<?php

namespace App\Services\Messaging;

use App\Models\Conversation;
use App\Models\ConversationParticipant;
use App\Models\Message;
use App\Models\MessageAttachment;
use App\Models\User;

class MessagingPayloadFactory
{
    public function message(Message $message, ?int $viewerId = null): array
    {
        $message->loadMissing([
            'sender:id,username,name',
            'attachments',
            'reactions',
        ]);

        return [
            'id' => (int) $message->id,
            'uuid' => (string) $message->uuid,
            'client_temp_id' => $message->client_temp_id,
            'conversation_id' => (int) $message->conversation_id,
            'sender_id' => (int) $message->sender_id,
            'sender' => $this->userSummary($message->sender),
            'message_type' => (string) ($message->message_type ?? 'text'),
            'body' => (string) ($message->body ?? ''),
            'reply_to_message_id' => $message->reply_to_message_id ? (int) $message->reply_to_message_id : null,
            'attachments' => $message->attachments->map(fn (MessageAttachment $attachment) => $this->attachment($attachment))->values()->all(),
            'reaction_summary' => $this->reactionSummary($message, $viewerId),
            'edited_at' => optional($message->edited_at)?->toIso8601String(),
            'deleted_at' => optional($message->deleted_at)?->toIso8601String(),
            'created_at' => optional($message->created_at)?->toIso8601String(),
            'updated_at' => optional($message->updated_at)?->toIso8601String(),
        ];
    }

    public function conversationSummary(Conversation $conversation, int $viewerId): array
    {
        $conversation->loadMissing([
            'allParticipants.user:id,username,name',
            'latestMessage.sender:id,username,name',
            'latestMessage.attachments',
            'latestMessage.reactions',
        ]);

        /** @var ConversationParticipant|null $myParticipant */
        $myParticipant = $conversation->allParticipants->firstWhere('user_id', $viewerId);

        return [
            'id' => (int) $conversation->id,
            'uuid' => (string) $conversation->uuid,
            'type' => (string) $conversation->type,
            'title' => $conversation->title,
            'is_active' => (bool) ($conversation->is_active ?? true),
            'last_message_at' => optional($conversation->last_message_at)?->toIso8601String(),
            'unread_count' => app(UnreadCounterService::class)->unreadCountForConversation($conversation, $viewerId),
            'my_participant' => $myParticipant ? $this->participant($myParticipant) : null,
            'all_participants' => $conversation->allParticipants
                ->whereNull('left_at')
                ->map(fn (ConversationParticipant $participant) => $this->participant($participant))
                ->values()
                ->all(),
            'latest_message' => $conversation->latestMessage
                ? $this->message($conversation->latestMessage, $viewerId)
                : null,
        ];
    }

    public function presenceUser(User $user): array
    {
        return [
            'id' => (int) $user->id,
            'username' => (string) $user->username,
            'display_name' => (string) ($user->name ?: $user->username),
            'avatar_thumb_url' => null,
        ];
    }

    public function userSummary(?User $user): array
    {
        if (! $user) {
            return [
                'id' => null,
                'username' => null,
                'display_name' => null,
                'avatar_thumb_url' => null,
            ];
        }

        return [
            'id' => (int) $user->id,
            'username' => (string) $user->username,
            'display_name' => (string) ($user->name ?: $user->username),
            'avatar_thumb_url' => null,
        ];
    }

    private function participant(ConversationParticipant $participant): array
    {
        return [
            'id' => (int) $participant->id,
            'user_id' => (int) $participant->user_id,
            'role' => (string) $participant->role,
            'last_read_at' => optional($participant->last_read_at)?->toIso8601String(),
            'last_read_message_id' => $participant->last_read_message_id ? (int) $participant->last_read_message_id : null,
            'is_muted' => (bool) $participant->is_muted,
            'is_archived' => (bool) $participant->is_archived,
            'is_pinned' => (bool) $participant->is_pinned,
            'is_hidden' => (bool) ($participant->is_hidden ?? false),
            'pinned_at' => optional($participant->pinned_at)?->toIso8601String(),
            'joined_at' => optional($participant->joined_at)?->toIso8601String(),
            'left_at' => optional($participant->left_at)?->toIso8601String(),
            'user' => $this->userSummary($participant->user),
        ];
    }

    private function attachment(MessageAttachment $attachment): array
    {
        return [
            'id' => (int) $attachment->id,
            'disk' => (string) ($attachment->disk ?: config('messaging.attachments.disk', 'local')),
            'type' => (string) $attachment->type,
            'mime' => (string) $attachment->mime,
            'size_bytes' => (int) $attachment->size_bytes,
            'width' => $attachment->width ? (int) $attachment->width : null,
            'height' => $attachment->height ? (int) $attachment->height : null,
            'original_name' => (string) $attachment->original_name,
        ];
    }

    private function reactionSummary(Message $message, ?int $viewerId = null): array
    {
        $counts = [];
        $mine = [];

        foreach ($message->reactions as $reaction) {
            $emoji = (string) $reaction->reaction;
            $counts[$emoji] = ($counts[$emoji] ?? 0) + 1;

            if ($viewerId !== null && (int) $reaction->user_id === $viewerId) {
                $mine[] = $emoji;
            }
        }

        $counts['me'] = array_values(array_unique($mine));

        return $counts;
    }
}