#!/bin/sh
# Send a Nowlark notification from anything that is not Python.
#
#   nowlark <source> [title] [body] [--url URL] [--priority N] [--group G]
#           [--dedupe D] [--replace R] [--check] [--quiet]
#   nowlark --register <source>
#
# The key comes from NOWLARK_API_KEY, or from the crontab, the same way the
# Python client finds it: a launchd agent does not inherit cron's environment.
#
# <source> is the sender's name on the phone and its row in Sources: one per
# script or job, the same on every run, never a shared machine name.
#
# --register lists <source> in the app now, without sending anything: for a
# job that only speaks when it fails. Registering an existing name is a no-op.
#
# Exits 0 when the server accepted it, 1 when it refused, 2 on a usage error.
# A duplicate and a muted source are acceptances, not failures.
set -eu

BASE_URL="${NOWLARK_BASE_URL:-https://nowlark.com}"
TIMEOUT="${NOWLARK_TIMEOUT:-20}"

usage() {
    sed -n '2,18p' "$0" | sed 's/^# \{0,1\}//'
    exit 2
}

api_key() {
    if [ -n "${NOWLARK_API_KEY:-}" ]; then
        printf '%s' "$NOWLARK_API_KEY"
        return 0
    fi
    /usr/bin/crontab -l 2>/dev/null \
        | sed -n 's/^[[:space:]]*NOWLARK_API_KEY[[:space:]]*=[[:space:]]*['"'"'"]\{0,1\}\([^'"'"'" ]*\).*/\1/p' \
        | head -1
}

# JSON-escape a string using the json module rather than sed, so a description
# containing a quote, a backslash or a newline does not produce invalid JSON.
json_string() {
    printf '%s' "$1" | /usr/bin/python3 -c 'import json,sys; print(json.dumps(sys.stdin.read()))'
}

SOURCE=""; TITLE=""; BODY=""; URL=""; PRIORITY=0; GROUP=""; DEDUPE=""; REPLACE=""
CHECK=0; QUIET=0; REGISTER=0

while [ $# -gt 0 ]; do
    case "$1" in
        --url)      URL="${2:?--url needs a value}"; shift 2 ;;
        --priority) PRIORITY="${2:?--priority needs a value}"; shift 2 ;;
        --group)    GROUP="${2:?--group needs a value}"; shift 2 ;;
        --dedupe)   DEDUPE="${2:?--dedupe needs a value}"; shift 2 ;;
        --replace)  REPLACE="${2:?--replace needs a value}"; shift 2 ;;
        --check)    CHECK=1; shift ;;
        --register) REGISTER=1; shift ;;
        --quiet)    QUIET=1; shift ;;
        -h|--help)  usage ;;
        -*)         echo "nowlark: unknown option $1" >&2; usage ;;
        *)
            if   [ -z "$SOURCE" ]; then SOURCE="$1"
            elif [ -z "$TITLE" ];  then TITLE="$1"
            elif [ -z "$BODY" ];   then BODY="$1"
            else echo "nowlark: too many arguments" >&2; usage
            fi
            shift ;;
    esac
done

KEY=$(api_key)
if [ -z "$KEY" ]; then
    echo "nowlark: NOWLARK_API_KEY is not set" >&2
    exit 2
fi

if [ "$CHECK" -eq 1 ]; then
    curl -sS --max-time "$TIMEOUT" -f \
        -H "X-Nowlark-Key: $KEY" "$BASE_URL/v1/key/check"
    printf '\n'
    exit 0
fi

[ -n "$SOURCE" ] || usage

if [ "$REGISTER" -eq 1 ]; then
    STATUS=$(curl -sS --max-time "$TIMEOUT" -o /dev/null -w '%{http_code}' \
        -H "X-Nowlark-Key: $KEY" -H 'Content-Type: application/json' \
        -d "{\"source\":$(json_string "$SOURCE")}" "$BASE_URL/v1/sources" 2>/dev/null) || STATUS=000
    if [ "$STATUS" = "200" ]; then
        [ "$QUIET" -eq 1 ] || echo "registered $SOURCE"
        exit 0
    fi
    [ "$QUIET" -eq 1 ] || echo "nowlark: could not register (HTTP $STATUS)" >&2
    exit 1
fi

[ -n "$TITLE" ] || [ -n "$BODY" ] || {
    echo "nowlark: a title or a body is required" >&2; exit 2; }

PAYLOAD="{\"source\":$(json_string "$SOURCE"),\"priority\":$PRIORITY"
[ -n "$TITLE" ]  && PAYLOAD="$PAYLOAD,\"title\":$(json_string "$TITLE")"
[ -n "$BODY" ]   && PAYLOAD="$PAYLOAD,\"body\":$(json_string "$BODY")"
[ -n "$URL" ]    && PAYLOAD="$PAYLOAD,\"url\":$(json_string "$URL")"
[ -n "$GROUP" ]  && PAYLOAD="$PAYLOAD,\"group_key\":$(json_string "$GROUP")"
[ -n "$DEDUPE" ] && PAYLOAD="$PAYLOAD,\"dedupe_key\":$(json_string "$DEDUPE")"
[ -n "$REPLACE" ] && PAYLOAD="$PAYLOAD,\"replace_key\":$(json_string "$REPLACE")"
PAYLOAD="$PAYLOAD}"

RESPONSE=$(curl -sS --max-time "$TIMEOUT" -w '\n%{http_code}' \
    -H "X-Nowlark-Key: $KEY" -H 'Content-Type: application/json' \
    -d "$PAYLOAD" "$BASE_URL/v1/notify" 2>&1) || {
        [ "$QUIET" -eq 1 ] || echo "nowlark: could not reach $BASE_URL" >&2
        exit 1
    }

STATUS=$(printf '%s' "$RESPONSE" | tail -1)
BODY_OUT=$(printf '%s' "$RESPONSE" | sed '$d')

if [ "$STATUS" = "200" ]; then
    [ "$QUIET" -eq 1 ] || printf '%s\n' "$BODY_OUT"
    exit 0
fi

[ "$QUIET" -eq 1 ] || printf 'nowlark: refused (HTTP %s) %s\n' "$STATUS" "$BODY_OUT" >&2
exit 1