<?php

namespace App\Models;

use App\Enums\TransactionStatus;
use App\Enums\TransactionType;
use App\Models\Traits\HasMinorUnits;
use App\Models\Traits\HasUuid;
use Illuminate\Database\Eloquent\Factories\HasFactory;

/**
 * transactions — IMMUTABLE LEDGER
 *
 * Once status = 'completed', this row is NEVER updated.
 * Reversals are new rows with type = 'refund'.
 *
 * @property string $uuid
 * @property string $reference_code     WASL-XXXXXXXX (user-visible)
 * @property string $type               TransactionType enum
 * @property string $status             TransactionStatus enum
 * @property int|null $debit_wallet_id
 * @property int|null $credit_wallet_id
 * @property int $amount_minor           BIGINT — never float/decimal
 * @property int $fee_minor             BIGINT
 * @property string $currency_code
 * @property string|null $description
 * @property array|null $metadata
 * @property string $idempotency_key
 * @property string|null $initiator_ip
 * @property string|null $device_id
 */
class Transaction extends BaseModel
{
    use HasFactory;
    use HasUuid;
    use HasMinorUnits;

    protected $fillable = [
        'uuid',
        'reference_code',
        'type',
        'status',
        'debit_wallet_id',
        'credit_wallet_id',
        'amount_minor',
        'fee_minor',
        'currency_code',
        'description',
        'metadata',
        'idempotency_key',
        'initiator_ip',
        'device_id',
        'initiated_at',
        'completed_at',
        'failure_reason',
    ];

    protected $casts = [
        'type'          => TransactionType::class,
        'status'        => TransactionStatus::class,
        'amount_minor'  => 'integer',
        'fee_minor'     => 'integer',
        'metadata'      => 'array',
        'initiated_at'  => 'datetime',
        'completed_at'  => 'datetime',
    ];

    // ── Relationships ──

    public function debitWallet()
    {
        return $this->belongsTo(Wallet::class, 'debit_wallet_id');
    }

    public function creditWallet()
    {
        return $this->belongsTo(Wallet::class, 'credit_wallet_id');
    }

    public function entries()
    {
        return $this->hasMany(TransactionEntry::class);
    }

    public function fraudAlerts()
    {
        return $this->hasMany(FraudAlert::class);
    }

    // ── Scopes ──

    public function scopePending($query)
    {
        return $query->where('status', TransactionStatus::PENDING);
    }

    public function scopeCompleted($query)
    {
        return $query->where('status', TransactionStatus::COMPLETED);
    }

    public function scopeFailed($query)
    {
        return $query->where('status', TransactionStatus::FAILED);
    }

    public function scopeForWallet($query, int $walletId)
    {
        return $query->where('debit_wallet_id', $walletId)
            ->orWhere('credit_wallet_id', $walletId);
    }

    public function scopeInFlight($query)
    {
        return $query->whereIn('status', [
            TransactionStatus::PENDING,
            TransactionStatus::PROCESSING,
        ]);
    }

    // ── Helpers ──

    public function formattedAmount(): string
    {
        return self::formatMoney($this->amount_minor, $this->currency_code);
    }

    public function formattedFee(): string
    {
        return self::formatMoney($this->fee_minor, $this->currency_code);
    }

    public function isFinal(): bool
    {
        return $this->status->isFinal();
    }

    /**
     * Generate a unique reference code: WASL-XXXXXXXX
     * Uses random alphanumeric characters for human readability.
     */
    public static function generateReferenceCode(): string
    {
        $prefix = config('wasl.reference.prefix', 'WASL');
        $length = config('wasl.reference.length', 8);
        $chars = 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789'; // no 0/O/1/I to avoid confusion

        do {
            $code = $prefix . '-' . substr(str_shuffle($chars), 0, $length);
        } while (self::where('reference_code', $code)->exists());

        return $code;
    }
}