defmodule Overpass do
    @moduledoc """
    """

    require Logger

    defmodule Tag do
        @moduledoc """
        http://wiki.openstreetmap.org/wiki/Tags
        """

        defstruct k: "",
                  v: ""

        @type t :: %__MODULE__{
            k: String.t,
            v: String.t
        }
    end

    defmodule Node do
        @moduledoc """
        http://wiki.openstreetmap.org/wiki/Node
        """

        defstruct id: 0,
                  lat: 0.0,
                  lon: 0.0,
                  tags: []

        @type t :: %__MODULE__{
            id: integer,
            lat: float,
            lon: float,
            tags: [%Overpass.Tag{}]
        }
    end

    defmodule Way do
        @moduledoc """
        http://wiki.openstreetmap.org/wiki/Way
        """

        defstruct id: 0,
                  nodes: [],
                  tags: []

        @type t :: %__MODULE__{
            id: integer,
            nodes: [%Overpass.Node{}],
            tags: [%Overpass.Tag{}]
        }

        @doc """
        Returns a List of `%Overpass.Node{}` with all nodes from the selected way.
        Set `resolve_missing` to `true` to query the nodes from the API.
        """
        @spec get_nodes(%Way{}, [%Node{}], false | true) :: [%Node{}]
        def get_nodes(way, nodes, resolve_missing \\ false)

        def get_nodes(
            %Way{
                id: id,
                nodes: node_ids
            },
            nodes,
            resolve_missing
        ) when not resolve_missing do
            Logger.debug fn -> inspect(id) end
            Logger.debug fn -> inspect(node_ids) end
            Logger.debug fn -> inspect(resolve_missing) end
            Enum.filter(nodes,
                fn %Node{id: node_id} ->
                    Enum.member?(node_ids, node_id)
                end
            )
        end

        def get_nodes(
            %Way{
                id: id,
                nodes: _node_ids
            },
            _nodes,
            resolve_missing
        ) when resolve_missing do
            Logger.debug fn -> inspect(id) end
            Logger.debug fn -> inspect(resolve_missing) end
            {:ok, %{nodes: nodes}} = Overpass.API.query("""
                way(#{id});node(w);out body;
            """) |> Overpass.Parser.parse()
            nodes
        end
    end

    defmodule RelationMember do
        @moduledoc """
        http://wiki.openstreetmap.org/wiki/Relation
        """

        defstruct type: "",
                  ref: "",
                  role: ""

        @type t :: %__MODULE__{
            type: String.t,
            ref: String.t,
            role: String.t,
        }
    end

    defmodule Relation do
        @moduledoc """
        http://wiki.openstreetmap.org/wiki/Relation
        """

        defstruct id: 0,
                  members: [],
                  tags: []

        @type t :: %__MODULE__{
            id: integer,
            members: [%Overpass.RelationMember{}],
            tags: [%Overpass.Tag{}]
        }
    end

    defmodule Response do
        @moduledoc """
        """
        defstruct nodes: [],
                  ways: [],
                  relations: []

        @type t :: %__MODULE__{
            nodes: [%Overpass.Node{}],
            ways: [%Overpass.Way{}],
            relations: [%Overpass.Relation{}]
        }
    end

end