<?php

namespace App\Events;

use Illuminate\Broadcasting\Channel;
use Illuminate\Broadcasting\InteractsWithSockets;
use Illuminate\Contracts\Broadcasting\ShouldBroadcastNow;
use Illuminate\Foundation\Events\Dispatchable;
use Illuminate\Queue\SerializesModels;
use Illuminate\Support\Arr;

class PerceptronTrainingIteration implements ShouldBroadcastNow
{
    use Dispatchable, InteractsWithSockets, SerializesModels;

    /**
     * Create a new event instance.
     */
    public function __construct(
        public array $iterations, // ["epoch" => int, "exampleIndex" => int, "error" => float, "synaptic_weights" => array]
        public string $sessionId,
        public string $trainingId,
    ) {
        //
    }

    /**
     * Get the channels the event should broadcast on.
     *
     * @return array<int, \Illuminate\Broadcasting\Channel>
     */
    public function broadcastOn(): array
    {
        // Log::debug("Broadcasting on channel: " . $this->sessionId . '-perceptron-training');
        return [
            new Channel($this->sessionId.'-perceptron-training'),
        ];
    }

    public function broadcastWith(): array
    {
        $iterations = self::normalizeForJson($this->iterations);
        $weights = collect($iterations)
            ->pluck('weights')
            ->first(fn (array $weights): bool => $weights !== []);
        $shouldBroadcastAllWeights = $weights !== null
            && count(Arr::flatten($weights)) <= config('perceptron.max_displayed_weights');

        $lastIterationIndex = count($iterations) - 1;
        $iterations = array_map(
            fn (array $iteration, int $index): array => $shouldBroadcastAllWeights || $index === $lastIterationIndex
                ? $iteration
                : [...$iteration, 'weights' => []],
            $iterations,
            array_keys($iterations),
        );

        return [
            'iterations' => $iterations,
            'trainingId' => $this->trainingId,
        ];
    }

    public static function normalizeForJson(mixed $value): mixed
    {
        if (is_float($value) && ! is_finite($value)) {
            return null;
        }

        if (! is_array($value)) {
            return $value;
        }

        return array_map(
            fn (mixed $item): mixed => self::normalizeForJson($item),
            $value,
        );
    }
}