#!/bin/bash
# Usage: curl -sL https://url/migrate.sh | bash -s -- <LOCAL_ID_OR_VOL> <USER@REMOTE_IP> <REMOTE_ID_OR_VOL> [SSH_KEY_PATH]

LOCAL_SEARCH="$1"
DEST_CONN="$2"
REMOTE_SEARCH="$3"
SSH_KEY_PATH="$4"

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

# --- 1. SSH SETUP ---
SSH_BASE_OPTS="-o BatchMode=yes -o ConnectTimeout=10 -o StrictHostKeyChecking=no"
if [ -n "$SSH_KEY_PATH" ]; then
    SSH_CMD="ssh -i $SSH_KEY_PATH $SSH_BASE_OPTS"
    RSYNC_SH="ssh -i $SSH_KEY_PATH $SSH_BASE_OPTS"
else
    SSH_CMD="ssh $SSH_BASE_OPTS"
    RSYNC_SH="ssh $SSH_BASE_OPTS"
fi

# --- 2. DETECT MODE (Container vs Volume) ---
MODE="container"
# Check if input is a valid volume
if docker volume inspect "$LOCAL_SEARCH" >/dev/null 2>&1; then
    MODE="volume"
    echo -e "${YELLOW}Info: Detected input as Volume Name, not Container.${NC}"
fi

# --- 3. EXECUTE MIGRATION ---

if [ "$MODE" == "volume" ]; then
    # === VOLUME MODE ===
    L_VOL="$LOCAL_SEARCH"
    R_VOL="$REMOTE_SEARCH"
    
    echo -e "   Source Volume: ${GREEN}$L_VOL${NC}"
    echo -e "   Target Volume: ${GREEN}$R_VOL${NC}"

    # Get Paths
    REAL_L_PATH=$(docker volume inspect --format '{{.Mountpoint}}' "$L_VOL")
    REAL_R_PATH=$($SSH_CMD "$DEST_CONN" "docker volume inspect --format '{{.Mountpoint}}' $R_VOL")
    
    if [ -z "$REAL_R_PATH" ]; then
        echo -e "${RED}Error: Remote volume '$R_VOL' not found on Server B.${NC}"
        exit 1
    fi

    # Attempt to stop any containers using these volumes (Safety)
    echo -e "\n🛑 Stopping any containers using these volumes..."
    # Local
    L_CONTAINER=$(docker ps -q --filter volume="$L_VOL")
    [ -n "$L_CONTAINER" ] && docker stop $L_CONTAINER
    # Remote
    R_CONTAINER=$($SSH_CMD "$DEST_CONN" "docker ps -q --filter volume='$R_VOL'")
    [ -n "$R_CONTAINER" ] && $SSH_CMD "$DEST_CONN" "docker stop $R_CONTAINER"

    # Sync
    echo -e "🚀 Transferring data..."
    rsync -az --info=progress2 -e "$RSYNC_SH" "${REAL_L_PATH}/" "$DEST_CONN:${REAL_R_PATH}/"
    
    echo -e "\n✅ Volume Transfer Complete!"
    [ -n "$L_CONTAINER" ] && docker start $L_CONTAINER
    [ -n "$R_CONTAINER" ] && $SSH_CMD "$DEST_CONN" "docker start $R_CONTAINER"

else
    # === CONTAINER MODE (Original Logic) ===
    L_ID=$(docker ps -aq --filter "name=${LOCAL_SEARCH}" | head -n 1)
    R_ID=$($SSH_CMD "$DEST_CONN" "docker ps -aq --filter 'name=${REMOTE_SEARCH}' | head -n 1")
    
    if [ -z "$L_ID" ]; then echo -e "${RED}Error: Container/Volume '$LOCAL_SEARCH' not found.${NC}"; exit 1; fi
    if [ -z "$R_ID" ]; then echo -e "${RED}Error: Remote container '$REMOTE_SEARCH' not found.${NC}"; exit 1; fi

    echo -e "🛑 Stopping containers..."
    docker stop "$L_ID"
    $SSH_CMD "$DEST_CONN" "docker stop $R_ID"

    echo -e "📦 Syncing volumes..."
    L_MOUNTS=$(docker inspect -f '{{range .Mounts}}{{.Type}}|{{.Source}}|{{.Destination}} {{end}}' "$L_ID")

    for MOUNT in $L_MOUNTS; do
        TYPE=$(echo "$MOUNT" | cut -d'|' -f1)
        L_PATH=$(echo "$MOUNT" | cut -d'|' -f2)
        TARGET=$(echo "$MOUNT" | cut -d'|' -f3)
        
        if [[ "$TARGET" == *".sock" ]] || [[ "$TARGET" == *".conf" ]]; then continue; fi

        R_PATH_RAW=$($SSH_CMD "$DEST_CONN" "docker inspect -f '{{range .Mounts}}{{if eq .Destination \"$TARGET\"}}{{.Source}}{{end}}{{end}}' $R_ID")
        
        if [ -n "$R_PATH_RAW" ]; then
             if [ "$TYPE" == "volume" ]; then
                REAL_L=$(docker volume inspect --format '{{.Mountpoint}}' "$L_PATH")
                REAL_R=$($SSH_CMD "$DEST_CONN" "docker volume inspect --format '{{.Mountpoint}}' $R_PATH_RAW" 2>/dev/null || echo $R_PATH_RAW)
             else
                REAL_L="$L_PATH"; REAL_R="$R_PATH_RAW"
             fi
             rsync -az --info=progress2 -e "$RSYNC_SH" "${REAL_L}/" "$DEST_CONN:${REAL_R}/"
        fi
    done
    
    echo -e "✅ Container Transfer Complete!"
    docker start "$L_ID"
    $SSH_CMD "$DEST_CONN" "docker start $R_ID"
fi