#!/usr/bin/env bash
# =============================================================================
# ES24N IOM Network Configuration Script
# TrueNAS ES24N Expansion Shelf — Serial Configuration Tool
# Based on ES24N Product Service Guide v.26011
# =============================================================================

# ── Colours & formatting ──────────────────────────────────────────────────────
RED='\033[0;31m'
GRN='\033[0;32m'
YEL='\033[1;33m'
CYN='\033[0;36m'
BLD='\033[1m'
DIM='\033[2m'
RST='\033[0m'

# ── Helpers ───────────────────────────────────────────────────────────────────
banner() {
    clear
    echo -e "${CYN}${BLD}"
    echo "  ╔══════════════════════════════════════════════════════════╗"
    echo "  ║        TrueNAS ES24N IOM Configuration Tool             ║"
    echo "  ║        Serial Network Setup  •  v1.0                    ║"
    echo "  ╚══════════════════════════════════════════════════════════╝"
    echo -e "${RST}"
}

info()    { echo -e "  ${CYN}[INFO]${RST}  $*"; }
ok()      { echo -e "  ${GRN}[ OK ]${RST}  $*"; }
warn()    { echo -e "  ${YEL}[WARN]${RST}  $*"; }
error()   { echo -e "  ${RED}[ERR ]${RST}  $*"; }
step()    { echo -e "\n  ${BLD}${YEL}──▶  $*${RST}"; }
divider() { echo -e "  ${DIM}──────────────────────────────────────────────────────────${RST}"; }

# ── Input validators ──────────────────────────────────────────────────────────
validate_ip() {
    local ip="$1"
    local re='^([0-9]{1,3}\.){3}[0-9]{1,3}$'
    if [[ ! $ip =~ $re ]]; then return 1; fi
    IFS='.' read -ra oct <<< "$ip"
    for o in "${oct[@]}"; do
        (( o > 255 )) && return 1
    done
    return 0
}

prompt_ip() {
    local label="$1"
    local var_name="$2"
    local ip
    while true; do
        read -rp "    ${label}: " ip
        if validate_ip "$ip"; then
            eval "$var_name='$ip'"
            return 0
        fi
        warn "Invalid IP address format. Please try again."
    done
}

prompt_password() {
    local var_name="$1"
    local pass
    while true; do
        read -rsp "    Admin password (BMC/chassis serial, e.g. MXE3000043CHA007): " pass
        echo
        if [[ -n "$pass" ]]; then
            eval "$var_name='$pass'"
            return 0
        fi
        warn "Password cannot be empty."
    done
}

# ── Step 1: Connect cable & detect USB device ─────────────────────────────────
detect_serial_device() {
    step "Serial Cable & Device Detection"
    divider
    echo
    echo -e "  ${BLD}Action required:${RST}"
    echo "    1. Connect the serial cable from the ES24N IOM1 port"
    echo "       to the active F-Series controller USB port."
    echo "    2. Press ${BLD}[Enter]${RST} once the cable is connected."
    echo
    read -rp "  Press [Enter] when the serial cable is connected... "
    echo

    info "Scanning for USB serial devices (/dev/ttyUSB* and /dev/ttyACM*)..."
    sleep 1

    mapfile -t devices < <(ls /dev/ttyUSB* /dev/ttyACM* 2>/dev/null)

    if [[ ${#devices[@]} -eq 0 ]]; then
        error "No USB serial device detected."
        echo
        echo "  Troubleshooting:"
        echo "    • Make sure the serial cable is fully seated."
        echo "    • Try a different USB port on the controller."
        echo "    • Verify the ES24N is powered on."
        echo
        read -rp "  Retry detection? [y/N]: " retry
        [[ "${retry,,}" == "y" ]] && detect_serial_device && return
        return 1
    fi

    if [[ ${#devices[@]} -eq 1 ]]; then
        SERIAL_DEV="${devices[0]}"
        ok "Device found: ${BLD}${SERIAL_DEV}${RST}"
    else
        echo
        echo "  Multiple devices detected:"
        local i=1
        for dev in "${devices[@]}"; do
            echo "    ${i}) ${dev}"
            (( i++ ))
        done
        echo
        while true; do
            read -rp "  Select device number [1-${#devices[@]}]: " sel
            if [[ "$sel" =~ ^[0-9]+$ ]] && (( sel >= 1 && sel <= ${#devices[@]} )); then
                SERIAL_DEV="${devices[$((sel-1))]}"
                ok "Selected: ${BLD}${SERIAL_DEV}${RST}"
                break
            fi
            warn "Invalid selection. Please enter a number between 1 and ${#devices[@]}."
        done
    fi

    # Fix permissions so the current user can access the port
    info "Setting group permission on ${SERIAL_DEV}..."
    if sudo chown ":wheel" "${SERIAL_DEV}" 2>/dev/null || \
       sudo chmod a+rw   "${SERIAL_DEV}" 2>/dev/null; then
        ok "Permissions updated."
    else
        warn "Could not update permissions automatically. You may need to run as root."
    fi
    echo
    return 0
}

# ── Step 2: Open serial connection ────────────────────────────────────────────
open_serial_connection() {
    local dev="$1"
    step "Opening Serial Connection → ${dev}"
    divider

    # Check that a terminal tool is available
    if command -v screen &>/dev/null; then
        SERIAL_TOOL="screen"
    elif command -v minicom &>/dev/null; then
        SERIAL_TOOL="minicom"
    elif command -v picocom &>/dev/null; then
        SERIAL_TOOL="picocom"
    else
        error "No serial terminal found (screen / minicom / picocom)."
        error "Install one of them and re-run this script."
        return 1
    fi

    info "Using ${BLD}${SERIAL_TOOL}${RST} at 115200 8N1"
    echo
    echo -e "  ${YEL}${BLD}NOTE:${RST} A serial session will now open."
    echo "  • Log into the ES24N IOM shell when the prompt appears."
    echo "  • Press Enter once or twice if you do not see a login prompt."
    echo "  • Exit the terminal session and return here when done:"
    case "$SERIAL_TOOL" in
        screen)   echo "      screen exit: Ctrl-A then K  (then 'y' to confirm)" ;;
        minicom)  echo "      minicom exit: Ctrl-A then X" ;;
        picocom)  echo "      picocom exit: Ctrl-A then Ctrl-X" ;;
    esac
    echo
    read -rp "  Press [Enter] to launch the serial terminal... "
    echo

    case "$SERIAL_TOOL" in
        screen)   screen "${dev}" 115200 ;;
        minicom)  minicom -D "${dev}" -b 115200 ;;
        picocom)  picocom -b 115200 "${dev}" ;;
    esac

    ok "Serial session closed. Returning to configuration menu."
    echo
}

# ── Step 3: Collect network config from user ──────────────────────────────────
collect_network_config() {
    step "IOM Network Configuration"
    divider
    echo
    echo "  How should the IOMs be configured?"
    echo "    1) Static IP addresses"
    echo "    2) DHCP"
    echo
    while true; do
        read -rp "  Select option [1-2]: " choice
        case "$choice" in
            1) IP_MODE="static"; break ;;
            2) IP_MODE="dhcp";   break ;;
            *) warn "Please enter 1 or 2." ;;
        esac
    done

    echo
    prompt_password ADMIN_PASS

    if [[ "$IP_MODE" == "static" ]]; then
        echo
        info "Enter static network details for IOM1:"
        prompt_ip "  IOM1 IP address   " IOM1_IP
        prompt_ip "  IOM1 Gateway      " IOM1_GW
        prompt_ip "  IOM1 Subnet Mask  " IOM1_NM

        echo
        info "Enter static network details for IOM2:"
        prompt_ip "  IOM2 IP address   " IOM2_IP

        read -rp "    IOM2 Gateway (same as IOM1? [Y/n]): " same_gw
        if [[ "${same_gw,,}" != "n" ]]; then
            IOM2_GW="$IOM1_GW"; IOM2_NM="$IOM1_NM"
        else
            prompt_ip "  IOM2 Gateway     " IOM2_GW
            prompt_ip "  IOM2 Subnet Mask " IOM2_NM
        fi
    fi
}

# ── Step 4: Apply configuration via Redfish over the serial loopback ──────────
apply_configuration() {
    step "Applying Configuration"
    divider
    echo

    local BASE="https://127.0.0.1/redfish/v1/Managers"

    if [[ "$IP_MODE" == "dhcp" ]]; then
        info "Setting IOM1 to DHCP..."
        curl -sk -u "Admin:${ADMIN_PASS}" -X PATCH \
            "${BASE}/IOM1/EthernetInterfaces/1" \
            -H "Content-Type: application/json" \
            -d '{"DHCPv4": {"DHCPEnabled": true}}' \
            -o /tmp/es24n_iom1.json
        show_result /tmp/es24n_iom1.json "IOM1"

        info "Setting IOM2 to DHCP..."
        curl -sk -u "Admin:${ADMIN_PASS}" -X PATCH \
            "${BASE}/IOM2/EthernetInterfaces/1" \
            -H "Content-Type: application/json" \
            -d '{"DHCPv4": {"DHCPEnabled": true}}' \
            -o /tmp/es24n_iom2.json
        show_result /tmp/es24n_iom2.json "IOM2"

    else
        info "Applying static IP to IOM1 (${IOM1_IP})..."
        curl -sk -u "Admin:${ADMIN_PASS}" -X PATCH \
            "${BASE}/IOM1/EthernetInterfaces/1" \
            -H "Content-Type: application/json" \
            -d "{\"DHCPv4\": {\"DHCPEnabled\": false}, \
                 \"IPv4StaticAddresses\": [{\"Address\": \"${IOM1_IP}\", \
                 \"Gateway\": \"${IOM1_GW}\", \"SubnetMask\": \"${IOM1_NM}\"}]}" \
            -o /tmp/es24n_iom1.json
        show_result /tmp/es24n_iom1.json "IOM1"

        info "Applying static IP to IOM2 (${IOM2_IP})..."
        curl -sk -u "Admin:${ADMIN_PASS}" -X PATCH \
            "${BASE}/IOM2/EthernetInterfaces/1" \
            -H "Content-Type: application/json" \
            -d "{\"DHCPv4\": {\"DHCPEnabled\": false}, \
                 \"IPv4StaticAddresses\": [{\"Address\": \"${IOM2_IP}\", \
                 \"Gateway\": \"${IOM2_GW}\", \"SubnetMask\": \"${IOM2_NM}\"}]}" \
            -o /tmp/es24n_iom2.json
        show_result /tmp/es24n_iom2.json "IOM2"
    fi

    echo
    info "Configuration applied. Verify settings in TrueNAS → System Settings → Enclosure."
}

# parse curl response and print a friendly summary
show_result() {
    local file="$1" label="$2"
    if [[ -f "$file" ]]; then
        local http_err
        http_err=$(python3 -c "import json,sys; d=json.load(open('$file')); \
            print(d.get('error',{}).get('message',''))" 2>/dev/null)
        if [[ -z "$http_err" ]]; then
            ok "${label}: Configuration accepted."
        else
            error "${label}: ${http_err}"
        fi
    else
        warn "${label}: No response received (curl may have failed)."
    fi
}

# ── Step 5: Print a config summary ────────────────────────────────────────────
print_summary() {
    echo
    divider
    echo -e "  ${BLD}Configuration Summary${RST}"
    divider
    echo "  Mode   : ${IP_MODE^^}"
    if [[ "$IP_MODE" == "static" ]]; then
        echo "  IOM1   : ${IOM1_IP}  GW ${IOM1_GW}  NM ${IOM1_NM}"
        echo "  IOM2   : ${IOM2_IP}  GW ${IOM2_GW}  NM ${IOM2_NM}"
    fi
    echo "  Device : ${SERIAL_DEV}"
    divider
    echo
    warn "IMPORTANT: Per the ES24N Service Guide, remove the serial cable ONLY"
    warn "after verifying each expander is configured in TrueNAS with matching"
    warn "drives in the expected slots (System Settings → Enclosure)."
    echo
}

# ── Step 6: Close serial connection (prompt) ──────────────────────────────────
close_serial_connection() {
    step "Close Serial Connection"
    echo
    echo "  When you have verified the configuration in TrueNAS, disconnect"
    echo "  the serial cable from the IOM1 port."
    echo
    read -rp "  Press [Enter] to confirm the serial cable has been disconnected... "
    ok "Serial connection closed."
}

# ── Main loop ─────────────────────────────────────────────────────────────────
main() {
    banner

    echo -e "  ${DIM}This tool guides you through ES24N IOM network configuration"
    echo -e "  over a serial connection. Based on TrueNAS ES24N Service Guide v.26011.${RST}"
    echo

    while true; do
        banner

        step "Main Menu"
        divider
        echo
        echo "    1) Configure a new ES24N shelf"
        echo "    2) Exit"
        echo
        read -rp "  Select [1-2]: " main_choice

        case "$main_choice" in
            1)  # ── Full configuration flow ──────────────────────────────────
                banner

                # 1. Cable & device
                detect_serial_device || { error "Aborting shelf configuration."; sleep 2; continue; }

                # 2. Open serial terminal so user can verify/log in
                open_serial_connection "${SERIAL_DEV}"

                # 3. Collect network settings
                collect_network_config

                # 4. Apply via Redfish (runs locally on the IOM over 127.0.0.1)
                echo
                echo -e "  ${YEL}${BLD}Ready to apply network configuration via Redfish API.${RST}"
                echo "  Ensure you are still logged into the IOM serial session"
                echo "  or that the Redfish API is reachable over the loopback."
                echo
                read -rp "  Apply configuration now? [Y/n]: " apply_now
                if [[ "${apply_now,,}" != "n" ]]; then
                    apply_configuration
                fi

                # 5. Summary
                print_summary

                # 6. Close serial
                close_serial_connection

                # 7. Another shelf?
                echo
                divider
                read -rp "  Configure another ES24N shelf? [y/N]: " another
                [[ "${another,,}" != "y" ]] && break
                ;;

            2)  # ── Exit ────────────────────────────────────────────────────
                echo
                ok "Exiting ES24N IOM Configuration Tool. Goodbye."
                echo
                exit 0
                ;;

            *)  warn "Invalid selection. Please enter 1 or 2." ; sleep 1 ;;
        esac
    done

    echo
    ok "All shelves configured. Exiting."
    echo
    exit 0
}

main "$@"