defmodule ConfientWeb.DepositController do
  use ConfientWeb, :controller
  import Phoenix.HTML

  def index(conn, _params) do
    works = Confient.Deposit.list_works()
    render(conn, "index.html", works: works)
  end

  def form(conn, params = %{"id" => id}) do
    case Confient.School.get_class(id) do
      {:error, :no_class} ->
        conn
        |> put_flash(
          :error,
          "La classe demandée n'existe pas."
        )
        |> redirect(to: "/")

      {:ok, class} ->
        next_assignments = Confient.Works.get_next_assignments(class)

        if length(next_assignments) > 0 && length(class.students) do
          changeset = Confient.Student.Work.changeset(%Confient.Student.Work{}, %{})

          student =
            with {:ok, id} <- Map.fetch(params, "student_id"),
                 {val, _} <- Integer.parse(id) do
              Enum.find(class.students, Enum.at(class.students, 0), &(&1.id == val))
            else
              :error -> Enum.at(class.students, 0)
            end

          assignment =
            with {:ok, id} <- Map.fetch(params, "assignment_id"),
                 {val, _} <- Integer.parse(id) do
              Enum.find(next_assignments, Enum.at(next_assignments, 0), &(&1.id == val))
            else
              :error -> Enum.at(next_assignments, 0)
            end

          render(conn, "form.html",
            assignment_id: assignment.id,
            student_id: student.id,
            changeset: changeset,
            class: class,
            assignments: next_assignments
          )
        else
          conn
          |> put_flash(
            :info,
            "Aucun devoir à rendre pour la classe #{class.name}"
          )
          |> redirect(to: "/")
        end
    end
  end

  def deposit(conn, %{
        "id" => id,
        "work" => %{"assignment_id" => assignment_id, "student_id" => student_id, "file" => work}
      }) do
    with {:ok, class} <- Confient.School.get_class(id),
         {:ok, student} <- Confient.School.get_student(student_id),
         {:ok, assignment} <- Confient.Works.get_assignment(assignment_id),
         :ok <- Confient.Deposit.verify_date(assignment.due),
         {:ok, ext} <- Confient.Deposit.verify_file(work) do
      dir =
        Confient.Deposit.get_upload_dir(class.name, assignment.slug)
        |> Confient.Deposit.ensure_upload_dir()

      fname = Confient.Deposit.gen_filename(class.name, assignment.slug, student, ext)

      case File.copy(work.path, "#{dir}/#{fname}") do
        {:ok, _} ->
          Confient.Works.create_or_update_work(%{
            path: fname,
            student_id: student.id,
            assignment_id: assignment.id
          })

          conn
          |> put_flash(
            :info,
            raw("Fichier <strong>#{work.filename}</strong> déposé avec succès<br>
            Elève : #{student.lastname} #{student.firstname}<br>
            Devoir : #{assignment.title}<br>
            Classe : #{class.name}")
          )
          |> redirect(to: "/")

        {:error, _} ->
          conn
          |> put_flash(
            :error,
            "Erreur lors du téléversement du fichier."
          )
          |> redirect(
            to:
              Routes.deposit_path(conn, :form, id,
                student_id: student.id,
                assignment_id: assignment.id
              )
          )
      end
    else
      {:error, :date_too_late} ->
        conn
        |> put_flash(
          :error,
          "La date de rendue pour le devoir sélectionné est dépassée."
        )
        |> redirect(to: Routes.deposit_path(conn, :form, id))

      {:error, :no_class} ->
        conn
        |> put_flash(
          :error,
          "La classe demandé n'existe pas."
        )
        |> redirect(to: "/")

      {:error, :no_student} ->
        conn
        |> put_flash(
          :error,
          "L'étudiant demandé n'existe pas."
        )
        |> redirect(to: "/")

      {:error, :no_assignment} ->
        conn
        |> put_flash(
          :error,
          "Le devoir demandé n'existe pas."
        )
        |> redirect(to: "/")

      {:error, :invalid_file_type} ->
        {:ok, student} = Confient.School.get_student(student_id)
        {:ok, assignment} = Confient.Works.get_assignment(assignment_id)

        conn
        |> put_flash(
          :error,
          raw("Format de fichier invalide pour le fichier <strong>#{work.filename}</strong><br>
            Elève : #{student.lastname} #{student.firstname}<br>
            Devoir : #{assignment.title}")
        )
        |> redirect(
          to:
            Routes.deposit_path(conn, :form, id,
              student_id: student.id,
              assignment_id: assignment.id
            )
        )
    end
  end

  def deposit(conn, %{"id" => id}),
    do:
      conn
      |> put_flash(:error, "Aucun fichier spécifié")
      |> redirect(to: Routes.deposit_path(conn, :form, id))
end