#!/bin/sh
# apricot-doctor                       Health snapshot of apricot's known-fragile parts
# apricot-doctor check                 Same as above
# apricot-doctor fix dnsmasq           Pull session-tools + regen wg-mesh.conf + restart
# apricot-doctor fix oomd              Install composefs PrivateTmp drop-in + start
# apricot-doctor fix quinn-ai          Stop, delete unit, mask (half-finished cutover)
# apricot-doctor fix all               All three fix subcommands
# apricot-doctor forensic [N]          Dump post-mortem artifacts for boot index N
#                                      (default: -1, the previous boot)
#
# Targets the recurring boot-time fragility surfaced during the 2026-05-21
# wedge investigation:
#
#   1. dnsmasq vs wg1 boot race  ("Cannot assign requested address" for the
#      mesh IP). Durable fix lives in session-tools/bin/wg-dns-sync; this
#      script pulls the latest, regenerates the conf, and restarts.
#
#   2. systemd-oomd vs composefs ("Failed at step NAMESPACE" — systemd
#      cannot create /run/systemd/mount-rootfs/var/tmp on the read-only
#      composefs rootfs when PrivateTmp=disconnected). Drop-in overrides to
#      PrivateTmp=no.
#
#   3. quinn-ai-auto-respond.service half-finished cutover from black —
#      crash-loops every 10s with getaddrinfo ENOTIMP. User has explicitly
#      asked for it stopped and prevented from starting; cannot mask while
#      the real unit file occupies the symlink target, so rm-then-mask.
#
# Idempotent: re-runs are safe and report no-op for already-correct state.
#
# Env:
#   APRICOT_DOCTOR_OUT   forensic output dir (default: /var/tmp/apricot-doctor)
#
# Exit codes:
#   0   success
#   1   precondition failed (wrong host, missing tool, repo missing)
#   2   usage error
#   3   fix could not be applied
#   4   fix applied but verification failed

set -eu

out_root="${APRICOT_DOCTOR_OUT:-/var/tmp/apricot-doctor}"
repo="$HOME/Code/@scripts/session-tools"

die()   { echo "apricot-doctor: $*" >&2; exit 1; }
usage() { sed -n '2,/^$/p' "$0" | sed 's/^# \{0,1\}//'; exit 2; }
ok()    { printf '  \033[32m✓\033[0m %s\n' "$*"; }
warn()  { printf '  \033[33m!\033[0m %s\n' "$*"; }
fail()  { printf '  \033[31m✗\033[0m %s\n' "$*"; }

require_apricot() {
    h=$(hostname -s)
    [ "$h" = "apricot" ] || die "must be run on apricot (got: $h)"
}

# ------------------------------------------------------------------ check ---

cmd_check() {
    require_apricot
    echo "apricot-doctor check"

    echo
    echo "Services:"
    for s in dnsmasq systemd-oomd quinn-ai-auto-respond apricot-pressure-guard; do
        state=$(systemctl is-active "$s" 2>/dev/null || true)
        enabled=$(systemctl is-enabled "$s" 2>/dev/null || true)
        case "$state" in
            active)            ok   "$s ($state, $enabled)" ;;
            inactive|masked)
                # inactive+masked or inactive+disabled is the desired
                # end-state for quinn-ai. Treat as ok.
                ok   "$s ($state, $enabled)" ;;
            failed|activating) fail "$s ($state, $enabled)" ;;
            *)                 warn "$s ($state, $enabled)" ;;
        esac
    done

    echo
    echo "Pressure (avg10):"
    for p in cpu io memory; do
        line=$(awk '/^some/ {print; exit}' "/proc/pressure/$p" 2>/dev/null || true)
        avg10=$(printf %s "$line" | sed -n 's/.*avg10=\([0-9.]*\).*/\1/p')
        printf '  %-7s %s\n' "$p" "${avg10:-?}"
    done

    # Wedge guard: the io-pressure responder freezes the auto-commit burst when
    # tank io saturates (see project-apricot-io-starvation-wedge). Its live
    # state lives on tmpfs (/run), never tank, so it is readable during a wedge.
    echo
    echo "Wedge guard:"
    gstate=$(cat /run/apricot-pressure-guard/state 2>/dev/null || echo "?")
    case "$gstate" in
        running) ok   "io-pressure guard: running (commits not throttled)" ;;
        frozen)  warn "io-pressure guard: FROZEN commits.service (io spike in progress)" ;;
        *)       warn "io-pressure guard: state unknown (daemon down?)" ;;
    esac
    # Auto-commit burst cadence: ~one burst of ~280 pipeline runs per cycle.
    # interval_seconds was raised 300→900 to cut the chronic io duty cycle.
    bursts=$(journalctl --since '20 minutes ago' -o cat 2>/dev/null \
        | grep -c 'Pipeline completed' || true)
    printf '  auto-commit pipelines (last 20m): %s\n' "${bursts:-?}"

    if command -v nvme >/dev/null 2>&1; then
        echo
        echo "NVMe composite temps:"
        for dev in /dev/nvme?n1; do
            [ -e "$dev" ] || continue
            # Match exactly the "temperature" line (not "temperature_sensor_*"),
            # then take the first integer after the colon.
            t=$(sudo -n nvme smart-log "$dev" 2>/dev/null \
                | grep -E '^temperature[[:space:]]*:' \
                | head -1 \
                | sed -E 's/.*:[[:space:]]*([0-9]+).*/\1/')
            printf '  %s  %s°C\n' "$dev" "${t:-?}"
        done
    fi

    echo
    echo "Boot history (last 3):"
    journalctl --list-boots --no-pager | tail -3

    echo
    # Detect "clean stop" on the previous boot by looking for the systemd
    # shutdown-target lines in its tail. Absent => journal cut off mid-stream
    # => unclean stop (wedge, crash, or hard power-off).
    if journalctl -b -1 --no-pager 2>/dev/null | tail -50 \
        | grep -q -e 'Reached target.*[Ss]hutdown' -e 'Stopped target' -e 'systemd-shutdown'; then
        ok "previous boot ended with orderly stop sequence"
    else
        warn "previous boot ended WITHOUT orderly stop sequence"
        warn "  -> run 'apricot-doctor forensic -1' to dump post-mortem artifacts"
    fi

    echo
    failed_count=$(systemctl --failed --no-pager --no-legend 2>/dev/null | wc -l | tr -d ' ')
    if [ "$failed_count" -eq 0 ]; then
        ok "no failed units"
    else
        warn "$failed_count failed unit(s):"
        # --no-legend output: "● unit-name loaded failed failed Description"
        # The first column is the bullet glyph; the unit name is $2.
        systemctl --failed --no-pager --no-legend | awk '{print "    " $2}'
    fi
}

# -------------------------------------------------------------- fix dnsmasq -

cmd_fix_dnsmasq() {
    require_apricot
    echo "fix dnsmasq: pull session-tools + regen + restart"

    [ -d "$repo/.git" ] || die "session-tools repo not at $repo"
    (cd "$repo" && git pull --ff-only --quiet) \
        || die "git pull failed in $repo (check network / merge state)"
    ok "session-tools updated"

    # Stale .prev was loaded by dnsmasq alongside the live conf, doubling
    # records. Newer wg-dns-sync writes the backup to /var/lib/. Remove the
    # stale file if the old script ever left one in dnsmasq.d/.
    if [ -e /etc/dnsmasq.d/wg-mesh.conf.prev ]; then
        sudo rm -f /etc/dnsmasq.d/wg-mesh.conf.prev
        ok "removed stale /etc/dnsmasq.d/wg-mesh.conf.prev"
    fi

    "$repo/bin/wg-dns-sync"

    sleep 1
    state=$(systemctl is-active dnsmasq 2>/dev/null || true)
    case "$state" in
        active) ok "dnsmasq active" ;;
        *)      fail "dnsmasq is $state after regen"; return 4 ;;
    esac
}

# ----------------------------------------------------------------- fix oomd -

cmd_fix_oomd() {
    require_apricot
    echo "fix oomd: composefs PrivateTmp drop-in"

    dropin_dir=/etc/systemd/system/systemd-oomd.service.d
    dropin_file="$dropin_dir/composefs-private-tmp.conf"
    desired='[Service]
# Bluefin composefs ro-rootfs vs systemd PrivateTmp=disconnected:
# systemd cannot create /run/systemd/mount-rootfs/var/tmp on the ro root,
# so the unit fails at step NAMESPACE (status=226) on every boot.
# Drop to PrivateTmp=no — oomd has no real need for a private /tmp.
PrivateTmp=no
'

    if [ -f "$dropin_file" ] && [ "$(cat "$dropin_file")" = "$desired" ]; then
        ok "drop-in already in place at $dropin_file"
    else
        sudo mkdir -p "$dropin_dir"
        printf '%s' "$desired" | sudo tee "$dropin_file" >/dev/null
        sudo systemctl daemon-reload
        ok "installed $dropin_file"
    fi

    sudo systemctl reset-failed systemd-oomd.service 2>/dev/null || true
    sudo systemctl start systemd-oomd.service
    sleep 1
    state=$(systemctl is-active systemd-oomd 2>/dev/null || true)
    case "$state" in
        active) ok "systemd-oomd active" ;;
        *)      fail "systemd-oomd is $state after start"; return 4 ;;
    esac
}

# ------------------------------------------------------------- fix quinn-ai -

cmd_fix_quinn_ai() {
    require_apricot
    echo "fix quinn-ai: stop, delete unit, mask"

    unit_file=/etc/systemd/system/quinn-ai-auto-respond.service

    sudo systemctl stop quinn-ai-auto-respond.service 2>/dev/null || true
    sudo systemctl disable quinn-ai-auto-respond.service 2>/dev/null || true

    if [ -e "$unit_file" ]; then
        sudo rm -f "$unit_file"
        ok "removed $unit_file"
    else
        ok "unit file already absent"
    fi

    sudo systemctl daemon-reload
    # mask now works because the symlink target is free
    sudo systemctl mask quinn-ai-auto-respond.service >/dev/null
    ok "masked"

    state=$(systemctl is-active quinn-ai-auto-respond.service 2>/dev/null || true)
    enabled=$(systemctl is-enabled quinn-ai-auto-respond.service 2>/dev/null || true)
    case "$enabled" in
        masked) ok "is-active=$state is-enabled=$enabled" ;;
        *)      fail "expected enabled=masked, got '$enabled'"; return 4 ;;
    esac
}

cmd_fix_all() {
    cmd_fix_dnsmasq
    echo
    cmd_fix_oomd
    echo
    cmd_fix_quinn_ai
}

# ------------------------------------------------------------------ forensic

cmd_forensic() {
    require_apricot
    idx=${1:--1}
    case "$idx" in
        -[0-9]*|[0-9]*) ;;
        *) die "boot index must be an integer (e.g. -1 for previous boot)" ;;
    esac

    boot_id=$(journalctl --list-boots --no-pager \
        | awk -v i="$idx" '$1 == i {print $2; exit}')
    [ -n "$boot_id" ] \
        || die "no boot at index $idx (see: journalctl --list-boots)"

    stamp=$(date -u +%Y%m%dT%H%M%SZ)
    out="$out_root/forensic-$stamp-boot$idx-$boot_id"
    sudo mkdir -p "$out"
    sudo chown "$(id -u):$(id -g)" "$out"
    echo "forensic dump: $out"

    journalctl --list-boots --no-pager           > "$out/01-boots.txt"            2>&1 || true
    journalctl -b "$idx" -k --no-pager           > "$out/02-kernel-ring.txt"      2>&1 || true
    journalctl -b "$idx" -p err --no-pager       > "$out/03-priority-err.txt"     2>&1 || true
    journalctl -b "$idx" --no-pager | tail -500  > "$out/04-tail-500.txt"         2>&1 || true
    # error-signature grep, written with -e to avoid alternation quoting
    journalctl -b "$idx" --no-pager 2>/dev/null \
        | grep -e panic -e hung_task -e MCE -e EDAC -e segfault \
               -e 'Hardware Error' -e 'Out of memory' -e 'nvme.*error' \
               -e throttl -e oom-kill \
        > "$out/05-error-signatures.txt" 2>&1 || true
    sudo coredumpctl list                        > "$out/06-coredumps.txt"        2>&1 || true
    systemctl --failed --no-pager                > "$out/07-failed-units.txt"     2>&1 || true
    rpm-ostree status                            > "$out/08-rpm-ostree.txt"       2>&1 || true
    {
        echo '--- /proc/pressure/cpu ---';    cat /proc/pressure/cpu    2>/dev/null
        echo '--- /proc/pressure/io ---';     cat /proc/pressure/io     2>/dev/null
        echo '--- /proc/pressure/memory ---'; cat /proc/pressure/memory 2>/dev/null
    } > "$out/09-pressure-now.txt" 2>&1 || true
    # Legacy detection-only guard logged here — on TANK, so it FROZE during the
    # very wedge it watched (silence in this file during a wedge window is
    # expected, not evidence of calm). The live guard now logs to the journal.
    [ -f "$HOME/apricot-pressure-alerts.log" ] \
        && cp "$HOME/apricot-pressure-alerts.log" "$out/10-pressure-alerts.log" || true
    # io-pressure guard daemon journal: freeze/thaw events across this boot.
    journalctl -b "$idx" -t apricot-pressure-guard --no-pager \
        > "$out/11-pressure-guard.txt" 2>&1 || true

    n=$(ls "$out" | wc -l | tr -d ' ')
    ok "wrote $n artifact(s) to $out"
}

# --------------------------------------------------------------- dispatch ---

case "${1:-check}" in
    check|'')
        cmd_check
        ;;
    fix)
        shift
        case "${1:-}" in
            dnsmasq)  cmd_fix_dnsmasq ;;
            oomd)     cmd_fix_oomd ;;
            quinn-ai) cmd_fix_quinn_ai ;;
            all)      cmd_fix_all ;;
            *)        usage ;;
        esac
        ;;
    forensic)
        shift
        cmd_forensic "${1:-}"
        ;;
    -h|--help|help)
        usage
        ;;
    *)
        usage
        ;;
esac