#!/bin/sh

github_license_api="https://api.github.com/licenses"
cache_dir="${XDG_CACHE_HOME:-${HOME}/.cache}/license-generator"

downloadFile() {
  url="${1}"
  dest="${2}"

  if command -v curl >/dev/null 2>&1; then
    curl -sS -L "${url}" --compressed > "${dest}" \
      || { printf "%s" "Error: Failed to fetch data using curl."; exit 1; }
  elif command -v wget >/dev/null 2>&1; then
    wget -r "${url}" --tries=5 -O "${dest}" \
      || { printf "%s" "Error: Failed to fetch data using wget."; exit 1; }
  elif command -v aria2c >/dev/null 2>&1; then
    aria2c --allow-overwrite=true "${url}" -o "${dest}" \
      || { printf "%s" "Error: Failed to fetch data using aria2c."; exit 1; }
  else
    printf "%s" "Error: Neither curl nor wget nor aria2c is available. Install one of them."
    exit 1
  fi
}

[ "$(command -v fzf)" ] \
  || { printf "%s" "Error: fzf is required for this script. Install it first."; exit 1; }

mkdir -p "${cache_dir}"

downloadFile "${github_license_api}" "${cache_dir}/licenses.json"

jq -r '.[] | select(.key) | .url' "${cache_dir}/licenses.json" \
  > "${cache_dir}/license_urls"

jq -r '.[] | select(.key) | .name' "${cache_dir}/licenses.json" \
  > "${cache_dir}/license_names"

chosen_license=$(grep '' "${cache_dir}/license_names" \
  | fzf --prompt "> Choose a license: " --height 40% --reverse)

[ "${chosen_license}" ] || exit 1
printf "%s" "Choose a license: ${chosen_license}"

line_number=$(grep -n "${chosen_license}" "${cache_dir}/license_names" \
  | cut -d ":" -f1)

license_url="$(sed -n "${line_number}p" "${cache_dir}/license_urls")"
license_name="$(printf "%s" "${license_url}" | cut -d "/" -f5)"

downloadFile "${license_url}" "${cache_dir}/${license_name}.json"

printf "\n%s" "Enter your name: "
read -r fullname

printf "%s" "Enter year: "
read -r year
[ "${year}" ] || year="$(date '+%Y')"

jq -r '.body' "${cache_dir}/${license_name}.json" \
  | sed "s/\[fullname\]/${fullname}/g" \
  | sed "s/\[year\]/${year}/g" > LICENSE