<?php
defined('BASEPATH') OR exit('No direct script access allowed');

require_once APPPATH . 'exceptions/BusinessException.php';

class CompanyContext
{
    private $CI;
    private $id;

    public function __construct()
    {
        $this->CI =& get_instance();
    }

    public function id()
    {
        if ($this->id) {
            return $this->id;
        }

        $userId = (int) $this->CI->session->userdata('user_id');
        $selected = (int) $this->CI->session->userdata('company_id');

        if ($selected && $this->hasAccess($userId, $selected)) {
            return $this->id = $selected;
        }

        $access = $this->CI->db
            ->where('user_id', $userId)
            ->order_by('is_default', 'DESC')
            ->order_by('id', 'ASC')
            ->get('user_companies')
            ->row();

        // Memulihkan user lama yang dibuat sebelum relasi perusahaan diterapkan.
        // Auto-assignment hanya aman jika memang hanya ada satu perusahaan aktif.
        if (!$access) {
            $access = $this->assignSoleActiveCompany($userId);
        }

        if (!$access) {
            throw new BusinessException('User belum diberi akses perusahaan. Hubungi administrator.');
        }

        $this->CI->session->set_userdata('company_id', (int) $access->company_id);
        return $this->id = (int) $access->company_id;
    }

    public function assertAccess($companyId)
    {
        if (!$this->hasAccess((int) $this->CI->session->userdata('user_id'), (int) $companyId)) {
            throw new BusinessException('Akses perusahaan ditolak.');
        }
        return true;
    }

    public function scope($builder, $column = 'company_id')
    {
        $builder->where($column, $this->id());
        return $builder;
    }

    private function hasAccess($userId, $companyId)
    {
        return (bool) $this->CI->db->get_where('user_companies', array(
            'user_id' => (int) $userId,
            'company_id' => (int) $companyId,
        ))->row();
    }

    private function assignSoleActiveCompany($userId)
    {
        if ($userId < 1 || !$this->CI->db->table_exists('companies')) {
            return null;
        }

        $companies = $this->CI->db
            ->select('id')
            ->where('is_active', 1)
            ->order_by('id', 'ASC')
            ->limit(2)
            ->get('companies')
            ->result();

        if (count($companies) !== 1) {
            return null;
        }

        $companyId = (int) $companies[0]->id;
        $this->CI->db->query(
            'INSERT IGNORE INTO user_companies (user_id, company_id, is_default, can_consolidate) VALUES (?, ?, 1, 0)',
            array($userId, $companyId)
        );

        if (!$this->hasAccess($userId, $companyId)) {
            throw new RuntimeException('Akses perusahaan pengguna gagal disiapkan.');
        }

        return (object) array('company_id' => $companyId);
    }
}