#!/usr/bin/env bash
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.

set -euo pipefail


function redraw_progress_bar { # int barsize, int base, int current, int top
    # Source: https://stackoverflow.com/a/20311674
    local barsize=$1
    local base=$2
    local current=$3
    local top=$4
    local j=0
    local progress=$(( (barsize * (current - base)) / (top - base ) ))
    echo -n "["
    for ((j=0; j < progress; j++)) ; do echo -n '='; done
    echo -n '=>'
    for ((j=progress; j < barsize ; j++)) ; do echo -n ' '; done
    echo -n "] $current / $top " $'\r'
}

function check_absolute_links {
  local env="$1"
  local exception_link="$2"
  local -n env_exception_links="$3"

  echo "Checking $env links."
  for external_link in "${external_links[@]}";
  do
  processed_external_link=`awk -F/ '{print $3}' <<<"$external_link"`
    if [[ "$processed_external_link" == "$exception_link" ]];
    then
      checked_word=`awk -F/ '{print $4}' <<<"$external_link"`
      if [[ $checked_word != "releases" ]]; then
        env_exception_links+=("${external_link}")
        echo "${external_link}"
      fi
    fi
  done
}

function report_absolute_links {
  local -n env_exception_links="$1"
  local env="$2"

  if [[ ${#env_exception_links[@]} -ne 0 ]]; then
      echo "Found ${#env_exception_links[@]} link(s) leading to $env site. Recommended to use relative links to Apache Beam website. Absolute links to Apache Beam $env website:"
      printf '%s\n' ${env_exception_links[@]}
  else
      echo "No absolute $env links"
  fi
}

if ! command -v lynx; then
    echo "This script requires lynx to work properly."
    echo
    echo "For more information, look at: https://lynx.browser.org/"
    exit 1
fi

MY_DIR="$(cd "$(dirname "$0")" && pwd)"
pushd "${MY_DIR}" &>/dev/null || exit 1

echo "Working directory: ${MY_DIR}"

DIST_DIR=${1:-"./dist"}
echo "Dist directory: ${DIST_DIR}"

echo ""

if [[ ! -f "${DIST_DIR}/index.html" ]]; then
   echo "You should build website first."
   exit 1
fi

mkdir -pv "${DIST_DIR}"

readarray -d '' pages < <(find "${DIST_DIR}" -name '*.html' -print0)
echo "Found ${#pages[@]} HTML files."

echo "Searching links."
mapfile -t links < <(printf '%s\n' "${pages[@]}" | xargs -n 1 lynx -listonly -nonumbers -dump -display_charset=iso-8859-1 | grep -v " ")
mapfile -t external_links < <(printf '%s\n' "${links[@]}" | grep "^https\?://" | grep -v "http://localhost" | grep -v "http://link/" | grep -v "http://docker.local" | grep -v "https://github.com/apache/beam/edit/master/website/www/site/content/" | sort | uniq)
echo "Found ${#links[@]} links including ${#external_links[@]} unique external links."

echo "Checking links."
prod_exception_links=()
staging_exception_links=()
check_absolute_links "production" "beam.apache.org" prod_exception_links
check_absolute_links "staging" "apache-beam-website-pull-requests.storage.googleapis.com" staging_exception_links

echo "Checking working links."
verified_list="https://reporter.apache.org/addrelease.html?beam,https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/creating-a-pull-request-from-a-fork,https://help.github.com/articles/securing-your-account-with-two-factor-authentication-2fa/,https://qwiklabs.com/focuses/608?locale=en&parent=catalog,https://www.artstation.com/jbruno,https://www.qwiklabs.com/focuses/1098?parent=catalog,https://www.infoworld.com/article/3336072/infoworlds-2019-technology-of-the-year-award-winners.html,https://be.linkedin.com/in/mattcasters,https://www.linkedin.com/company/beam-summit/,https://www.linkedin.com/company/beam-summit/?viewAsMember=true,https://www.ricardo.ch/,https://www.linkedin.com/company/apache-beam/,https://repository.apache.org/content/repositories/orgapachebeam-NNNN/),https://www.meetup.com/Apache-Beam-Stockholm/?_cookie-check=v_YHSSjYcT9rpm61,https://www.meetup.com/Apache-Beam-Stockholm/events/260634514"
invalid_links=()

function handle_urls {
  i=1
  for external_link in "${external_links[@]}"
  do
      redraw_progress_bar 50 1 $i ${#external_links[@]}

      curl_result=$(curl -sSfL --max-filesize 1000000 --max-time 10 --connect-timeout 10 --retry 2 -4 "$external_link" 2>&1 > /dev/null) && status=$? || status=$?
      if [ $status -ne 0 ] ; then
          if [[ $curl_result =~ (error: )([0-9]{3}) ]]; then
              error_code=${BASH_REMATCH[0]}

              # Check if link is in verified_list
              if [[ $verified_list =~ "$external_link" ]]; then
                  continue
              fi

              invalid_links+=("${error_code} ${external_link}")
              echo "${external_link}"
          fi
      fi
      i=$((i+1))
  done
  # Clear line - hide progress bar
  echo -n -e "\033[2K"
}

handle_urls

report_absolute_links prod_exception_links "production"
report_absolute_links staging_exception_links "staging"

# Sort invalid links by error status
IFS=$'\n'
sorted_invalid_links=($(sort <<<"${invalid_links[*]}"));
unset IFS

if [[ ${#sorted_invalid_links[@]} -ne 0 ]]; then
    echo "Found ${#sorted_invalid_links[@]} invalid links: "
    printf '%s\n' "${sorted_invalid_links[@]}"
else
    echo "All links work"
fi

popd &>/dev/null || exit 1