<?php

namespace App\Services\Pos;

use App\Models\PosCustomerDisplay;
use App\Models\PosLocation;
use App\Models\PosSale;
use Illuminate\Support\Str;

class CustomerDisplayService
{
    public function ensureForLocation(PosLocation $location): PosCustomerDisplay
    {
        $display = PosCustomerDisplay::query()->where('location_id', $location->id)->first();

        if ($display) {
            return $display;
        }

        return PosCustomerDisplay::create([
            'location_id' => $location->id,
            'owner_ref' => $location->owner_ref,
            'token' => $this->freshToken(),
            'phase' => PosCustomerDisplay::PHASE_IDLE,
            'payload' => $this->defaultPayload($location),
            'last_pushed_at' => now(),
        ]);
    }

    public function rotateToken(PosCustomerDisplay $display): PosCustomerDisplay
    {
        $display->update(['token' => $this->freshToken()]);

        return $display->fresh();
    }

    /**
     * @param  array<string, mixed>  $payload
     */
    public function push(PosLocation $location, string $phase, array $payload = []): PosCustomerDisplay
    {
        if (! in_array($phase, PosCustomerDisplay::PHASES, true)) {
            $phase = PosCustomerDisplay::PHASE_IDLE;
        }

        $display = $this->ensureForLocation($location);
        $base = $this->defaultPayload($location);
        $merged = array_replace_recursive($base, $payload);
        $merged['phase'] = $phase;
        $merged['updated_at'] = now()->toIso8601String();

        $display->update([
            'phase' => $phase,
            'payload' => $merged,
            'customer_action' => null,
            'last_pushed_at' => now(),
        ]);

        return $display->fresh();
    }

    /**
     * @param  array{name: string, quantity: int|float, unit_price_minor: int, discount_minor?: int, note?: string}[]  $lines
     * @param  array<string, mixed>  $extras
     */
    public function pushCart(PosLocation $location, array $lines, array $extras = []): PosCustomerDisplay
    {
        $normalized = [];
        $subtotal = 0;
        $discount = (int) ($extras['discount_minor'] ?? 0);

        foreach ($lines as $line) {
            $qty = max(0, (float) ($line['quantity'] ?? 0));
            $unit = (int) ($line['unit_price_minor'] ?? 0);
            $lineDiscount = (int) ($line['discount_minor'] ?? 0);
            $lineTotal = (int) round($unit * $qty) - $lineDiscount;
            $subtotal += $lineTotal;
            $normalized[] = [
                'name' => (string) ($line['name'] ?? 'Item'),
                'quantity' => $qty,
                'unit_price_minor' => $unit,
                'discount_minor' => $lineDiscount,
                'line_total_minor' => max(0, $lineTotal),
                'note' => isset($line['note']) ? (string) $line['note'] : null,
            ];
        }

        $total = max(0, $subtotal - $discount);

        if ($normalized === []) {
            return $this->push($location, PosCustomerDisplay::PHASE_IDLE, $extras);
        }

        return $this->push($location, PosCustomerDisplay::PHASE_CART, array_merge($extras, [
            'lines' => $normalized,
            'subtotal_minor' => $subtotal,
            'discount_minor' => $discount,
            'total_minor' => $total,
            'currency' => $location->currency,
        ]));
    }

    /**
     * @param  array<string, mixed>  $extras
     */
    public function pushPayment(PosLocation $location, PosSale $sale, array $extras = []): PosCustomerDisplay
    {
        return $this->push($location, PosCustomerDisplay::PHASE_PAYMENT, array_merge([
            'lines' => $this->linesFromSale($sale),
            'subtotal_minor' => (int) $sale->subtotal_minor,
            'total_minor' => (int) $sale->total_minor,
            'currency' => $sale->currency,
            'payment' => [
                'method' => $sale->payment_method,
                'status' => $sale->status,
                'message' => $extras['message'] ?? 'Complete payment on the terminal or scan the code',
                'qr_url' => $extras['qr_url'] ?? null,
                'checkout_url' => $extras['checkout_url'] ?? null,
                'options' => $extras['options'] ?? ['Card / MoMo', 'Cash'],
            ],
            'sale_reference' => $sale->reference,
        ], $extras));
    }

    /**
     * @param  array<string, mixed>  $extras
     */
    public function pushReceipt(PosLocation $location, PosSale $sale, array $extras = []): PosCustomerDisplay
    {
        return $this->push($location, PosCustomerDisplay::PHASE_RECEIPT, array_merge([
            'lines' => $this->linesFromSale($sale),
            'subtotal_minor' => (int) $sale->subtotal_minor,
            'discount_minor' => (int) $sale->loyalty_discount_minor,
            'tip_minor' => (int) $sale->tip_minor,
            'total_minor' => (int) $sale->total_minor,
            'currency' => $sale->currency,
            'receipt' => [
                'reference' => $sale->reference,
                'sale_id' => $sale->id,
                'total_minor' => (int) $sale->total_minor,
                'digital_url' => $extras['digital_url'] ?? null,
                'message' => $extras['message'] ?? 'Thank you for your purchase',
                'email_prompt' => true,
            ],
            'sale_reference' => $sale->reference,
            'sale_id' => $sale->id,
            'tip' => [
                'selected_minor' => (int) $sale->tip_minor,
                'base_minor' => max(0, (int) $sale->subtotal_minor - (int) $sale->loyalty_discount_minor),
            ],
        ], $extras));
    }

    /**
     * @param  array<string, mixed>  $action
     */
    public function recordCustomerAction(PosCustomerDisplay $display, array $action): PosCustomerDisplay
    {
        $display->update([
            'customer_action' => array_merge($action, [
                'received_at' => now()->toIso8601String(),
            ]),
        ]);

        return $display->fresh();
    }

    public function clearCustomerAction(PosCustomerDisplay $display): void
    {
        $display->update(['customer_action' => null]);
    }

    /**
     * Public payload for the customer-facing screen (no operator secrets).
     *
     * @return array<string, mixed>
     */
    public function publicState(PosCustomerDisplay $display): array
    {
        $payload = is_array($display->payload) ? $display->payload : [];
        $location = $display->location;

        return [
            'phase' => $display->phase,
            'updated_at' => optional($display->last_pushed_at)->toIso8601String()
                ?? ($payload['updated_at'] ?? null),
            'location_name' => $location?->name ?? ($payload['location_name'] ?? 'Store'),
            'currency' => $payload['currency'] ?? ($location?->currency ?? 'GHS'),
            'brand' => [
                'logo_url' => $location?->receiptLogoUrl(),
                'header' => $location?->receipt_header,
                'footer' => $location?->receipt_footer,
            ],
            'lines' => $payload['lines'] ?? [],
            'subtotal_minor' => (int) ($payload['subtotal_minor'] ?? 0),
            'discount_minor' => (int) ($payload['discount_minor'] ?? 0),
            'tax_minor' => (int) ($payload['tax_minor'] ?? 0),
            'tip_minor' => (int) ($payload['tip_minor'] ?? ($payload['tip']['selected_minor'] ?? 0)),
            'total_minor' => (int) ($payload['total_minor'] ?? 0),
            'loyalty' => $payload['loyalty'] ?? null,
            'payment' => $payload['payment'] ?? null,
            'tip' => $payload['tip'] ?? null,
            'signature' => $payload['signature'] ?? null,
            'receipt' => $payload['receipt'] ?? null,
            'promo' => $payload['promo'] ?? ($this->defaultPayload($location ?? new PosLocation)['promo'] ?? null),
            'customer_name' => $payload['customer_name'] ?? null,
            'sale_reference' => $payload['sale_reference'] ?? null,
            'sale_id' => $payload['sale_id'] ?? ($payload['receipt']['sale_id'] ?? null),
            'message' => $payload['message'] ?? null,
        ];
    }

    /**
     * @return array<string, mixed>
     */
    public function defaultPayload(?PosLocation $location): array
    {
        $name = $location?->name ?? 'Welcome';
        $promo = $location
            ? $location->customerPromo()
            : ['headline' => $name, 'body' => 'Thank you for shopping with us.', 'image_url' => null];

        return [
            'location_name' => $name,
            'currency' => $location?->currency ?? 'GHS',
            'lines' => [],
            'subtotal_minor' => 0,
            'discount_minor' => 0,
            'tax_minor' => 0,
            'tip_minor' => 0,
            'total_minor' => 0,
            'loyalty' => null,
            'payment' => null,
            'tip' => [
                'enabled' => (bool) $location?->isRestaurant(),
                'options_percent' => [10, 15, 18, 20],
                'custom_allowed' => true,
                'selected_percent' => null,
                'selected_minor' => null,
                'base_minor' => 0,
            ],
            'signature' => [
                'required' => false,
                'data_url' => null,
                'prompt' => 'Please sign below',
            ],
            'receipt' => null,
            'promo' => $promo,
            'message' => null,
        ];
    }

    public function displayUrl(PosCustomerDisplay $display): string
    {
        return route('pos.customer-display.show', ['token' => $display->token]);
    }

    private function freshToken(): string
    {
        return Str::random(48);
    }

    /**
     * @return list<array{name: string, quantity: float|int, unit_price_minor: int, discount_minor: int, line_total_minor: int, note: null}>
     */
    private function linesFromSale(PosSale $sale): array
    {
        $sale->loadMissing('lines');

        return $sale->lines->map(function ($line) {
            $qty = (float) $line->quantity;
            $unit = (int) $line->unit_price_minor;
            $total = (int) ($line->line_total_minor ?? round($unit * $qty));

            return [
                'name' => (string) $line->name,
                'quantity' => $qty,
                'unit_price_minor' => $unit,
                'discount_minor' => 0,
                'line_total_minor' => $total,
                'note' => $line->notes ?? null,
            ];
        })->values()->all();
    }
}