#!/bin/bash
# connect to iot services
THIS_DIR=$( cd "$( dirname "${BASH_SOURCE[0]:-${(%):-%x}}" )" && pwd )
source "$THIS_DIR/../tools/common.sh"

# get target settings
# provides:
SERVER=""
PORT=""
SSH_USERNAME=""
SSH_OPTIONS=""
get_server_meta()
{
    local domain=${1##*.}
    local host=${1%.*}
    if [[ "$host" == "$domain" ]]; then
        domain=""
    fi
    case $domain in
        ibd|ebd )
            SERVER=$host.$domain.ink
            PORT=12022
            SSH_USERNAME=root
            ;;
        nasp )
            SERVER=$host
            PORT=22
            SSH_USERNAME=dictxiong
            SSH_OPTIONS='-o ProxyJump="ssh@nasp.ob.ac.cn:36022"'
            ;;
        "" )
            SERVER=proxy.beardic.cn
            local tmp=$(sha256sum <<< "$host" | tr -cd "[:digit:]")
            tmp=${tmp:0:4}
            PORT=$((tmp+36000))
            SSH_USERNAME=root
            ;;
        * )
            fmt_fatal "unknown domain: $domain"
    esac
}

# ssh
run_ssh()
{
    CMD="ssh -p $PORT $SSH_OPTIONS $SSH_USERNAME@$SERVER"
    fmt_note "-->" $CMD
    eval $CMD
}

# sshl
run_sshl()
{
    if [[ -z "$1" || "$1" != *":"* ]]; then
        fmt_fatal "invalid remote address: $1"
    fi
    while
        local port=$(shuf -n 1 -i 49152-65535)
        netstat -atun | grep -q "$port"
    do
        continue
    done
    CMD="ssh -p $PORT $SSH_OPTIONS -NC -L $port:$1 $SSH_USERNAME@$SERVER"
    fmt_note "-->" $CMD
    fmt_note "  > please access localhost:$port"
    eval $CMD
}

# main
print_help()
{
    fmt_info "usage: $0 <service> [command] [options]"
    echo "available commands: ssh (default), sshl (ssh -L)"
}

router()
{
    if [[ -z "$1" || "$1" == "-h" || "$1" == "--help" ]]; then
        print_help
        exit
    fi
    get_server_meta "$1"
    case $2 in
        -h|--help)
            print_help
            exit
            ;;
        ssh|"" )
            run_ssh
            ;;
        sshl )
            run_sshl "$3"
            ;;
        * )
            print_help
            fmt_fatal "unknown command: $2"
            ;;
    esac
}

router "${GOT_OPTS[@]}"