#!/usr/bin/env bash
set -euo pipefail

# Script to create a RAID volume on r630-01 using sdc-sdh
# For fast access, we'll use RAID 10 (mirrored stripes) for best performance + redundancy
# or RAID 0 (striping) for maximum performance (no redundancy)

set -u

TARGET_NODE="r630-01"
TARGET_NODE_IP="192.168.11.11"
TARGET_NODE_PASS="password"

# Disks to use for RAID
DISKS=("sdc" "sdd" "sde" "sdf" "sdg" "sdh")
RAID_LEVEL="${1:-10}"  # Default to RAID 10, can override with argument (0, 5, 6, 10)

# Colors
GREEN='\033[0;32m'
RED='\033[0;31m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

log_info() { echo -e "${BLUE}[INFO]${NC} $1"; }
log_success() { echo -e "${GREEN}[✓]${NC} $1"; }
log_error() { echo -e "${RED}[✗]${NC} $1"; }
log_warn() { echo -e "${YELLOW}[⚠]${NC} $1"; }

ssh_r630_01() {
    sshpass -p "$TARGET_NODE_PASS" ssh -o StrictHostKeyChecking=no -o ConnectTimeout=10 root@"$TARGET_NODE_IP" "$@" 2>&1
}

check_prerequisites() {
    log_info "Checking prerequisites..."
    
    # Check if mdadm is installed
    if ! ssh_r630_01 "which mdadm >/dev/null 2>&1"; then
        log_warn "mdadm is not installed. Installing..."
        ssh_r630_01 "apt-get update && apt-get install -y mdadm" || {
            log_error "Failed to install mdadm"
            return 1
        }
    fi
    log_success "mdadm is available"
    
    # Check if disks exist
    for disk in "${DISKS[@]}"; do
        if ! ssh_r630_01 "test -b /dev/$disk"; then
            log_error "Disk /dev/$disk does not exist"
            return 1
        fi
    done
    log_success "All disks exist"
    
    # Check if disks are in use
    log_info "Checking disk usage..."
    local in_use_disks=()
    for disk in "${DISKS[@]}"; do
        if ssh_r630_01 "pvs 2>/dev/null | grep -q /dev/$disk || mount | grep -q /dev/$disk"; then
            in_use_disks+=("$disk")
        fi
    done
    
    if [ ${#in_use_disks[@]} -gt 0 ]; then
        log_warn "The following disks are currently in use: ${in_use_disks[*]}"
        log_warn "sdc and sdd are part of the pve volume group"
        log_warn "You will need to migrate data off these disks before creating RAID"
        log_warn "This script will NOT proceed automatically to prevent data loss"
        return 1
    fi
    
    return 0
}

check_disk_status() {
    log_info "Checking disk status..."
    for disk in "${DISKS[@]}"; do
        local size=$(ssh_r630_01 "lsblk -bno SIZE /dev/$disk 2>/dev/null")
        local fstype=$(ssh_r630_01 "lsblk -no FSTYPE /dev/$disk 2>/dev/null")
        log_info "  /dev/$disk: ${size} bytes, FSTYPE: ${fstype:-none}"
    done
}

create_raid() {
    log_info "Creating RAID $RAID_LEVEL array..."
    
    # Prepare disk list
    local disk_list=""
    for disk in "${DISKS[@]}"; do
        disk_list+="/dev/$disk "
    done
    
    log_info "Disks to use: $disk_list"
    
    # Create RAID array
    case "$RAID_LEVEL" in
        0)
            log_info "Creating RAID 0 (striping) - Maximum performance, NO redundancy"
            log_warn "RAID 0 provides no fault tolerance. One disk failure will lose all data."
            ssh_r630_01 "mdadm --create /dev/md0 --level=0 --raid-devices=6 $disk_list" || {
                log_error "Failed to create RAID 0"
                return 1
            }
            ;;
        5)
            log_info "Creating RAID 5 - Good performance with single disk redundancy"
            ssh_r630_01 "mdadm --create /dev/md0 --level=5 --raid-devices=6 $disk_list" || {
                log_error "Failed to create RAID 5"
                return 1
            }
            ;;
        6)
            log_info "Creating RAID 6 - Good performance with double disk redundancy"
            ssh_r630_01 "mdadm --create /dev/md0 --level=6 --raid-devices=6 $disk_list" || {
                log_error "Failed to create RAID 6"
                return 1
            }
            ;;
        10)
            log_info "Creating RAID 10 (mirrored stripes) - Best performance + redundancy"
            log_info "RAID 10 requires even number of disks (6 disks = 3x capacity)"
            ssh_r630_01 "mdadm --create /dev/md0 --level=10 --raid-devices=6 $disk_list" || {
                log_error "Failed to create RAID 10"
                return 1
            }
            ;;
        *)
            log_error "Invalid RAID level: $RAID_LEVEL"
            log_info "Supported levels: 0, 5, 6, 10"
            return 1
            ;;
    esac
    
    log_success "RAID array created successfully"
    
    # Wait for array to sync
    log_info "Waiting for RAID array to initialize..."
    ssh_r630_01 "watch -n 1 'cat /proc/mdstat' &" &
    local watch_pid=$!
    
    # Monitor sync progress
    while true; do
        local sync_status=$(ssh_r630_01 "cat /proc/mdstat | grep -A 2 md0 | tail -1")
        if echo "$sync_status" | grep -q "\[UUUUUU\]\|\[UUUUU_\]"; then
            log_success "RAID array is fully synchronized"
            kill $watch_pid 2>/dev/null
            break
        elif echo "$sync_status" | grep -q "recovery\|resync"; then
            local progress=$(echo "$sync_status" | grep -oP '\d+\.\d+%' || echo "in progress")
            log_info "RAID sync progress: $progress"
            sleep 10
        else
            sleep 5
        fi
    done
    
    # Save RAID configuration
    log_info "Saving RAID configuration..."
    ssh_r630_01 "mdadm --detail --scan >> /etc/mdadm/mdadm.conf" || {
        log_warn "Failed to save to mdadm.conf, but RAID is created"
    }
    
    # Show RAID status
    log_info "RAID array status:"
    ssh_r630_01 "mdadm --detail /dev/md0"
    
    log_success "RAID array /dev/md0 is ready"
}

show_raid_info() {
    log_info "=== RAID Array Information ==="
    ssh_r630_01 "cat /proc/mdstat"
    echo ""
    ssh_r630_01 "mdadm --detail /dev/md0 2>/dev/null || echo 'RAID not created yet'"
}

main() {
    echo ""
    log_info "=== RAID Creation Script for R630-01 ==="
    log_info "Target: Create RAID $RAID_LEVEL using disks: ${DISKS[*]}"
    echo ""
    
    # Show current disk status
    check_disk_status
    echo ""
    
    # Check prerequisites
    if ! check_prerequisites; then
        log_error "Prerequisites check failed"
        log_info "Please review the warnings above and ensure disks are available"
        exit 1
    fi
    
    # Show RAID info before creation
    show_raid_info
    echo ""
    
    # Confirm before proceeding
    log_warn "WARNING: This will destroy all data on the specified disks!"
    log_warn "Disks: ${DISKS[*]}"
    log_warn "RAID Level: $RAID_LEVEL"
    echo ""
    read -p "Do you want to proceed? (yes/no): " confirm
    if [ "$confirm" != "yes" ]; then
        log_info "Operation cancelled"
        exit 0
    fi
    
    # Create RAID
    if create_raid; then
        log_success "RAID creation completed successfully!"
        log_info "Next steps:"
        log_info "1. Create filesystem: mkfs.ext4 /dev/md0 (or mkfs.xfs /dev/md0)"
        log_info "2. Create mount point: mkdir -p /mnt/raid-fast"
        log_info "3. Mount: mount /dev/md0 /mnt/raid-fast"
        log_info "4. Add to /etc/fstab for permanent mounting"
        log_info "5. Optionally add to Proxmox as storage"
    else
        log_error "RAID creation failed"
        exit 1
    fi
}

main "$@"