<?php

namespace App\Http\Controllers;

use App\Http\Requests\DockerImageBuildRequest;
use App\Jobs\RunDockerImageBuild;
use App\Models\DockerImageBuild;
use Carbon\CarbonInterface;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Str;
use Inertia\Inertia;
use Inertia\Response;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;

class DockerImageBuilderController extends Controller
{
    /**
     * Show the Docker image builder page.
     */
    public function index(Request $request): Response
    {
        return Inertia::render('docker/ImageBuilder', [
            'build' => $this->detailedPayload($this->resolveActiveBuild($request)),
        ]);
    }

    /**
     * Show the Docker image build history page.
     */
    public function history(Request $request): Response
    {
        return Inertia::render('docker/BuildHistory', [
            'builds' => $request->user()
                ->dockerImageBuilds()
                ->latest('id')
                ->limit(25)
                ->get()
                ->map(fn (DockerImageBuild $dockerImageBuild): array => $this->summaryPayload($dockerImageBuild))
                ->all(),
        ]);
    }

    /**
     * Return the latest persisted status for a specific build.
     */
    public function show(Request $request, DockerImageBuild $dockerImageBuild): JsonResponse
    {
        return response()->json([
            'build' => $this->detailedPayload(
                $this->ownedBuild($request, $dockerImageBuild)->fresh(),
            ),
        ]);
    }

    /**
     * Queue a Docker image build from the submitted Dockerfile contents.
     */
    public function store(DockerImageBuildRequest $request): RedirectResponse
    {
        $validated = $request->validated();
        $environment = $this->normalizeEnvironment($validated['environment'] ?? []);

        $dockerImageBuild = DB::transaction(function () use ($request, $validated, $environment): DockerImageBuild {
            $dockerImageBuild = $request->user()->dockerImageBuilds()->create([
                'image_name' => $validated['image_name'],
                'image_tag' => $validated['image_tag'],
                'dockerfile_content' => $validated['dockerfile'],
                'environment' => $environment,
                'status' => DockerImageBuild::STATUS_QUEUED,
                'queued_at' => now(),
            ]);

            RunDockerImageBuild::dispatch($dockerImageBuild->id)->afterCommit();

            return $dockerImageBuild;
        });

        Inertia::flash('toast', [
            'type' => 'success',
            'message' => __('Docker build queued. Logs will update automatically while the queue worker runs.'),
        ]);

        return to_route('docker-builder.index', [
            'build' => $dockerImageBuild->id,
        ]);
    }

    /**
     * Resolve the currently selected build for the authenticated user.
     *
     * @throws NotFoundHttpException
     */
    protected function resolveActiveBuild(Request $request): ?DockerImageBuild
    {
        $buildId = $request->integer('build');

        if ($buildId > 0) {
            return $request->user()
                ->dockerImageBuilds()
                ->findOrFail($buildId);
        }

        return $request->user()
            ->dockerImageBuilds()
            ->latest('id')
            ->first();
    }

    /**
     * Ensure the given build belongs to the authenticated user.
     */
    protected function ownedBuild(Request $request, DockerImageBuild $dockerImageBuild): DockerImageBuild
    {
        abort_unless(
            $dockerImageBuild->user_id === $request->user()->getAuthIdentifier(),
            404,
        );

        return $dockerImageBuild;
    }

    /**
     * Normalize environment rows before they are saved.
     *
     * @param  array<int, array{key?: string, value?: string}>  $environment
     * @return array<int, array{key: string, value: string}>
     */
    protected function normalizeEnvironment(array $environment): array
    {
        return collect($environment)
            ->map(fn (array $variable): array => [
                'key' => trim($variable['key'] ?? ''),
                'value' => $variable['value'] ?? '',
            ])
            ->filter(fn (array $variable): bool => $variable['key'] !== '' || $variable['value'] !== '')
            ->values()
            ->all();
    }

    /**
     * Transform a build into the detailed payload used by the builder page.
     */
    protected function detailedPayload(?DockerImageBuild $dockerImageBuild): ?array
    {
        if ($dockerImageBuild === null) {
            return null;
        }

        return [
            'id' => $dockerImageBuild->id,
            'image' => $dockerImageBuild->image(),
            'image_name' => $dockerImageBuild->image_name,
            'image_tag' => $dockerImageBuild->image_tag,
            'dockerfile_content' => $dockerImageBuild->dockerfile_content,
            'environment' => $dockerImageBuild->environment ?? [],
            'environment_count' => count($dockerImageBuild->environment ?? []),
            'status' => $dockerImageBuild->status,
            'status_label' => Str::headline($dockerImageBuild->status),
            'successful' => $dockerImageBuild->successful,
            'exit_code' => $dockerImageBuild->exit_code,
            'build_output' => $dockerImageBuild->build_output ?? '',
            'queued_at' => $dockerImageBuild->queued_at?->toIso8601String(),
            'queued_at_human' => $dockerImageBuild->queued_at?->diffForHumans(),
            'started_at' => $dockerImageBuild->started_at?->toIso8601String(),
            'started_at_human' => $dockerImageBuild->started_at?->diffForHumans(),
            'finished_at' => $dockerImageBuild->finished_at?->toIso8601String(),
            'finished_at_human' => $dockerImageBuild->finished_at?->diffForHumans(),
            'duration' => $this->durationFor(
                $dockerImageBuild->started_at,
                $dockerImageBuild->finished_at,
            ),
        ];
    }

    /**
     * Transform a build into the summary payload used by the history page.
     */
    protected function summaryPayload(DockerImageBuild $dockerImageBuild): array
    {
        $output = trim((string) $dockerImageBuild->build_output);
        $dockerfilePreview = collect(preg_split('/\R/', trim($dockerImageBuild->dockerfile_content)) ?: [])
            ->take(4)
            ->implode(PHP_EOL);

        return [
            'id' => $dockerImageBuild->id,
            'image' => $dockerImageBuild->image(),
            'status' => $dockerImageBuild->status,
            'status_label' => Str::headline($dockerImageBuild->status),
            'successful' => $dockerImageBuild->successful,
            'exit_code' => $dockerImageBuild->exit_code,
            'environment_count' => count($dockerImageBuild->environment ?? []),
            'queued_at_human' => $dockerImageBuild->queued_at?->diffForHumans(),
            'duration' => $this->durationFor(
                $dockerImageBuild->started_at,
                $dockerImageBuild->finished_at,
            ),
            'dockerfile_preview' => $dockerfilePreview !== ''
                ? $dockerfilePreview
                : 'Dockerfile was empty.',
            'output_preview' => $output !== ''
                ? Str::limit($output, 220)
                : null,
        ];
    }

    /**
     * Render a short duration string for build timing metadata.
     */
    protected function durationFor(?CarbonInterface $startedAt, ?CarbonInterface $finishedAt): ?string
    {
        if ($startedAt === null) {
            return null;
        }

        $totalSeconds = $startedAt->diffInSeconds($finishedAt ?? now());
        $hours = intdiv($totalSeconds, 3600);
        $minutes = intdiv($totalSeconds % 3600, 60);
        $seconds = $totalSeconds % 60;

        $parts = collect([
            $hours > 0 ? "{$hours}h" : null,
            $minutes > 0 ? "{$minutes}m" : null,
            $hours === 0 ? "{$seconds}s" : null,
        ])->filter()->take(2);

        return $parts->isNotEmpty()
            ? $parts->implode(' ')
            : '0s';
    }
}