<?php

namespace Modules\AssetExchange\Services;

use App\Business;
use App\User;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;
use Modules\AssetExchange\Models\Listing;
use Modules\AssetExchange\Models\PipelineEvent;
use Modules\AssetExchange\Models\PipelineLink;

class PipelineService
{
    public const STAGES = [
        'draft_listing',
        'submitted',
        'under_review',
        'appraisal_in_progress',
        'appraised',
        'deal_negotiation',
        'company_buy',
        'broker_sale',
        'renovation_contract',
        'acquired',
        'in_renovation',
        'ready_for_sale',
        'sold',
        'rejected',
    ];

    public const STAGE_LABELS = [
        'draft_listing' => 'پیش‌نویس عرضه',
        'submitted' => 'ارسال‌شده',
        'under_review' => 'در حال بررسی',
        'appraisal_in_progress' => 'کارشناسی در جریان',
        'appraised' => 'کارشناسی‌شده',
        'deal_negotiation' => 'مذاکره معامله',
        'company_buy' => 'خرید شرکت',
        'broker_sale' => 'واسطه‌گری',
        'renovation_contract' => 'قرارداد نوسازی',
        'acquired' => 'تحصیل‌شده',
        'in_renovation' => 'در حال نوسازی',
        'ready_for_sale' => 'آماده فروش',
        'sold' => 'فروخته‌شده',
        'rejected' => 'رد‌شده',
    ];

    public function logEvent(
        Business $business,
        string $entityType,
        int $entityId,
        string $eventType,
        ?string $description = null,
        ?User $user = null,
        array $metadata = []
    ): ?PipelineEvent {
        if (! Schema::hasTable('aex_pipeline_events')) {
            return null;
        }

        return PipelineEvent::create([
            'business_id' => $business->id,
            'entity_type' => $entityType,
            'entity_id' => $entityId,
            'event_type' => $eventType,
            'description' => $description,
            'user_id' => $user?->id,
            'metadata' => $metadata ?: null,
        ]);
    }

    public function getPipelineForListing(Listing $listing): array
    {
        $listing->loadMissing(['pipelineLinks', 'deals']);

        $events = collect();
        if (Schema::hasTable('aex_pipeline_events')) {
            $events = PipelineEvent::where('business_id', $listing->business_id)
                ->where(function ($q) use ($listing) {
                    $q->where(function ($inner) use ($listing) {
                        $inner->where('entity_type', Listing::class)
                            ->where('entity_id', $listing->id);
                    });

                    if ($listing->appraisals()->exists()) {
                        $appraisalIds = $listing->appraisals()->pluck('id');
                        $inner = \Modules\AssetExchange\Models\Appraisal::class;
                        $q->orWhere(function ($sub) use ($inner, $appraisalIds) {
                            $sub->where('entity_type', $inner)
                                ->whereIn('entity_id', $appraisalIds);
                        });
                    }

                    if ($listing->deals()->exists()) {
                        $dealIds = $listing->deals()->pluck('id');
                        $inner = \Modules\AssetExchange\Models\Deal::class;
                        $q->orWhere(function ($sub) use ($inner, $dealIds) {
                            $sub->where('entity_type', $inner)
                                ->whereIn('entity_id', $dealIds);
                        });
                    }
                })
                ->orderBy('created_at')
                ->get();
        }

        $links = $listing->pipelineLinks->sortBy('created_at');

        return [
            'listing_id' => $listing->id,
            'current_stage' => $this->resolveCurrentStage($listing),
            'stages' => $this->buildStageTimeline($listing, $links, $events),
            'events' => $events,
            'links' => $links,
        ];
    }

    public function advanceStage(
        Business $business,
        Listing $listing,
        string $stage,
        ?int $dealId = null,
        ?string $linkedType = null,
        ?int $linkedId = null,
        ?User $user = null
    ): PipelineLink {
        if (! in_array($stage, self::STAGES, true)) {
            throw new \InvalidArgumentException('مرحله خط لوله نامعتبر است: '.$stage);
        }

        return DB::transaction(function () use ($business, $listing, $stage, $dealId, $linkedType, $linkedId, $user) {
            $previous = PipelineLink::where('business_id', $business->id)
                ->where('listing_id', $listing->id)
                ->whereNull('completed_at')
                ->latest('id')
                ->first();

            if ($previous) {
                $previous->update(['completed_at' => now()]);
            }

            $link = PipelineLink::create([
                'business_id' => $business->id,
                'listing_id' => $listing->id,
                'deal_id' => $dealId,
                'stage' => $stage,
                'linked_type' => $linkedType,
                'linked_id' => $linkedId,
            ]);

            $this->logEvent(
                $business,
                Listing::class,
                $listing->id,
                'stage_advanced',
                'انتقال به مرحله: '.(self::STAGE_LABELS[$stage] ?? $stage),
                $user,
                ['stage' => $stage, 'pipeline_link_id' => $link->id]
            );

            return $link;
        });
    }

    protected function resolveCurrentStage(Listing $listing): string
    {
        $latest = $listing->pipelineLinks()
            ->orderByDesc('id')
            ->value('stage');

        if ($latest) {
            return $latest;
        }

        return match ($listing->status) {
            'draft' => 'draft_listing',
            'submitted' => 'submitted',
            'under_review' => 'under_review',
            'appraised' => 'appraised',
            'in_deal' => 'deal_negotiation',
            'sold' => 'sold',
            'rejected' => 'rejected',
            default => 'draft_listing',
        };
    }

    protected function buildStageTimeline(Listing $listing, Collection $links, Collection $events): array
    {
        $completedStages = $links->pluck('stage')->unique()->values()->all();

        return collect(self::STAGES)->map(function ($stage) use ($completedStages, $links) {
            $link = $links->firstWhere('stage', $stage);

            return [
                'stage' => $stage,
                'label' => self::STAGE_LABELS[$stage] ?? $stage,
                'completed' => in_array($stage, $completedStages, true),
                'completed_at' => $link?->completed_at,
                'linked_type' => $link?->linked_type,
                'linked_id' => $link?->linked_id,
            ];
        })->values()->all();
    }
}