#!/bin/bash
# ==============================================================================================
# ============================= Conf Cache Save ================================================
# ==============================================================================================
#
# PURPOSE
# ─────────────────────────────────────────────────────────────────────────────
# Snapshots the partner conf RAM cache to $PERSISTENT_CONF_CACHE on
# array stop. Survives reboot. Used by conf_cache_restore.sh at next array start
# to reload partner vars into RAM when the partner is unreachable at boot time.
#
# Runs as the first step in ARRAY_STOP_SCRIPTS — while the RAM cache is fresh
# and before anything else changes. If partner is reachable at next start,
# conf_sync.sh gets a fresh copy and the backup is never used. If partner is
# down, the backup fills the gap so fallback.sh has the vars it needs.
#
# Only partner confs are saved — own conf is always on disk.
# Path adapts to storage mode: $SCRIPTS_DIR/.cache/vv/d (internal or appdata).
#
# ==============================================================================================
# DESIGN PRINCIPLES
# ==============================================================================================
#
# Save at Shutdown, Not at Boot
#   The backup is created at array stop while the RAM cache is at its freshest.
#   By the next boot the partner may be unreachable — but the conf is already
#   preserved and available the moment conf_cache_restore.sh runs.
#
# Partner Only
#   Own conf is on disk — always present, never needs saving. Only partner confs
#   live in RAM and can be missing at the next boot.
#
# ==============================================================================================
# OPERATIONAL SAFEGUARDS
# ==============================================================================================
#
#   require_partnership — exits early if PARTNERSHIP_ENABLED=false
#   detect_hosts()      — determines which confs to save (partner confs only)
#   No-cache guard      — exits cleanly if RAM cache is empty or missing
#
# ==============================================================================================

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "$SCRIPT_DIR/../load_config.sh"

parse_args "$@"
detect_hosts
require_partnership

RAM_CACHE="/tmp/.cache/vv/d"
SAVE_DIR="$PERSISTENT_CONF_CACHE"

[[ "$DRY_RUN" == true ]] && warn "DRY RUN — no files will be written"

if [[ ! -d "$RAM_CACHE" ]]; then
    log "No RAM conf cache found — nothing to save"
    exit 0
fi

saved=0
for conf in "$RAM_CACHE"/host*.conf; do
    [[ -f "$conf" ]] || continue
    base="$(basename "$conf")"
    [[ "${base,,}" == "${MY_ID,,}.conf" ]] && continue

    if [[ "$DRY_RUN" == true ]]; then
        warn "DRY RUN — would save $base → $SAVE_DIR/"
        (( saved++ ))
        continue
    fi

    mkdir -p "$SAVE_DIR"
    if cp "$conf" "$SAVE_DIR/$base"; then
        echo "Saved $base → $SAVE_DIR ✅"
        (( saved++ ))
    else
        warn "Failed to save $base"
    fi
done

if [[ "$saved" -eq 0 ]]; then
    log "No partner confs in RAM cache — nothing saved"
else
    echo "Conf cache saved: $saved partner conf(s) → $SAVE_DIR"
fi
