<?php

namespace App\Actions\Projects;

use App\Models\Project;
use App\Models\ProjectTemplate;

class ResolveProjectTemplateState
{
    public function __construct(
        private readonly DuplicateProjectConfiguration $duplicateProjectConfiguration,
    ) {}

    /**
     * @param  list<string>|null  $areas
     * @return array<string, mixed>|null
     */
    public function handle(Project $project, ?array $areas = null): ?array
    {
        $project->loadMissing('projectTemplate');

        /** @var ProjectTemplate|null $projectTemplate */
        $projectTemplate = $project->projectTemplate;

        if ($projectTemplate === null) {
            return null;
        }

        $selectedAreas = $areas === null
            ? DuplicateProjectConfiguration::copyableAreas()
            : $this->duplicateProjectConfiguration->normalizeCopyAreas($areas);

        $normalizedTemplateConfiguration = $this->duplicateProjectConfiguration->normalizeConfiguration(
            $projectTemplate->configuration_snapshot ?? [],
        );
        $templateConfiguration = collect($normalizedTemplateConfiguration)
            ->only($selectedAreas)
            ->all();
        $currentConfiguration = $this->duplicateProjectConfiguration->export($project, $selectedAreas);
        $persistedOverrides = $projectTemplate->is_published
            ? array_values(array_intersect($project->template_overrides ?? [], $selectedAreas))
            : [];

        $overriddenAreas = [];
        $inheritedAreas = [];

        foreach ($selectedAreas as $area) {
            $label = $this->labelForArea($area);
            $hasTemplateValue = array_key_exists($area, $templateConfiguration);

            if (! $hasTemplateValue) {
                continue;
            }

            if (! in_array($area, $persistedOverrides, true)) {
                $inheritedAreas[] = [
                    'label' => $label,
                    'value' => $area,
                ];

                continue;
            }

            $overriddenAreas[] = [
                'label' => $label,
                'value' => $area,
            ];
        }

        $overriddenAreaValues = array_flip(array_column($overriddenAreas, 'value'));
        $inheritedAreaValues = array_flip(array_column($inheritedAreas, 'value'));

        return [
            'effectiveConfiguration' => $currentConfiguration,
            'localConfiguration' => array_diff_key($currentConfiguration, $templateConfiguration),
            'localAreas' => collect(array_diff(array_keys($currentConfiguration), array_keys($templateConfiguration)))->map(fn (string $area): array => ['label' => $this->labelForArea($area), 'value' => $area])->values()->all(),
            'inheritedAreas' => $inheritedAreas,
            'inheritedConfiguration' => array_intersect_key($templateConfiguration, $inheritedAreaValues),
            'inheritsFromTemplate' => $projectTemplate->is_published,
            'overriddenAreas' => $overriddenAreas,
            'overriddenConfiguration' => array_intersect_key($currentConfiguration, $overriddenAreaValues),
            'resetRequirements' => $this->resetRequirements($project, $templateConfiguration, $persistedOverrides),
            'templateConfiguration' => $templateConfiguration,
            'templateId' => $projectTemplate->id,
            'templateName' => $projectTemplate->name,
            'templateSlug' => $projectTemplate->slug,
        ];
    }

    /**
     * @param  array<string, mixed>  $templateConfiguration
     * @param  list<string>  $persistedOverrides
     * @return array<string, mixed>
     */
    private function resetRequirements(Project $project, array $templateConfiguration, array $persistedOverrides): array
    {
        if (! in_array(DuplicateProjectConfiguration::COPY_TICKET_STATUSES, $persistedOverrides, true)) {
            return [];
        }

        $templateStatuses = $templateConfiguration[DuplicateProjectConfiguration::COPY_TICKET_STATUSES] ?? null;
        if (! is_array($templateStatuses)) {
            return [];
        }

        $statuses = $project->ticketStatuses()->withCount('tickets')->get();
        $templateKeys = array_column($templateStatuses, 'configuration_key');
        $replacementOptions = collect($templateStatuses)->map(
            static fn (array $status): array => ['id' => $status['configuration_key'], 'name' => $status['name']],
        )->all();
        $removedStatuses = $statuses
            ->filter(static fn ($status): bool => ! in_array($status->configuration_key, $templateKeys, true) && $status->tickets_count > 0)
            ->map(static fn ($status): array => ['id' => $status->id, 'name' => $status->name, 'ticketCount' => $status->tickets_count])
            ->values()->all();

        return $removedStatuses === [] ? [] : [
            DuplicateProjectConfiguration::COPY_TICKET_STATUSES => [
                'removedStatuses' => $removedStatuses,
                'replacementOptions' => $replacementOptions,
            ],
        ];
    }

    private function labelForArea(string $area): string
    {
        foreach (DuplicateProjectConfiguration::copyAreaOptions() as $option) {
            if ($option['value'] === $area) {
                return $option['label'];
            }
        }

        return $area;
    }
}