<?php

namespace App\Services\AiEditing;

use App\Models\AiEditRequest;
use App\Models\AiUsageLedger;
use App\Models\Event;
use Illuminate\Support\Facades\DB;

class AiUsageLedgerService
{
    public function __construct(private readonly AiStylingEntitlementService $entitlements) {}

    /**
     * @param  array<string, mixed>  $metadata
     */
    public function recordDebitForRequest(AiEditRequest $request, ?float $costUsd = null, array $metadata = []): AiUsageLedger
    {
        return DB::transaction(function () use ($request, $costUsd, $metadata): AiUsageLedger {
            $lockedRequest = AiEditRequest::query()
                ->whereKey($request->id)
                ->lockForUpdate()
                ->firstOrFail();

            $existing = AiUsageLedger::query()
                ->where('request_id', $lockedRequest->id)
                ->where('entry_type', AiUsageLedger::TYPE_DEBIT)
                ->first();
            if ($existing) {
                return $existing;
            }

            $resolvedCost = $costUsd;
            if ($resolvedCost === null || $resolvedCost < 0) {
                $resolvedCost = (float) config('ai-editing.billing.default_unit_cost_usd', 0.01);
            }

            $event = Event::query()->find($lockedRequest->event_id);
            $entitlement = $event ? $this->entitlements->resolveForEvent($event) : [
                'allowed' => false,
                'granted_by' => null,
            ];

            $packageContext = $entitlement['granted_by'] === 'package'
                ? 'package_included'
                : ($entitlement['granted_by'] === 'addon' ? 'addon_unlock' : 'unentitled');

            return AiUsageLedger::query()->create([
                'tenant_id' => $lockedRequest->tenant_id,
                'event_id' => $lockedRequest->event_id,
                'request_id' => $lockedRequest->id,
                'entry_type' => AiUsageLedger::TYPE_DEBIT,
                'quantity' => 1,
                'unit_cost_usd' => $resolvedCost,
                'amount_usd' => $resolvedCost,
                'currency' => 'USD',
                'package_context' => $packageContext,
                'recorded_at' => now(),
                'metadata' => array_merge([
                    'provider' => $lockedRequest->provider,
                    'provider_model' => $lockedRequest->provider_model,
                    'granted_by' => $entitlement['granted_by'],
                ], $metadata),
            ]);
        });
    }
}