<?php

namespace App\Livewire\Admin\Cms;

use App\Models\Display;
use App\Models\DisplayPlaylist;
use App\Models\DisplayPlaylistItem;
use App\Models\DisplayVersion;
use Illuminate\Contracts\View\View;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\DB;
use Livewire\Component;

class DisplayList extends Component
{
    public $showModal = false;

    public $displayId = null;

    public $displayName = '';

    public $displayLocation = '';

    /** @var array<int> */
    public $selectedVersionIds = [];

    public $displayIsActive = true;

    public $displayIsTest = false;

    public $addVersionSelect = null;

    public $editingPlaylistStatus = DisplayPlaylist::STATUS_PUBLISHED;

    public ?string $draftPreviewToken = null;

    public int $previewFrameRefreshCounter = 0;

    public function openModal(?int $id = null, string $playlistStatus = DisplayPlaylist::STATUS_PUBLISHED): void
    {
        $this->editingPlaylistStatus = in_array($playlistStatus, [
            DisplayPlaylist::STATUS_PUBLISHED,
            DisplayPlaylist::STATUS_DRAFT,
        ], true) ? $playlistStatus : DisplayPlaylist::STATUS_PUBLISHED;

        if ($id) {
            $display = Display::with(['livePlaylist.modules', 'draftPlaylist.modules', 'versions'])->findOrFail($id);
            $this->displayId = $display->id;
            $this->displayName = $display->name;
            $this->displayLocation = $display->location ?? '';
            $this->selectedVersionIds = $this->selectedVersionIdsFor($display);
            $this->displayIsActive = $display->is_active;
            $this->displayIsTest = $display->is_test;

            if ($this->editingPlaylistStatus === DisplayPlaylist::STATUS_DRAFT) {
                $this->draftPreviewToken = $display->ensurePreviewToken();
                $this->previewFrameRefreshCounter++;
            }
        } else {
            $this->resetForm();
        }

        $this->showModal = true;
    }

    public function addVersion(?int $versionId = null): void
    {
        $id = $versionId ?? $this->addVersionSelect ?? $this->firstAvailableVersionId();

        if ($id && ! in_array((int) $id, $this->selectedVersionIds)) {
            $this->selectedVersionIds[] = (int) $id;
        }

        $this->addVersionSelect = null;
        $this->persistDraftPreviewIfNeeded();
    }

    private function firstAvailableVersionId(): ?int
    {
        return DisplayVersion::active()
            ->whereNotIn('id', $this->selectedVersionIds)
            ->orderBy('name')
            ->value('id');
    }

    public function removeVersion(int $index): void
    {
        array_splice($this->selectedVersionIds, $index, 1);
        $this->persistDraftPreviewIfNeeded();
    }

    public function moveVersion(int $index, string $direction): void
    {
        $newIndex = $direction === 'up' ? $index - 1 : $index + 1;

        if ($newIndex < 0 || $newIndex >= count($this->selectedVersionIds)) {
            return;
        }

        $temp = $this->selectedVersionIds[$index];
        $this->selectedVersionIds[$index] = $this->selectedVersionIds[$newIndex];
        $this->selectedVersionIds[$newIndex] = $temp;

        $this->persistDraftPreviewIfNeeded();
    }

    public function save(): void
    {
        $this->validate([
            'displayName' => 'required|string|max:255',
            'displayLocation' => 'nullable|string|max:255',
            'selectedVersionIds' => 'array',
            'selectedVersionIds.*' => 'exists:display_versions,id',
        ], [
            'displayName.required' => 'Bitte geben Sie einen Namen ein.',
        ]);

        $data = [
            'name' => $this->displayName,
            'location' => $this->displayLocation ?: null,
            'is_active' => $this->displayIsActive,
            'is_test' => $this->displayIsTest,
        ];

        if ($this->displayId) {
            $display = Display::findOrFail($this->displayId);
            $display->update($data);
            session()->flash('success', 'Display erfolgreich aktualisiert!');
        } else {
            $display = Display::create($data);
            session()->flash('success', 'Display erfolgreich erstellt!');
        }

        if ($this->editingPlaylistStatus === DisplayPlaylist::STATUS_DRAFT && $this->displayId) {
            $this->syncDraftPlaylist($display);
            $this->draftPreviewToken = $display->ensurePreviewToken();
            $this->previewFrameRefreshCounter++;
        } else {
            $this->syncPublishedPlaylist($display);
            $this->syncLegacyPivot($display, $this->selectedVersionIds);
        }

        $this->closeModal();
    }

    public function createDraft(int $displayId): void
    {
        $display = Display::with(['livePlaylist.modules', 'draftPlaylist'])->findOrFail($displayId);

        if ($display->draftPlaylist) {
            session()->flash('success', 'Für dieses Display existiert bereits ein Entwurf.');

            return;
        }

        $draft = $display->playlists()->create([
            'status' => DisplayPlaylist::STATUS_DRAFT,
            'published_at' => null,
            'published_by' => null,
        ]);

        $this->syncPlaylistItems($draft, $this->moduleIdsForPlaylist($display->livePlaylist));
        $display->ensurePreviewToken();

        session()->flash('success', 'Entwurf wurde aus dem Live-Stand angelegt.');
    }

    public function discardDraft(int $displayId): void
    {
        $display = Display::with('draftPlaylist')->findOrFail($displayId);

        if (! $display->draftPlaylist) {
            session()->flash('success', 'Für dieses Display gibt es keinen Entwurf.');

            return;
        }

        $display->draftPlaylist->delete();

        session()->flash('success', 'Entwurf wurde verworfen.');
    }

    public function publishDraft(int $displayId): void
    {
        $display = Display::with(['draftPlaylist.modules'])->findOrFail($displayId);

        if (! $display->draftPlaylist) {
            session()->flash('success', 'Für dieses Display gibt es keinen Entwurf zum Veröffentlichen.');

            return;
        }

        $publishedPlaylist = DB::transaction(function () use ($display): DisplayPlaylist {
            $display->livePlaylist()->delete();

            $display->draftPlaylist->update([
                'status' => DisplayPlaylist::STATUS_PUBLISHED,
                'published_at' => now(),
                'published_by' => Auth::id(),
            ]);

            return $display->draftPlaylist->fresh('modules');
        });

        $this->syncLegacyPivot($display, $this->moduleIdsForPlaylist($publishedPlaylist));

        session()->flash('success', 'Entwurf wurde veröffentlicht.');
    }

    /**
     * @param  array<int>  $versionIds
     */
    private function syncLegacyPivot(Display $display, array $versionIds): void
    {
        $syncData = [];
        foreach ($versionIds as $sortOrder => $versionId) {
            $syncData[$versionId] = ['sort_order' => $sortOrder];
        }

        $display->versions()->sync($syncData);
    }

    private function syncPublishedPlaylist(Display $display): void
    {
        $playlist = $display->playlists()->firstOrCreate(
            ['status' => DisplayPlaylist::STATUS_PUBLISHED],
            ['published_at' => now(), 'published_by' => Auth::id()]
        );

        $playlist->update([
            'published_at' => now(),
            'published_by' => Auth::id(),
        ]);

        $this->syncPlaylistItems($playlist, $this->selectedVersionIds);
    }

    private function syncDraftPlaylist(Display $display): void
    {
        $playlist = $display->playlists()->firstOrCreate(
            ['status' => DisplayPlaylist::STATUS_DRAFT],
            ['published_at' => null, 'published_by' => null]
        );

        $this->syncPlaylistItems($playlist, $this->selectedVersionIds);
    }

    private function persistDraftPreviewIfNeeded(): void
    {
        if ($this->editingPlaylistStatus !== DisplayPlaylist::STATUS_DRAFT || ! $this->displayId) {
            return;
        }

        $display = Display::findOrFail($this->displayId);

        $this->syncDraftPlaylist($display);
        $this->draftPreviewToken = $display->ensurePreviewToken();
        $this->previewFrameRefreshCounter++;
    }

    /**
     * @param  array<int>  $versionIds
     */
    private function syncPlaylistItems(DisplayPlaylist $playlist, array $versionIds): void
    {
        $playlist->items()->delete();

        foreach (array_values($versionIds) as $sortOrder => $versionId) {
            DisplayPlaylistItem::query()->create([
                'display_playlist_id' => $playlist->id,
                'display_version_id' => $versionId,
                'sort_order' => $sortOrder,
            ]);
        }
    }

    /**
     * @return array<int>
     */
    private function moduleIdsForPlaylist(?DisplayPlaylist $playlist): array
    {
        if (! $playlist) {
            return [];
        }

        $playlist->loadMissing('modules');

        return $playlist->modules->pluck('id')->all();
    }

    /**
     * @return array<int>
     */
    private function selectedVersionIdsFor(Display $display): array
    {
        if ($this->editingPlaylistStatus === DisplayPlaylist::STATUS_DRAFT) {
            return $this->moduleIdsForPlaylist($display->draftPlaylist);
        }

        return $this->moduleIdsForPlaylist($display->livePlaylist)
            ?: $display->versions->pluck('id')->all();
    }

    public function deleteDisplay(int $id): void
    {
        $display = Display::findOrFail($id);
        $name = $display->name;
        $display->delete();

        session()->flash('success', 'Display "'.$name.'" wurde gelöscht!');
    }

    public function toggleActive(int $id): void
    {
        $display = Display::findOrFail($id);
        $display->update(['is_active' => ! $display->is_active]);
    }

    public function closeModal(): void
    {
        $this->showModal = false;
        $this->resetForm();
    }

    public function resetForm(): void
    {
        $this->displayId = null;
        $this->displayName = '';
        $this->displayLocation = '';
        $this->selectedVersionIds = [];
        $this->displayIsActive = true;
        $this->displayIsTest = false;
        $this->addVersionSelect = null;
        $this->editingPlaylistStatus = DisplayPlaylist::STATUS_PUBLISHED;
        $this->draftPreviewToken = null;
        $this->previewFrameRefreshCounter = 0;
    }

    public function render(): View
    {
        $displays = Display::with(['livePlaylist.modules', 'draftPlaylist.modules'])
            ->orderByDesc('is_test')
            ->orderBy('name')
            ->get();

        $versions = DisplayVersion::active()
            ->orderBy('name')
            ->get();

        return view('livewire.admin.cms.display-list', [
            'displays' => $displays,
            'versions' => $versions,
        ]);
    }
}