#!/bin/sh

# ============================================================
# wwand-config-probe.sh
#
# OpenWrt / wwand modem diagnostic + configuration generator
#
# Detects:
#   - MBIM / QMI
#   - /dev/cdc-wdmX
#   - wwanX
#   - AT ttyUSB/ttyACM
#   - USB device path
#   - modem model
#   - CGDCONT profiles
#   - wwand status
#   - MBIM status 9 / attach-profile errors
#
# Does NOT modify /etc/config/network.
# ============================================================

PATH="/usr/sbin:/usr/bin:/sbin:/bin"

MODEM="wwmodem0"
MODEM_DEV=""
NETDEV=""
AT_TTY=""
USB_PATH=""
PROTOCOL=""
MODEL=""
APN_MODE=""
PDP_TYPE="ipv4"

log()
{
    echo "[wwand-probe] $*"
}

section()
{
    echo
    echo "============================================================"
    echo "$*"
    echo "============================================================"
}

# ------------------------------------------------------------
# Find MBIM/QMI control device and network interface
# ------------------------------------------------------------

find_modem()
{
    section "WYKRYWANIE MODEMU"

    for d in /sys/class/usbmisc/cdc-wdm*; do
        [ -e "$d" ] || continue

        dev="$(basename "$d")"

        if [ -e "/dev/$dev" ]; then
            MODEM_DEV="/dev/$dev"
            break
        fi
    done

    if [ -z "$MODEM_DEV" ]; then
        log "Nie znaleziono /dev/cdc-wdmX."
        return
    fi

    log "Control device: $MODEM_DEV"

    sys="/sys/class/usbmisc/$(basename "$MODEM_DEV")/device"

    # Network device attached to cdc-wdm device
    for n in "$sys"/net/*; do
        [ -e "$n" ] || continue
        NETDEV="$(basename "$n")"
        break
    done

    if [ -z "$NETDEV" ]; then
        # Fallback - prefer wwan0 if it exists
        if [ -e /sys/class/net/wwan0 ]; then
            NETDEV="wwan0"
        fi
    fi

    log "Network device: ${NETDEV:-unknown}"

    # Detect kernel driver
    driver="$(readlink "$sys/driver" 2>/dev/null)"
    driver="$(basename "$driver" 2>/dev/null)"

    case "$driver" in
        cdc_mbim)
            PROTOCOL="mbim"
            ;;
        qmi_wwan)
            PROTOCOL="qmi"
            ;;
        *)
            PROTOCOL="$driver"
            ;;
    esac

    log "Kernel driver: ${driver:-unknown}"
    log "Protocol: ${PROTOCOL:-unknown}"
}

# ------------------------------------------------------------
# Find correct USB DEVICE parent.
#
# Example:
#
#   .../usb2/2-1/2-1:1.12
#
# becomes:
#
#   .../usb2/2-1
#
# The :1.12 part is a USB INTERFACE, not the modem device.
# ------------------------------------------------------------

find_usb_path()
{
    section "USB / SYSFS"

    [ -n "$MODEM_DEV" ] || return

    sys="/sys/class/usbmisc/$(basename "$MODEM_DEV")/device"
    real="$(readlink -f "$sys" 2>/dev/null)"

    log "sysfs device: ${real:-unknown}"

    [ -n "$real" ] || return

    p="$real"

    while [ "$p" != "/" ] && [ -n "$p" ]; do
        base="$(basename "$p")"

        # USB device names:
        #   1-1
        #   2-1
        #   2-1.3
        #   3-2.1
        #
        # USB interfaces contain ':' e.g. 2-1:1.12
        case "$base" in
            [0-9]-[0-9]*)
                case "$base" in
                    *:* )
                        # USB interface - continue upward
                        ;;
                    *)
                        USB_PATH="$(echo "$p" | sed 's#^.*/\(platform/.*\)#\1#')"
                        ;;
                esac

                if [ -n "$USB_PATH" ]; then
                    break
                fi
                ;;
        esac

        p="$(dirname "$p")"
    done

    if [ -n "$USB_PATH" ]; then
        log "USB device path: $USB_PATH"
    else
        log "Nie udało się ustalić USB device path."
    fi
}

# ------------------------------------------------------------
# Get wwand status
# ------------------------------------------------------------

query_wwand()
{
    section "WWAND STATUS"

    if ! command -v ubus >/dev/null 2>&1; then
        log "Brak ubus."
        return
    fi

    if ! ubus list 2>/dev/null | grep -q '^wwand$'; then
        log "wwand nie jest dostępny przez ubus."
        return
    fi

    status="$(ubus call wwand status 2>/dev/null)"

    if [ -z "$status" ]; then
        log "Nie udało się pobrać statusu wwand."
        return
    fi

    echo "$status"

    # Extract modem information.
    value="$(echo "$status" | sed -n 's/.*"model": "\(.*\)",/\1/p' | head -n 1)"
    [ -n "$value" ] && MODEL="$value"

    value="$(echo "$status" | sed -n 's/.*"at_tty": "\(.*\)",/\1/p' | head -n 1)"
    [ -n "$value" ] && AT_TTY="$value"

    value="$(echo "$status" | sed -n 's/.*"protocol": "\(.*\)",/\1/p' | head -n 1)"
    [ -n "$value" ] && PROTOCOL="$value"

    value="$(echo "$status" | sed -n 's/.*"netdev": "\(.*\)",/\1/p' | head -n 1)"
    [ -n "$value" ] && NETDEV="$value"

    # Detect actual modem name if present.
    if echo "$status" | grep -q '"wwmodem'; then
        detected_modem="$(echo "$status" |
            sed -n 's/.*"\(wwmodem[0-9][0-9]*\)".*/\1/p' |
            head -n 1)"

        [ -n "$detected_modem" ] && MODEM="$detected_modem"
    fi

    log "wwand modem: $MODEM"
    log "Model: ${MODEL:-unknown}"
    log "Protocol: ${PROTOCOL:-unknown}"
    log "AT port: ${AT_TTY:-unknown}"
    log "Network: ${NETDEV:-unknown}"
}

# ------------------------------------------------------------
# Query CGDCONT through wwand
# ------------------------------------------------------------

detect_profile()
{
    section "MODEM PROFILE / CGDCONT"

    [ -n "$AT_TTY" ] || {
        log "Brak AT TTY."
        return
    }

    if ! command -v ubus >/dev/null 2>&1; then
        return
    fi

    resp="$(ubus call wwand modem_at \
        "{\"modem\":\"$MODEM\",\"command\":\"AT+CGDCONT?\"}" \
        2>/dev/null)"

    if [ -z "$resp" ]; then
        log "Nie udało się odczytać CGDCONT."
        return
    fi

    echo "$resp"

    # CID 1 exists -> use modem profile #1.
    if echo "$resp" | grep -q '+CGDCONT: 1'; then
        log "Wykryto modemowy profil CID 1."

        APN_MODE="#1"

        if echo "$resp" | grep -q '+CGDCONT: 1,"IP"'; then
            PDP_TYPE="ipv4"
            log "CID 1: IPv4."
        elif echo "$resp" | grep -q '+CGDCONT: 1,"IPV4V6"'; then
            PDP_TYPE="ipv4v6"
            log "CID 1: IPv4 + IPv6."
        fi

        log "Rekomendacja APN: #1"
    else
        log "Nie znaleziono CID 1."
    fi
}

# ------------------------------------------------------------
# Analyze logs.
#
# If LTE_ATTACH_CONFIG SET returns MBIM status 9,
# recommend modem-provisioned profile #1.
# ------------------------------------------------------------

analyze_logs()
{
    section "ANALIZA LOGÓW WWAND"

    if ! command -v logread >/dev/null 2>&1; then
        log "Brak logread."
        return
    fi

    logs="$(logread 2>/dev/null | grep 'wwand' | tail -n 250)"

    if [ -z "$logs" ]; then
        log "Brak wpisów wwand."
        return
    fi

    echo "$logs"

    echo
    echo "--- WNIOSKI ---"

    if echo "$logs" | grep -q 'status": 9'; then
        log "Wykryto MBIM status 9."

        if echo "$logs" | grep -q 'attach profile set failed'; then
            log "Status 9 wystąpił podczas ustawiania attach profile."
            log "Dla tego przypadku zalecany jest modemowy profil #1."
            APN_MODE="#1"
        fi
    fi

    if echo "$logs" | grep -q 'state ACTIVATING -> CONNECTED'; then
        log "WWAN: CONNECTED."
    fi

    if echo "$logs" | grep -q 'datapath: raw_ip'; then
        log "Datapath: raw_ip."
    fi

    if echo "$logs" | grep -q 'AT port: /dev/ttyUSB'; then
        detected_at="$(echo "$logs" |
            sed -n 's/.*AT port: \(\/dev\/ttyUSB[0-9][0-9]*\).*/\1/p' |
            tail -n 1)"

        [ -n "$detected_at" ] && AT_TTY="$detected_at"
    fi
}

# ------------------------------------------------------------
# Generate final UCI configuration
# ------------------------------------------------------------

generate_config()
{
    section "GENEROWANA KONFIGURACJA"

    [ -n "$MODEM" ] || MODEM="wwmodem0"

    # For this project wwan0 is preferred.
    # If detection found wwan0, keep it.
    # Otherwise use detected network device.
    if [ -e /sys/class/net/wwan0 ]; then
        NETDEV="wwan0"
    fi

    [ -n "$NETDEV" ] || NETDEV="wwan0"

    [ -n "$AT_TTY" ] || AT_TTY="/dev/ttyUSB2"

    [ -n "$APN_MODE" ] || APN_MODE="#1"

    [ -n "$PDP_TYPE" ] || PDP_TYPE="ipv4"

    if [ -z "$USB_PATH" ]; then
        USB_PATH="UNKNOWN"
    fi

    cat <<EOF

config wwand_modem '$MODEM'
        option path '$USB_PATH'
        option tty '$AT_TTY'


config interface 'LTE'
        option proto 'wwand'
        option modem '$MODEM'
        option device '$NETDEV'
#       option apn 'internet'
        option apn '$APN_MODE'
        option pdp_type '$PDP_TYPE'
        option auth 'none'
        option peerdns '0'
        list dns '127.0.0.1'
        option metric '10'
        option multipath 'off'

EOF
}

# ------------------------------------------------------------
# Summary
# ------------------------------------------------------------

summary()
{
    section "PODSUMOWANIE"

    echo "Model:       ${MODEL:-unknown}"
    echo "Protocol:    ${PROTOCOL:-unknown}"
    echo "MBIM/QMI:    ${MODEM_DEV:-unknown}"
    echo "Network:     ${NETDEV:-unknown}"
    echo "AT port:     ${AT_TTY:-unknown}"
    echo "wwand modem: ${MODEM:-wwmodem0}"
    echo "APN mode:    ${APN_MODE:-unknown}"
    echo "PDP type:    ${PDP_TYPE:-unknown}"
    echo "USB path:    ${USB_PATH:-unknown}"

    echo
    echo "Konfiguracja NIE została zapisana."
    echo "Skrypt wykonał diagnostykę i wygenerował propozycję."
}

# ============================================================
# MAIN
# ============================================================

section "WWAND CONFIG PROBE"

find_modem
find_usb_path
query_wwand
detect_profile
analyze_logs
generate_config
summary

exit 0