#!/bin/bash
# -----------------------------------------------------------------------------------------------
# ----------------------- Common Helpers for Unraid Scripts -------------------------------------
# -----------------------------------------------------------------------------------------------

# ----------------------------- Logging Helper -----------------------------
log() {
    [[ "$ENABLE_LOGGING" == true ]] && echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*"
}

# ----------------------------- Argument Parsing -----------------------------
parse_args() {
    DRY_RUN=${DRY_RUN:-false}
    for ARG in "$@"; do
        if [[ "$ARG" == *=* ]]; then
            VAR_NAME="${ARG%%=*}"
            VAR_VALUE="${ARG#*=}"
            if declare -p "$VAR_NAME" &>/dev/null; then
                printf -v "$VAR_NAME" '%s' "$VAR_VALUE"
                log "Overriding $VAR_NAME -> $VAR_VALUE"
            else
                log "Warning: Unknown variable $VAR_NAME, ignoring."
            fi
        else
            case "$ARG" in
                --dry-run|-n) DRY_RUN=true ;;
                --help|-h) echo "Usage: script [--dry-run|-n] [VAR=value ...]"; exit 0 ;;
                *) log "Warning: Unknown argument $ARG" ;;
            esac
        fi
    done
}

# ----------------------------- Validation -----------------------------
require_var() {
    local var="$1"
    [[ -z "${!var:-}" ]] && { log "Error: Required variable $var is not set."; exit 1; }
}

validate_int() {
    local name="$1"
    local value="$2"
    [[ ! "$value" =~ ^[0-9]+$ ]] && { log "Error: $name must be a non-negative integer."; exit 1; }
}

# ----------------------------- Host Detection & SSH -----------------------------
LOCAL_HOSTNAME="$(hostname)"
if [[ "$LOCAL_HOSTNAME" == "$HOST1" ]]; then
    LOCAL_SERVER_NAME="$HOST1"
    REMOTE_SERVER_NAME="$HOST2"
elif [[ "$LOCAL_HOSTNAME" == "$HOST2" ]]; then
    LOCAL_SERVER_NAME="$HOST2"
    REMOTE_SERVER_NAME="$HOST1"
else
    log "Error: Local hostname ($LOCAL_HOSTNAME) not recognized."
    exit 1
fi

declare -A SSH_KEYS
SSH_KEYS["$HOST1|$HOST2"]="$HOST1_SSH_KEY"
SSH_KEYS["$HOST2|$HOST1"]="$HOST2_SSH_KEY"

KEY_ID="$LOCAL_SERVER_NAME|$REMOTE_SERVER_NAME"
SSH_KEY="${SSH_KEYS[$KEY_ID]}"
[[ -z "$SSH_KEY" ]] && { log "Error: No SSH key defined for $LOCAL_SERVER_NAME → $REMOTE_SERVER_NAME"; exit 1; }

# ----------------------------- Remote Server IP -----------------------------
REMOTE_SERVER=$(tailscale ip -4 "$REMOTE_SERVER_NAME" 2>/dev/null)
[[ -z "$REMOTE_SERVER" ]] && { log "Error: Could not resolve Tailscale IP for $REMOTE_SERVER_NAME"; exit 1; }
log "Local server: $LOCAL_SERVER_NAME, Remote server: $REMOTE_SERVER_NAME, IP: $REMOTE_SERVER"

# ----------------------------- Container Helpers -----------------------------
declare -a RUNNING_CONTAINERS=()

stop_containers() {
    log "[$LOCAL_SERVER_NAME] Checking containers on $REMOTE_SERVER_NAME..."
    RUNNING_CONTAINERS=()
    for container in "${CRITICAL_CONTAINER_NAMES[@]}"; do
        STATUS=$(ssh -i "$SSH_KEY" root@"$REMOTE_SERVER" "docker inspect -f '{{.State.Running}}' $container 2>/dev/null" || echo "false")
        if [[ "$STATUS" == "true" ]]; then
            log "Stopping $container"
            RUNNING_CONTAINERS+=("$container")
            ssh -i "$SSH_KEY" root@"$REMOTE_SERVER" "docker stop $container"
        fi
    done
}

start_containers() {
    log "[$LOCAL_SERVER_NAME] Restarting containers on $REMOTE_SERVER_NAME..."
    for container in "${RUNNING_CONTAINERS[@]}"; do
        if [[ " ${DELAYED_CONTAINERS[*]} " == *" $container "* ]]; then
            log "Delaying start of $container by ${CONTAINER_DELAY}s..."
            sleep "$CONTAINER_DELAY"
        fi
        ssh -i "$SSH_KEY" root@"$REMOTE_SERVER" "docker start $container"
    done
}

# ----------------------------- Rsync Options Builder -----------------------------
get_rsync_opts() {
    if [[ -n "${PROFILE_RSYNC_OPTS[$PROFILE_NAME]:-}" ]]; then
        read -r -a RSYNC_OPTS <<< "${PROFILE_RSYNC_OPTS[$PROFILE_NAME]}"
    else
        RSYNC_OPTS=("${DEFAULT_RSYNC_OPTS[@]}")
    fi
}

# ----------------------------- Wait for Rsync -----------------------------
wait_for_rsync() {
    for attempt in $(seq 1 "$RETRY_COUNT"); do
        RSYNC_COUNT=$(pgrep -fc "rsync.*root@${REMOTE_SERVER}" || true)
        if [ "$RSYNC_COUNT" -ge "$MAX_RSYNC_PROCS" ]; then
            log "[$LOCAL_SERVER_NAME] Waiting... ($RSYNC_COUNT active rsync processes)"
            sleep "$SLEEP"
        else
            return 0
        fi
    done
    log "Too many rsync processes, exiting."
    exit 1
}

# ----------------------------- Check Server -----------------------------
check_server_online() {
    if ping -c 1 "$REMOTE_SERVER" &>/dev/null; then
        return 0
    else
        return 1
    fi
}