<?php

declare(strict_types=1);

namespace Modules\Helpdesk\Livewire;

use App\Models\User;
use Illuminate\Contracts\View\View;
use Illuminate\Database\Eloquent\Collection as EloquentCollection;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\Rule;
use Illuminate\Support\Facades\Schema;
use Livewire\Attributes\Validate;
use Livewire\Component;
use Livewire\Features\SupportFileUploads\TemporaryUploadedFile;
use Livewire\WithFileUploads;
use Modules\Helpdesk\Models\CannedResponse;
use Modules\Helpdesk\Models\ChecklistItem;
use Modules\Helpdesk\Models\Priority;
use Modules\Helpdesk\Models\Status;
use Modules\Helpdesk\Models\Ticket;
use Modules\Helpdesk\Services\CannedResponseRenderer;
use Modules\Helpdesk\Services\ChecklistService;
use Modules\Helpdesk\Services\SlaService;
use Modules\Helpdesk\Services\TicketService;
use Modules\Helpdesk\Services\WorkflowNotificationService;

final class TicketShow extends Component
{
    use WithFileUploads;

    public Ticket $ticket;

    #[Validate('required|string|min:2')]
    public string $commentBody = '';

    public bool $internal = false;

    /** @var array<int, TemporaryUploadedFile> */
    public array $attachments = [];

    public ?int $status_id = null;

    public ?int $priority_id = null;

    public ?int $agent_id = null;

    public ?int $reply_parent_id = null;

    public string $replyBody = '';

    public ?int $canned_response_id = null;

    public function mount(Ticket $ticket): void
    {
        $this->ticket = $this->freshTicket($ticket);
        $this->authorize('view', $this->ticket);
        $this->status_id = $this->ticket->status_id;
        $this->priority_id = $this->ticket->priority_id;
        $this->agent_id = $this->ticket->agent_id;
    }

    public function startReply(int $commentId): void
    {
        $this->reply_parent_id = $commentId;
        $this->replyBody = '';
    }

    public function cancelReply(): void
    {
        $this->reply_parent_id = null;
        $this->replyBody = '';
    }

    public function addComment(TicketService $tickets): void
    {
        $this->authorize('comment', $this->ticket);

        $this->validate([
            'commentBody' => ['required', 'string', 'min:2'],
            'attachments.*' => 'file|max:'.config('helpdesk.max_upload_kb', 10240).'|mimes:'.implode(',', config('helpdesk.allowed_mimes', ['jpg', 'jpeg', 'png', 'pdf', 'txt', 'log', 'zip'])),
        ]);

        $tickets->comment($this->ticket, Auth::user(), $this->commentBody, $this->internal, $this->attachments);

        $this->reset(['commentBody', 'internal', 'attachments']);
        $this->ticket = $this->freshTicket($this->ticket);
        $this->dispatch('helpdesk-editor-reset', model: 'commentBody');
        $this->dispatch('helpdesk-comment-added');
    }

    public function addReply(TicketService $tickets): void
    {
        $this->authorize('comment', $this->ticket);

        $this->validate([
            'reply_parent_id' => ['required', 'integer', 'exists:helpdesk_comments,id'],
            'replyBody' => ['required', 'string', 'min:2'],
        ]);

        $tickets->comment($this->ticket, Auth::user(), $this->replyBody, $this->internal, [], $this->reply_parent_id);

        $this->reset(['reply_parent_id', 'replyBody']);
        $this->ticket = $this->freshTicket($this->ticket);
        $this->dispatch('helpdesk-editor-reset', model: 'replyBody');
        $this->dispatch('helpdesk-reply-added');
    }

    public function applyCannedResponse(CannedResponseRenderer $renderer): void
    {
        $this->authorize('comment', $this->ticket);

        if ($this->canned_response_id === null) {
            return;
        }

        $response = CannedResponse::query()
            ->where('is_active', true)
            ->findOrFail($this->canned_response_id);

        $rendered = $renderer->render($response->body, $this->ticket, Auth::user());
        $this->commentBody = trim($this->commentBody."\n\n".$rendered);
        $this->dispatch('helpdesk-canned-response-applied', body: $this->commentBody);
    }

    public function toggleChecklistItem(int $itemId, ChecklistService $checklists): void
    {
        $this->authorize('update', $this->ticket);

        $item = ChecklistItem::query()
            ->where('ticket_id', $this->ticket->id)
            ->findOrFail($itemId);

        $checklists->toggle($item, Auth::user());
        $this->ticket = $this->freshTicket($this->ticket);
    }

    /**
     * Persist the selected ticket status using a direct table update so Livewire UI wrappers cannot silently fail.
     */
    public function updateStatus(WorkflowNotificationService $workflow, SlaService $sla): void
    {
        $this->authorize('update', $this->ticket);

        $statusId = $this->normaliseNullableInt($this->status_id);

        validator(
            ['status_id' => $statusId],
            ['status_id' => ['required', 'integer', Rule::exists('helpdesk_statuses', 'id')]],
        )->validate();

        $status = Status::query()->findOrFail($statusId);

        $updates = [
            'status_id' => $status->id,
            'completed_at' => $status->is_closed ? now() : null,
            'last_activity_at' => now(),
        ];

        if (Schema::hasColumn('helpdesk_tickets', 'updated_at')) {
            $updates['updated_at'] = now();
        }

        DB::table('helpdesk_tickets')
            ->where('id', $this->ticket->id)
            ->update($updates);

        $this->ticket = $this->freshTicket($this->ticket);
        $this->status_id = (int) $this->ticket->status_id;

        if ($status->is_closed) {
            $sla->recordClosure($this->ticket);
        }

        $workflow->dispatch($this->ticket, $status->is_closed ? 'ticket.closed' : 'ticket.updated', Auth::user());

        session()->flash('ticket-action-updated', 'Status updated to '.$this->ticket->status?->name.'.');
        $this->dispatch('helpdesk-status-updated', statusId: $this->status_id);
    }

    /**
     * Persist the selected ticket priority using a direct table update.
     */
    public function updatePriority(WorkflowNotificationService $workflow): void
    {
        $this->authorize('update', $this->ticket);

        $priorityId = $this->normaliseNullableInt($this->priority_id);

        validator(
            ['priority_id' => $priorityId],
            ['priority_id' => ['required', 'integer', Rule::exists('helpdesk_priorities', 'id')]],
        )->validate();

        $updates = [
            'priority_id' => $priorityId,
            'last_activity_at' => now(),
        ];

        if (Schema::hasColumn('helpdesk_tickets', 'updated_at')) {
            $updates['updated_at'] = now();
        }

        DB::table('helpdesk_tickets')
            ->where('id', $this->ticket->id)
            ->update($updates);

        $this->ticket = $this->freshTicket($this->ticket);
        $this->priority_id = (int) $this->ticket->priority_id;

        $workflow->dispatch($this->ticket, 'ticket.updated', Auth::user());

        session()->flash('ticket-action-updated', 'Priority updated to '.$this->ticket->priority?->name.'.');
        $this->dispatch('helpdesk-priority-updated', priorityId: $this->priority_id);
    }

    /**
     * Persist the selected ticket assignee.
     */
    public function updateAgent(WorkflowNotificationService $workflow): void
    {
        $this->authorize('update', $this->ticket);

        $agentId = $this->normaliseNullableInt($this->agent_id);

        validator(
            ['agent_id' => $agentId],
            ['agent_id' => ['nullable', 'integer', Rule::exists('users', 'id')]],
        )->validate();

        abort_unless(Schema::hasColumn('helpdesk_tickets', 'agent_id'), 500, 'The helpdesk_tickets.agent_id column is missing.');

        $updates = [
            'agent_id' => $agentId,
            'last_activity_at' => now(),
        ];

        if (Schema::hasColumn('helpdesk_tickets', 'updated_at')) {
            $updates['updated_at'] = now();
        }

        DB::table('helpdesk_tickets')
            ->where('id', $this->ticket->id)
            ->update($updates);

        $this->ticket = $this->freshTicket($this->ticket);
        $this->agent_id = $this->ticket->agent_id === null ? null : (int) $this->ticket->agent_id;

        $workflow->dispatch($this->ticket, 'ticket.updated', Auth::user());

        session()->flash('ticket-action-updated', $this->agent_id === null
            ? 'Ticket is now unassigned.'
            : 'Ticket assigned to '.$this->ticket->agent?->name.'.');

        $this->dispatch('helpdesk-agent-updated', agentId: $this->agent_id);
    }

    public function render(): View
    {
        return view('helpdesk::livewire.ticket-show', [
            'statuses' => Status::query()->orderBy('sort_order')->get(),
            'priorities' => Priority::query()->orderBy('sort_order')->get(),
            'agents' => $this->agentOptions(),
            'cannedResponses' => CannedResponse::query()->where('is_active', true)->orderBy('sort_order')->orderBy('name')->get(),
        ])->layout('layouts.app');
    }

    /**
     * Convert Livewire select values into a nullable integer.
     */
    private function normaliseNullableInt(mixed $value): ?int
    {
        if ($value === null || $value === '' || $value === '0' || $value === 0) {
            return null;
        }

        return (int) $value;
    }

    private function freshTicket(Ticket $ticket): Ticket
    {
        $ticket = $ticket->fresh([
            'status',
            'priority',
            'category',
            'project',
            'team',
            'product',
            'slaPolicy',
            'slaEvents',
            'ratings',
            'tags',
            'checklistItems',
            'attachments',
            'gitCommits.repository',
        ]) ?? $ticket;

        $this->hydrateTicketUsers($ticket);

        $comments = \Modules\Helpdesk\Models\Comment::query()
            ->where('ticket_id', $ticket->id)
            ->with(['user.company', 'attachments'])
            ->oldest()
            ->get();

        $ticket->setRelation('comments', $this->buildCommentTree($comments->groupBy('parent_id')));

        return $ticket;
    }

    /**
     * Load owner and agent users with one query and attach aliases used by the view/workflow.
     */
    private function hydrateTicketUsers(Ticket $ticket): void
    {
        $userIds = collect([$ticket->user_id, $ticket->agent_id])
            ->filter()
            ->map(static fn (mixed $id): int => (int) $id)
            ->unique()
            ->values();

        if ($userIds->isEmpty()) {
            $ticket->setRelation('user', null);
            $ticket->setRelation('owner', null);
            $ticket->setRelation('agent', null);

            return;
        }

        $users = User::query()
            ->with('company')
            ->whereIn('id', $userIds)
            ->get()
            ->keyBy('id');

        $owner = $users->get((int) $ticket->user_id);
        $agent = $ticket->agent_id === null ? null : $users->get((int) $ticket->agent_id);

        $ticket->setRelation('user', $owner);
        $ticket->setRelation('owner', $owner);
        $ticket->setRelation('agent', $agent);
    }

    /**
     * Return assignable users for this ticket.
     *
     * The dropdown must never be blank just because optional helpdesk_agent/helpdesk_admin
     * flags are missing or false. Prefer tenant/company users, then fall back to all users.
     *
     * @return EloquentCollection<int, User>
     */
    private function agentOptions(): EloquentCollection
    {
        $columns = ['id', 'name', 'email'];

        if (Schema::hasColumn('users', 'company_id')) {
            $columns[] = 'company_id';
        }

        $query = User::query()->select($columns)->orderBy('name');

        if ($this->ticket->company_id !== null && Schema::hasColumn('users', 'company_id')) {
            $tenantUsers = (clone $query)
                ->where(function ($query): void {
                    $query->where('company_id', $this->ticket->company_id)
                        ->orWhereNull('company_id');
                })
                ->when($this->agent_id !== null, function ($query): void {
                    $query->orWhere('id', $this->agent_id);
                })
                ->get();

            if ($tenantUsers->isNotEmpty()) {
                return $tenantUsers;
            }
        }

        return $query->get();
    }

    private function buildCommentTree(Collection $grouped, ?int $parentId = null): Collection
    {
        return $grouped->get($parentId, collect())->map(function ($comment) use ($grouped) {
            $comment->setRelation('replies', $this->buildCommentTree($grouped, (int) $comment->id));

            return $comment;
        })->values();
    }
}