<?php

namespace App\Services\Automation;

use App\Models\Automation;
use App\Models\AutomationDelayedJob;
use App\Models\Customer;
use App\Models\Product;
use Carbon\Carbon;
use Illuminate\Support\Facades\Log;

class AutomationEngine
{
    public function __construct(
        private readonly AutomationConditionQuery $conditions,
        private readonly AutomationSender $sender,
    ) {
    }

    public function runDue(): void
    {
        $this->runSchedule();
        $this->processDelayedJobs();
    }

    public function onCustomerEvent(string $event, int $customerId): void
    {
        $customer = Customer::query()->find($customerId);
        if (! $customer || (int) $customer->type !== 2 || $customer->is_archive) {
            return;
        }

        $rows = Automation::query()
            ->where('is_active', true)
            ->where('trigger_type', AutomationCatalog::TRIGGER_EVENT)
            ->get();

        foreach ($rows as $auto) {
            if (! $this->inWindow($auto)) {
                continue;
            }
            $cfg = $auto->trigger_config ?? [];
            if (($cfg['event'] ?? '') !== $event) {
                continue;
            }
            if (! $this->conditions->matchesCustomer($customer, $auto->conditions ?? [])) {
                continue;
            }
            $this->enqueueCustomer($auto, $customer, (int) ($cfg['delay_hours'] ?? 0));
        }
    }

    public function evaluatePriceMove(array $payload = []): void
    {
        $rows = Automation::query()
            ->where('is_active', true)
            ->where('trigger_type', AutomationCatalog::TRIGGER_PRICE)
            ->get();
        if ($rows->isEmpty()) {
            return;
        }

        foreach ($rows as $auto) {
            try {
                $this->tryPriceFire($auto, $payload);
            } catch (\Throwable $e) {
                Log::warning('Automation price evaluate failed', [
                    'id' => $auto->id,
                    'message' => $e->getMessage(),
                ]);
            }
        }
    }

    public function previewCount(array $conditions): int
    {
        return $this->conditions->apply($this->conditions->baseQuery(), $conditions)->count();
    }

    private function tryPriceFire(Automation $auto, array $payload): void
    {
        if (! $this->inWindow($auto)) {
            return;
        }

        $current = $this->currentPrice($auto, $payload);
        if ($current <= 0) {
            return;
        }

        $anchor = $auto->last_anchor_price;
        if ($anchor === null || (float) $anchor <= 0) {
            Automation::query()->where('id', $auto->id)->update(['last_anchor_price' => $current]);
            $auto->last_anchor_price = $current;

            return;
        }

        $cfg = $auto->trigger_config ?? [];
        $step = (float) ($cfg['step_toman'] ?? 0);
        if ($step <= 0) {
            return;
        }

        $delta = $current - (float) $anchor;
        $dir = (string) ($cfg['direction'] ?? 'both');
        $moved = match ($dir) {
            'up' => $delta >= $step,
            'down' => $delta <= -$step,
            default => abs($delta) >= $step,
        };
        if (! $moved) {
            return;
        }

        $anyHour = false;
        foreach ($this->channels($auto) as $channel) {
            if ($this->hourMatches($auto, $channel)) {
                $anyHour = true;
                break;
            }
        }
        if (! $anyHour) {
            return;
        }

        $this->enqueueAudience($auto, 0);
        Automation::query()->where('id', $auto->id)->update(['last_anchor_price' => $current]);
        $auto->last_anchor_price = $current;
    }

    private function runSchedule(): void
    {
        $rows = Automation::query()
            ->where('is_active', true)
            ->where('trigger_type', AutomationCatalog::TRIGGER_SCHEDULE)
            ->get();

        foreach ($rows as $auto) {
            if (! $this->inWindow($auto)) {
                continue;
            }
            foreach ($this->channels($auto) as $channel) {
                if (! $this->hourMatches($auto, $channel)) {
                    continue;
                }
                if ($this->alreadyRanThisHour($auto, $channel)) {
                    continue;
                }
                $this->sendAudienceNow($auto, $channel);
                $this->markHourRun($auto, $channel);
            }
        }
    }

    private function processDelayedJobs(): void
    {
        $jobs = AutomationDelayedJob::query()
            ->whereNull('processed_at')
            ->where('run_at', '<=', now())
            ->orderBy('id')
            ->limit(200)
            ->get();

        foreach ($jobs as $job) {
            $auto = Automation::query()->find($job->automation_id);
            $customer = Customer::query()->find($job->customer_id);
            $job->processed_at = now();
            $job->save();

            if (! $auto || ! $auto->is_active || ! $this->inWindow($auto) || ! $customer) {
                continue;
            }
            if (! $this->conditions->matchesCustomer($customer, $auto->conditions ?? [])) {
                continue;
            }
            $this->sender->send($auto, $customer, $job->channel);
        }
    }

    private function sendAudienceNow(Automation $auto, string $channel): void
    {
        $this->conditions
            ->apply($this->conditions->baseQuery(), $auto->conditions ?? [])
            ->select(['id', 'name', 'fname', 'lname', 'mobile', 'type', 'is_archive'])
            ->chunkById(80, function ($customers) use ($auto, $channel) {
                foreach ($customers as $customer) {
                    $this->sender->send($auto, $customer, $channel);
                }
            });
    }

    private function enqueueAudience(Automation $auto, int $delayHours): void
    {
        $this->conditions
            ->apply($this->conditions->baseQuery(), $auto->conditions ?? [])
            ->select(['id'])
            ->chunkById(200, function ($customers) use ($auto, $delayHours) {
                foreach ($customers as $customer) {
                    $this->enqueueCustomer($auto, $customer, $delayHours);
                }
            });
    }

    private function enqueueCustomer(Automation $auto, Customer $customer, int $delayHours): void
    {
        $after = now()->addHours(max(0, $delayHours));
        foreach ($this->channels($auto) as $channel) {
            $exists = AutomationDelayedJob::query()
                ->where('automation_id', $auto->id)
                ->where('customer_id', $customer->id)
                ->where('channel', $channel)
                ->whereNull('processed_at')
                ->exists();
            if ($exists) {
                continue;
            }
            if ($delayHours === 0 && $this->hourMatches($auto, $channel) && $this->sender->maySend($auto, $customer, $channel)) {
                $this->sender->send($auto, $customer, $channel);
                continue;
            }
            AutomationDelayedJob::create([
                'automation_id' => $auto->id,
                'customer_id' => $customer->id,
                'channel' => $channel,
                'run_at' => $this->snapToHour($auto, $channel, $after),
            ]);
        }
    }

    private function inWindow(Automation $auto): bool
    {
        $now = now();
        if ($auto->starts_at && $now->lt($auto->starts_at)) {
            return false;
        }
        if ($auto->ends_at && $now->gt($auto->ends_at)) {
            return false;
        }

        return true;
    }

    private function hourMatches(Automation $auto, string $channel): bool
    {
        $h = $channel === AutomationCatalog::CHANNEL_SMS
            ? $auto->sms_send_hour
            : $auto->in_app_send_hour;
        if ($h === null) {
            return true;
        }

        return (int) now('Asia/Tehran')->hour === (int) $h;
    }

    private function alreadyRanThisHour(Automation $auto, string $channel): bool
    {
        $at = $channel === AutomationCatalog::CHANNEL_SMS
            ? $auto->last_sms_run_at
            : $auto->last_in_app_run_at;
        if (! $at) {
            return false;
        }

        return $at->copy()->timezone('Asia/Tehran')->format('Y-m-d H')
            === now('Asia/Tehran')->format('Y-m-d H');
    }

    private function markHourRun(Automation $auto, string $channel): void
    {
        $col = $channel === AutomationCatalog::CHANNEL_SMS
            ? 'last_sms_run_at'
            : 'last_in_app_run_at';
        $now = now();
        Automation::query()->where('id', $auto->id)->update([$col => $now]);
        $auto->{$col} = $now;
    }

    private function snapToHour(Automation $auto, string $channel, Carbon $after): Carbon
    {
        $h = $channel === AutomationCatalog::CHANNEL_SMS
            ? $auto->sms_send_hour
            : $auto->in_app_send_hour;
        if ($h === null) {
            return $after;
        }
        $local = $after->copy()->timezone('Asia/Tehran');
        if ((int) $local->hour === (int) $h) {
            return $after;
        }
        $target = $local->copy()->setTime((int) $h, 0, 0);
        if ($target->lt($local)) {
            $target->addDay();
        }

        return $target;
    }

    /** @return list<string> */
    private function channels(Automation $auto): array
    {
        $out = [];
        foreach ([AutomationCatalog::CHANNEL_SMS, AutomationCatalog::CHANNEL_IN_APP] as $ch) {
            if ($auto->usesChannel($ch)) {
                $out[] = $ch;
            }
        }

        return $out;
    }

    private function currentPrice(Automation $auto, array $payload): float
    {
        $board = (float) ($payload['price'] ?? 0);
        $productId = (int) (($auto->trigger_config ?? [])['product_id'] ?? 0);
        if ($productId <= 0) {
            return $board;
        }
        $product = Product::query()->find($productId);
        if (! $product) {
            return $board;
        }
        $enriched = (float) (($product->price ?? 0) + ($product->price_profit ?? 0));

        return $enriched > 0 ? $enriched : $board;
    }
}