<?php

namespace app\controller\api;

use app\model\Conversation as ConversationModel;
use app\model\Message;
use app\service\PermissionService;
use think\exception\HttpResponseException;

class Conversation extends BaseApi
{
    public function index()
    {
        $user = $this->authUser();
        $page = max(1, (int) $this->request->get('page', 1));
        $limit = min(50, max(1, (int) $this->request->get('limit', 20)));

        $query = ConversationModel::alias('c')
            ->leftJoin('ai_models m', 'c.model_id = m.id')
            ->where('c.user_id', $user['id'])
            ->whereNull('c.deleted_at')
            ->field('c.*,m.name as model_name')
            ->order(['c.is_pinned' => 'desc', 'c.updated_at' => 'desc']);

        $total = (clone $query)->count();
        $list = $query->page($page, $limit)->select();

        return $this->success([
            'list'  => $list,
            'total' => $total,
            'page'  => $page,
            'limit' => $limit,
        ]);
    }

    public function create()
    {
        $user = $this->authUser();
        PermissionService::checkConversationLimit($user);

        $input = $this->request->post();
        $conversation = ConversationModel::create([
            'user_id'  => $user['id'],
            'title'    => trim($input['title'] ?? '新对话'),
            'model_id' => $input['model_id'] ?? null,
        ]);

        return $this->success($this->findConversation((int) $conversation->id, (int) $user['id']), '创建成功');
    }

    public function show($id)
    {
        $user = $this->authUser();
        return $this->success($this->findConversation((int) $id, (int) $user['id']));
    }

    public function update($id)
    {
        $user = $this->authUser();
        $conversation = ConversationModel::where('id', $id)
            ->where('user_id', $user['id'])
            ->whereNull('deleted_at')
            ->find();

        if (!$conversation) {
            return $this->error('会话不存在', 404);
        }

        $input = $this->request->put();
        $data = [];
        if (isset($input['title'])) {
            $data['title'] = trim($input['title']);
        }
        if (isset($input['is_pinned'])) {
            $data['is_pinned'] = (int) $input['is_pinned'];
        }
        if (array_key_exists('model_id', $input)) {
            $data['model_id'] = $input['model_id'];
        }

        if (empty($data)) {
            return $this->error('无更新内容');
        }

        $conversation->save($data);
        return $this->success($this->findConversation((int) $id, (int) $user['id']));
    }

    public function delete($id)
    {
        $user = $this->authUser();
        $conversation = ConversationModel::where('id', $id)
            ->where('user_id', $user['id'])
            ->whereNull('deleted_at')
            ->find();

        if (!$conversation) {
            return $this->error('会话不存在', 404);
        }

        $conversation->save(['deleted_at' => date('Y-m-d H:i:s')]);
        return $this->success(null, '删除成功');
    }

    public function messages($id)
    {
        $user = $this->authUser();
        $this->findConversation((int) $id, (int) $user['id']);

        $messages = Message::where('conversation_id', $id)
            ->field('id,role,content,content_type,attachments,created_at')
            ->order('created_at', 'asc')
            ->select()
            ->each(function ($item) {
                if (is_string($item->attachments)) {
                    $item->attachments = json_decode($item->attachments, true) ?: [];
                }
                return $item;
            });

        return $this->success($messages);
    }

    private function findConversation(int $id, int $userId): array
    {
        $conversation = ConversationModel::alias('c')
            ->leftJoin('ai_models m', 'c.model_id = m.id')
            ->where('c.id', $id)
            ->where('c.user_id', $userId)
            ->whereNull('c.deleted_at')
            ->field('c.*,m.name as model_name')
            ->find();

        if (!$conversation) {
            throw new HttpResponseException(json([
                'code'    => 1,
                'message' => '会话不存在',
                'data'    => null,
            ], 404));
        }

        return $conversation->toArray();
    }
}