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

require_once APPPATH . 'exceptions/BusinessException.php';

class FiscalPeriodService
{
    private $CI;

    public function __construct()
    {
        $this->CI =& get_instance();
        $this->CI->load->model('FiscalPeriodModel', 'fiscalPeriodModel');
        $this->CI->load->library('TransactionService');
        $this->CI->load->library('AuditService');
    }

    public function periodForDate($date)
    {
        $parsed = DateTime::createFromFormat('Y-m-d', (string) $date);
        if (!$parsed || $parsed->format('Y-m-d') !== $date) {
            throw new BusinessException('Tanggal periode accounting tidak valid.');
        }

        $period = $this->CI->fiscalPeriodModel->findByDate($date);
        if (!$period) {
            throw new BusinessException('Periode accounting untuk tanggal ' . $date . ' belum tersedia.');
        }
        return $period;
    }

    public function assertOpen($date)
    {
        $period = $this->periodForDate($date);
        if ($period->status !== 'open') {
            throw new BusinessException('Periode ' . $period->name . ' berstatus ' . $period->status . ' dan tidak menerima transaksi.');
        }
        return $period;
    }

    public function changeStatus($periodId, $targetStatus, $userId, $reason = '')
    {
        $allowed = array('open', 'soft_closed', 'closed');
        if (!in_array($targetStatus, $allowed, true)) {
            throw new BusinessException('Status periode tidak valid.');
        }

        return $this->CI->transactionservice->run(function () use ($periodId, $targetStatus, $userId, $reason) {
            $period = $this->CI->db->query('SELECT * FROM accounting_periods WHERE id = ? FOR UPDATE', array((int) $periodId))->row();
            if (!$period) {
                throw new BusinessException('Periode accounting tidak ditemukan.', array(), 404);
            }
            if ($period->status === $targetStatus) {
                return $period;
            }

            $transitions = array(
                'open' => array('soft_closed', 'closed'),
                'soft_closed' => array('open', 'closed'),
                'closed' => array('open')
            );
            if (!in_array($targetStatus, $transitions[$period->status], true)) {
                throw new BusinessException('Perubahan status periode tidak diizinkan.');
            }
            if ($targetStatus === 'open' && $period->status !== 'open' && trim($reason) === '') {
                throw new BusinessException('Alasan membuka kembali periode wajib diisi.');
            }
            if (in_array($targetStatus, array('soft_closed', 'closed'), true)) {
                $pending = $this->CI->db
                    ->where('tanggal >=', $period->start_date)
                    ->where('tanggal <=', $period->end_date)
                    ->where_in('status', array('draft', 'submitted', 'approved'))
                    ->count_all_results('journals');
                if ($pending > 0) {
                    throw new BusinessException('Periode masih mempunyai ' . $pending . ' jurnal yang belum diposting atau ditolak.');
                }
            }

            $update = array('status' => $targetStatus, 'updated_at' => date('Y-m-d H:i:s'));
            if ($targetStatus === 'closed') {
                $update['closed_at'] = date('Y-m-d H:i:s');
                $update['closed_by'] = (int) $userId;
            } elseif ($targetStatus === 'open') {
                $update['reopened_at'] = date('Y-m-d H:i:s');
                $update['reopened_by'] = (int) $userId;
            }
            $this->CI->db->where('id', $period->id)->update('accounting_periods', $update);
            $this->CI->db->insert('accounting_period_logs', array(
                'accounting_period_id' => $period->id,
                'from_status' => $period->status,
                'to_status' => $targetStatus,
                'reason' => trim($reason) ?: null,
                'changed_by' => (int) $userId,
                'changed_at' => date('Y-m-d H:i:s')
            ));
            $notClosed = $this->CI->db
                ->where('fiscal_year_id', $period->fiscal_year_id)
                ->where('status !=', 'closed')
                ->count_all_results('accounting_periods');
            $this->CI->db->where('id', $period->fiscal_year_id)->update('fiscal_years', array(
                'status' => $notClosed === 0 ? 'closed' : 'open'
            ));
            $after=$this->CI->fiscalPeriodModel->find($period->id);
            $this->CI->auditservice->record('accounting_period','accounting_period',$period->id,'change_status',$period,$after,$userId);
            return $after;
        });
    }

    public function createCalendarYear($year, $userId)
    {
        $year = (int) $year;
        if ($year < 2000 || $year > 2200) {
            throw new BusinessException('Tahun buku tidak valid.');
        }
        return $this->CI->transactionservice->run(function () use ($year, $userId) {
            $start = $year . '-01-01';
            $end = $year . '-12-31';
            $overlap = $this->CI->db
                ->where('start_date <=', $end)
                ->where('end_date >=', $start)
                ->count_all_results('fiscal_years');
            if ($overlap > 0) {
                throw new BusinessException('Tahun buku tersebut sudah tersedia atau bertumpang tindih.');
            }
            $this->CI->db->insert('fiscal_years', array(
                'name' => 'Tahun Buku ' . $year,
                'start_date' => $start,
                'end_date' => $end,
                'status' => 'open',
                'created_at' => date('Y-m-d H:i:s'),
                'created_by' => (int) $userId
            ));
            $fiscalId = (int) $this->CI->db->insert_id();
            for ($month = 1; $month <= 12; $month++) {
                $periodStart = sprintf('%04d-%02d-01', $year, $month);
                $this->CI->db->insert('accounting_periods', array(
                    'fiscal_year_id' => $fiscalId,
                    'period_number' => $month,
                    'name' => date('F Y', strtotime($periodStart)),
                    'start_date' => $periodStart,
                    'end_date' => date('Y-m-t', strtotime($periodStart)),
                    'status' => 'open'
                ));
            }
            $this->CI->auditservice->record('fiscal_year','fiscal_year',$fiscalId,'create',null,array('year'=>$year),$userId);
            return $fiscalId;
        });
    }
}