<?php

namespace App\Services;

use App\Models\Priority;
use App\Models\Status;
use App\Models\Team;
use App\Models\Ticket;
use App\Models\Trigger;
use App\Models\User;
use Illuminate\Support\Facades\Log;

/**
 * Event-based business rules, configured entirely by admins through the
 * Wyzwalacze tab — additive and independent from AutomationRule (which is
 * time/silence-based and evaluated by a scheduled command instead). Fires
 * synchronously on every matching ticket-lifecycle event (see the
 * TicketService call sites), same as the app's other side effects — there
 * is no queue worker in this stack to defer work to.
 */
class TriggerEngine
{
    private static int $depth = 0;

    private const MAX_DEPTH = 5;

    public function __construct(protected TicketService $tickets) {}

    /**
     * Guarded two ways against runaway loops: an action that would only
     * reassert the ticket's current value is a no-op before it ever gets
     * here (see the apply* methods below), which kills the common case of a
     * trigger re-matching its own result; the depth counter below is the
     * hard backstop for genuine cycles between two or more different
     * triggers.
     */
    public function handle(Ticket $ticket, string $event): void
    {
        if (self::$depth >= self::MAX_DEPTH) {
            Log::warning('TriggerEngine: max depth reached, aborting further evaluation', [
                'ticket_id' => $ticket->id,
                'event' => $event,
            ]);

            return;
        }

        self::$depth++;

        try {
            $triggers = Trigger::query()->where('enabled', true)->where('event', $event)->orderBy('sort_order')->get();

            foreach ($triggers as $trigger) {
                $current = $ticket->fresh();

                if ($current && $this->matches($trigger, $current)) {
                    $this->applyActions($trigger, $current);
                }
            }
        } finally {
            self::$depth--;
        }
    }

    protected function matches(Trigger $trigger, Ticket $ticket): bool
    {
        foreach ($trigger->conditions as $condition) {
            $field = $condition['field'] ?? null;

            if (! in_array($field, Trigger::CONDITION_FIELDS, true)) {
                return false;
            }

            if (! $this->conditionMatches($condition, $ticket->{$field})) {
                return false;
            }
        }

        return true;
    }

    protected function conditionMatches(array $condition, mixed $actual): bool
    {
        $value = $condition['value'] ?? null;

        return match ($condition['operator'] ?? null) {
            'equals' => (string) $actual === (string) $value,
            'not_equals' => (string) $actual !== (string) $value,
            'is_empty' => $actual === null || $actual === '',
            'is_not_empty' => $actual !== null && $actual !== '',
            'contains' => is_string($actual) && $value !== null && str_contains(mb_strtolower($actual), mb_strtolower((string) $value)),
            default => false,
        };
    }

    protected function applyActions(Trigger $trigger, Ticket $ticket): void
    {
        foreach ($trigger->actions as $action) {
            match ($action['type'] ?? null) {
                'set_status' => $this->applySetStatus($ticket, $action['value'] ?? null),
                'set_priority' => $this->applySetPriority($ticket, $action['value'] ?? null),
                'set_team' => $this->applySetTeam($ticket, $action['value'] ?? null),
                'set_assignee' => $this->applySetAssignee($ticket, $action['value'] ?? null),
                'send_notification' => $this->applySendNotification($ticket, $action),
                default => null,
            };
        }
    }

    protected function applySetStatus(Ticket $ticket, ?string $value): void
    {
        if (! $value || ! Status::query()->where('key', $value)->exists() || $ticket->status_key === $value) {
            return;
        }

        $this->tickets->setStatus($ticket, $value);
    }

    protected function applySetPriority(Ticket $ticket, ?string $value): void
    {
        if (! $value || ! Priority::query()->where('key', $value)->exists() || $ticket->priority_key === $value) {
            return;
        }

        $this->tickets->setPriority($ticket, $value);
    }

    protected function applySetTeam(Ticket $ticket, null|string|int $value): void
    {
        if ($value === null || (int) $ticket->team_id === (int) $value) {
            return;
        }

        $team = Team::query()->find($value);

        if ($team) {
            $this->tickets->setTeam($ticket, $team);
        }
    }

    protected function applySetAssignee(Ticket $ticket, null|string|int $value): void
    {
        if ($value === null || (int) $ticket->assignee_id === (int) $value) {
            return;
        }

        $assignee = User::query()->find($value);

        if ($assignee) {
            $this->tickets->setAssignee($ticket, $assignee);
        }
    }

    protected function applySendNotification(Ticket $ticket, array $action): void
    {
        $templateId = $action['email_template_id'] ?? null;

        if (! $templateId) {
            return;
        }

        $this->tickets->sendCustomNotification($ticket, $action['recipient'] ?? 'client', (int) $templateId);
    }
}