<?php

namespace UseCases\Command;

/**
 * Command for sending a chat message.
 */
final class SendChatMessageCommand
{
    /**
     * @param array<string> $collections
     */
    public function __construct(
        public readonly string $sessionUuid,
        public readonly string $message,
        public readonly string $model,
        public readonly array $collections,
        public readonly int $contextLimit,
        public readonly int $authorProfileId,
        public readonly int $systemPromptId,
        public readonly float $temperature,
        public readonly int $maxTokens,
    ) {
    }

    /**
     * @param array<string, mixed> $data
     */
    public static function fromRequest(string $sessionUuid, array $data): self
    {
        $collections = $data['collections'] ?? ['documents'];
        if (!is_array($collections)) {
            $collections = [$collections];
        }

        return new self(
            sessionUuid: $sessionUuid,
            message: trim((string) ($data['message'] ?? '')),
            model: (string) ($data['model'] ?? 'mistral'),
            collections: $collections,
            contextLimit: (int) ($data['context_limit'] ?? 5),
            authorProfileId: (int) ($data['author_profile_id'] ?? 0),
            systemPromptId: (int) ($data['system_prompt_id'] ?? 1),
            temperature: (float) ($data['temperature'] ?? 0.7),
            maxTokens: (int) ($data['max_tokens'] ?? 4096),
        );
    }

    /**
     * @return array<string>
     */
    public function validate(): array
    {
        $errors = [];

        if ($this->sessionUuid === '') {
            $errors[] = 'Session-ID ist erforderlich.';
        }

        if ($this->message === '') {
            $errors[] = 'Nachricht ist erforderlich.';
        }

        if ($this->model === '') {
            $errors[] = 'Modell ist erforderlich.';
        }

        if ($this->temperature < 0.0 || $this->temperature > 2.0) {
            $errors[] = 'Temperature muss zwischen 0 und 2 liegen.';
        }

        if ($this->maxTokens < 100 || $this->maxTokens > 16000) {
            $errors[] = 'Max-Tokens muss zwischen 100 und 16000 liegen.';
        }

        return $errors;
    }

    public function isValid(): bool
    {
        return $this->validate() === [];
    }
}