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

require_once APPPATH . 'exceptions/BusinessException.php';

class NumberingService
{
    private $CI;
    private $sequenceTableAvailable;

    public function __construct()
    {
        $this->CI =& get_instance();
        $this->CI->config->load('accounting', true);
        $this->CI->load->library('CompanyContext');
        $this->sequenceTableAvailable = $this->CI->db->table_exists('document_sequences');
    }

    public function next($type, $date = null)
    {
        $date = $date ?: date('Y-m-d');
        $timestamp = strtotime($date);
        if ($timestamp === false) {
            throw new BusinessException('Tanggal penomoran dokumen tidak valid.');
        }

        $settings = (array) $this->CI->config->item('document_numbering', 'accounting');
        if (!isset($settings[$type])) {
            throw new BusinessException('Jenis penomoran "' . $type . '" belum dikonfigurasi.');
        }

        $prefix = $settings[$type]['prefix'] . '-' . date('Ymd', $timestamp) . '-';
        $padding = (int) $settings[$type]['padding'];
        $period = date('Ymd', $timestamp);

        if ($this->sequenceTableAvailable) {
            $initialValue = $this->nextLegacyValue($type, $prefix);
            $number = $this->nextAtomicValue($type, $period, $prefix, $initialValue);
        } else {
            $number = $this->nextLegacyValue($type, $prefix);
        }

        return $prefix . str_pad($number, $padding, '0', STR_PAD_LEFT);
    }

    private function nextAtomicValue($type, $period, $prefix, $initialValue)
    {
        $companyId = (int) $this->CI->companycontext->id();
        $sql = 'INSERT INTO document_sequences (company_id, document_type, period_key, prefix, current_value, updated_at) '
            . 'VALUES (?, ?, ?, ?, ?, NOW()) '
            . 'ON DUPLICATE KEY UPDATE prefix = VALUES(prefix), current_value = LAST_INSERT_ID(current_value + 1), updated_at = NOW()';

        if (!$this->CI->db->query($sql, array($companyId, $type, $period, $prefix, $initialValue))) {
            throw new RuntimeException('Gagal mengambil nomor dokumen berikutnya.');
        }

        if ($this->CI->db->affected_rows() === 1) {
            return (int) $initialValue;
        }

        return (int) $this->CI->db->insert_id();
    }

    private function nextLegacyValue($type, $prefix)
    {
        $source = $type === 'invoice' ? array('invoices', 'no_invoice') : array('journals', 'no_ref');
        $builder = $this->CI->db->select($source[1]);
        if ($this->CI->db->field_exists('company_id', $source[0])) $builder->where('company_id', (int)$this->CI->companycontext->id());
        $row = $builder->like($source[1], $prefix, 'after')
            ->order_by($source[1], 'DESC')
            ->limit(1)
            ->get($source[0])
            ->row();

        if (!$row) {
            return 1;
        }

        $value = $row->{$source[1]};
        return ((int) substr($value, strlen($prefix))) + 1;
    }
}