#!/usr/bin/env bash
# ensure-cpu-performance.sh — audit + enforce max CPU performance per host [#737][#769]
#
# Founder directive 2026-09-04: "all hosts set for maximum CPU performance
# at all times". Audit (default) checks tuned profile + per-CPU governor +
# EPP hint; --fix re-asserts governor (and EPP where the driver exposes it)
# via sysfs for the running system — persistence stays with the tuned
# virtual-host profile (verified to carry these settings; `tuned-adm verify`).
#
# Usage: PROX_HOST=pfv-tsys1 bash ensure-cpu-performance.sh [--fix]
# Exit 0 = at max performance, 1 = drift found (run with --fix to correct).
set -uo pipefail
FIX=""
[ "${1:-}" = "--fix" ] && FIX="yes"

REMOTE="${REMOTE:-$HOME/projects/PFVCluster/tests/remote.sh}"
[ -e "$REMOTE" ] || { echo "FAIL: SSH chokepoint not found at $REMOTE" >&2; exit 1; }
prox() { timeout "${PROX_TIMEOUT:-60}" env PROX_HOST="$PROX_HOST" bash "$REMOTE" prox "$1"; }

echo "== $PROX_HOST"
tuned="$(prox 'tuned-adm active 2>/dev/null' | head -1)"
echo "  $tuned"

govs="$(prox 'grep -h . /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor 2>/dev/null | sort | uniq -c')"
if [ -z "$govs" ]; then
    mhz="$(prox 'grep MHz /proc/cpuinfo | head -1' | awk '{print $4}')"
    echo "  NO cpufreq driver — cores run fixed at firmware max (e.g. ${mhz} MHz). Nothing to set."
    exit 0
fi
echo "  governors: $govs"

nongov="$(printf '%s\n' "$govs" | awk '$2!="performance" {print $2}' | head -1)"
epp="$(prox 'cat /sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference 2>/dev/null')"

if [ -n "$nongov" ]; then
    if [ -z "$FIX" ]; then
        echo "  DRIFT: governor=$nongov on some CPUs (run with --fix)"
        exit 1
    fi
    # shellcheck disable=SC2016  # must expand on the remote host
    prox 'for g in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do echo performance > "$g"; done'
    echo "  FIXED: governors -> performance"
fi
if [ -n "$epp" ] && [ "$epp" != "performance" ]; then
    if [ -z "$FIX" ]; then
        echo "  DRIFT: EPP=$epp (run with --fix)"
        exit 1
    fi
    # shellcheck disable=SC2016  # must expand on the remote host
    prox 'for e in /sys/devices/system/cpu/cpu*/cpufreq/energy_performance_preference; do echo performance > "$e" 2>/dev/null; done'
    echo "  FIXED: EPP -> performance"
fi
if [ -z "$nongov" ] && ! printf '%s' "$epp" | grep -qv performance; then
    echo "  OK: max performance (governor=performance$( [ -n "$epp" ] && echo ", EPP=performance" ))"
fi
exit 0