<?php

namespace App\Services;

use App\Models\StudentContract;
use App\Models\StudentContractInstallment;
use App\Models\StudentMedia;
use Carbon\Carbon;
use Illuminate\Database\Eloquent\Collection;
use Illuminate\Support\Facades\Storage;

class StudentContractService
{
    public function getFranchisorSummary(array $unitIds = []): array
    {
        $base = StudentContract::query()
            ->when(!empty($unitIds), fn ($q) => $q->whereIn('unit_id', $unitIds));

        return [
            'active'    => (clone $base)->where('status', 'active')->count(),
            'frozen'    => (clone $base)->where('status', 'frozen')->count(),
            'cancelled' => (clone $base)->where('status', 'cancelled')->count(),
        ];
    }

    public function getFranchisorByStatus(string $status, array $unitIds = []): Collection
    {
        return StudentContract::with(['student', 'unit'])
            ->where('status', $status)
            ->when(!empty($unitIds), fn ($q) => $q->whereIn('unit_id', $unitIds))
            ->orderBy('created_at', 'desc')
            ->get();
    }

    public function getAll(int $unitId, ?int $studentId = null): Collection
    {
        return StudentContract::with(['student.city', 'student.state', 'classPackageUnit'])
            ->where('unit_id', $unitId)
            ->when($studentId, fn ($q) => $q->where('student_id', $studentId))
            ->orderBy('created_at', 'desc')
            ->get();
    }

    public function findById(int $id): ?StudentContract
    {
        return StudentContract::with(['student', 'classPackageUnit'])->find($id);
    }

    public function create(array $data): StudentContract
    {
        if (!empty($data['due_day'])) {
            $data['recurring_day'] = (int) $data['due_day'];
        }
        unset($data['due_day']);

        $contract = StudentContract::create($data);

        $this->generateInstallments($contract);

        return $contract;
    }

    private function generateInstallments(StudentContract $contract): void
    {
        $recurringDay = $contract->recurring_day ?? 1;
        $rows = [];
        $now  = now();

        // Matrícula
        if ($contract->tax_register && $contract->installments && $contract->enrollment_due_date) {
            $value = round($contract->tax_register / $contract->installments, 2);

            $dates = $this->buildInstallmentDates(
                $contract->enrollment_due_date->format('Y-m-d'),
                $recurringDay,
                $contract->installments,
            );

            foreach ($dates as $i => $date) {
                $rows[] = [
                    'student_contract_id' => $contract->id,
                    'unit_id'             => $contract->unit_id,
                    'student_id'          => $contract->student_id,
                    'type'                => 'enrollment',
                    'history'             => 'REF. MATRÍCULA',
                    'installment_number'  => $i + 1,
                    'total_installments'  => $contract->installments,
                    'value'               => $value,
                    'paid_value'          => 0,
                    'discount'            => 0,
                    'fine'                => 0,
                    'due_date'            => $date->format('Y-m-d'),
                    'status'              => 'pending',
                    'created_at'          => $now,
                    'updated_at'          => $now,
                ];
            }
        }

        // Pacote
        if ($contract->package_value && $contract->package_installments && $contract->package_due_date) {
            $value = round($contract->package_value / $contract->package_installments, 2);
           
            $dates = $this->buildInstallmentDates(
                $contract->package_due_date->format('Y-m-d'),
                $recurringDay,
                $contract->package_installments,
            );

            foreach ($dates as $i => $date) {
                $rows[] = [
                    'student_contract_id' => $contract->id,
                    'unit_id'             => $contract->unit_id,
                    'student_id'          => $contract->student_id,
                    'type'                => 'package',
                    'history'             => 'REF. PACOTE',
                    'installment_number'  => $i + 1,
                    'total_installments'  => $contract->package_installments,
                    'value'               => $value,
                    'paid_value'          => 0,
                    'discount'            => 0,
                    'fine'                => 0,
                    'due_date'            => $date->format('Y-m-d'),
                    'status'              => 'pending',
                    'created_at'          => $now,
                    'updated_at'          => $now,
                ];
            }
        }

        if (!empty($rows)) {
            StudentContractInstallment::insert($rows);

            // Dispatch Asaas sync for the generated installments
            $installments = StudentContractInstallment::where('student_contract_id', $contract->id)
                ->where('status', 'pending')
                ->get();

            foreach ($installments as $installment) {
                \App\Jobs\SyncStudentChargeJob::dispatch($installment->id);
            }
        }
    }

    /**
     * Monta o array de datas para N parcelas.
     *
     * - 1ª parcela: usa exatamente $firstDate (data escolhida pelo usuário)
     * - 2ª em diante: dia $recurringDay avançando mês a mês a partir do mês da 1ª
     *
     * Exemplo: firstDate=25/05/2026, recurringDay=5, count=3
     *   → [25/05/2026, 05/06/2026, 05/07/2026]
     */
    private function buildInstallmentDates(string $firstDate, int $recurringDay, int $count): array
    {
        $dates     = [];
        $first     = Carbon::createFromFormat('Y-m-d', $firstDate);
        $dates[]   = $first->copy();

        $baseMonth = $first->copy()->startOfMonth();

        for ($i = 1; $i < $count; $i++) {
            $next = $baseMonth->copy()->addMonths($i);
            $day  = min($recurringDay, $next->daysInMonth);
            $next->setDay($day);
            $dates[] = $next;
        }

        return $dates;
    }

    public function update(int $id, array $data): ?StudentContract
    {
        $model = $this->findById($id);

        if (!$model) {
            return null;
        }

        if (!empty($data['due_day'])) {
            $data['recurring_day'] = (int) $data['due_day'];
        }
        unset($data['due_day']);

        $model->update($data);
        return $model->fresh();
    }

    public function attachFile(int $id, $file): ?StudentContract
    {
        $model = $this->findById($id);

        if (!$model) {
            return null;
        }

        /** @var \Illuminate\Http\UploadedFile $file */
        $path = $file->store('student-media');

        StudentMedia::create([
            'student_id'          => $model->student_id,
            'student_contract_id' => $model->id,
            'url'                 => $path,
            'file_type'           => $file->getMimeType(),
            'type'                => 'contract',
        ]);

        $model->update(['file_url' => Storage::url($path), 'file_type' => $file->getMimeType()]);

        return $model->fresh();
    }

    public function getInstallments(int $contractId): Collection
    {
        return StudentContractInstallment::where('student_contract_id', $contractId)
            ->where('status', 'pending')
            ->orderBy('due_date')
            ->orderBy('installment_number')
            ->get();
    }

    public function freeze(int $id, int $months = 0): ?StudentContract
    {
        $model = $this->findById($id);

        if (!$model) {
            return null;
        }

        if ($months > 0) {
            StudentContractInstallment::where('student_contract_id', $id)
                ->where('status', 'pending')
                ->get()
                ->each(function ($installment) use ($months) {
                    $newDate = Carbon::parse($installment->due_date)->addMonths($months);
                    $installment->update(['due_date' => $newDate->format('Y-m-d')]);
                });
        }

        $model->update(['status' => 'frozen']);
        return $model->fresh();
    }

    public function cancel(int $id): ?StudentContract
    {
        $model = $this->findById($id);

        if (!$model) {
            return null;
        }

        $model->update(['status' => 'cancelled']);
        return $model->fresh();
    }

    public function reactivate(int $id): ?StudentContract
    {
        $model = $this->findById($id);

        if (!$model) {
            return null;
        }

        $model->update(['status' => 'active']);
        return $model->fresh();
    }

    public function delete(int $id): bool
    {
        $model = $this->findById($id);

        if (!$model) {
            return false;
        }

        if ($model->file_url) {
            Storage::delete($model->file_url);
        }

        return $model->delete();
    }
}