defmodule WorkloadServiceWeb.TaskController do
  use WorkloadServiceWeb, :controller
  use OpenApiSpex.ControllerSpecs

  alias WorkloadService.CommandedApp
  alias WorkloadService.Workload.Queries
  alias WorkloadService.Aggregates.TaskId
  alias WorkloadServiceWeb.Schemas.Task, as: S
  alias WorkloadServiceWeb.QueryHelpers

  tags(["Tasks"])

  operation(:list,
    summary: "List tasks",
    parameters:
      QueryHelpers.flop(
        [:status, :application_id, :policy_type],
        [:created_at, :updated_at, :status]
      ),
    responses: [
      ok: {"Task list", "application/json", S.TaskListResponse},
      bad_request: {"Invalid params", "application/json", S.ErrorResponse}
    ]
  )

  def list(conn, params) do
    case Queries.list_tasks(params) do
      {:ok, {tasks, meta}} ->
        conn
        |> put_status(:ok)
        |> json(%{
          data: Enum.map(tasks, &task_summary/1),
          meta: meta_json(meta)
        })

      {:error, _} ->
        conn |> put_status(:bad_request) |> json(%{error: "invalid parameters"})
    end
  end

  operation(:show,
    summary: "Get task by ID",
    parameters: [
      id: [in: :path, type: :string, required: true]
    ],
    responses: [
      ok: {"Task detail", "application/json", S.TaskDetailResponse},
      not_found: {"Not found", "application/json", S.ErrorResponse}
    ]
  )

  def show(conn, %{"id" => id}) do
    case Queries.get_task_by_id(id) do
      {:error, :not_found} ->
        conn |> put_status(:not_found) |> json(%{error: "task not found"})

      {:ok, task} ->
        conn |> put_status(:ok) |> json(%{data: task_detail(task)})
    end
  end

  operation(:submit,
    summary: "Submit task data (quote response or confirm delivery)",
    parameters: [
      id: [in: :path, type: :string, required: true]
    ],
    request_body: {"Task submission", "application/json", S.SubmitRequest, required: true},
    responses: [
      ok: {"Task submitted", "application/json", S.TaskDetailResponse},
      not_found: {"Not found", "application/json", S.ErrorResponse},
      unprocessable_entity: {"Error", "application/json", S.ErrorResponse}
    ]
  )

  def submit(conn, %{"id" => id} = params) do
    task_type = get_task_type(id)

    case task_type do
      "quote" ->
        handle_quote_submit(conn, id, params)

      "solicitation" ->
        handle_solicitation_submit(conn, id, params)

      _ ->
        conn |> put_status(:unprocessable_entity) |> json(%{error: "invalid task type"})
    end
  end

  defp handle_quote_submit(conn, id, params) do
    case Queries.get_task_by_id(id) do
      {:error, :not_found} ->
        conn |> put_status(:not_found) |> json(%{error: "task not found"})

      {:ok, %{status: "created"} = _task} ->
        task_id = TaskId.parse!(id)

        command = %WorkloadService.Commands.QuoteTask.SubmitResponse{
          id: task_id,
          submission: %{
            "quote_id" => params["quote_id"],
            "plans" => params["plans"],
            "valid_until" => params["valid_until"],
            "recorded_by" => "system",
            "document_data" => params["document_data"]
          },
          attachments: params["document_urls"] || []
        }

        dispatch_and_respond(conn, id, command)

      {:ok, _task} ->
        conn |> put_status(:unprocessable_entity) |> json(%{error: "invalid state for submit"})
    end
  end

  defp handle_solicitation_submit(conn, id, params) do
    case Queries.get_task_by_id(id) do
      {:error, :not_found} ->
        conn |> put_status(:not_found) |> json(%{error: "task not found"})

      {:ok, %{status: "created"} = _task} ->
        task_id = TaskId.parse!(id)

        command = %WorkloadService.Commands.SolicitationTask.SubmitResponse{
          id: task_id,
          submission: %{
            "provider_policy_number" => params["provider_policy_number"],
            "effective_date" => params["effective_date"],
            "expiry_date" => params["expiry_date"],
            "recorded_by" => "system"
          },
          attachments: params["document_urls"] || []
        }

        dispatch_and_respond(conn, id, command)

      {:ok, _task} ->
        conn |> put_status(:unprocessable_entity) |> json(%{error: "invalid state for submit"})
    end
  end

  operation(:approve,
    summary: "Approve submission",
    parameters: [
      id: [in: :path, type: :string, required: true]
    ],
    responses: [
      ok: {"Task approved", "application/json", S.TaskDetailResponse},
      not_found: {"Not found", "application/json", S.ErrorResponse},
      unprocessable_entity: {"Error", "application/json", S.ErrorResponse}
    ]
  )

  def approve(conn, %{"id" => id}) do
    task_type = get_task_type(id)

    case task_type do
      "quote" ->
        handle_approve(conn, id, WorkloadService.Commands.QuoteTask.ApproveSubmission)

      "solicitation" ->
        handle_approve(conn, id, WorkloadService.Commands.SolicitationTask.ApproveSubmission)

      _ ->
        conn |> put_status(:unprocessable_entity) |> json(%{error: "invalid task type"})
    end
  end

  defp handle_approve(conn, id, command_module) do
    case Queries.get_task_by_id(id) do
      {:error, :not_found} ->
        conn |> put_status(:not_found) |> json(%{error: "task not found"})

      {:ok, %{status: "draft"} = _task} ->
        task_id = TaskId.parse!(id)
        command = struct(command_module, id: task_id)
        dispatch_and_respond(conn, id, command)

      {:ok, _task} ->
        conn |> put_status(:unprocessable_entity) |> json(%{error: "invalid state for approve"})
    end
  end

  operation(:complete,
    summary: "Complete task",
    parameters: [
      id: [in: :path, type: :string, required: true]
    ],
    request_body: {"Complete request", "application/json", S.CompleteRequest, required: false},
    responses: [
      ok: {"Task completed", "application/json", S.TaskDetailResponse},
      not_found: {"Not found", "application/json", S.ErrorResponse},
      unprocessable_entity: {"Error", "application/json", S.ErrorResponse}
    ]
  )

  def complete(conn, %{"id" => id} = params) do
    task_type = get_task_type(id)
    completed_by = params["completed_by"] || "system"

    case task_type do
      "quote" ->
        handle_complete(conn, id, completed_by, WorkloadService.Commands.QuoteTask.CompleteTask)

      "solicitation" ->
        handle_complete(
          conn,
          id,
          completed_by,
          WorkloadService.Commands.SolicitationTask.CompleteTask
        )

      _ ->
        conn |> put_status(:unprocessable_entity) |> json(%{error: "invalid task type"})
    end
  end

  defp handle_complete(conn, id, completed_by, command_module) do
    case Queries.get_task_by_id(id) do
      {:error, :not_found} ->
        conn |> put_status(:not_found) |> json(%{error: "task not found"})

      {:ok, %{status: "approved"} = _task} ->
        task_id = TaskId.parse!(id)
        command = struct(command_module, id: task_id, completed_by: completed_by)
        dispatch_and_respond(conn, id, command)

      {:ok, _task} ->
        conn |> put_status(:unprocessable_entity) |> json(%{error: "invalid state for complete"})
    end
  end

  defp dispatch_and_respond(conn, id, command) do
    case CommandedApp.dispatch(command) do
      :ok ->
        {:ok, task} = Queries.get_task_by_id(id)
        conn |> put_status(:ok) |> json(%{data: task_detail(task)})

      {:error, reason} ->
        conn |> put_status(:unprocessable_entity) |> json(%{error: inspect(reason)})
    end
  end

  defp get_task_type(id) do
    case WorkloadService.Aggregates.TaskId.parse(id) do
      {:ok, %{type: type}} -> type
      _ -> "unknown"
    end
  end

  defp task_summary(t) do
    %{
      id: t.id,
      org_id: t.org_id,
      application_id: t.application_id,
      policy_type: t.policy_type,
      task_info: t.task_info,
      status: t.status,
      created_at: t.inserted_at
    }
  end

  defp task_detail(t) do
    %{
      id: t.id,
      org_id: t.org_id,
      application_id: t.application_id,
      policy_type: t.policy_type,
      task_info: t.task_info,
      submission: t.submission,
      attachments: t.attachments,
      status: t.status,
      created_at: t.inserted_at,
      updated_at: t.updated_at
    }
  end

  defp meta_json(meta) do
    %{
      total_count: meta.total_count,
      total_pages: meta.total_pages,
      current_page: meta.current_page,
      page_size: meta.page_size,
      has_next: meta.has_next_page?,
      has_prev: meta.has_previous_page?
    }
  end
end