combinations of alignment of the end-of-message delimiter
# with the end of a stdio buffer

set -e

. $MH_TEST_COMMON

THISDIR="tests/inc"

if [ "$VALGRIND_ME" ]; then
    require_prog valgrind
    # Lack of quotes here is important
    VALGRIND="valgrind --quiet --error-exitcode=1"
    echo "Running tests under valgrind: takes ages!"
else
    VALGRIND=
fi

# First check that all our various pieces of text are
# intact. (Since we're dealing in exact byte alignment
# minor corruptions such as line ending changes could
# render the tests useless.)
(cd "$THISDIR" && md5sum *.txt > "$MH_TEST_DIR/inctest.md5sums")
diff -u "$THISDIR/md5sums" "$MH_TEST_DIR/inctest.md5sums"

FILLER="$THISDIR/filler.txt"
FROMLINE="$THISDIR/fromline.txt"
HDR="$THISDIR/msgheader.txt"

if grep -q From "$FILLER"; then
   echo "Somebody's messed with $FILLER -- it must not contain"
   echo "anything that might look like a message delimiter!"
   exit 1
fi

# a sort of worst-case guess for the buffer size;
# obviously a buffer boundary for this will be a boundary
# for any smaller power of two size.
# If you need to increase this you'll need to make filler.txt
# bigger as well.
STDIO_BUFSZ=16384

FROMLINESZ="$(wc -c "$FROMLINE" | cut -d ' ' -f 1)"
HDRSZ="$(wc -c "$HDR" | cut -d ' ' -f 1)"

# makembox_A mboxname sz
# Assemble a mailbox into file mboxname, with two messages, such
# that the first is exactly sz bytes long (including its header
# and its initial 'From' line and the newline which terminates it
# but not the newline which mbox format demands after each message)
# We also leave the body of message one in mboxname.body
# (the body of message two is always $FILLER in its entirety)
makembox_A () {
  MBOX="$1"
  SZ=$2

  WANTSZ="$(($SZ - $HDRSZ - $FROMLINESZ - 1))"
  dd if="$FILLER" of="$MBOX.body" bs="$WANTSZ" count=1 2>/dev/null
  echo >> "$MBOX.body"
  cat "$FROMLINE" "$HDR" "$MBOX.body" > "$MBOX"
  echo >> "$MBOX"
  cat "$FROMLINE" "$HDR" "$FILLER" >> "$MBOX"
  echo >> "$MBOX"
}

# make_mbox_B mboxname sz
# Test B makes a mailbox with one message of sz bytes long,
# which ends in a partial mbox delimiter (ie part of the string
# \n\nFrom '). To both do this and be a valid mbox this means
# it has to end with two newlines (one of which is in the message
# body and one of which is the mbox format mandated one)
makembox_B () {
  MBOX="$1"
  SZ=$2

  WANTSZ="$(($SZ - $HDRSZ - $FROMLINESZ - 1))"
  dd if="$FILLER" of="$MBOX.body" bs="$WANTSZ" count=1 2>/dev/null
  echo >> "$MBOX.body"
  cat "$FROMLINE" "$HDR" "$MBOX.body" > "$MBOX"
  echo >> "$MBOX"
}

# do_one_test_A sz
# Do a single test with message one's body of size sz.
do_one_test_A () {
  SZ=$1
  makembox_A "$MH_TEST_DIR/eom-align.mbox" $STDIO_BUFSZ
  $VALGRIND inc -silent -file "$MH_TEST_DIR/eom-align.mbox"
  # We know the messages should be 11 and 12 in inbox
  # Now get the bodies back out.
  sed -e '1,/^$/d' "$MH_TEST_DIR/Mail/inbox/11" > "$MH_TEST_DIR/eom-align.inbox.body1"
  sed -e '1,/^$/d' "$MH_TEST_DIR/Mail/inbox/12" > "$MH_TEST_DIR/eom-align.inbox.body2"
  diff -u "$MH_TEST_DIR/eom-align.mbox.body" "$MH_TEST_DIR/eom-align.inbox.body1"
  diff -u "$FILLER" "$MH_TEST_DIR/eom-align.inbox.body2"
  rmm 11 12
}

# do_one_test_B sz
# Do a test type B
do_one_test_B () {
  SZ=$1
  makembox_B "$MH_TEST_DIR/eom-align.mbox" $STDIO_BUFSZ
  $VALGRIND inc -silent -file "$MH_TEST_DIR/eom-align.mbox"
  # We know the message should be 11 in the inbox
  sed -e '1,/^$/d' "$MH_TEST_DIR/Mail/inbox/11" > "$MH_TEST_DIR/eom-align.inbox.body1"
  diff -u "$MH_TEST_DIR/eom-align.mbox.body" "$MH_TEST_DIR/eom-align.inbox.body1"
  rmm 11
}


# Cover a decent range around the stdio buffer size to make sure we catch
# any corner cases whether they relate to total message size equal to
# buffer size or to body size equal to buffer size.
START=$(($STDIO_BUFSZ - 16))
FINISH=$(($STDIO_BUFSZ + $HDRSZ + $FROMLINESZ + 32))
echo "Testing inc of files with various alignments of eom marker with buffer size..."
for sz in $(seq $START $FINISH); do
  progress_update $sz $START $FINISH
  do_one_test_A $sz
  do_one_test_B $sz
done
progress_done