<?php

namespace Modules\Content\Http\Controllers;

use App\Http\Controllers\Controller;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\Rule;
use Illuminate\View\View;
use Modules\Content\Models\ContentDocument;
use Modules\Content\Models\PageContent;
use Modules\Pages\Models\Page;

final class PageCompositionController extends Controller
{
    private const REGIONS = ['header', 'body', 'footer'];

    public function edit(string $pageKey): View
    {
        $placements = PageContent::query()
            ->with('document.type')
            ->where('page_key', $pageKey)
            ->orderByRaw("CASE region WHEN 'header' THEN 1 WHEN 'body' THEN 2 ELSE 3 END")
            ->orderBy('sort_order')
            ->get()
            ->groupBy('region');

        $documents = ContentDocument::query()
            ->with('type')
            ->withCount('placements')
            ->orderBy('title')
            ->get();

        return view('content::admin.composition', compact('pageKey', 'placements', 'documents'));
    }


    public function editPage(Page $page): View
    {
        $placements = PageContent::query()
            ->with('document.type')
            ->where(fn ($query) => $query->where('page_id', $page->id)->orWhere('page_key', $page->slug))
            ->orderByRaw("CASE region WHEN 'header' THEN 1 WHEN 'body' THEN 2 ELSE 3 END")
            ->orderBy('sort_order')
            ->get();

        PageContent::query()
            ->whereNull('page_id')
            ->where('page_key', $page->slug)
            ->update(['page_id' => $page->id]);

        $documents = ContentDocument::query()
            ->with('type')
            ->withCount('placements')
            ->orderBy('title')
            ->get();

        return view('content::admin.composition', [
            'pageKey' => $page->slug,
            'page' => $page,
            'placements' => $placements->groupBy('region'),
            'documents' => $documents,
        ]);
    }

    public function preview(string $pageKey): View
    {
        abort_unless($pageKey === 'home', 404, 'This phase currently provides the Saasland homepage preview.');

        return view('stylist-theme-saasland::home', ['pageKey' => $pageKey]);
    }

    public function store(Request $request, string $pageKey): RedirectResponse
    {
        $validated = $request->validate([
            'content_document_id' => ['required', 'integer', Rule::exists('content_documents', 'id')->whereNull('deleted_at')],
            'region' => ['required', Rule::in(self::REGIONS)],
        ]);

        $document = ContentDocument::query()->with('type')->findOrFail($validated['content_document_id']);
        abort_unless(in_array($validated['region'], $document->type?->allowed_regions ?? [], true), 422, 'This content type is not allowed in the selected region.');

        $page = Page::query()->where('slug', $pageKey)->first();
        $nextOrder = ((int) PageContent::query()->where(fn ($query) => $query->where('page_key', $pageKey)->when($page, fn ($q) => $q->orWhere('page_id', $page->id)))->where('region', $validated['region'])->max('sort_order')) + 10;
        PageContent::query()->create([
            'page_id' => $page?->id,
            'page_key' => $pageKey,
            'content_document_id' => $document->id,
            'region' => $validated['region'],
            'sort_order' => $nextOrder,
            'is_enabled' => true,
        ]);

        return back()->with('status', 'Document added to the '.$validated['region'].' region.');
    }

    public function update(Request $request, PageContent $placement): RedirectResponse
    {
        $validated = $request->validate([
            'is_enabled' => ['nullable', 'boolean'],
            'starts_at' => ['nullable', 'date'],
            'ends_at' => ['nullable', 'date', 'after:starts_at'],
        ]);

        $placement->update([
            'is_enabled' => $request->boolean('is_enabled'),
            'starts_at' => $validated['starts_at'] ?? null,
            'ends_at' => $validated['ends_at'] ?? null,
        ]);

        return back()->with('status', 'Page placement updated.');
    }

    public function destroy(PageContent $placement): RedirectResponse
    {
        $placement->delete();
        $this->normaliseRegion($placement->page_key, $placement->region);

        return back()->with('status', 'Document removed from this page. The reusable document was not deleted.');
    }

    public function duplicate(Request $request, PageContent $placement): RedirectResponse
    {
        $source = $placement->document()->firstOrFail();
        $copy = DB::transaction(function () use ($request, $placement, $source): ContentDocument {
            $copy = $source->replicate(['slug', 'status', 'published_at', 'created_by', 'updated_by']);
            $copy->title = $source->title.' copy';
            $copy->slug = $source->slug.'-copy-'.strtolower(str()->random(6));
            $copy->status = 'draft';
            $copy->published_at = null;
            $copy->created_by = $request->user()?->id;
            $copy->updated_by = $request->user()?->id;
            $copy->save();

            PageContent::query()->create([
                'page_id' => $placement->page_id,
                'page_key' => $placement->page_key,
                'content_document_id' => $copy->id,
                'region' => $placement->region,
                'sort_order' => $placement->sort_order + 5,
                'is_enabled' => false,
                'visibility_rules' => $placement->visibility_rules,
                'presentation' => $placement->presentation,
            ]);

            return $copy;
        });

        $this->normaliseRegion($placement->page_key, $placement->region);

        return redirect()->route('content.documents.edit', $copy)->with('status', 'Page-specific draft copy created and added after the original.');
    }

    public function reorder(Request $request, string $pageKey): JsonResponse|RedirectResponse
    {
        $validated = $request->validate([
            'region' => ['required', Rule::in(self::REGIONS)],
            'placements' => ['required', 'array'],
            'placements.*' => ['required', 'integer'],
        ]);

        $ids = array_values(array_unique(array_map('intval', $validated['placements'])));
        $owned = PageContent::query()->where('page_key', $pageKey)->where('region', $validated['region'])->whereIn('id', $ids)->pluck('id')->all();
        abort_unless(count($owned) === count($ids), 422, 'One or more placements do not belong to this page region.');

        DB::transaction(function () use ($ids): void {
            PageContent::query()->whereIn('id', $ids)->increment('sort_order', 100000);
            foreach ($ids as $index => $id) {
                PageContent::query()->whereKey($id)->update(['sort_order' => ($index + 1) * 10]);
            }
        });

        return $request->expectsJson()
            ? response()->json(['message' => 'Order saved.'])
            : back()->with('status', 'Page order updated.');
    }

    private function normaliseRegion(?string $pageKey, string $region): void
    {
        $ids = PageContent::query()->where('page_key', $pageKey)->where('region', $region)->orderBy('sort_order')->pluck('id');
        DB::transaction(function () use ($ids): void {
            foreach ($ids as $index => $id) {
                PageContent::query()->whereKey($id)->update(['sort_order' => ($index + 1) * 10]);
            }
        });
    }
}