#!/usr/bin/env bash
set -eau -o pipefail

# API where to list arcep files
GOUV_API_URL=https://www.data.gouv.fr/api/1/datasets/le-marche-du-haut-et-tres-haut-debit-fixe-deploiements/
# File to store last versions downloaded
VERSIONS_FILENAME=.arcep_versions
## Content of version file:
# LAST_ARCEP_ZIP=<file date>__<file name>.zip
# BEFORE_ARCEP_ZIP=<file date>__<file name>.zip

# Global vars
g_last_arcep_zip=""
g_before_arcep_zip=""
g_penultimate_arcep_zip=""
g_arcep_to_unzip=""

# Script usage
usage() {
  echo
  echo "Usage : $0 -d|--dir-out <dir to put downloads in> (-r|--remove-penultimate)"
  echo
  echo "  With:"
  echo "    -d|--dir-out: folder where to store zip files"
  echo "    (-r|--remove-penultimate): if set, remove 2nd before last version after dl latest file"
  echo "    (-f|--force-dl): if set, will force re-download data and process it"
  echo
}

# Get already dl data info
source_versions() {
  dir_out=$1
  ver_file=${dir_out}/${VERSIONS_FILENAME}
  LAST_ARCEP_ZIP=""
  BEFORE_ARCEP_ZIP=""
  [[ -f ${ver_file} ]] && source "${ver_file}"
  g_last_arcep_zip=${LAST_ARCEP_ZIP}
  g_before_arcep_zip=${BEFORE_ARCEP_ZIP}
}

# Dl arcep latest data if needed
dl_latest_arcep() {
  dir_out=$1
  force_dl=$2
  rc=0

  echo "Create out dir ${dir_out} if not exist"
  mkdir -p "${dir_out}"
  ver_file=${dir_out}/${VERSIONS_FILENAME}
  touch "${ver_file}"

  latest_file_url="$(curl -s ${GOUV_API_URL} | jq -r '.resources[] |objects | .url' | grep -i immeubles | head -1)"
  file_date=$(echo "$latest_file_url" | cut -f6 -d '/')
  file_name=$(echo "$latest_file_url" | cut -f7 -d '/')
  latest_f=${file_date}__${file_name}

  echo "Found ${latest_f} Check if already exist"
  if [[ -n ${g_last_arcep_zip} && "${latest_f}" = "${g_last_arcep_zip}" && $force_dl != "true" ]]; then
    echo "File ${latest_f} is already the latest ! Do not do anything"
  else
    echo "File ${latest_f} not there, download it"
    wget -O "${dir_out}"/"${latest_f}" "${latest_file_url}" || rc=1
    g_penultimate_arcep_zip=${g_before_arcep_zip}
    g_before_arcep_zip=${g_last_arcep_zip}
    g_last_arcep_zip=${latest_f}
    g_arcep_to_unzip=${latest_f}
    echo "OK, update versions file"
    echo "LAST_ARCEP_ZIP=${g_last_arcep_zip}" >"${ver_file}"
    echo "BEFORE_ARCEP_ZIP=${g_before_arcep_zip}" >>"${ver_file}"
  fi

  return ${rc}
}

# Unzip a dl arcep file
unzip_arcep() {
  dir_out=$1
  zip_file=$2
  zip_dir=$(echo "${zip_file}" | rev | cut -f2- -d '.' | rev)
  mkdir -p "${dir_out}/$zip_dir"
  echo "Unzip file ${dir_out}/${zip_file}"
  unzip "${dir_out}"/"${zip_file}" -d "${dir_out}"/"$zip_dir" || return 1
  return 0
}

# main
main() {
  # Init input vars
  remove_penultimate=false
  force_dl=false
  dir_out=""

  # Read inputs
  [[ $# -eq 0 ]] && usage && return 1
  while [ -n "$1" ]; do
    case $1 in
    -d | --dir-out)
      dir_out=$(realpath "$2")
      shift
      ;;
    -r | --remove-penultimate)
      remove_penultimate=true
      ;;
    -f | --force-dl)
      force_dl=true
      ;;
    -h | --help)
      usage && exit 0
      ;;
    *)
      echo "Unknown command: $1"
      usage && exit 1
      ;;
    esac
    [[ $# -le 1 ]] && break
    shift
  done

  # check inputs
  if [[ -z ${dir_out} ]]; then
    echo "Error: You need to specify an output dir -d|--dir-out <dir path>"
    usage
    return 1
  fi

  rc=0
  # Read existing dl versions
  source_versions "${dir_out}" || rc=1
  # Download latest zip file if needed
  [[ $rc -eq 0 ]] && dl_latest_arcep "${dir_out}" $force_dl || rc=1
  # If download succeeded and there is a file to unzip
  if [[ $rc -eq 0 && -n $g_arcep_to_unzip ]]; then
    # unzip file
    unzip_arcep "${dir_out}" "${g_last_arcep_zip}" || rc=1

    # Unzip succeeded and need to remove penultimate arcep data (if exists)
    if [[ $rc -eq 0 && \
      $remove_penultimate && -n \
      $g_penultimate_arcep_zip && -f \
      ${dir_out}/$g_penultimate_arcep_zip ]]; then

      echo "Delete penultimate zip ${dir_out}/$g_penultimate_arcep_zip"
      rm -f "${dir_out}"/"$g_penultimate_arcep_zip"
      zip_dir=$(echo "${g_penultimate_arcep_zip}" | rev | cut -f2- -d '.' | rev)
      if [[ -d ${dir_out}/${zip_dir} ]]; then
        echo "remove dir ${dir_out}/${zip_dir}"
        rm -rf "${dir_out}"/"${zip_dir}"
      fi
    elif [[ $rc -ne 0 ]]; then
      echo "Failed to unzip ${g_last_arcep_zip} !"
    fi
  fi
  return $rc
}

### Call main
main "$@" || exit 1

exit 0