<?php

namespace App\Services\AiEditing\Safety;

use App\Services\AiEditing\AiEditingRuntimeConfig;
use App\Services\AiEditing\AiProviderResult;
use Illuminate\Support\Arr;
use Illuminate\Support\Str;

class AiSafetyPolicyService
{
    public function __construct(private readonly AiEditingRuntimeConfig $runtimeConfig) {}

    public function evaluatePrompt(?string $prompt, ?string $negativePrompt): AiSafetyDecision
    {
        $blockedTerms = array_filter(array_map(
            static fn (mixed $term): string => Str::lower(trim((string) $term)),
            $this->runtimeConfig->blockedTerms()
        ));

        if ($blockedTerms === []) {
            return AiSafetyDecision::passed();
        }

        $fullPrompt = Str::lower(trim(sprintf('%s %s', (string) $prompt, (string) $negativePrompt)));
        if ($fullPrompt === '') {
            return AiSafetyDecision::passed();
        }

        $matched = [];
        foreach ($blockedTerms as $term) {
            if ($term !== '' && str_contains($fullPrompt, $term)) {
                $matched[] = 'prompt_blocked_term';
            }
        }

        if ($matched === []) {
            return AiSafetyDecision::passed();
        }

        return AiSafetyDecision::blocked(
            reasonCodes: $matched,
            failureCode: 'prompt_policy_blocked',
            failureMessage: 'The provided prompt violates the AI editing safety policy.'
        );
    }

    public function evaluateProviderOutput(AiProviderResult $result): AiSafetyDecision
    {
        if ($result->status === 'blocked') {
            return AiSafetyDecision::blocked(
                reasonCodes: $result->safetyReasons !== [] ? $result->safetyReasons : ['provider_blocked'],
                failureCode: $result->failureCode ?: 'output_policy_blocked',
                failureMessage: $result->failureMessage ?: 'The generated output was blocked by safety policy.'
            );
        }

        if ($result->safetyState === 'blocked') {
            return AiSafetyDecision::blocked(
                reasonCodes: $result->safetyReasons !== [] ? $result->safetyReasons : ['provider_nsfw_content'],
                failureCode: 'output_policy_blocked',
                failureMessage: 'The generated output was blocked by safety policy.'
            );
        }

        $payloadItems = (array) Arr::get($result->responsePayload, 'data', []);
        foreach ($payloadItems as $item) {
            if (! is_array($item)) {
                continue;
            }

            if ($this->toBool(Arr::get($item, 'NSFWContent')) || $this->toBool(Arr::get($item, 'nsfwContent'))) {
                return AiSafetyDecision::blocked(
                    reasonCodes: ['provider_nsfw_content'],
                    failureCode: 'output_policy_blocked',
                    failureMessage: 'The generated output was blocked by safety policy.'
                );
            }
        }

        return AiSafetyDecision::passed();
    }

    private function toBool(mixed $value): bool
    {
        if (is_bool($value)) {
            return $value;
        }

        if (is_numeric($value)) {
            return (int) $value === 1;
        }

        if (is_string($value)) {
            return in_array(Str::lower(trim($value)), ['1', 'true', 'yes'], true);
        }

        return false;
    }
}