<?php

namespace App\Http\Controllers;

use App\Jobs\BatchImportFromGutendex;
use App\Jobs\GenerateSummary;
use App\Models\Book;
use App\Models\Summary;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;

class GutendexController extends Controller
{
    /**
     * Display the Gutendex admin dashboard.
     */
    public function dashboard()
    {
        $stats = $this->getStatistics();
        $recentImports = $this->getRecentImports();
        $recentFailures = $this->getRecentFailures();

        return view('admin.gutendex.dashboard', compact('stats', 'recentImports', 'recentFailures'));
    }

    /**
     * Display processing status.
     */
    public function status()
    {
        $stats = $this->getStatistics();
        $processing = Summary::processing()->with('book')->get();
        $pending = Summary::pending()->with('book')->limit(20)->get();
        $failed = Summary::failed()->with('book')->limit(20)->get();

        $queueStats = $this->getQueueStatistics();

        return view('admin.gutendex.status', compact('stats', 'processing', 'pending', 'failed', 'queueStats'));
    }

    /**
     * Trigger a new import.
     */
    public function import(Request $request)
    {
        $request->validate([
            'language' => 'required|string|max:10',
            'limit' => 'required|integer|min:1|max:500',
            'page' => 'required|integer|min:1',
            'generate_summaries' => 'boolean',
        ]);

        $language = $request->input('language', 'en');
        $limit = (int) $request->input('limit', 50);
        $page = (int) $request->input('page', 1);
        $generateSummaries = $request->boolean('generate_summaries', true);

        $filters = [
            'languages' => $language,
            'copyright' => 'false',
        ];

        // Calculate end page
        $booksPerPage = 32;
        $endPage = $page + (int) ceil($limit / $booksPerPage) - 1;

        // Dispatch batch import job
        BatchImportFromGutendex::dispatch(
            $filters,
            $page,
            $endPage,
            $limit,
            $generateSummaries
        );

        return response()->json([
            'success' => true,
            'message' => "Import job dispatched for up to {$limit} books",
            'details' => [
                'language' => $language,
                'limit' => $limit,
                'start_page' => $page,
                'end_page' => $endPage,
                'generate_summaries' => $generateSummaries,
            ],
        ]);
    }

    /**
     * Retry a failed book summary.
     */
    public function retry(Book $book)
    {
        if (!$book->summary) {
            return response()->json([
                'success' => false,
                'message' => 'Book does not have a summary record',
            ], 404);
        }

        if ($book->summary->processing_status === 'completed') {
            return response()->json([
                'success' => false,
                'message' => 'Summary is already completed',
            ], 400);
        }

        // Dispatch job to regenerate summary
        GenerateSummary::dispatch($book->id);

        return response()->json([
            'success' => true,
            'message' => "Retry job dispatched for: {$book->title}",
            'book_id' => $book->id,
        ]);
    }

    /**
     * Get overall statistics.
     */
    protected function getStatistics(): array
    {
        $totalBooks = Book::count();
        $gutendexBooks = Book::gutendex()->count();
        $booksWithText = Book::whereNotNull('full_text_url')->count();
        $booksWithoutSummaries = Book::gutendex()
            ->whereNotNull('full_text_url')
            ->doesntHave('summary')
            ->count();

        $totalSummaries = Summary::count();
        $completedSummaries = Summary::completed()->count();
        $pendingSummaries = Summary::pending()->count();
        $processingSummaries = Summary::processing()->count();
        $failedSummaries = Summary::failed()->count();

        $completionRate = $totalSummaries > 0
            ? round(($completedSummaries / $totalSummaries) * 100, 2)
            : 0;

        return [
            'total_books' => $totalBooks,
            'gutendex_books' => $gutendexBooks,
            'books_with_text' => $booksWithText,
            'books_without_summaries' => $booksWithoutSummaries,
            'total_summaries' => $totalSummaries,
            'completed_summaries' => $completedSummaries,
            'pending_summaries' => $pendingSummaries,
            'processing_summaries' => $processingSummaries,
            'failed_summaries' => $failedSummaries,
            'completion_rate' => $completionRate,
        ];
    }

    /**
     * Get recent imports.
     */
    protected function getRecentImports(int $limit = 10): array
    {
        return Book::gutendex()
            ->with('category')
            ->orderByDesc('created_at')
            ->limit($limit)
            ->get()
            ->toArray();
    }

    /**
     * Get recent failures.
     */
    protected function getRecentFailures(int $limit = 10): array
    {
        return Summary::failed()
            ->with('book')
            ->orderByDesc('updated_at')
            ->limit($limit)
            ->get()
            ->toArray();
    }

    /**
     * Get queue statistics.
     */
    protected function getQueueStatistics(): array
    {
        try {
            $pendingJobs = DB::table('jobs')->count();
            $failedJobs = DB::table('failed_jobs')->count();

            return [
                'pending_jobs' => $pendingJobs,
                'failed_jobs' => $failedJobs,
            ];
        } catch (\Exception $e) {
            return [
                'pending_jobs' => 0,
                'failed_jobs' => 0,
            ];
        }
    }
}