<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

class BankReconciliation extends Model
{
    use HasFactory;

    protected $fillable = [
        'reconciliation_month',
        'bank_statement_balance',
        'bank_statement_date',
        'bank_statement_file_path',
        'system_book_balance',
        'outstanding_checks',
        'deposits_in_transit',
        'bank_charges',
        'adjusted_balance',
        'discrepancy_amount',
        'reconciliation_status',
        'prepared_by_cashier_id',
        'reviewed_by_accountant_id',
        'approved_by_manager_id',
        'prepared_at',
        'reviewed_at',
        'approved_at',
        'notes',
    ];

    protected $casts = [
        'reconciliation_month' => 'date',
        'bank_statement_balance' => 'decimal:2',
        'bank_statement_date' => 'date',
        'system_book_balance' => 'decimal:2',
        'outstanding_checks' => 'array',
        'deposits_in_transit' => 'array',
        'bank_charges' => 'array',
        'adjusted_balance' => 'decimal:2',
        'discrepancy_amount' => 'decimal:2',
        'prepared_at' => 'datetime',
        'reviewed_at' => 'datetime',
        'approved_at' => 'datetime',
    ];

    /**
     * 狀態常數
     */
    const STATUS_PENDING = 'pending';
    const STATUS_COMPLETED = 'completed';
    const STATUS_DISCREPANCY = 'discrepancy';

    /**
     * 製作調節表的出納人員
     */
    public function preparedByCashier(): BelongsTo
    {
        return $this->belongsTo(User::class, 'prepared_by_cashier_id');
    }

    /**
     * 覆核的會計人員
     */
    public function reviewedByAccountant(): BelongsTo
    {
        return $this->belongsTo(User::class, 'reviewed_by_accountant_id');
    }

    /**
     * 核准的主管
     */
    public function approvedByManager(): BelongsTo
    {
        return $this->belongsTo(User::class, 'approved_by_manager_id');
    }

    /**
     * 計算調整後餘額
     */
    public function calculateAdjustedBalance(): float
    {
        $adjusted = $this->system_book_balance;

        // 加上在途存款
        if ($this->deposits_in_transit) {
            foreach ($this->deposits_in_transit as $deposit) {
                $adjusted += floatval($deposit['amount'] ?? 0);
            }
        }

        // 減去未兌現支票
        if ($this->outstanding_checks) {
            foreach ($this->outstanding_checks as $check) {
                $adjusted -= floatval($check['amount'] ?? 0);
            }
        }

        // 減去銀行手續費
        if ($this->bank_charges) {
            foreach ($this->bank_charges as $charge) {
                $adjusted -= floatval($charge['amount'] ?? 0);
            }
        }

        return $adjusted;
    }

    /**
     * 計算差異金額
     */
    public function calculateDiscrepancy(): float
    {
        return abs($this->adjusted_balance - $this->bank_statement_balance);
    }

    /**
     * 檢查是否有差異
     */
    public function hasDiscrepancy(float $tolerance = 0.01): bool
    {
        return $this->calculateDiscrepancy() > $tolerance;
    }

    /**
     * 是否待覆核
     */
    public function isPending(): bool
    {
        return $this->reconciliation_status === self::STATUS_PENDING;
    }

    /**
     * 是否已完成
     */
    public function isCompleted(): bool
    {
        return $this->reconciliation_status === self::STATUS_COMPLETED;
    }

    /**
     * 是否有差異待處理
     */
    public function hasUnresolvedDiscrepancy(): bool
    {
        return $this->reconciliation_status === self::STATUS_DISCREPANCY;
    }

    /**
     * 是否可以被會計覆核
     */
    public function canBeReviewed(): bool
    {
        return $this->isPending() && $this->prepared_at !== null;
    }

    /**
     * 是否可以被主管核准
     */
    public function canBeApproved(): bool
    {
        return $this->reviewed_at !== null && $this->approved_at === null;
    }

    /**
     * 取得狀態文字
     */
    public function getStatusText(): string
    {
        return match ($this->reconciliation_status) {
            self::STATUS_PENDING => '待覆核',
            self::STATUS_COMPLETED => '已完成',
            self::STATUS_DISCREPANCY => '有差異',
            default => '未知',
        };
    }

    /**
     * 取得未達帳項總計
     */
    public function getOutstandingItemsSummary(): array
    {
        $checksTotal = 0;
        if ($this->outstanding_checks) {
            foreach ($this->outstanding_checks as $check) {
                $checksTotal += floatval($check['amount'] ?? 0);
            }
        }

        $depositsTotal = 0;
        if ($this->deposits_in_transit) {
            foreach ($this->deposits_in_transit as $deposit) {
                $depositsTotal += floatval($deposit['amount'] ?? 0);
            }
        }

        $chargesTotal = 0;
        if ($this->bank_charges) {
            foreach ($this->bank_charges as $charge) {
                $chargesTotal += floatval($charge['amount'] ?? 0);
            }
        }

        return [
            'outstanding_checks_total' => $checksTotal,
            'deposits_in_transit_total' => $depositsTotal,
            'bank_charges_total' => $chargesTotal,
            'net_adjustment' => $depositsTotal - $checksTotal - $chargesTotal,
        ];
    }
}