<?php

namespace App\Services\Demo;

use App\Models\Tenants\Tenant;
use App\Services\Service;
use Illuminate\Support\Facades\DB;

/**
 * 데모 테넌트 분석 서비스
 *
 * - 전환율 분석 (데모 → 정식)
 * - 활동 모니터링 (데모 테넌트별 사용량)
 * - 파트너별 영업 성과 분석
 *
 * 기존 코드 영향 없음: 데모 전용 분석 로직만 포함
 *
 * @see docs/features/sales/demo-tenant-policy.md
 */
class DemoAnalyticsService extends Service
{
    /**
     * 전환율 분석 (전체 또는 파트너별)
     */
    public function conversionFunnel(array $params = []): array
    {
        $partnerId = $params['partner_id'] ?? null;
        $period = $params['period'] ?? 'all'; // all, monthly, quarterly

        $baseQuery = Tenant::withoutGlobalScopes();

        if ($partnerId) {
            $baseQuery->where('demo_source_partner_id', $partnerId);
        }

        // Tier 3 체험 테넌트 전체 (현재 + 전환 완료)
        $totalTrials = (clone $baseQuery)
            ->where(function ($q) {
                $q->where('tenant_type', Tenant::TYPE_DEMO_TRIAL)
                    ->orWhere(function ($q2) {
                        // 정식 전환된 테넌트 (demo_source_partner_id가 있으면서 STD)
                        $q2->where('tenant_type', Tenant::TYPE_STD)
                            ->whereNotNull('demo_source_partner_id');
                    });
            })
            ->count();

        // 활성 체험 중
        $activeTrials = (clone $baseQuery)
            ->where('tenant_type', Tenant::TYPE_DEMO_TRIAL)
            ->where(function ($q) {
                $q->whereNull('demo_expires_at')
                    ->orWhere('demo_expires_at', '>', now());
            })
            ->count();

        // 만료된 체험
        $expiredTrials = (clone $baseQuery)
            ->where('tenant_type', Tenant::TYPE_DEMO_TRIAL)
            ->whereNotNull('demo_expires_at')
            ->where('demo_expires_at', '<', now())
            ->count();

        // 정식 전환 완료
        $converted = (clone $baseQuery)
            ->where('tenant_type', Tenant::TYPE_STD)
            ->whereNotNull('demo_source_partner_id')
            ->count();

        $conversionRate = $totalTrials > 0
            ? round($converted / $totalTrials * 100, 1) : 0;

        // 평균 전환 기간 (정식 전환된 건의 생성일 → 전환일 차이)
        $avgConversionDays = Tenant::withoutGlobalScopes()
            ->where('tenant_type', Tenant::TYPE_STD)
            ->whereNotNull('demo_source_partner_id')
            ->when($partnerId, fn ($q) => $q->where('demo_source_partner_id', $partnerId))
            ->selectRaw('AVG(DATEDIFF(updated_at, created_at)) as avg_days')
            ->value('avg_days');

        return [
            'funnel' => [
                'total_trials' => $totalTrials,
                'active_trials' => $activeTrials,
                'expired_trials' => $expiredTrials,
                'converted' => $converted,
            ],
            'conversion_rate' => $conversionRate,
            'avg_conversion_days' => $avgConversionDays ? (int) round($avgConversionDays) : null,
        ];
    }

    /**
     * 파트너별 성과 분석
     */
    public function partnerPerformance(array $params = []): array
    {
        $partners = DB::table('sales_partners as sp')
            ->leftJoin('users as u', 'sp.user_id', '=', 'u.id')
            ->where('sp.status', 'active')
            ->select('sp.id', 'sp.partner_code', 'u.name as partner_name')
            ->get();

        $results = [];

        foreach ($partners as $partner) {
            $demos = Tenant::withoutGlobalScopes()
                ->where('demo_source_partner_id', $partner->id)
                ->get();

            $trials = $demos->where('tenant_type', Tenant::TYPE_DEMO_TRIAL);
            $convertedCount = Tenant::withoutGlobalScopes()
                ->where('tenant_type', Tenant::TYPE_STD)
                ->where('demo_source_partner_id', $partner->id)
                ->count();

            $totalTrials = $trials->count() + $convertedCount;
            $conversionRate = $totalTrials > 0
                ? round($convertedCount / $totalTrials * 100, 1) : 0;

            $results[] = [
                'partner_id' => $partner->id,
                'partner_code' => $partner->partner_code,
                'partner_name' => $partner->partner_name,
                'demo_count' => $demos->count(),
                'active_trials' => $trials->filter(fn ($t) => ! $t->isDemoExpired())->count(),
                'expired_trials' => $trials->filter(fn ($t) => $t->isDemoExpired())->count(),
                'converted' => $convertedCount,
                'conversion_rate' => $conversionRate,
            ];
        }

        // 전환율 내림차순 정렬
        usort($results, fn ($a, $b) => $b['conversion_rate'] <=> $a['conversion_rate']);

        return $results;
    }

    /**
     * 데모 테넌트 활동 현황
     */
    public function activityReport(array $params = []): array
    {
        $demos = Tenant::withoutGlobalScopes()
            ->whereIn('tenant_type', Tenant::DEMO_TYPES)
            ->when(
                ! empty($params['partner_id']),
                fn ($q) => $q->where('demo_source_partner_id', $params['partner_id'])
            )
            ->get();

        $report = [];

        foreach ($demos as $tenant) {
            // 각 데모 테넌트의 데이터 입력량 조회
            $dataCounts = $this->getDataCounts($tenant->id);
            $totalRecords = array_sum($dataCounts);

            // 최근 활동 시점 (가장 최근 레코드의 updated_at)
            $lastActivity = $this->getLastActivity($tenant->id);

            $daysSinceActivity = $lastActivity
                ? (int) now()->diffInDays($lastActivity) : null;

            $report[] = [
                'tenant_id' => $tenant->id,
                'company_name' => $tenant->company_name,
                'tenant_type' => $tenant->tenant_type,
                'demo_expires_at' => $tenant->demo_expires_at?->toDateString(),
                'is_expired' => $tenant->isDemoExpired(),
                'data_counts' => $dataCounts,
                'total_records' => $totalRecords,
                'last_activity' => $lastActivity?->toDateString(),
                'days_since_activity' => $daysSinceActivity,
                'activity_status' => $this->classifyActivity($daysSinceActivity),
            ];
        }

        return $report;
    }

    /**
     * 전체 요약 (대시보드용)
     */
    public function summary(): array
    {
        $funnel = $this->conversionFunnel();

        $allDemos = Tenant::withoutGlobalScopes()
            ->whereIn('tenant_type', Tenant::DEMO_TYPES)
            ->get();

        $inactiveCount = 0;
        foreach ($allDemos as $tenant) {
            $lastActivity = $this->getLastActivity($tenant->id);
            if ($lastActivity && now()->diffInDays($lastActivity) >= 7) {
                $inactiveCount++;
            }
        }

        return [
            'funnel' => $funnel['funnel'],
            'conversion_rate' => $funnel['conversion_rate'],
            'avg_conversion_days' => $funnel['avg_conversion_days'],
            'total_demos' => $allDemos->count(),
            'inactive_count' => $inactiveCount,
            'by_type' => [
                'showcase' => $allDemos->where('tenant_type', Tenant::TYPE_DEMO_SHOWCASE)->count(),
                'partner' => $allDemos->where('tenant_type', Tenant::TYPE_DEMO_PARTNER)->count(),
                'trial' => $allDemos->where('tenant_type', Tenant::TYPE_DEMO_TRIAL)->count(),
            ],
        ];
    }

    // ──────────────────────────────────────────────
    // Private Helpers
    // ──────────────────────────────────────────────

    private function getDataCounts(int $tenantId): array
    {
        $tables = ['departments', 'clients', 'items', 'quotes', 'orders'];
        $counts = [];

        foreach ($tables as $table) {
            if (\Schema::hasTable($table) && \Schema::hasColumn($table, 'tenant_id')) {
                $counts[$table] = DB::table($table)->where('tenant_id', $tenantId)->count();
            }
        }

        return $counts;
    }

    private function getLastActivity(int $tenantId): ?\Carbon\Carbon
    {
        $tables = ['orders', 'quotes', 'items', 'clients'];
        $latest = null;

        foreach ($tables as $table) {
            if (! \Schema::hasTable($table) || ! \Schema::hasColumn($table, 'tenant_id')) {
                continue;
            }

            $date = DB::table($table)
                ->where('tenant_id', $tenantId)
                ->max('updated_at');

            if ($date) {
                $parsed = \Carbon\Carbon::parse($date);
                if (! $latest || $parsed->gt($latest)) {
                    $latest = $parsed;
                }
            }
        }

        return $latest;
    }

    private function classifyActivity(?int $daysSinceActivity): string
    {
        if ($daysSinceActivity === null) {
            return 'no_data';
        }

        return match (true) {
            $daysSinceActivity <= 1 => 'active',
            $daysSinceActivity <= 3 => 'normal',
            $daysSinceActivity <= 7 => 'low',
            default => 'inactive',
        };
    }
}