# Copyright 2023 Arkemis S.r.l.
#
# Licensed 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.

defmodule Arke.Utils.Gcp do
  @storage Application.get_env(:arke, :storage)
  @service_account @storage[:gcp][:service_account]
  @default_bucket @storage[:gcp][:default_bucket]

  def upload_file(file_name, file_data, opts \\ []) do
    bucket = opts[:bucket] || @default_bucket
    conn = get_connection()

    {:ok, object} =
      GoogleApi.Storage.V1.Api.Objects.storage_objects_insert_iodata(
        conn,
        bucket,
        "multipart",
        %{name: file_name},
        file_data
      )
  end

  def get_file(file_path, opts \\ []) do
    bucket = opts[:bucket] || @default_bucket
    conn = get_connection()

    GoogleApi.Storage.V1.Api.Objects.storage_objects_get(
      conn,
      bucket,
      file_path
    )
  end

  def delete_file(file_path, opts \\ []) do
    bucket = opts[:bucket] || @default_bucket
    conn = get_connection()

    GoogleApi.Storage.V1.Api.Objects.storage_objects_delete(
      conn,
      bucket,
      file_path
    )
  end

  # def get_url() do
  #   service_account = "arke-storage@arkemis-lab.iam.gserviceaccount.com"
  #   bucket = "arke_demo"
  #   object = "file.txt"

  #   get_signed_url(service_account, bucket, object)
  # end

  def get_bucket_file_signed_url(file_path, opts \\ []) do
    gcp_service_account = opts[:service_account] || @service_account
    bucket = opts[:bucket] || @default_bucket

    %Tesla.Client{pre: [{Tesla.Middleware.Headers, :call, [auth_headers]}]} = get_connection()
    headers = [{"Content-Type", "application/json"}] ++ auth_headers

    url =
      "https://iamcredentials.googleapis.com/v1/projects/-/serviceAccounts/#{gcp_service_account}:signBlob"

    expires = DateTime.utc_now() |> DateTime.to_unix() |> Kernel.+(1 * 3600)
    resource = "/#{bucket}/#{file_path}"
    signature = ["GET", "", "", expires, resource] |> Enum.join("\n") |> Base.encode64()
    body = %{"payload" => signature} |> Poison.encode!()
    {:ok, %{status_code: 200, body: result}} = HTTPoison.post(url, body, headers)

    %{"signedBlob" => signed_blob} = Poison.decode!(result)

    qs =
      %{
        "GoogleAccessId" => gcp_service_account,
        "Expires" => expires,
        "Signature" => signed_blob
      }
      |> URI.encode_query()

    Enum.join(["https://storage.googleapis.com#{resource}", "?", qs])
  end

  defp get_connection() do
    {:ok, token} = Goth.Token.fetch([])
    GoogleApi.Storage.V1.Connection.new(token.token)
  end
end