defmodule ALF.Components.Recomposer do
use ALF.Components.Basic
defstruct Basic.common_attributes() ++
[
type: :recomposer,
module: nil,
function: nil,
opts: [],
source_code: nil,
collected_ips: []
]
alias ALF.{DSLError, IP, ErrorIP, Manager.Streamer}
@dsl_options [:name, :opts]
def start_link(%__MODULE__{} = state) do
GenStage.start_link(__MODULE__, state)
end
def init(state) do
state = %{
state
| pid: self(),
opts: init_opts(state.module, state.opts),
source_code: read_source_code(state.module, state.function)
}
{:producer_consumer, state, subscribe_to: state.subscribe_to}
end
def handle_events([%ALF.IP{} = ip], _from, %__MODULE__{telemetry_enabled: true} = state) do
:telemetry.span(
[:alf, :component],
telemetry_data(ip, state),
fn ->
case process_ip(ip, state) do
{nil, state} ->
{{:noreply, [], state}, telemetry_data(nil, state)}
{%IP{} = ip, state} ->
{{:noreply, [ip], state}, telemetry_data(ip, state)}
{%ErrorIP{} = error_ip, state} ->
{{:noreply, [], state}, telemetry_data(error_ip, state)}
end
end
)
end
def handle_events([%ALF.IP{} = ip], _from, %__MODULE__{telemetry_enabled: false} = state) do
case process_ip(ip, state) do
{nil, state} ->
{:noreply, [], state}
{%IP{} = ip, state} ->
{:noreply, [ip], state}
{%ErrorIP{}, state} ->
{:noreply, [], state}
end
end
defp process_ip(ip, state) do
collected_data = Enum.map(state.collected_ips, & &1.event)
case call_function(
state.module,
state.function,
ip.event,
collected_data,
state.opts
) do
{:ok, :continue} ->
collected_ips = state.collected_ips ++ [ip]
{nil, %{state | collected_ips: collected_ips}}
{:ok, {event, events}} ->
Streamer.cast_remove_from_registry(
ip.manager_name,
[ip | state.collected_ips],
ip.stream_ref
)
ip =
build_ip(event, ip.stream_ref, ip.manager_name, [{state.name, ip.event} | ip.history])
collected =
Enum.map(events, fn event ->
build_ip(event, ip.stream_ref, ip.manager_name, [{state.name, ip.event} | ip.history])
end)
Streamer.cast_add_to_registry(ip.manager_name, [ip], ip.stream_ref)
{ip, %{state | collected_ips: collected}}
{:ok, event} ->
Streamer.cast_remove_from_registry(
ip.manager_name,
[ip | state.collected_ips],
ip.stream_ref
)
ip =
build_ip(event, ip.stream_ref, ip.manager_name, [{state.name, ip.event} | ip.history])
Streamer.cast_add_to_registry(ip.manager_name, [ip], ip.stream_ref)
{ip, %{state | collected_ips: []}}
{:error, error, stacktrace} ->
error_ip = send_error_result(ip, error, stacktrace, state)
{error_ip, state}
end
end
defp build_ip(event, stream_ref, manager_name, history) do
%IP{
stream_ref: stream_ref,
ref: make_ref(),
init_datum: event,
event: event,
manager_name: manager_name,
recomposed: true,
history: history
}
end
def validate_options(name, options) do
wrong_options = Keyword.keys(options) -- @dsl_options
unless is_atom(name) do
raise DSLError, "Recomposer name must be an atom: #{inspect(name)}"
end
if Enum.any?(wrong_options) do
raise DSLError,
"Wrong options for the #{name} recomposer: #{inspect(wrong_options)}. " <>
"Available options are #{inspect(@dsl_options)}"
end
end
defp call_function(module, function, event, collected_data, opts)
when is_atom(module) and is_atom(function) do
{:ok, apply(module, function, [event, collected_data, opts])}
rescue
error ->
{:error, error, __STACKTRACE__}
catch
kind, value ->
{:error, kind, value}
end
end