#! /usr/bin/env bash

set -euo pipefail

#### Detect Toolkit Project Root ####
# if realpath is not available, create a semi-equivalent function
command -v realpath >/dev/null 2>&1 || realpath() {
  [[ $1 = /* ]] && echo "$1" || echo "$PWD/${1#./}"
}
SCRIPT_PATH="$(realpath "${BASH_SOURCE[0]}")"
SCRIPT_DIR="$(dirname "$SCRIPT_PATH")"
TOOLKIT_ROOT="$(realpath "$SCRIPT_DIR/..")"
if [[ ! -d "$TOOLKIT_ROOT/bin" ]] || [[ ! -d "$TOOLKIT_ROOT/config" ]]; then
  echo "ERROR: could not find root of overleaf-toolkit project (inferred project root as '$TOOLKIT_ROOT')"
  exit 1
fi

SPACES_PER_INDENT=4

WARNINGS_FILE="$(mktemp)"

function add_warning() {
  echo "$@" >> "$WARNINGS_FILE"
}

function indent_to_level() {
  levels="$1"
  number_of_spaces=$(( levels * SPACES_PER_INDENT ))
  spaces="$(printf %${number_of_spaces}s)"
  echo -n "${spaces}"
}

function print_section_separator() {
  echo "====== $* ======"
}

function print_point() {
  indent_level="0"
  if [[ "${1:-null}" =~ [0-9]{1} ]]; then
    indent_level="$1"
    shift
  fi
  # shellcheck disable=SC2086
  echo "$(indent_to_level $indent_level)- $*"
}

function check_host_information() {
  print_point 0 "Host Information"

  # Linux or not?
  if [[ $(uname -a) =~ .*Linux.* ]]; then
    print_point 1 "Linux"
  else
    print_point 1 "Not Linux !"
    add_warning "This system seems to not be Linux"
  fi

  # LSB Information (particular distribution of Linux, and version)
  if [[ -n $(command -v lsb_release) ]]; then
    print_point 1 "Output of 'lsb_release -a':"
    lsb_release -a 2>&1 | while read -r _line; do
      echo "$(indent_to_level 3)$_line"
    done
  else
    print_point 1 "lsb_release not found !"
  fi
}


function check_dependencies() {

  function get_version() {
    binary_name="$1"
    if [[ "bash" == "$binary_name" ]]; then
      bash -c 'echo $BASH_VERSION'
    elif [[ "perl" == "$binary_name" ]]; then
      perl -e 'print $];'
    else
      $binary_name --version | head -n 1
    fi
  }

  function check_for_binary() {
    binary_name="$1"
    print_point 1 "$binary_name"
    if [[ -n $(command -v "$binary_name") ]]; then
      print_point 2 "status: present"
      version=$(get_version "$binary_name")
      print_point 2 "version info: $version"
      if [[ "$binary_name" == "realpath" ]] \
          && [[ "$(command -V "$binary_name")" =~ .*function.* ]]; then
        message="Could not find 'realpath' binary, falling back to custom function"
        print_point 2 "WARNING: $message"
        add_warning "$message"
      fi
    else
      print_point 2 "status: MISSING !"
      add_warning "$binary_name not found"
    fi
  }

  print_point 0 "Dependencies"
  declare -a binaries=(
    bash
    docker
    docker-compose
    realpath
    perl
    awk
  )

  for binary in "${binaries[@]}"; do
    check_for_binary "$binary"
  done
}

function check_docker_daemon() {
  print_point 0 "Docker Daemon"
  if docker ps &>/dev/null;  then
    print_point 1 "status: up"
  else
    print_point 1 "status: DOWN !"
    add_warning "Docker daemon is not running"
  fi
}

function print_warnings() {
  print_section_separator "Warnings"
  if [[ -n $(head -n 1 "$WARNINGS_FILE") ]]; then
    while read -r _line; do
      echo "! $_line"
    done < "$WARNINGS_FILE"
  else
    echo "- None, all good"
  fi
}

function check_config_files() {
  print_section_separator "Configuration"

  config_files=(
    "config/version"
    "config/overleaf.rc"
    "config/variables.env"
  )
  for config_file in "${config_files[@]}"
  do

    print_point 0 "$config_file"

    if [[ ! -f "$TOOLKIT_ROOT/$config_file" ]]; then
      print_point 1 "status: MISSING !"
      add_warning "configuration file $config_file not found"
    else

      print_point 1 "status: present"

      if [[ "$config_file" == "config/version" ]]; then
        print_point 1 "version: $(head -n 1 "$TOOLKIT_ROOT/$config_file")"
      elif [[ "$config_file" == "config/overleaf.rc" ]]; then
        print_point 1 "values"

        # Load vars from the rc file
        # shellcheck disable=SC1090
        source "$TOOLKIT_ROOT/$config_file"

        # Check some vars from the RC file
        if [[ "${SHARELATEX_DATA_PATH:-null}" != "null" ]]; then
          print_point 2 "SHARELATEX_DATA_PATH: $SHARELATEX_DATA_PATH"
        else
          print_point 2 "SHARELATEX_DATA_PATH: MISSING !"
          add_warning "rc file, SHARELATEX_DATA_PATH not set"
        fi

        print_point 2 "SERVER_PRO: $SERVER_PRO"
        if [[ "${SERVER_PRO:-null}" == "true" ]]; then
          local logged_in
          logged_in="$(grep -q quay.io ~/.docker/config.json && echo 'true' || echo 'false')"
          print_point 3 "logged in to quay.io: $logged_in"
          if [[ "${logged_in}" == "false" ]]; then
            local warning_message=(
              "Server Pro enabled, but not logged in to quay.io repository."
              "These credentials are supplied by Overleaf with a Server Pro"
              "license. See https://www.overleaf.com/for/enterprises/features"
              "for more details about Server Pro, or contact support@overleaf.com"
              "if you have any questions."
            )
            add_warning "${warning_message[@]}"
          fi
          print_point 2 "SIBLING_CONTAINERS_ENABLED: $SIBLING_CONTAINERS_ENABLED"
        fi

        print_point 2 "MONGO_ENABLED: $MONGO_ENABLED"
        if [[ "${MONGO_URL:-null}" != "null" ]]; then
          print_point 2 "MONGO_URL: [set here]"
        fi
        if [[ "${MONGO_IMAGE:-null}" != "null" ]]; then
          print_point 2 "MONGO_IMAGE: $MONGO_IMAGE"
        fi

        print_point 2 "REDIS_ENABLED: $REDIS_ENABLED"
        if [[ "${REDIS_HOST:-null}" != "null" ]]; then
          print_point 2 "REDIS_HOST: [set here]"
        fi
        if [[ "${REDIS_PORT:-null}" != "null" ]]; then
          print_point 2 "REDIS_PORT: [set here]"
        fi
        if [[ "${REDIS_IMAGE:-null}" != "null" ]]; then
          print_point 2 "REDIS_IMAGE: $REDIS_IMAGE"
        fi
      fi
    fi
  done
}

function cleanup() {
  rm "$WARNINGS_FILE"
}

function __main__() {
  print_section_separator "Overleaf Doctor"
  check_host_information
  check_dependencies
  check_docker_daemon
  check_config_files
  print_warnings
  print_section_separator "End"
  cleanup
}

__main__ "$@"