#!/bin/bash -e
################################################################################
##  File:  yq.sh
##  Desc:  Installs YQ with checksum validation
################################################################################
# source: https://github.com/actions/runner-images/blob/5d6938f680075d63fa71f8aa70990866cd12884b/images/linux/scripts/installers/yq.sh

download_with_retries() {
  local URL="$1"
  local DEST="${2:-.}"
  local NAME="${3:-${URL##*/}}"
  echo "Downloading '$URL' to '${DEST}/${NAME}'..."
  local retries=20
  local interval=30
  while [ "$retries" -gt 0 ]; do
    ((retries--)) || true
    if curl -fsSL -o "${DEST}/${NAME}" "$URL"; then
      echo "Download completed"
      return 0
    fi
    echo "Error downloading. Waiting ${interval}s before retry, ${retries} attempts left"
    sleep "$interval"
  done
  echo "Could not download $URL"
  return 1
}

get_hash_from_remote_file() {
  local url=$1
  local keywords=("$2" "$3")
  local delimiter=${4:-' '}
  local word_number=${5:-1}
  local matching_line
  matching_line=$(curl -fsSL "$url" | sed 's/  */ /g' | tr -d '`')
  for keyword in "${keywords[@]}"; do
    matching_line=$(echo "$matching_line" | grep "$keyword" || true)
  done
  matching_line=$(echo "$matching_line" | head -n1)
  if [ -z "$matching_line" ]; then
    echo "Keywords (${keywords[*]}) not found in the file with hashes." >&2
    exit 1
  fi
  echo "$matching_line" | cut -d "$delimiter" -f "$word_number" | tr -d -c '[:alnum:]'
}

use_checksum_comparison() {
  local file_path=$1
  local checksum=$2
  local sha_type=${3:-256}
  local local_file_hash
  echo "Performing checksum verification"
  if [ ! -f "$file_path" ]; then
    echo "File not found: $file_path" >&2
    exit 1
  fi
  local_file_hash=$(shasum -a "$sha_type" "$file_path" | awk '{print $1}')
  if [ "$local_file_hash" != "$checksum" ]; then
    echo "Checksum verification failed. Expected: $checksum; Actual: $local_file_hash." >&2
    exit 1
  fi
  echo "Checksum verification passed"
}

yq_arch() {
  case "$(uname -m)" in
    'aarch64') echo 'arm64' ;;
    'x86_64') echo 'amd64' ;;
    'armv7l') echo 'arm' ;;
    *) exit 1 ;;
  esac
}

base_url="https://github.com/mikefarah/yq/releases/latest/download"
filename="yq_linux_$(yq_arch)"
download_with_retries "${base_url}/${filename}" "/tmp" "yq"
external_hash=$(get_hash_from_remote_file "${base_url}/checksums" "${filename} " "" " " "19")
use_checksum_comparison "/tmp/yq" "${external_hash}"
sudo install /tmp/yq /usr/bin/yq