defmodule Aerospike.Protocol.ScanQuery do
  @moduledoc false

  import Bitwise

  alias Aerospike.Exp
  alias Aerospike.Filter
  alias Aerospike.Policy
  alias Aerospike.Protocol.AsmMsg
  alias Aerospike.Protocol.AsmMsg.Field
  alias Aerospike.Protocol.AsmMsg.Operation
  alias Aerospike.Protocol.Filter, as: FilterCodec
  alias Aerospike.Protocol.Message
  alias Aerospike.Protocol.UdfArgs
  alias Aerospike.Query
  alias Aerospike.Scan

  @info3_partition_done 0x04

  @type node_partitions :: %{
          required(:parts_full) => [non_neg_integer()],
          required(:parts_partial) => [partition_entry()],
          required(:record_max) => non_neg_integer()
        }

  @type partition_entry :: %{
          required(:id) => non_neg_integer(),
          optional(:digest) => binary() | nil,
          optional(:bval) => integer() | nil
        }

  @spec build_scan(Scan.t(), node_partitions(), Policy.ScanQueryRuntime.t()) :: iodata()
  def build_scan(%Scan{} = scan, node_partitions, %Policy.ScanQueryRuntime{} = policy) do
    timeout = policy.timeout
    socket_timeout = effective_socket_timeout(policy)
    query_id = policy.task_id
    filter_wire = merge_exp_filters(scan.filters)

    %AsmMsg{
      info1: scan_info1(scan, policy),
      info3: @info3_partition_done,
      timeout: timeout,
      fields:
        [
          Field.namespace(scan.namespace)
        ]
        |> maybe_append_table(scan.set)
        |> Kernel.++(pid_array_fields(node_partitions.parts_full))
        |> Kernel.++(digest_array_fields(node_partitions.parts_partial))
        |> Kernel.++(filter_exp_fields(filter_wire))
        |> Kernel.++(max_records_fields(node_partitions.record_max))
        |> Kernel.++(records_per_second_fields(effective_records_per_second(scan, policy)))
        |> Kernel.++([socket_timeout_field(socket_timeout), query_id_field(query_id)]),
      operations: scan_operations(scan, policy)
    }
    |> AsmMsg.encode()
    |> Message.encode_as_msg_iodata()
  end

  @spec build_query(Query.t(), node_partitions(), Policy.ScanQueryRuntime.t()) :: iodata()
  def build_query(%Query{} = query, node_partitions, %Policy.ScanQueryRuntime{} = policy) do
    timeout = policy.timeout
    socket_timeout = effective_socket_timeout(policy)
    query_id = policy.task_id

    filter =
      query.index_filter ||
        raise ArgumentError, "build_query/3 requires query.index_filter set via Query.where/2"

    filter_wire = merge_exp_filters(query.filters)

    %AsmMsg{
      info1: query_info1(query, policy),
      info2: query_info2(policy),
      info3: @info3_partition_done,
      timeout: timeout,
      fields:
        [
          Field.namespace(query.namespace),
          Field.set(query.set),
          query_id_field(query_id)
        ]
        |> Kernel.++(index_type_fields(filter))
        |> Kernel.++([index_range_field(filter)])
        |> Kernel.++(index_context_fields(filter))
        |> Kernel.++(index_name_fields(filter))
        |> Kernel.++(pid_array_fields(node_partitions.parts_full))
        |> Kernel.++(digest_array_fields(node_partitions.parts_partial))
        |> Kernel.++(bval_array_fields(node_partitions.parts_partial))
        |> Kernel.++(max_records_fields(node_partitions.record_max))
        |> Kernel.++(filter_exp_fields(filter_wire))
        |> Kernel.++(records_per_second_fields(effective_records_per_second(query, policy)))
        |> Kernel.++([socket_timeout_field(socket_timeout)]),
      operations: query_operations(query, policy)
    }
    |> AsmMsg.encode()
    |> Message.encode_as_msg_iodata()
  end

  @spec build_query_execute(
          Query.t(),
          node_partitions(),
          [Operation.t()],
          Policy.ScanQueryRuntime.t()
        ) ::
          iodata()
  def build_query_execute(
        %Query{} = query,
        node_partitions,
        operations,
        %Policy.ScanQueryRuntime{} = policy
      )
      when is_list(operations) do
    build_background_query(query, node_partitions, policy, operations: operations)
  end

  @spec build_query_udf(
          Query.t(),
          node_partitions(),
          String.t(),
          String.t(),
          list(),
          Policy.ScanQueryRuntime.t()
        ) :: iodata()
  def build_query_udf(
        %Query{} = query,
        node_partitions,
        package,
        function,
        args,
        %Policy.ScanQueryRuntime{} = policy
      )
      when is_binary(package) and is_binary(function) and is_list(args) do
    build_background_query(query, node_partitions, policy, udf: {2, package, function, args})
  end

  @spec build_query_aggregate(
          Query.t(),
          node_partitions(),
          String.t(),
          String.t(),
          list(),
          Policy.ScanQueryRuntime.t()
        ) :: iodata()
  def build_query_aggregate(
        %Query{} = query,
        node_partitions,
        package,
        function,
        args,
        %Policy.ScanQueryRuntime{} = policy
      )
      when is_binary(package) and is_binary(function) and is_list(args) do
    case query.index_filter do
      nil ->
        raise ArgumentError,
              "build_query_aggregate/6 requires query.index_filter set via Query.where/2"

      %Filter{} = index_filter ->
        build_query_with_filter(query, node_partitions, policy, index_filter,
          udf: {1, package, function, args}
        )
    end
  end

  defp scan_info1(%Scan{}, %Policy.ScanQueryRuntime{include_bin_data: false}) do
    AsmMsg.info1_read() ||| AsmMsg.info1_nobindata()
  end

  defp scan_info1(%Scan{no_bins: true}, %Policy.ScanQueryRuntime{}) do
    AsmMsg.info1_read() ||| AsmMsg.info1_nobindata()
  end

  defp scan_info1(%Scan{bin_names: []}, %Policy.ScanQueryRuntime{}) do
    AsmMsg.info1_read() ||| AsmMsg.info1_get_all()
  end

  defp scan_info1(%Scan{}, %Policy.ScanQueryRuntime{}), do: AsmMsg.info1_read()

  defp query_info1(%Query{}, %Policy.ScanQueryRuntime{include_bin_data: false} = policy) do
    (AsmMsg.info1_read() ||| AsmMsg.info1_nobindata())
    |> add_expected_duration(policy)
  end

  defp query_info1(%Query{no_bins: true}, %Policy.ScanQueryRuntime{} = policy) do
    (AsmMsg.info1_read() ||| AsmMsg.info1_nobindata())
    |> add_expected_duration(policy)
  end

  defp query_info1(%Query{bin_names: bins}, %Policy.ScanQueryRuntime{} = policy)
       when bins != [] do
    AsmMsg.info1_read()
    |> add_expected_duration(policy)
  end

  defp query_info1(%Query{}, %Policy.ScanQueryRuntime{} = policy) do
    (AsmMsg.info1_read() ||| AsmMsg.info1_get_all())
    |> add_expected_duration(policy)
  end

  defp query_info2(%Policy.ScanQueryRuntime{expected_duration: :long_relax_ap}) do
    AsmMsg.info2_relax_ap_long_query()
  end

  defp query_info2(%Policy.ScanQueryRuntime{}), do: 0

  defp add_expected_duration(info1, %Policy.ScanQueryRuntime{expected_duration: :short}) do
    info1 ||| AsmMsg.info1_short_query()
  end

  defp add_expected_duration(info1, %Policy.ScanQueryRuntime{}), do: info1

  defp scan_operations(%Scan{}, %Policy.ScanQueryRuntime{include_bin_data: false}), do: []
  defp scan_operations(%Scan{no_bins: true}, %Policy.ScanQueryRuntime{}), do: []
  defp scan_operations(%Scan{bin_names: []}, %Policy.ScanQueryRuntime{}), do: []

  defp scan_operations(%Scan{bin_names: bins}, %Policy.ScanQueryRuntime{}) do
    Enum.map(bins, &Operation.read/1)
  end

  defp query_operations(%Query{}, %Policy.ScanQueryRuntime{include_bin_data: false}), do: []
  defp query_operations(%Query{no_bins: true}, %Policy.ScanQueryRuntime{}), do: []
  defp query_operations(%Query{bin_names: []}, %Policy.ScanQueryRuntime{}), do: []

  defp query_operations(%Query{bin_names: bins}, %Policy.ScanQueryRuntime{}) do
    Enum.map(bins, &Operation.read/1)
  end

  defp build_background_query(
         query,
         node_partitions,
         %Policy.ScanQueryRuntime{} = policy,
         background
       ) do
    case query.index_filter do
      nil ->
        raise ArgumentError, "background query requires query.index_filter set via Query.where/2"

      %Filter{} = index_filter ->
        build_background_query_with_filter(
          query,
          node_partitions,
          policy,
          index_filter,
          background
        )
    end
  end

  defp build_query_with_filter(
         query,
         node_partitions,
         %Policy.ScanQueryRuntime{} = policy,
         %Filter{} = index_filter,
         background
       ) do
    timeout = policy.timeout
    socket_timeout = effective_socket_timeout(policy)
    query_id = policy.task_id
    filter_wire = merge_exp_filters(query.filters)

    fields =
      [
        Field.namespace(query.namespace),
        Field.set(query.set),
        query_id_field(query_id)
      ]
      |> Kernel.++(index_type_fields(index_filter))
      |> Kernel.++([index_range_field(index_filter)])
      |> Kernel.++(index_context_fields(index_filter))
      |> Kernel.++(index_name_fields(index_filter))
      |> Kernel.++(pid_array_fields(node_partitions.parts_full))
      |> Kernel.++(digest_array_fields(node_partitions.parts_partial))
      |> Kernel.++(bval_array_fields(node_partitions.parts_partial))
      |> Kernel.++(max_records_fields(node_partitions.record_max))
      |> Kernel.++(filter_exp_fields(filter_wire))
      |> Kernel.++(records_per_second_fields(effective_records_per_second(query, policy)))
      |> Kernel.++([socket_timeout_field(socket_timeout)])
      |> Kernel.++(background_query_fields(background))

    %AsmMsg{
      info1: query_info1(query, policy),
      info2: query_info2(policy),
      info3: @info3_partition_done,
      timeout: timeout,
      fields: fields,
      operations: background_query_operations(background)
    }
    |> AsmMsg.encode()
    |> Message.encode_as_msg_iodata()
  end

  defp build_background_query_with_filter(
         query,
         node_partitions,
         %Policy.ScanQueryRuntime{} = policy,
         %Filter{} = index_filter,
         background
       ) do
    timeout = policy.timeout
    socket_timeout = effective_socket_timeout(policy)
    query_id = policy.task_id
    filter_wire = merge_exp_filters(query.filters)

    fields =
      [
        Field.namespace(query.namespace),
        Field.set(query.set),
        query_id_field(query_id)
      ]
      |> Kernel.++(index_type_fields(index_filter))
      |> Kernel.++([index_range_field(index_filter)])
      |> Kernel.++(index_context_fields(index_filter))
      |> Kernel.++(index_name_fields(index_filter))
      |> Kernel.++(pid_array_fields(node_partitions.parts_full))
      |> Kernel.++(digest_array_fields(node_partitions.parts_partial))
      |> Kernel.++(bval_array_fields(node_partitions.parts_partial))
      |> Kernel.++(max_records_fields(node_partitions.record_max))
      |> Kernel.++(filter_exp_fields(filter_wire))
      |> Kernel.++(records_per_second_fields(effective_records_per_second(query, policy)))
      |> Kernel.++([socket_timeout_field(socket_timeout)])
      |> Kernel.++(background_query_fields(background))

    %AsmMsg{
      info1: 0,
      info2: AsmMsg.info2_write(),
      info3: 0,
      timeout: timeout,
      fields: fields,
      operations: background_query_operations(background)
    }
    |> AsmMsg.encode()
    |> Message.encode_as_msg_iodata()
  end

  defp background_query_fields(operations: _operations), do: []

  defp background_query_fields(udf: {mode, package, function, args}) do
    query_udf_fields(udf: {mode, package, function, args})
  end

  defp background_query_operations(operations: operations), do: operations
  defp background_query_operations(udf: _udf), do: []

  defp query_udf_fields(udf: {mode, package, function, args}) do
    arglist = UdfArgs.pack!(args)

    [
      Field.udf_op(mode),
      Field.udf_package_name(package),
      Field.udf_function(function),
      Field.udf_arglist(arglist)
    ]
  end

  defp maybe_append_table(fields, nil), do: fields
  defp maybe_append_table(fields, set) when is_binary(set), do: fields ++ [Field.set(set)]

  defp pid_array_fields([]), do: []

  defp pid_array_fields(ids) when is_list(ids) do
    data = for id <- ids, into: <<>>, do: <<id::16-little>>
    [%Field{type: Field.type_pid_array(), data: data}]
  end

  defp digest_array_fields([]), do: []

  defp digest_array_fields(partials) when is_list(partials) do
    data =
      partials
      |> Enum.map(fn %{digest: digest} -> digest end)
      |> Enum.filter(&is_binary/1)
      |> IO.iodata_to_binary()

    if data == <<>> do
      []
    else
      [%Field{type: Field.type_digest_array(), data: data}]
    end
  end

  defp bval_array_fields([]), do: []

  defp bval_array_fields(partials) when is_list(partials) do
    data =
      for partition <- partials, into: <<>> do
        bval =
          case Map.get(partition, :bval) do
            value when is_integer(value) -> value
            _ -> 0
          end

        <<bval::64-signed-little>>
      end

    [%Field{type: Field.type_bval_array(), data: data}]
  end

  defp index_type_fields(%Filter{index_type: index_type})
       when index_type in [:list, :mapkeys, :mapvalues] do
    [%Field{type: Field.type_index_type(), data: index_type_string(index_type)}]
  end

  defp index_type_fields(_), do: []

  defp index_range_field(%Filter{} = filter) do
    %Field{type: Field.type_index_range(), data: FilterCodec.encode(filter)}
  end

  defp index_context_fields(%Filter{ctx: nil}), do: []

  defp index_context_fields(%Filter{ctx: ctx}) when is_list(ctx) do
    [%Field{type: Field.type_index_context(), data: FilterCodec.encode_ctx(ctx)}]
  end

  defp index_name_fields(%Filter{index_name: nil}), do: []

  defp index_name_fields(%Filter{index_name: index_name}) do
    [%Field{type: Field.type_index_name(), data: index_name}]
  end

  defp index_type_string(:list), do: "LIST"
  defp index_type_string(:mapkeys), do: "MAPKEYS"
  defp index_type_string(:mapvalues), do: "MAPVALUES"

  defp socket_timeout_field(ms) when is_integer(ms) do
    %Field{type: Field.type_socket_timeout(), data: <<ms::32-signed-big>>}
  end

  defp query_id_field(id) when is_integer(id) and id >= 0 do
    %Field{type: Field.type_query_id(), data: <<id::64-unsigned-big>>}
  end

  defp max_records_fields(n) when is_integer(n) and n > 0 do
    [%Field{type: Field.type_max_records(), data: <<n::64-signed-big>>}]
  end

  defp max_records_fields(_), do: []

  defp records_per_second_fields(0), do: []

  defp records_per_second_fields(n) when is_integer(n) and n > 0 do
    [%Field{type: Field.type_records_per_second(), data: <<n::32-signed-big>>}]
  end

  defp records_per_second_fields(_), do: []

  defp effective_records_per_second(_scannable, %Policy.ScanQueryRuntime{
         records_per_second: n
       })
       when is_integer(n) do
    n
  end

  defp effective_records_per_second(%Scan{records_per_second: n}, %Policy.ScanQueryRuntime{}),
    do: n

  defp effective_records_per_second(%Query{records_per_second: n}, %Policy.ScanQueryRuntime{}),
    do: n

  defp effective_socket_timeout(%Policy.ScanQueryRuntime{timeout: total, socket_timeout: socket})
       when total > 0 and socket > total do
    total
  end

  defp effective_socket_timeout(%Policy.ScanQueryRuntime{socket_timeout: n}) when n > 0, do: n
  defp effective_socket_timeout(%Policy.ScanQueryRuntime{timeout: n}), do: n

  defp filter_exp_fields(nil), do: []

  defp filter_exp_fields(wire) when is_binary(wire) and wire != "" do
    [%Field{type: Field.type_filter_exp(), data: wire}]
  end

  defp filter_exp_fields(_), do: []

  defp merge_exp_filters([]), do: nil

  defp merge_exp_filters([%Exp{wire: wire}]), do: wire

  defp merge_exp_filters([%Exp{wire: first_wire} | rest]) do
    Enum.reduce(rest, %Exp{wire: first_wire}, fn %Exp{wire: next_wire}, %Exp{} = merged ->
      Exp.and_([merged, %Exp{wire: next_wire}])
    end).wire
  end
end