<?php

namespace App\Actions\Projects;

use App\Models\Project;
use App\Models\ProjectTemplate;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\DB;

class UpdateProjectTemplate
{
    public function __construct(
        private readonly DuplicateProjectConfiguration $duplicateProjectConfiguration,
        private readonly ProjectTemplateOverrideManager $projectTemplateOverrideManager,
    ) {}

    /**
     * @param  array{name: string, copy_areas?: array<int, string>}  $attributes
     */
    public function handle(ProjectTemplate $projectTemplate, array $attributes): ProjectTemplate
    {
        $projectTemplate->loadMissing('sourceProject');

        $sourceProject = $projectTemplate->sourceProject;
        abort_if($sourceProject === null, 422, 'This template cannot be edited because the source project is missing.');

        $copyAreas = array_values(Arr::get($attributes, 'copy_areas', []));
        $normalizedCopyAreas = $this->duplicateProjectConfiguration->normalizeCopyAreas($copyAreas);
        $previousConfiguration = $this->duplicateProjectConfiguration->normalizeConfiguration(
            $projectTemplate->configuration_snapshot ?? [],
        );
        $nextConfiguration = $this->duplicateProjectConfiguration->export($sourceProject, $normalizedCopyAreas);
        $affectedAreas = collect(array_unique([...array_keys($previousConfiguration), ...array_keys($nextConfiguration)]))
            ->filter(fn (string $area): bool => ($previousConfiguration[$area] ?? null) !== ($nextConfiguration[$area] ?? null))
            ->values()
            ->all();

        DB::transaction(function () use ($projectTemplate, $attributes, $normalizedCopyAreas, $nextConfiguration, $previousConfiguration, $affectedAreas): void {
            ProjectTemplate::query()->whereKey($projectTemplate->id)->lockForUpdate()->firstOrFail();

            $projectTemplate->forceFill([
                'name' => $attributes['name'],
                'copy_areas' => $normalizedCopyAreas,
                'configuration_snapshot' => $nextConfiguration,
            ])->save();

            Project::query()
                ->where('project_template_id', $projectTemplate->id)
                ->orderBy('id')
                ->chunkById(100, function ($linkedProjects) use ($affectedAreas, $nextConfiguration, $previousConfiguration): void {
                    foreach ($linkedProjects as $linkedProject) {
                        $linkedProject = Project::query()->whereKey($linkedProject->id)->lockForUpdate()->firstOrFail();
                        $currentConfiguration = $this->duplicateProjectConfiguration->export($linkedProject, $affectedAreas);
                        $overrides = $linkedProject->template_overrides ?? [];
                        $replacementConfiguration = [];

                        foreach ($affectedAreas as $area) {
                            if (in_array($area, $overrides, true)) {
                                continue;
                            }

                            if (! array_key_exists($area, $nextConfiguration)) {
                                $this->projectTemplateOverrideManager->mark($linkedProject, $area);

                                continue;
                            }

                            if (! array_key_exists($area, $previousConfiguration)
                                && array_key_exists($area, $currentConfiguration)
                                && $currentConfiguration[$area] !== []) {
                                $this->projectTemplateOverrideManager->mark($linkedProject, $area);

                                continue;
                            }

                            $replacementConfiguration[$area] = $nextConfiguration[$area];
                        }

                        if ($replacementConfiguration !== []) {
                            $this->duplicateProjectConfiguration->apply($linkedProject, $replacementConfiguration);
                        }
                    }
                });
        });

        return $projectTemplate->fresh(['sourceProject'])->loadCount('linkedProjects');
    }
}