#! /usr/bin/env bash

set -euo pipefail

DEFAULT_LINES=20

function usage() {
    echo "Usage: bin/logs [OPTIONS] [SERVICES...]"
    echo ""
    echo "Services:  chat, clsi, contacts, docstore, document-updater,"
    echo "           filestore, notifications, real-time, spelling,"
    echo "           tags, track-changes, web"
    echo ""
    echo "Options:"
    echo "  -f              follow log output"
    echo "  -n {number}     number of lines to print (default $DEFAULT_LINES)"
    echo ""
    echo "Examples:"
    echo ""
    echo "    bin/logs -n 50 web clsi"
    echo ""
    echo "    bin/logs -f web"
    echo ""
    echo "    bin/logs -f web chat docstore"
    echo ""
    echo "    bin/logs -n 100 -f filestore "
    echo ""
    echo "    bin/logs -f"
}

function __main__() {
    LINES="$DEFAULT_LINES"
    FOLLOW_FLAG=""

    while getopts "fn:" opt
    do
        case $opt in
            f ) FOLLOW_FLAG="-f" ;;
            n ) LINES="${OPTARG}" ;;
            \?) usage && exit ;;
        esac
    done
    shift $(( OPTIND -1 ))

    if [[ "${1:-null}" == "null" ]] \
        || [[ "${1:-null}" == "help" ]] \
        || [[ "${1:-null}" == "--help" ]] ; then
        usage && exit
    fi

    log_base_path="/var/log/sharelatex"

    declare -a services
    IFS=" " read -r -a services <<< "$*"

    path_spec="$log_base_path/*.log"

    if [[ ! "0" == "${#services[@]}" ]]; then
        log_paths=()
        for service in "${services[@]}"; do
            log_paths+=("$log_base_path/${service}.log")
        done
        path_spec="${log_paths[*]}"
    fi

    bash_exec_command_string="tail $FOLLOW_FLAG -n $LINES $path_spec"

    exec ./bin/docker-compose exec sharelatex bash -c "$bash_exec_command_string"
}

__main__ "$@"