# Called once after boot or resume. No network access is required.
set -euo pipefail
nic="/sys/bus/pci/devices/$NIC_PCI"
bridge="/sys/bus/pci/devices/$NIC_BRIDGE"
log() { echo "rtl8125-recovery: $*"; }

# Let normal PCI and network resume finish before diagnosing anything.
sleep 10
if [[ ! -d "$bridge" ]]; then
    log "Parent bridge $NIC_BRIDGE is absent; refusing recovery."
    exit 1
fi
if [[ $(cat "$bridge/vendor") != 0x1022 || $(cat "$bridge/device") != 0x43f5 ]]; then
    log "Parent bridge identity changed; refusing recovery."
    exit 1
fi

if [[ -d "$nic" ]]; then
    if [[ $(cat "$nic/vendor") != 0x10ec || $(cat "$nic/device") != 0x8125 ]]; then
        log "Device at $NIC_PCI is not an RTL8125; refusing recovery."
        exit 1
    fi
    if [[ $(dirname "$(readlink -f "$nic")") != "$(readlink -f "$bridge")" ]]; then
        log "NIC is no longer directly below the configured bridge; refusing recovery."
        exit 1
    fi
    power=$(cat "$nic/power_state")
    command=$(timeout 5 setpci -s "$NIC_PCI" COMMAND 2>/dev/null || true)
    # Both memory decoding and bus mastering should be enabled on this host.
    # Disconnected cables do not disable these PCI command bits.
    if [[ "$power" != D3cold && "$command" =~ ^[[:xdigit:]]{4}$ ]] &&
        (( (16#$command & 6) == 6 )); then
        log "PCI state healthy ($power, COMMAND=$command); no recovery needed."
        exit 0
    fi
    # An administratively disabled NIC should not be automatically reset.
    netdirs=("$nic"/net/*)
    if [[ -e "${netdirs[0]}/flags" ]]; then
        flags=$(cat "${netdirs[0]}/flags")
        if (( (flags & 1) == 0 )); then
            log "Interface is administratively down; leaving it alone."
            exit 0
        fi
    fi
    log "Failed PCI state: power=$power COMMAND=$command."
else
    log "NIC missing; attempting one rescan of its known bridge."
fi

# Retain evidence from the latest failure without accumulating unlimited logs.
evidence="${STATE_DIRECTORY:-/var/lib/rtl8125-recovery}/last-failure.log"
mkdir -p "$(dirname "$evidence")"
{
    date -Is
    timeout 5 lspci -s "$NIC_PCI" -vv || true
    timeout 5 lspci -s "$NIC_BRIDGE" -vv || true
    journalctl -b -k --since '10 minutes ago' -n 250 --no-pager || true
} > "$evidence" 2>&1

# This is the remove/rescan recovery that worked on this machine. Never reset
# or remove the parent bridge, which could affect other hardware.
if [[ -d "$nic" ]]; then
    echo 1 > "$nic/remove"
fi
echo 1 > "$bridge/rescan"

for ((attempt=0; attempt<20; attempt++)); do
    netdirs=("$nic"/net/*)
    if [[ -e "${netdirs[0]}/ifindex" ]]; then
        iface=$(basename "${netdirs[0]}")
        power=$(cat "$nic/power_state")
        command=$(timeout 5 setpci -s "$NIC_PCI" COMMAND 2>/dev/null || true)
        if [[ "$power" == D0 && "$command" =~ ^[[:xdigit:]]{4}$ ]] &&
            (( (16#$command & 6) == 6 )); then
            # NetworkManager also reapplies the saved profile. Explicitly
            # restore WoL here so recovery does not depend on its timing.
            ethtool -s "$iface" wol g
            if ! ethtool "$iface" | grep -Eq '^[[:space:]]*Wake-on: g$'; then
                log "PCI recovered, but magic-packet WoL could not be confirmed."
                exit 1
            fi
            log "Recovered $iface in D0; magic-packet WoL enabled. Evidence: $evidence"
            exit 0
        fi
    fi
    sleep 1
done
log "Recovery did not restore operational PCI state; no further attempt this invocation."
exit 1