#!/bin/bash

# script to run the dev guide's docker image.
# creates a settings.sh file where the path of directory holding the persistent data
# accepts --no-nis as first argument to not start nis in the container


################################################################################
# preamble: functions definitions, variable setting, etc
################################################################################

# we look for the config file in the same directory as the script, whose location
# is stored in this variable
script_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd -P )"
# by default start nis
with_nis=1
# by default, do not pass a user to run the command as
# if we run in the tools container, this will be set to run the command as user nem.
docker_user_flag=""
pull=0
# tools_dir is the directory mounted in the tools container to /home/nem/code
# currently hard-coded in this variable
tools_dir="./code"

usage() {
    cat <<-EOF
	Usage: $0 [options] [command]
	
	The command can be run without flags or commands. In that case it will:
	    * if missing, create $script_dir/settings.sh, prompting the user for values
	    * if missing, download the docker-compose.yml to $script_dir
	    * if missing, create the directory where you store your code, also available in the
	         tools container. By default it is '$tools_dir'.
	    * start the containers
	The user running $0 needs to have the right to start and stop docker containers.

	Options are:
	    -c name
	    --container name
	       apply command to container. name can be nis or tools
	    -n
	    --no-nis
	       do not start NIS in the container.
	    -p
	    --pull
	       pull new images from the Docker Hub and exit
	    -s
	    --shutdown
	       shutdown containers. This flag has the highest priotity and
	       will be handled befor all others.
	       Note that **THIS DELETES ALL DATA IN THE CONTAINER**.
	    -S
	    --status
		   display running containers before handling other flags 

	Command is a command available in the container. 
	Custom commands are also available:
	    ts-node : opens a Typescript nodejs repl in which you can load nem-library
	    repl.js : opens a nodejs repl with nem-sdk loaded and available under the variable 'nem'
	    mitm    : opens a mitmproxy console in your terminal, listening on port 7892

	EOF
    exit
}
# function to handle arguments passed to the script
handle_args() {

    while [[ $# -gt 0 ]]; do
        key="$1"

        case $key in
            -c|--container)
            container="$2"
            shift # passed argument
            shift
            ;;
            -n|--no-nis)
            with_nis=0
            shift # no argument
            ;;
	    -h|--help)
	    usage
	    shift
	    ;;
	    -p|--pull)
	    pull=1
	    shift
	    ;;
	    -s|--shutdown)
	    shutdown=1
	    shift
	    ;;
	    -S|--status)
	    state=1
	    shift
	    ;;
            # an unrecognised option is interpreted as the end of options
	    # and sets the remaining value as the command to be run
            *)
	    if [[ $key =~ ^-.* ]]; then
                 echo "Unrecognised option, please run \"$0 --help\""
                 exit 1
            else
                cmd="$@"
	        return 0
            fi
            ;;
        esac
    done
}

container_name() {
    container=$1
    echo $(eval "echo \$${container}_container")
}

service_name() {
    container=$1
    echo nemdev${container}
}

handle_config_file() {
    # we store the persistent data location for ease
    if [[ ! -f $script_dir/settings.sh ]]; then 
      echo "It appears no saved settings have been detected. We will create one now, please answer the questions below"
      while [[ ! -d "$persistent_location" ]] ; do
        [[ -z $persistent_location ]] || echo "Directory not found: $persistent_location"
        echo "In which *existing* directory should the persistent data of the container be stored? (it should exist, no directory will be created)"
        read persistent_location
      done
      echo "#if you change this, change also tools/.env!" >> settings.sh
      echo "export persistent_location=\"$persistent_location\"" >> settings.sh
      echo "export tools_dir=\"$PWD/code\"" >> settings.sh
    fi
    . $script_dir/settings.sh

}

# makes sure we have consistent data with cmd
handle_command() {
	case $1 in
	  tsc)
	    container="tools"
	        ;;
	  node)
	    container="tools"
	      ;;
	  ts-node)
	    container="tools"
	    ;;
	  repl.js)
	    container="tools"
	    ;;
	  bash)
	    [[ -z $container ]] && container="tools"
	    ;;
          # by default, execute command in tools container
	  *)
	    [[ -z $container ]] && container="tools"
	    ;;
	esac  

}

check_running_containers() {
    containers=$(docker ps --format '{{.Names}}' | grep $(basename $script_dir)_nemdev)
    nis_container=$(echo "$containers" | grep nis)
    tools_container=$(echo "$containers" | grep tools)
}


check_compose_file() {
    cd $script_dir
    [[ -f docker-compose.yml ]] || { curl -q https://raw.githubusercontent.com/rb2nem/nem-dev-guide/master/docker/docker-compose.yml > docker-compose.yml ; echo "The required docker-compose.yml file has been downloaded and saved under $script_dir" ; }
}

start_containers() {
# start docker containers if needed, possibly with nis
    if [[ -z "$nis_container" ]] ; then 
      mkdir -p $persistent_location/nem
      mkdir -p $tools_dir
      docker-compose up -d
      [[ $with_nis -eq 1 ]] && sleep 1 && docker exec -it docker_nemdevnis_1 supervisorctl start nis ;
      # update running containers variable after starting containers
      check_running_containers
      cat <<-EOF
	
	
	###############################################################################
	Welcome to the NEM developer's guide Docker containers.
	By default, two containers have been started, 
        one running NIS ($nis_container), and the
	other ($tools_container) running mitmproxy.
	
	Only the tools container has ports mapped to your host:
	- http://localhost:7890 : to contact the NIS instance running in the nis container through mitmproxy
	- http://localhost:7778 : to contact the NIS instance' websocket port through mitmproxy
	- http://localhost:8081 : to view requests to NIS intercepted by mitmproxy
	- http://localhost:8082 : to view websocket requests to NIS intercepted by mitmproxy
	
	Run with --help to get an overview of flags and supported commands.

	###############################################################################
	
	EOF
    fi
}

pull_images() {
	# no container specified, update both images
	if [[ -z $container ]] ; then
	    docker pull rb2nem/nem-dev-guide:nis
	    docker pull rb2nem/nem-dev-guide:tools
	else
	# container specified, only update its images
	    docker pull rb2nem/nem-dev-guide:$container
        fi
}


set_docker_user_flag() {

    if [[ $container = "tools" ]]; then
        docker_user_flag="-u nem"
    fi
}

# go to script directory to have Dockerfile available
cd $script_dir
handle_args "$@"
handle_config_file
check_compose_file
check_running_containers

if [[ $pull -eq 1 ]] ; then
    pull_images
    exit
fi
if [[ $state -eq 1 ]] ; then
    echo "running containers are:"
    echo "$containers"
    exit
fi

if [[ $shutdown -eq 1 ]] ; then
    # if we pass a container, check if it is running, and set action accordingly
    if [[ -n $container ]]; then
        check_running_containers
        set -x
        if [[ $(eval "echo \$${container}_container") == "" ]]; then
            action="up -d"
        else
            action="stop"
        fi
        docker-compose $action $(service_name $container)
        # if we stop the container, also remove it
        [[ $action == "stop" ]] && docker-compose rm -f $(service_name $container)
    else
        docker-compose down
    fi
    exit
fi
# make args consistent with command
handle_command $cmd
set_docker_user_flag

start_containers
if [[ -n "$cmd" ]]; then
set -x
  docker exec ${docker_user_flag} -it $(container_name $container) bash -i -c "$cmd"
fi