<?php

namespace App\Models;

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

class Invoice extends Model
{
    use HasFactory;

    const STATUS_DRAFT = 'draft';
    const STATUS_OPEN = 'open';
    const STATUS_PAID = 'paid';
    const STATUS_VOID = 'void';
    const STATUS_UNCOLLECTIBLE = 'uncollectible';

    const REASON_SUBSCRIPTION_CREATE = 'subscription_create';
    const REASON_SUBSCRIPTION_CYCLE = 'subscription_cycle';
    const REASON_SUBSCRIPTION_UPDATE = 'subscription_update';
    const REASON_MANUAL = 'manual';

    protected $fillable = [
        'user_id',
        'subscription_id',
        'number',
        'status',
        'billing_reason',
        'currency',
        'subtotal',
        'tax',
        'tax_percent',
        'total',
        'description',
        'due_date',
        'paid_at',
        'paypal_payment_id',
        'paypal_capture_id',
        'paypal_data',
        'pdf_path',
        'billing_info',
    ];

    protected $casts = [
        'due_date' => 'datetime',
        'paid_at' => 'datetime',
        'subtotal' => 'decimal:2',
        'tax' => 'decimal:2',
        'tax_percent' => 'decimal:2',
        'total' => 'decimal:2',
        'paypal_data' => 'array',
        'billing_info' => 'array',
    ];

    // ==================== BOOT ====================

    protected static function boot()
    {
        parent::boot();

        static::creating(function ($invoice) {
            if (empty($invoice->number)) {
                $invoice->number = static::generateNumber();
            }
        });
    }

    // ==================== RELATIONSHIPS ====================

    public function user(): BelongsTo
    {
        return $this->belongsTo(User::class);
    }

    public function subscription(): BelongsTo
    {
        return $this->belongsTo(Subscription::class);
    }

    // ==================== SCOPES ====================

    public function scopePaid($query)
    {
        return $query->where('status', self::STATUS_PAID);
    }

    public function scopeOpen($query)
    {
        return $query->where('status', self::STATUS_OPEN);
    }

    public function scopeForUser($query, int $userId)
    {
        return $query->where('user_id', $userId);
    }

    public function scopeRecent($query)
    {
        return $query->orderBy('created_at', 'desc');
    }

    // ==================== STATUS CHECKS ====================

    public function isPaid(): bool
    {
        return $this->status === self::STATUS_PAID;
    }

    public function isOpen(): bool
    {
        return $this->status === self::STATUS_OPEN;
    }

    public function isDraft(): bool
    {
        return $this->status === self::STATUS_DRAFT;
    }

    public function isVoid(): bool
    {
        return $this->status === self::STATUS_VOID;
    }

    public function isOverdue(): bool
    {
        return $this->status === self::STATUS_OPEN 
            && $this->due_date 
            && $this->due_date->isPast();
    }

    // ==================== ACCESSORS ====================

    public function getStatusLabelAttribute(): string
    {
        return match ($this->status) {
            self::STATUS_DRAFT => 'Borrador',
            self::STATUS_OPEN => 'Pendiente',
            self::STATUS_PAID => 'Pagada',
            self::STATUS_VOID => 'Anulada',
            self::STATUS_UNCOLLECTIBLE => 'Incobrable',
            default => $this->status,
        };
    }

    public function getStatusColorAttribute(): string
    {
        return match ($this->status) {
            self::STATUS_DRAFT => 'secondary',
            self::STATUS_OPEN => 'warning',
            self::STATUS_PAID => 'success',
            self::STATUS_VOID => 'dark',
            self::STATUS_UNCOLLECTIBLE => 'danger',
            default => 'secondary',
        };
    }

    public function getFormattedTotalAttribute(): string
    {
        $symbols = [
            'EUR' => '€',
            'USD' => '$',
            'BRL' => 'R$',
        ];

        $symbol = $symbols[$this->currency] ?? $this->currency;
        return $symbol . number_format($this->total, 2, ',', '.');
    }

    public function getBillingReasonLabelAttribute(): string
    {
        return match ($this->billing_reason) {
            self::REASON_SUBSCRIPTION_CREATE => 'Nueva suscripción',
            self::REASON_SUBSCRIPTION_CYCLE => 'Renovación',
            self::REASON_SUBSCRIPTION_UPDATE => 'Cambio de plan',
            self::REASON_MANUAL => 'Manual',
            default => $this->billing_reason,
        };
    }

    // ==================== METHODS ====================

    /**
     * Generate a unique invoice number
     * Format: WM-YYYY-NNNNNN
     */
    public static function generateNumber(): string
    {
        $year = now()->year;
        $prefix = "WM-{$year}-";

        $lastInvoice = static::where('number', 'like', "{$prefix}%")
            ->orderBy('number', 'desc')
            ->first();

        if ($lastInvoice) {
            $lastNumber = (int) substr($lastInvoice->number, strlen($prefix));
            $newNumber = $lastNumber + 1;
        } else {
            $newNumber = 1;
        }

        return $prefix . str_pad($newNumber, 6, '0', STR_PAD_LEFT);
    }

    /**
     * Mark invoice as paid
     */
    public function markAsPaid(?string $paypalPaymentId = null, ?string $paypalCaptureId = null): self
    {
        $this->status = self::STATUS_PAID;
        $this->paid_at = now();
        
        if ($paypalPaymentId) {
            $this->paypal_payment_id = $paypalPaymentId;
        }
        if ($paypalCaptureId) {
            $this->paypal_capture_id = $paypalCaptureId;
        }
        
        $this->save();

        return $this;
    }

    /**
     * Mark invoice as void
     */
    public function markAsVoid(): self
    {
        $this->status = self::STATUS_VOID;
        $this->save();

        return $this;
    }

    /**
     * Calculate and set totals
     */
    public function calculateTotals(float $subtotal, float $taxPercent = 0): self
    {
        $this->subtotal = $subtotal;
        $this->tax_percent = $taxPercent;
        $this->tax = round($subtotal * ($taxPercent / 100), 2);
        $this->total = $this->subtotal + $this->tax;
        
        return $this;
    }

    /**
     * Create invoice for a subscription
     */
    public static function createForSubscription(
        Subscription $subscription, 
        string $billingReason = self::REASON_SUBSCRIPTION_CYCLE,
        ?string $description = null
    ): self {
        $plan = $subscription->plan;
        $user = $subscription->user;

        $invoice = new self([
            'user_id' => $user->id,
            'subscription_id' => $subscription->id,
            'status' => self::STATUS_DRAFT,
            'billing_reason' => $billingReason,
            'currency' => $subscription->currency,
            'description' => $description ?? "{$plan->name} - " . now()->format('F Y'),
            'due_date' => now()->addDays(7),
        ]);

        // Calculate with VAT (21% for EU)
        $invoice->calculateTotals($plan->price, 21);

        // Store billing info snapshot
        $invoice->billing_info = [
            'name' => $user->full_name,
            'email' => $user->email,
            'phone' => $user->full_phone,
            'country' => $user->country,
        ];

        $invoice->save();

        return $invoice;
    }
}