<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\ClientInvoice;
use App\Services\ClientInvoiceApprovalService;
use App\Services\ClientInvoicePaymentSyncService;
use App\Services\ClientLookupService;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;
use Illuminate\Validation\ValidationException;

class ClientInvoiceController extends Controller
{
    public function __construct(
        private ClientInvoiceApprovalService $approvalService,
        private ClientInvoicePaymentSyncService $paymentSyncService,
        private ClientLookupService $clientLookupService,
    ) {
    }

    public function pending(): JsonResponse
    {
        $invoices = ClientInvoice::query()
            ->with('client:id,name,customer_id', 'payments.items.billingItemType')
            ->whereNull('approved_at')
            ->latest('id')
            ->get([
                'id',
                'client_id',
                'pending_sql_acc_code',
                'pending_client_name',
                'invoice_no',
                'is_credit_card',
                'is_paid',
                'start_date',
                'end_date',
                'payment_no',
                'amount',
                'management_fee',
                'management_fee_amount',
                'management_fee_tax',
                'media_fee',
                'media_fee_amount',
                'media_fee_tax',
                'tax_percent',
                'nett_amount',
                'total_spending',
                'total_sem_amount',
                'total_net_amount',
                'created_at',
            ]);

        return response()->json([
            'count' => $invoices->count(),
            'invoices' => $invoices->map(function (ClientInvoice $invoice) {
                $previousPayments = $this->previousPaymentsForInvoice($invoice);
                $invoiceBillingTotals = $this->invoiceBillingTotalsFromPayments($previousPayments);

                return [
                    ...$invoice->toArray(),
                    'requires_client' => $invoice->client_id === null,
                    'previous_payments' => $previousPayments,
                    'invoice_billing_totals' => $invoiceBillingTotals,
                ];
            }),
        ]);
    }

    public function store(Request $request): JsonResponse
    {
        $validated = $request->validate([
            'client_id' => ['nullable', 'exists:clients,id'],
            'sql_acc_code' => ['required_without:client_id', 'nullable', 'string'],
            'client_name' => ['nullable', 'string'],
            'linked_invoice_id' => ['nullable', 'integer'],
            'is_credit_card' => ['nullable', 'boolean'],
            'payments' => ['nullable', 'array', 'min:1'],
            'invoice' => ['nullable', 'array'],
            'nett_amount' => ['nullable', 'numeric', 'min:0'],
            'total_spending' => ['nullable', 'numeric', 'min:0'],
            'sem_invoice_items' => ['nullable', 'array'],
            'sem_items' => ['nullable', 'array'],
        ]);

        // return response()->json($validated['sem_invoice_items']);
        // Log::debug('Validated request data for creating client invoice.', [
        //     'validated' => $validated,
        // ]);
        // Log::info('Received request to create client invoice.');

        // return response()->json([
        //     'message' => 'Invoice creation endpoint is under development.',
        // ], 501);
        $sqlAccCode = $this->clientLookupService->normalizeSqlAccCode($validated['sql_acc_code'] ?? null);
        $client = ! empty($validated['client_id'])
            ? \App\Models\Client::find($validated['client_id'])
            : $this->clientLookupService->findBySqlAccCode($sqlAccCode);

        if (! empty($validated['linked_invoice_id'])) {
            $linkedInvoiceExists = $client !== null && ClientInvoice::query()
                ->where('id', $validated['linked_invoice_id'])
                ->where('client_id', $client->id)
                ->exists();

            if (! $linkedInvoiceExists) {
                throw ValidationException::withMessages([
                    'linked_invoice_id' => 'The linked invoice must belong to the resolved client.',
                ]);
            }
        }

        // return response()->json([
        //     'message' => 'Invoice creation endpoint is under development.',
        //     'items' => $validated['sem_items']
        // ], 501);
        $semItems = [];
        if (! empty($validated['sem_items'])) {
            foreach ($validated['sem_items'] as $item) {
                $semItems[] = [
                    'sql_acc_code' => $item['sql_acc_code'] ?? null,
                    'amount' => $item['exact_price'] ?? null,
                    'tax_percent' => $item['item']['sql_acc_tax_percent'] ?? 0,
                ];
            }
        }
        // return response()->json([
        //     'message' => 'Invoice creation endpoint is under development.',
        // ], 501);
        // if (! empty($validated['sem_invoice_items'])) {
        //     foreach ($validated['sem_invoice_items'] as $item) {
        //         Log::debug('Validating SEM invoice item.', [
        //             'item' => $item,
        //         ]);
        //         // if (! isset($item['sql_acc_code']) || ! isset($item['amount'])) {
        //         //     throw ValidationException::withMessages([
        //         //         'sem_invoice_items' => 'Each SEM invoice item must include sql_acc_code and amount.',
        //         //     ]);
        //         // }
        //     }
        // }
        return response()->json([
            'message' => 'Invoice creation endpoint is under development.',
            'items' => $semItems
        ], 501);
        $invoice = ClientInvoice::create([
            'client_id' => $client?->id,
            'pending_sql_acc_code' => $client === null ? $sqlAccCode : null,
            'pending_client_name' => $client === null ? ($validated['client_name'] ?? null) : null,
            'invoice_no' => $validated['invoice_no'],
            // 'linked_invoice_id' => $validated['linked_invoice_id'] ?? null,
            'is_credit_card' => (bool) ($validated['is_credit_card'] ?? false),
            // 'is_paid' => (bool) ($validated['is_paid'] ?? false),
            'approved_at' => null,
            // 'payment_no' => $validated['payment_no'] ?? null,
            // 'start_date' => $validated['start_date'] ?? null,
            // 'end_date' => $validated['end_date'] ?? null,
            // 'amount' => $mediaFee + $managementFee,
            // 'total_spending' => $validated['total_spending'] ?? null,
        ]);

        $invoice = $this->paymentSyncService->sync(
            $invoice,
            $validated['payments'] ?? $this->paymentSyncService->legacyPaymentsFor($invoice)
        );

        // $this->approvalService->requireApproval($invoice);

        // return response()->json([
        //     'message' => 'Invoice created and marked for approval.',
        //     'invoice' => $invoice->fresh('payments.items.billingItemType'),
        // ], 201);
    }

    public function approve(ClientInvoice $invoice): JsonResponse
    {
        if ($invoice->client_id === null) {
            return response()->json([
                'message' => 'Create and link the client before approving this invoice.',
            ], 409);
        }

        $invoice = $this->approvalService->approve($invoice);

        return response()->json([
            'message' => 'Invoice approved successfully.',
            'invoice' => $invoice,
        ]);
    }

    private function previousPaymentsForInvoice(ClientInvoice $invoice): array
    {
        if (empty($invoice->invoice_no)) {
            return [];
        }

        try {
            $response = Http::acceptJson()
                ->withHeaders([
                    'X-Secret' => config('app.billing_key'),
                    'Accept' => 'application/json',
                ])
                ->get(config('app.billing_url').'/customer/invoices/getInvoicePaymentDetailsByInvoiceGoogle', [
                    'invoice_number' => $invoice->invoice_no,
                ]);

            if (! $response->successful()) {
                Log::warning('Unable to fetch invoice payment details.', [
                    'invoice_no' => $invoice->invoice_no,
                    'status' => $response->status(),
                ]);

                return [];
            }

            $records = $this->normalizePaymentRecords($response->json('data'));

            return collect($records)
                ->filter(fn (array $payment) => ($payment['payment_number'] ?? null) !== $invoice->payment_no)
                ->map(fn (array $payment) => $this->formatPreviousPayment($payment))
                ->values()
                ->all();
        } catch (\Throwable $e) {
            Log::warning('Unable to fetch invoice payment details.', [
                'invoice_no' => $invoice->invoice_no,
                'message' => $e->getMessage(),
            ]);

            return [];
        }
    }

    private function normalizePaymentRecords(mixed $data): array
    {
        if (! is_array($data)) {
            return [];
        }

        if (array_is_list($data)) {
            return $data;
        }

        return [$data];
    }

    private function formatPreviousPayment(array $payment): array
    {
        $items = collect($payment['items'] ?? [])
            ->filter(fn (mixed $paymentItem) => is_array($paymentItem))
            ->values();

        $paymentAmount = (float) ($payment['amount'] ?? 0);
        $estimatedItemsTotal = $items->sum(
            fn (array $paymentItem) => $this->paymentItemEstimatedTotal($paymentItem)
        );
        $itemAmounts = $items
            ->map(fn (array $paymentItem) => (float) ($paymentItem['amount'] ?? 0))
            ->filter(fn (float $amount) => $amount > 0)
            ->unique()
            ->values();
        $usesRepeatedPaymentAmount = $items->count() > 1
            && $paymentAmount > 0
            && $estimatedItemsTotal > 0
            && $itemAmounts->count() === 1
            && abs($itemAmounts->first() - $paymentAmount) < 0.01;

        $totals = $items->reduce(function (array $totals, array $paymentItem) use ($usesRepeatedPaymentAmount, $paymentAmount, $estimatedItemsTotal) {
            $sqlAccCode = $this->paymentItemSqlAccCode($paymentItem);
            $estimatedTotal = $this->paymentItemEstimatedTotal($paymentItem);
            $exact_tax = $this->paymentItemTax($paymentItem);
            $taxPercent = $this->paymentTaxPercent($paymentItem) / 100 + 1;
            $amount = $usesRepeatedPaymentAmount
                ? $paymentAmount * ($estimatedTotal / $estimatedItemsTotal)
                : (float) ($paymentItem['amount'] ?? 0);

            if ($sqlAccCode === 'G03') {
                $totals['media_fee'] += $amount;
                $totals['invoice_media_fee'] += $estimatedTotal;
            }

            if ($sqlAccCode === 'GOOGLE') {
                $totals['management_fee'] += $amount;
                $totals['invoice_management_fee'] += $estimatedTotal;
            }

            return $totals;
        }, [
            'media_fee' => 0.0,
            'management_fee' => 0.0,
            'invoice_media_fee' => 0.0,
            'invoice_management_fee' => 0.0,
        ]);

        return [
            'payment_number' => $payment['payment_number'] ?? null,
            'pending_client_name' => $payment['company_name'] ?? null,
            'status' => $payment['status'] ?? null,
            'sql_created_at' => $payment['sql_created_at'] ?? null,
            'amount' => $payment['amount'] ?? null,
            'media_fee' => $totals['media_fee'] / 1.08,
            'management_fee' => $totals['management_fee'] / 1.08,
            'invoice_media_fee' => $totals['invoice_media_fee'] / 1.08,
            'invoice_management_fee' => $totals['invoice_management_fee'] / 1.08,
            'invoice_number' => data_get($payment, 'invoice.invoice_number'),
        ];
    }

    private function paymentItemSqlAccCode(array $paymentItem): ?string
    {
        $sqlAccCode = data_get($paymentItem, 'item.item.sql_acc_code')
            ?? data_get($paymentItem, 'item.sql_acc_code')
            ?? data_get($paymentItem, 'sql_acc_code');

        return is_string($sqlAccCode) ? strtoupper(trim($sqlAccCode)) : null;
    }

    private function paymentItemEstimatedTotal(array $paymentItem): float
    {
        return (float) (
            data_get($paymentItem, 'item.estimated_total')
            ?? data_get($paymentItem, 'estimated_total')
            ?? 0
        );
    }

    private function paymentItemTax(array $paymentItem): float
    {
        return (float) (
            data_get($paymentItem, 'exact_tax')
            ?? 0
        );
    }

    private function paymentTaxPercent(array $paymentItem): float
    {
        return (float) (
            data_get($paymentItem, 'item.sql_acc_tax_percent')
            ?? 0
        );
    }

    private function invoiceBillingTotalsFromPayments(array $payments): array
    {
        $payment = $payments[0] ?? null;

        return [
            'media_fee' => $payment['invoice_media_fee'] ?? 0,
            'management_fee' => $payment['invoice_management_fee'] ?? 0,
        ];
    }

    private function netFromGross(float $grossAmount, float $taxPercent): float
    {
        return $taxPercent > 0
            ? $grossAmount / (1 + ($taxPercent / 100))
            : $grossAmount;
    }
}