<?php

namespace App\Http\Controllers;

use App\Exceptions\ListingAlreadyMappedException;
use App\Models\Project;
use App\Models\ProjectEvent;
use App\Models\ProjectListingLink;
use App\Services\Etsy;
use Illuminate\Database\QueryException;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Carbon;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\Rule;
use Throwable;

class ProjectListingLinkController extends Controller
{
    public function store(Request $request, Project $project, Etsy $etsy): RedirectResponse
    {
        abort_unless($request->user()->can('manageListings', $project), 403);
        $data = $request->validate([
            'listing_id' => ['required', 'integer', 'min:1'],
            // Per-variant mapping is not implemented or verified against Etsy yet,
            // so only the "all variations" mapping is accepted — anything else
            // would be an unverified ownership claim over a specific variant.
            'variation_key' => ['sometimes', Rule::in([ProjectListingLink::ALL_VARIATIONS])],
        ]);
        $variationKey = $data['variation_key'] ?? ProjectListingLink::ALL_VARIATIONS;

        try {
            $connection = $etsy->connectedShop();
            $listing = $etsy->getListing($connection, (int) $data['listing_id']);
        } catch (Throwable $exception) {
            return back()->withErrors(['listing_id' => $exception->getMessage()]);
        }

        // Re-checked against a fresh (non-cached) fetch above, so this also catches
        // a listing that was active/draft when the dropdown was rendered but has
        // since gone inactive, expired or sold out.
        if (! in_array($listing['state'] ?? null, ['active', 'draft'], true)) {
            return back()->withErrors(['listing_id' => 'That listing is no longer Live or Draft and cannot be linked.']);
        }

        try {
            $link = DB::transaction(function () use ($request, $project, $connection, $data, $listing, $variationKey): ProjectListingLink {
                $locked = Project::query()->whereKey($project->id)->lockForUpdate()->firstOrFail();

                $existing = ProjectListingLink::query()
                    ->where('shop_id', $connection->shop_id)
                    ->where('listing_id', $data['listing_id'])
                    ->where('variation_key', $variationKey)
                    ->lockForUpdate()
                    ->first();

                if ($existing && $existing->project_id !== $locked->id) {
                    throw new ListingAlreadyMappedException('That listing is already mapped to a different project.');
                }

                $wasReleased = $existing !== null && $existing->live_release_id !== null;

                $link = ProjectListingLink::updateOrCreate(
                    ['shop_id' => $connection->shop_id, 'listing_id' => $data['listing_id'], 'variation_key' => $variationKey],
                    [
                        'project_id' => $locked->id,
                        'title_snapshot' => $listing['title'] ?? null,
                        'state_snapshot' => $listing['state'] ?? null,
                        'remote_updated_at' => isset($listing['last_modified_timestamp'])
                            ? Carbon::createFromTimestamp((int) $listing['last_modified_timestamp']) : null,
                        'synced_at' => now(),
                        'created_by' => $request->user()->id,
                        'detached_at' => null,
                    ],
                );

                // A brand-new (or re-synced-but-unreleased) mapping on a project already
                // marked Live would otherwise leave Live claiming full release coverage
                // it no longer has. Drop back to Design rather than silently keep Live.
                if ($locked->stage === 'live' && ! $wasReleased) {
                    $locked->update(['stage' => 'design']);
                    ProjectEvent::record($locked->id, 'stage_changed', $request->user()->id, metadata: [
                        'from' => 'live', 'to' => 'design', 'reason' => 'unready_listing_mapping_attached',
                    ]);
                }

                ProjectEvent::record(
                    $locked->id,
                    $existing ? 'listing_resynced' : 'listing_attached',
                    $request->user()->id,
                    ProjectListingLink::class,
                    $link->id,
                    ['listing_id' => (int) $data['listing_id'], 'variation_key' => $variationKey],
                );

                return $link;
            });
        } catch (ListingAlreadyMappedException $exception) {
            return back()->withErrors(['listing_id' => $exception->getMessage()]);
        } catch (QueryException $exception) {
            if (! $this->isUniqueConstraintViolation($exception)) {
                throw $exception;
            }

            return back()->withErrors(['listing_id' => 'That listing was just claimed by another request. Please try again.']);
        }

        return redirect()->route('projects.show', $project)->with('status', 'Listing linked.');
    }

    public function destroy(Request $request, Project $project, ProjectListingLink $listingLink): RedirectResponse
    {
        abort_unless($listingLink->project_id === $project->id, 404);
        abort_unless($request->user()->can('manageListings', $project), 403);

        DB::transaction(function () use ($request, $project, $listingLink): void {
            Project::query()->whereKey($project->id)->lockForUpdate()->firstOrFail();
            $listingLink->update(['detached_at' => now()]);
            ProjectEvent::record($project->id, 'listing_detached', $request->user()->id, ProjectListingLink::class, $listingLink->id);
        });

        return redirect()->route('projects.show', $project)->with('status', 'Listing detached.');
    }

    private function isUniqueConstraintViolation(QueryException $exception): bool
    {
        return in_array($exception->getCode(), ['23000', '23505'], true);
    }
}