. "$BST_LIB"
require ifup ifupdown/present

# ifupdown ships ifup and ifdown (a hard link to the same binary, dispatching on
# argv[0]) plus the interfaces(5) parser. Everything below drives a sample
# interfaces file in a scratch dir via -i, with --state-dir pointing at that same
# scratch dir, so the suite never reads or writes the live /etc/network/interfaces
# or /run/network/ifstate. --no-scripts keeps the /etc/network/if-*.d hooks out:
# run-parts hooks are not part of what this port delivers.

tmp=${TMPDIR:-/tmp}/bst-ifupdown.$$
mkdir -p "$tmp"
cfg="$tmp/interfaces"
IF="ifup -i $cfg --state-dir $tmp --no-scripts"
ID="ifdown -i $cfg --state-dir $tmp --no-scripts"

cat > "$cfg" <<'EOF'
auto lo
iface lo inet loopback

allow-hotplug bst0
iface bst0 inet static
	address 10.99.0.1
	netmask 255.255.255.0
EOF

command -v ifdown >/dev/null 2>&1 \
  && bst_ok ifupdown/ifdown-present \
  || bst_notok ifupdown/ifdown-present "ifdown missing (recipe installs it as a hard link to ifup)"

# `ifup -V` prints "<argv0> version <PV>" -- the binary names itself, not the
# package, so the needle is "ifup version" and not "ifupdown".
check_out ifupdown/version "ifup version" sh -c 'ifup -V 2>&1'

# --- interfaces(5) parsing, via the dry run (-n) -----------------------------
# With -n, execute.c prints each command it *would* run to stderr and runs
# nothing, so this asserts the parse and the address->command conversion without
# needing the interface to exist.
check    ifupdown/parse-dryrun  sh -c "$IF -n bst0 >/dev/null 2>&1"
check_out ifupdown/dryrun-addr  "10.99.0.1"            sh -c "$IF -n bst0 2>&1"
check_out ifupdown/dryrun-mask  "10.99.0.1/255.255.255.0" sh -c "$IF -n bst0 2>&1"
check_out ifupdown/dryrun-link  "ip link set dev bst0" sh -c "$IF -n bst0 2>&1"

# --- the state record, consulted in the dry run ------------------------------
# Before either tool acts it consults the PER-INTERFACE state file,
# <state-dir>/ifstate.<iface>, whose presence is what "configured" means; the
# ifstate summary file is not what that decision reads. ifdown refuses an
# interface it has no record of, dry run or not, so the down direction is
# asserted against a seeded record in a state dir of its own. That drives the
# same path ifdown really takes -- as opposed to --force, which reaches the down
# commands by skipping the state check, and so would assert the stanza
# conversion while dropping the consult that guards it.
#
# lock_interface() tolerates a failed advisory lock under -n (main.c: its err()
# arms are `if (!no_act)`), which is why these three assert on a target where the
# real transitions below cannot -- see the BRINTOS-WORKAROUND note there.
seed="$tmp/seeded"
mkdir -p "$seed"
printf 'bst0\n' > "$seed/ifstate.bst0"
SIF="ifup -i $cfg --state-dir $seed --no-scripts"
SID="ifdown -i $cfg --state-dir $seed --no-scripts"

# The static `down` sequence flushes and downs the link.
check_out ifupdown/dryrun-down  "ip addr del"  sh -c "$SID -n bst0 2>&1"
# The refusal is correct behaviour and is asserted, not worked around: with no
# record, ifdown declines rather than emitting a down sequence for an interface
# it never brought up.
check_out ifupdown/down-unconfigured "not configured" sh -c "$ID -n bst0 2>&1"
# ifup reads the same record and declines the redo.
check_out ifupdown/dryrun-already "already configured" sh -c "$SIF -n bst0 2>&1"

# An interface with no stanza is an error, not a silent success.
check_rc ifupdown/unknown-iface 1 sh -c "$IF -n nosuchif0 >/dev/null 2>&1"

# A malformed stanza must fail the parse rather than be skipped.
bad="$tmp/interfaces.bad"
printf 'iface bst9 inet static\n\taddress\n' > "$bad"
check_rc ifupdown/parse-error 1 \
  sh -c "ifup -i $bad --state-dir $tmp --no-scripts -n bst9 >/dev/null 2>&1"

# --- real state transitions (not a dry run) ---------------------------------
# `iface lo inet loopback` is the one stanza whose up/down commands are guarded
# by `if (!iface_is_lo())`, so ifup/ifdown on lo run NO kernel command while still
# taking the full real path: fcntl(F_SETLK/F_SETLKW) on the state lock, and the
# read/modify/write of ifstate. That makes it a safe on-target exercise of the
# machinery the dry run skips.
#
# BRINTOS-WORKAROUND: brintos/linux#16 remove -- glibc on this 32-bit target
# always sends the LFS lock commands (F_GETLK64/F_SETLK64/F_SETLKW64 = 12/13/14)
# and sys_fcntl64 is unwired, so every POSIX advisory lock returns EINVAL and ifup
# exits before it can write state. The capability is probed, not assumed, and only
# that one signature skips: any other failure still fails the case. When #16
# closes the probe stops matching and all five assert unconditionally.
probe="$tmp/lockprobe"
mkdir -p "$probe"
lock_err=$(ifup -i "$cfg" --state-dir "$probe" --no-scripts lo 2>&1)
rm -rf "$probe"
case $lock_err in
	*"failed to lock lockfile"*) posix_lock=no ;;
	*)                           posix_lock=yes ;;
esac

if [ "$posix_lock" = yes ]; then
	check ifupdown/state-up sh -c "$IF lo >/dev/null 2>&1"
	check_out ifupdown/state-file "lo=lo" sh -c "cat $tmp/ifstate 2>&1"
	# A second ifup is a no-op that says so (rc is non-zero; the message is the point).
	check_out ifupdown/state-already "already configured" sh -c "$IF lo 2>&1 || true"
	check ifupdown/state-down sh -c "$ID lo >/dev/null 2>&1"
	check ifupdown/state-cleared sh -c "! grep -q '^lo=' $tmp/ifstate 2>/dev/null"
else
	for c in state-up state-file state-already state-down state-cleared; do
		bst_skip "ifupdown/$c" \
		  "POSIX advisory locking returns EINVAL, so ifup cannot take its ifstate lock and no real transition can run -- brintos/linux#16"
	done
fi

# --- dummy interface, up then down ------------------------------------------
# The ticket's deliverable: bring a real interface up from the interfaces file
# and back down, checking the address lands and is withdrawn. Needs `ip` and a
# kernel that can create a dummy link; both are probed, and a kernel without
# dummy support is reported as skip (a coverage gap to close) rather than a
# failure of ifupdown.
if ! command -v ip >/dev/null 2>&1; then
	bst_skip ifupdown/dummy-up   "iproute2 ip not installed on this image"
	bst_skip ifupdown/dummy-down "iproute2 ip not installed on this image"
elif ! ip link add bst0 type dummy >/dev/null 2>&1; then
	bst_skip ifupdown/dummy-up   "kernel cannot create a dummy link (no CONFIG_DUMMY)"
	bst_skip ifupdown/dummy-down "kernel cannot create a dummy link (no CONFIG_DUMMY)"
else
	check_out ifupdown/dummy-up "10.99.0.1" \
	  sh -c "$IF bst0 >/dev/null 2>&1; ip -4 addr show dev bst0 2>&1"
	check ifupdown/dummy-down \
	  sh -c "$ID bst0 >/dev/null 2>&1; ! ip -4 addr show dev bst0 2>/dev/null | grep -q 10.99.0.1"
	ip link del bst0 >/dev/null 2>&1
fi

rm -rf "$tmp"