#! /usr/bin/env bash

# Sleeps until an HTTP server becomes responsive, i.e., responds with code 200.
# When passing the optional <required keys> parameter, the script also checks
# that the payload sent by the server contains the keys.

if [ $# -ne 3 ] && [ $# -ne 4 ]; then
    echo >&2 "usage: $0 <port> <path> <max secs to wait> [<required keys>]"
    exit 1
fi

base_dir=`dirname "$0"`
port=`awk -F/ '{print $1}' <<< $1`
wait_url="http://localhost:$port/$2"
max_wait=$3
required_keys=$4
wait_count=0
tmp_file=wait-for-http-tmp

function get_status_code() {
  rm -f $tmp_file
  curl -s -o $tmp_file -w "%{http_code}" $wait_url
}

while true; do
    # try to get a valid response from the server
    response_code=`get_status_code`
    if [ "$response_code" = "200" ]; then
        if [ -z "$search_string" ]; then
            rm -f $tmp_file
            exit 0
        else
            if python3 "$base_dir/extract-json-keys.py" $tmp_file $required_keys; then
                rm -f $tmp_file
                exit 0
            fi
        fi
    fi
    # wait for a second unless we've hit the maximum wait time
    let "wait_count += 1"
    if [ $wait_count -ge $max_wait ]; then
        rm -f $tmp_file
        echo >&2 "error: server does not respond on $wait_url after $max_wait seconds"
        exit 1
    fi
    sleep 1
done