#!/bin/bash
set -e
#-----------------------------------------------------------------------------------------------
# Main Rsync Script for unRAID
#-----------------------------------------------------------------------------------------------

#---------------------------------------------
# Detect script directory
#---------------------------------------------
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

#---------------------------------------------
# Load Master.conf (hosts, keys, profiles, helpers)
#---------------------------------------------
MASTER_CONF="$SCRIPT_DIR/../Master.conf"
if [ -f "$MASTER_CONF" ]; then
    source "$MASTER_CONF"
    echo "Loaded Master.conf from $MASTER_CONF"
else
    echo "Error: Master.conf not found at $MASTER_CONF"
    exit 1
fi

#---------------------------------------------
# Input Arguments: Directory (positional)
#---------------------------------------------
DIRECTORY="$1"
if [[ -z "$DIRECTORY" ]]; then
    echo "Usage: $0 <directory-to-sync> [--dry-run|-n] [VAR=value ...]"
    exit 1
fi
shift 1   # Remove directory from $@ so parse_args sees only options/VARs

#---------------------------------------------
# Parse optional arguments (dry-run / VAR=VALUE)
#---------------------------------------------
parse_args "$@"

echo "Detected profile: $(basename "$DIRECTORY" | tr '[:upper:]' '[:lower:]')"

#---------------------------------------------
# Apply profile defaults or fallback to Master.conf
#---------------------------------------------
PROFILE_NAME=$(basename "$DIRECTORY" | tr '[:upper:]' '[:lower:]')

MAX_RSYNC_PROCS=${PROFILE_MAX_PROCS[$PROFILE_NAME]:-$MAX_RSYNC_PROCS}
BW_LIMIT=${PROFILE_BW_LIMIT[$PROFILE_NAME]:-$BW_LIMIT}
CRITICAL_CONTAINER_NAMES=(${PROFILE_CRITICAL_CONTAINER_NAMES[$PROFILE_NAME]})
DELAYED_CONTAINERS=(${PROFILE_DELAYED_CONTAINERS[$PROFILE_NAME]})
CONTAINER_DELAY=${PROFILE_CONTAINER_DELAY[$PROFILE_NAME]:-$CONTAINER_DELAY}
RETRY_COUNT=${PROFILE_RETRY_COUNT[$PROFILE_NAME]:-$RETRY_COUNT}
SLEEP=${PROFILE_SLEEP[$PROFILE_NAME]:-$SLEEP}
EXCLUDE_DIRS=(${PROFILE_EXCLUDE_DIRS[$PROFILE_NAME]:-${EXCLUDE_DIRS[@]}})

echo "Settings: MAX_RSYNC_PROCS=$MAX_RSYNC_PROCS, BW_LIMIT=$BW_LIMIT, CONTAINERS=${CRITICAL_CONTAINER_NAMES[*]}, EXCLUDES=${EXCLUDE_DIRS[*]}"

#---------------------------------------------
# Dependency check
#---------------------------------------------
for cmd in rsync ssh ping timeout docker tailscale; do
    command -v "$cmd" >/dev/null 2>&1 || {
        echo "Error: Required command '$cmd' is not installed."
        exit 1
    }
done

trap 'echo "Script interrupted. Exiting."; exit 130' INT TERM

#---------------------------------------------
# Helper Functions
#---------------------------------------------
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
            echo "[$LOCAL_SERVER_NAME] Waiting... ($RSYNC_COUNT active rsync processes)"
            sleep "$SLEEP"
        else
            return 0
        fi
    done
    echo "Too many rsync processes, exiting."
    exit 1
}

check_server_online() {
    timeout 5 ping -c 1 "$REMOTE_SERVER" &>/dev/null
}

declare -a RUNNING_CONTAINERS=()

stop_containers() {
    echo "[$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
            echo "Stopping $container"
            RUNNING_CONTAINERS+=("$container")
            ssh -i "$SSH_KEY" root@"$REMOTE_SERVER" "docker stop $container"
        fi
    done
}

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

#---------------------------------------------
# Main sync logic
#---------------------------------------------
main() {
    echo "[$LOCAL_SERVER_NAME] Syncing $DIRECTORY → $REMOTE_SERVER:$DIRECTORY"

    for i in $(seq 1 "$RETRY_COUNT"); do
        if check_server_online; then
            break
        fi
        echo "Remote $REMOTE_SERVER_NAME down, retrying in $SLEEP seconds..."
        sleep "$SLEEP"
    done

    check_server_online || { echo "Remote $REMOTE_SERVER_NAME unreachable. Exiting."; exit 1; }

    wait_for_rsync
    stop_containers

    RSYNC_OPTS=(
        -av
        --info=progress2
        --human-readable
        --bwlimit="$BW_LIMIT"
        --delete
        --inplace
        --no-whole-file
    )

    for ex in "${EXCLUDE_DIRS[@]}"; do
        RSYNC_OPTS+=(--exclude="$ex")
    done

    [ "$DRY_RUN" = true ] && RSYNC_OPTS+=("--dry-run")

    for attempt in $(seq 1 "$RETRY_COUNT"); do
        echo "Starting rsync attempt $attempt/$RETRY_COUNT..."
        if rsync "${RSYNC_OPTS[@]}" \
            -e "ssh -i \"$SSH_KEY\" -T -o Compression=no -o IPQoS=throughput" \
            "$DIRECTORY" "root@${REMOTE_SERVER}:$DIRECTORY"; then
            echo "Rsync completed successfully."
            break
        else
            echo "Rsync attempt $attempt failed."
            if [ "$attempt" -lt "$RETRY_COUNT" ]; then
                echo "Retrying in $SLEEP seconds..."
                sleep "$SLEEP"
            else
                echo "All $RETRY_COUNT rsync attempts failed."
                start_containers
                exit 1
            fi
        fi
    done

    start_containers
    echo "[$LOCAL_SERVER_NAME] Sync complete."
}

#---------------------------------------------
# Execute
#---------------------------------------------
main