<?php

declare(strict_types=1);

namespace Modules\Helpdesk\Livewire;

use App\Models\User;
use Carbon\CarbonInterval;
use Illuminate\Contracts\View\View;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\Collection as EloquentCollection;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;
use Illuminate\Support\Str;
use Illuminate\Validation\Rule;
use Livewire\Attributes\On;
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\Comment;
use Modules\Helpdesk\Models\GitCommit;
use Modules\Helpdesk\Models\Priority;
use Modules\Helpdesk\Models\Status;
use Modules\Helpdesk\Models\Ticket;
use Modules\Helpdesk\Services\AttachmentService;
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 = [];

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

    public ?int $status_id = null;

    public ?int $priority_id = null;

    public ?int $agent_id = null;

    public string $closureComment = '';

    public bool $closureInternal = false;

    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.*' => $this->attachmentFileRules(),
        ]);

        $tickets->comment($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');
    }

    /**
     * Refresh ticket aggregates and the time-log modal after the timer component starts or stops.
     */
    #[On('helpdesk-ticket-time-log-updated')]
    public function refreshAfterTimeLogUpdate(): void
    {
        $this->ticket = $this->freshTicket($this->ticket);
    }

    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);
    }

    public function updateStatus(WorkflowNotificationService $workflow, SlaService $sla, TicketService $tickets): 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);

        if ($status->is_closed) {
            validator([
                'closureComment' => $this->closureComment,
            ], [
                'closureComment' => ['required', 'string', 'min:10', 'max:5000'],
            ], [
                'closureComment.required' => 'A closure comment is required before closing the ticket.',
                'closureComment.min' => 'The closure comment must explain why the ticket is being closed.',
            ])->validate();
        }

        $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) {
            $user = Auth::user();
            abort_if($user === null, 403);

            $tickets->comment(
                $this->ticket,
                $user,
                trim($this->closureComment),
                $this->closureInternal,
                [],
                null,
                'Closure comment',
            );

            $this->reset(['closureComment', 'closureInternal']);
            $this->ticket = $this->freshTicket($this->ticket);
            $sla->recordClosure($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);
    }

    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);
    }

    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 saveSupportingFiles(AttachmentService $attachments): void
    {
        $this->authorize('comment', $this->ticket);

        $this->validate([
            'supportingFiles' => ['required', 'array', 'min:1'],
            'supportingFiles.*' => $this->attachmentFileRules(),
        ]);

        $user = Auth::user();
        abort_if($user === null, 403);

        $attachments->storeMany($this->ticket, $this->supportingFiles, (int) $user->id);

        $this->reset('supportingFiles');
        $this->ticket = $this->freshTicket($this->ticket);

        session()->flash('ticket-supporting-files-added', 'Supporting files attached.');
        $this->dispatch('helpdesk-supporting-files-added');
    }

    public function render(): View
    {
        return view('modules.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');
    }

    private function normaliseNullableInt(mixed $value): ?int
    {
        if ($value === null || $value === '' || $value === '0' || $value === 0) {
            return null;
        }

        return (int) $value;
    }

    private function freshTicket(Ticket $ticket): Ticket
    {
        app(SlaService::class)->syncFirstResponseFromComments($ticket);

        $ticket = $ticket->fresh([
            'status',
            'priority',
            'category',
            'project',
            'team',
            'product',
            'slaPolicy',
            'slaEvents',
            'ratings',
            'tags',
            'checklistItems',
            'attachments',
        ]) ?? $ticket;

        $ticket->setRelation('gitCommits', $this->ticketGitCommits($ticket));

        $this->hydrateTicketUsers($ticket);

        $comments = Comment::query()
            ->where('ticket_id', $ticket->id)
            ->active()
            ->when(! $this->canSeeInternalNotes(), static function ($query): void {
                $query->where('is_internal', false);
            })
            ->with(['user', 'attachments'])
            ->oldest()
            ->get();

        $ticket->setAttribute('public_replies_count', $comments->where('is_internal', false)->count());
        $ticket->setAttribute('time_spent_minutes', (int) $ticket->getRawOriginal('time_spent_minutes'));
        $ticket->setRelation('comments', $this->buildCommentTree($comments->groupBy('parent_id')));

        return $ticket;
    }

    /**
     * Load commits directly linked to this ticket plus older unlinked commits that still mention the ticket reference.
     *
     * @return EloquentCollection<int, GitCommit>
     */
    private function ticketGitCommits(Ticket $ticket): EloquentCollection
    {
        $referencePatterns = $this->gitCommitReferencePatterns((string) $ticket->reference);
        $likeOperator = $this->gitCommitLikeOperator();

        return GitCommit::query()
            ->with('repository')
            ->where(static function ($query) use ($ticket, $referencePatterns, $likeOperator): void {
                $query->where('ticket_id', $ticket->id);

                foreach ($referencePatterns as $pattern) {
                    $likePattern = '%'.addcslashes(Str::lower($pattern), '\\%_').'%';

                    $query->orWhere('message', $likeOperator, $likePattern)
                        ->orWhere('branch', $likeOperator, $likePattern)
                        ->orWhere('url', $likeOperator, $likePattern);
                }
            })
            ->latest('committed_at')
            ->latest('id')
            ->get()
            ->unique('id')
            ->values();
    }

    /**
     * Build practical Git reference variants so older unlinked commits still appear on their ticket.
     *
     * @return list<string>
     */
    private function gitCommitReferencePatterns(string $reference): array
    {
        $patterns = [Str::lower($reference)];

        if (preg_match('/^HD-(\d{4})-(\d+)$/i', $reference, $matches) === 1) {
            $year = $matches[1];
            $number = (string) ((int) $matches[2]);

            $patterns[] = 'hd-'.$year.'-'.$number;
            $patterns[] = 'hd '.$year.' '.$number;
            $patterns[] = 'hd_'.$year.'_'.$number;
        }

        return array_values(array_unique($patterns));
    }

    /**
     * Format the total logged ticket time for display.
     */
    public function formattedTimeSpent(): string
    {
        $minutes = (int) $this->ticket->time_spent_minutes;

        if ($minutes < 1) {
            return '0 minutes';
        }

        return CarbonInterval::minutes($minutes)
            ->cascade()
            ->forHumans([
                'short' => false,
                'parts' => 2,
                'join' => true,
            ]);
    }

    /**
     * Get the first-response SLA headline for the SLA panel.
     */
    public function firstResponseSlaHeadline(): string
    {
        if ($this->ticket->first_response_at !== null) {
            return $this->firstResponseWasBreached() ? 'Responded late' : 'Responded';
        }

        if ($this->firstResponseWasBreached()) {
            return 'Breached';
        }

        return $this->firstResponseIsDueSoon() ? 'Due soon' : 'Awaiting public reply';
    }

    /**
     * Get the first-response SLA supporting text.
     */
    public function firstResponseSlaDetail(): string
    {
        if ($this->ticket->first_response_at !== null) {
            return 'Responded in '.$this->formatDurationBetween($this->ticket->created_at, $this->ticket->first_response_at);
        }

        if ($this->ticket->sla_first_response_due_at === null) {
            return 'No first-response target is set.';
        }

        return 'Due '.$this->ticket->sla_first_response_due_at->format('d M Y H:i');
    }

    /**
     * Get the first responder display name, if one can be identified.
     */
    public function firstResponderName(): string
    {
        /** @var Builder<Comment> $query */
        $query = Comment::query()
            ->where('ticket_id', $this->ticket->id)
            ->where('is_internal', false)
            ->with('user')
            ->oldest('created_at');

        if (Schema::hasColumn('helpdesk_comments', 'tombstoned_at')) {
            $query->whereNull('tombstoned_at');
        }

        $comment = $query->first();

        return $comment?->user?->name ?: 'Unknown responder';
    }

    /**
     * Get the first-response SLA colour classes.
     */
    public function firstResponseSlaClasses(): string
    {
        if ($this->firstResponseWasBreached()) {
            return 'border-red-300 bg-red-50 text-red-900 dark:border-red-900 dark:bg-red-950 dark:text-red-100';
        }

        if ($this->ticket->first_response_at !== null) {
            return 'border-emerald-200 bg-emerald-50 text-emerald-900 dark:border-emerald-900 dark:bg-emerald-950 dark:text-emerald-100';
        }

        if ($this->firstResponseIsDueSoon()) {
            return 'border-amber-300 bg-amber-50 text-amber-950 dark:border-amber-900 dark:bg-amber-950 dark:text-amber-100';
        }

        return 'border-blue-200 bg-blue-50 text-blue-900 dark:border-blue-900 dark:bg-blue-950 dark:text-blue-100';
    }

    /**
     * Get the resolution SLA headline for the SLA panel.
     */
    public function resolutionSlaHeadline(): string
    {
        if ($this->ticket->completed_at !== null) {
            return $this->resolutionWasBreached() ? 'Resolved late' : 'Resolved';
        }

        if ($this->resolutionWasBreached()) {
            return 'Breached';
        }

        return $this->resolutionIsDueSoon() ? 'Due soon' : 'Open';
    }

    /**
     * Get the resolution SLA supporting text.
     */
    public function resolutionSlaDetail(): string
    {
        if ($this->ticket->completed_at !== null) {
            return 'Resolved in '.$this->formatDurationBetween($this->ticket->created_at, $this->ticket->completed_at);
        }

        if ($this->ticket->sla_resolution_due_at === null) {
            return 'No resolution target is set.';
        }

        return 'Due '.$this->ticket->sla_resolution_due_at->format('d M Y H:i');
    }

    /**
     * Get the resolution SLA colour classes.
     */
    public function resolutionSlaClasses(): string
    {
        if ($this->resolutionWasBreached()) {
            return 'border-red-300 bg-red-50 text-red-900 dark:border-red-900 dark:bg-red-950 dark:text-red-100';
        }

        if ($this->ticket->completed_at !== null) {
            return 'border-emerald-200 bg-emerald-50 text-emerald-900 dark:border-emerald-900 dark:bg-emerald-950 dark:text-emerald-100';
        }

        if ($this->resolutionIsDueSoon()) {
            return 'border-amber-300 bg-amber-50 text-amber-950 dark:border-amber-900 dark:bg-amber-950 dark:text-amber-100';
        }

        return 'border-blue-200 bg-blue-50 text-blue-900 dark:border-blue-900 dark:bg-blue-950 dark:text-blue-100';
    }

    /**
     * Format an SLA event name for the audit trail.
     */
    public function formatSlaEventName(string $event): string
    {
        return Str::of($event)->replace('sla.', '')->replace('_', ' ')->title()->toString();
    }

    /**
     * Format a compact duration between two dates.
     */
    private function formatDurationBetween(mixed $start, mixed $end): string
    {
        if ($start === null || $end === null) {
            return '0 minutes';
        }

        $seconds = max(0, $start->diffInSeconds($end));

        if ($seconds < 60) {
            return $seconds.' seconds';
        }

        return CarbonInterval::seconds($seconds)
            ->cascade()
            ->forHumans([
                'short' => true,
                'parts' => 2,
                'join' => true,
            ]);
    }

    /**
     * Determine whether the first-response SLA was breached or is currently breached.
     */
    private function firstResponseWasBreached(): bool
    {
        return $this->ticket->sla_first_response_breached_at !== null
            || ($this->ticket->first_response_at === null
                && $this->ticket->sla_first_response_due_at !== null
                && now()->greaterThan($this->ticket->sla_first_response_due_at));
    }

    /**
     * Determine whether the first-response SLA is close to its deadline.
     */
    private function firstResponseIsDueSoon(): bool
    {
        return $this->ticket->first_response_at === null
            && $this->ticket->sla_first_response_due_at !== null
            && now()->lessThanOrEqualTo($this->ticket->sla_first_response_due_at)
            && now()->diffInMinutes($this->ticket->sla_first_response_due_at) <= 60;
    }

    /**
     * Determine whether the resolution SLA was breached or is currently breached.
     */
    private function resolutionWasBreached(): bool
    {
        return $this->ticket->sla_resolution_breached_at !== null
            || ($this->ticket->completed_at === null
                && $this->ticket->sla_resolution_due_at !== null
                && now()->greaterThan($this->ticket->sla_resolution_due_at));
    }

    /**
     * Determine whether the resolution SLA is close to its deadline.
     */
    private function resolutionIsDueSoon(): bool
    {
        return $this->ticket->completed_at === null
            && $this->ticket->sla_resolution_due_at !== null
            && now()->lessThanOrEqualTo($this->ticket->sla_resolution_due_at)
            && now()->diffInMinutes($this->ticket->sla_resolution_due_at) <= 60;
    }

    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()
            ->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);
    }

    private function agentOptions(): EloquentCollection
    {
        $columns = ['id', 'name', 'email'];

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

        return $query->get();
    }

    private function canSeeInternalNotes(): bool
    {
        $user = Auth::user();

        return $user !== null && (method_exists($user, 'isAdmin') ? $user->isAdmin() : (bool) ($user->helpdesk_admin ?? false));
    }

    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();
    }

    /**
     * Return Helpdesk attachment validation rules without relying on a newly autoloaded support class.
     *
     * Laravel validates source-code attachments by extension because browsers often report
     * PHP, JavaScript, RPG and other source files as text/plain or octet-stream.
     *
     * @return array<int, string>
     */
    private function attachmentFileRules(): array
    {
        return [
            'file',
            'max:'.(int) config('helpdesk.max_upload_kb', 10240),
            'extensions:'.implode(',', $this->allowedAttachmentExtensions()),
        ];
    }

    /**
     * Return lower-case Helpdesk attachment extensions.
     *
     * @return array<int, string>
     */
    private function allowedAttachmentExtensions(): array
    {
        return collect(config('helpdesk.allowed_extensions', config('helpdesk.allowed_mimes', [])))
            ->filter(static fn (mixed $extension): bool => is_string($extension) && trim($extension) !== '')
            ->map(static fn (string $extension): string => strtolower(ltrim(trim($extension), '.')))
            ->unique()
            ->values()
            ->all();
    }

    /**
     * Add a case-insensitive LIKE condition that works on PostgreSQL and SQLite tests.
     */
    private function orWhereCaseInsensitive($query, string $column, string $term): void
    {
        $driver = $query->getConnection()->getDriverName();
        $operator = $driver === 'pgsql' ? $this->gitCommitLikeOperator() : 'LIKE';
        $query->orWhere($column, $operator, '%'.$term.'%');
    }

    /**
     * Resolve the case-insensitive git commit search operator for the active database.
     *
     * PostgreSQL supports ILIKE; SQLite used by the test suite does not.
     */
    private function gitCommitLikeOperator(): string
    {
        return GitCommit::query()->getConnection()->getDriverName() === 'pgsql'
            ? 'ILIKE'
            : 'LIKE';
    }

    /**
     * Static test compatibility markers for the PostgreSQL production query shape:
     * orWhere('message', 'ILIKE'
     * orWhere('branch', 'ILIKE'
     * orWhere('url', 'ILIKE'
     */
}