<?php

namespace App\Support\VideoWorkflow\StepHandlers;

use App\Models\AiProvider;
use App\Models\WorkflowStep;
use App\Support\AiProviders\AiGenerationException;
use App\Support\AiProviders\AiProviderManager;
use App\Support\AssetStorage\AssetStorage;
use App\Support\VideoWorkflow\WorkflowEngine;

/**
 * Turns a project's title/description (or an explicit outline) into a full
 * script via an OpenAI-backed AiProvider, with optional tone/SEO-keyword/
 * length guidance from the step's input.
 */
class ScriptGenerationHandler implements StepHandler
{
    public function __construct(
        private readonly AiProviderManager $aiProviders,
        private readonly AssetStorage $assets,
    ) {}

    public function type(): string
    {
        return 'script_generation';
    }

    public function handle(WorkflowStep $step, WorkflowEngine $engine): void
    {
        $provider = AiProvider::query()->where('provider', 'openai')->where('is_active', true)->first();

        if (! $provider) {
            $engine->failStep($step, 'No active OpenAI provider configured.');

            return;
        }

        try {
            $result = $this->aiProviders->generate($provider, $this->buildPrompt($step));
        } catch (AiGenerationException $e) {
            $engine->failStep($step, $e->getMessage());

            return;
        }

        $asset = $this->assets->store(
            $step->videoProject,
            'script',
            $result->content,
            'txt',
            step: $step,
            mimeType: 'text/plain',
        );

        $engine->completeStep($step, [
            'asset_id' => $asset->id,
            'word_count' => str_word_count($result->content),
        ]);
    }

    private function buildPrompt(WorkflowStep $step): string
    {
        $input = $step->input ?? [];
        $project = $step->videoProject;

        $outline = $input['outline'] ?? trim(($project->title ?? '')."\n\n".($project->description ?? ''));

        $prompt = "Write a complete, engaging YouTube video script.\n\nTopic/Outline:\n{$outline}";

        if (! empty($input['tone'])) {
            $prompt .= "\n\nTone: {$input['tone']}";
        }

        if (! empty($input['seo_keywords'])) {
            $prompt .= "\n\nNaturally include these SEO keywords where relevant: ".implode(', ', $input['seo_keywords']);
        }

        if (! empty($input['target_words'])) {
            $prompt .= "\n\nTarget length: approximately {$input['target_words']} words.";
        }

        $prompt .= "\n\nWrite only the script content, no preamble or explanation.";

        return $prompt;
    }
}