<?php

namespace App\Modules\Movies\Services;

use App\Modules\Movies\Models\{Movie, Genre, Actor, Director, Studio, Country, Language};
use Illuminate\Support\Facades\DB;
use App\Modules\Movies\Services\Contracts\UpsertMovieServiceInterface;

class UpsertMovieFromProvider implements UpsertMovieServiceInterface
{
    /**
     * Persist a movie and all relations from normalized provider details.
     *
     * @param array $details Output of MovieProvider::details
     * @param string $mode 'overwrite'|'duplicate'
     * @return Movie
     */
    public function handle(array $details, string $mode = 'overwrite'): Movie
    {
        return DB::transaction(function () use ($details, $mode) {
            $provider = $details['provider'] ?? null;
            $providerId = $details['provider_id'] ?? null;

            $movie = null;
            if ($mode === 'overwrite' && $provider && $providerId) {
                $movie = Movie::query()
                    ->where('provider', $provider)
                    ->where('provider_id', $providerId)
                    ->first();
            }

            if (!$movie) {
                $movie = new Movie();
            }

            // Fill scalar fields
            $movie->fill([
                'provider' => $provider,
                'provider_id' => $providerId,
                'external_ids' => $details['external_ids'] ?? null,
                'title' => $details['title'] ?? '',
                'original_title' => $details['original_title'] ?? null,
                'description' => $details['description'] ?? null,
                'poster_url' => $details['poster_url'] ?? null,
                'backdrop_url' => $details['backdrop_url'] ?? null,
                'rating' => $details['rating'] ?? null,
                'release_date' => $details['release_date'] ?? null,
                'year' => $details['year'] ?? null,
                'runtime' => $details['runtime'] ?? null,
            ]);

            $movie->save();

            // Sync relations using names from details payload
            $this->syncByNames($movie, Genre::class, 'genres', $details['genres'] ?? []);
            $this->syncByNames($movie, Actor::class, 'actors', $details['actors'] ?? []);
            $this->syncByNames($movie, Director::class, 'directors', $details['directors'] ?? []);
            $this->syncByNames($movie, Studio::class, 'studios', $details['studios'] ?? []);
            $this->syncByNames($movie, Country::class, 'countries', $details['countries'] ?? []);
            $this->syncByNames($movie, Language::class, 'languages', $details['languages'] ?? []);

            return $movie->refresh();
        });
    }

    /**
     * @param Movie $movie
     * @param class-string $modelClass
     * @param string $relation
     * @param array $names Names to sync
     */
    protected function syncByNames(Movie $movie, string $modelClass, string $relation, array $names): void
    {
        // Create or fetch IDs by name (case-insensitive normalization)
        $ids = collect($names)
            ->filter()
            ->map(function ($name) use ($modelClass) {
                $original = (string) $name;
                $normalized = $this->normalizeName($original);
                if ($normalized === '') return null;

                // Find existing row in a case-insensitive way
                /** @var \Illuminate\Database\Eloquent\Model|null $existing */
                $existing = $modelClass::query()
                    ->whereRaw('lower(name) = ?', [mb_strtolower($normalized)])
                    ->first();

                if ($existing) {
                    return $existing->getKey();
                }

                /** @var \Illuminate\Database\Eloquent\Model $model */
                $model = new $modelClass();
                $model->setAttribute('name', $normalized);
                $model->save();
                return $model->getKey();
            })
            ->filter()
            ->values()
            ->all();

        // Sync relation if method exists
        if (method_exists($movie, $relation)) {
            $movie->{$relation}()->sync($ids);
        }
    }

    /**
     * Normalize a person/genre/studio/etc name for de-duplication.
     */
    protected function normalizeName(string $name): string
    {
        // Trim, collapse internal whitespace to single spaces
        $name = trim(preg_replace('/\s+/u', ' ', $name) ?? '');
        // Leave original casing (provider’s) but comparisons will be lowercase.
        return $name;
    }
}