#!/bin/bash
#
# send-sms.sh
#
# Usage:
#   echo "Hello world" | ./send-sms.sh +41791234567
#
# Environment:
#   ASPSMS_USERKEY
#   ASPSMS_PASSWORD
#
# Exit codes:
#
#   0  SMS delivered
#
#   1  Usage/configuration error
#   2  Local/network/API communication failure
#   3  ASPSMS authentication failure
#   4  Invalid phone number
#   5  Recipient unavailable (phone off / no coverage / expired)
#   6  Mobile operator/provider failure
#   7  ASPSMS rejected request
#   8  Delivery timeout (status never became final)
#   9  Unknown failure
#

set -euo pipefail

API="https://webapi.aspsms.com"

if [[ $# -ne 1 ]]
then
    echo "Usage: $0 PHONE_NUMBER" >&2
    exit 1
fi

: "${ASPSMS_USERKEY:?ASPSMS_USERKEY not set}"
: "${ASPSMS_PASSWORD:?ASPSMS_PASSWORD not set}"

PHONE="$1"
MESSAGE="$(cat -)"

if [[ -z "$MESSAGE" ]]
then
    echo "Empty message" >&2
    exit 1
fi

TRANSREF="$(date +%s)-$$-$RANDOM"

#
# Send SMS
#
SEND_JSON="$(
curl -fsS \
    --get \
    "$API/SendSimpleSMS" \
    --data-urlencode "Userkey=$ASPSMS_USERKEY" \
    --data-urlencode "Password=$ASPSMS_PASSWORD" \
    --data-urlencode "Recipient=$PHONE" \
    --data-urlencode "MessageData=$MESSAGE" \
    --data-urlencode "TransactionReferenceNumber=$TRANSREF"
)" || {
    echo "Communication with ASPSMS failed" >&2
    exit 2
}

ERROR_CODE=$(jq -r '.ErrorCode // empty' <<<"$SEND_JSON")
ERROR_DESC=$(jq -r '.ErrorDescription // empty' <<<"$SEND_JSON")

case "$ERROR_CODE" in
    1)
        ;;
    3|8|9)
        echo "$ERROR_DESC" >&2
        exit 3
        ;;
    20|206)
        echo "$ERROR_DESC" >&2
        exit 4
        ;;
    24)
        echo "$ERROR_DESC" >&2
        exit 7
        ;;
    "")
        echo "Unexpected response:" >&2
        echo "$SEND_JSON" >&2
        exit 2
        ;;
    *)
        echo "$ERROR_DESC" >&2
        exit 7
        ;;
esac

#
# Poll delivery status
#
#
# DeliveryStatus:
#   -1 not yet known
#    0 delivered
#    1 buffered
#    2 failed
#
# Reason codes of interest:
#
# 000 unknown subscriber
# 101 unknown subscriber
# 107 absent subscriber
# 108 delivery failed
# 105/113 SC congestion
# 118-126 network/provider failures
# 206 invalid destination address
#

for ((i=0;i<60;i++))
do
    SEC=$(expr $i / 10)
    # Wait at least 100ms, then go up every second by 1 second
    sleep $SEC.1
    STATUS_JSON="$(
    curl -fsS \
        --get \
        "$API/SendingStat03/Get" \
        --data-urlencode "Userkey=$ASPSMS_USERKEY" \
        --data-urlencode "Password=$ASPSMS_PASSWORD" \
        --data-urlencode "TransactionReferenceNumber=$TRANSREF"
    )" || continue

    DELIVERY=$(jq -r '.[0].DeliveryStatus // empty' <<<"$STATUS_JSON")
    REASON=$(jq -r '.[0].ReasonCode // ""' <<<"$STATUS_JSON")

    case "$DELIVERY" in

        0)
            exit 0
            ;;

        1)
            continue
            ;;

        2)
            case "$REASON" in

                206|000|101)
                    exit 4
                    ;;

                107|108)
                    exit 5
                    ;;

                105|113|118|119|120|121|122|123|124|125|126)
                    exit 6
                    ;;

                *)
                    exit 9
                    ;;
            esac
            ;;

        -1|"")
            continue
            ;;

    esac

done

exit 8

#| Exit | Meaning                                                                       |
#| ---- | ----------------------------------------------------------------------------- |
#| 0    | SMS successfully delivered                                                    |
#| 1    | Usage or local configuration error                                            |
#| 2    | Unable to contact ASPSMS/API/network error                                    |
#| 3    | Authentication failure (invalid user key/password)                            |
#| 4    | Invalid or unknown recipient number                                           |
#| 5    | Recipient unreachable (phone switched off, out of coverage, delivery expired) |
#| 6    | Mobile operator/network/provider failure                                      |
#| 7    | ASPSMS rejected the request (temporary service issues, invalid request, etc.) |
#| 8    | Timed out waiting for a final delivery report                                 |
#| 9    | Delivery failed for an unclassified reason                                    |