<?php

namespace App\Models;

use App\User;
use Carbon\Carbon;
use Illuminate\Database\Eloquent\Collection;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\HasMany;

/**
 * Version eines Angebots (Modul 6).
 *
 * Jede versendete Fassung wird hier festgehalten — Texte, Positionen
 * und PDF bleiben damit unveränderlich, sobald ein Kunde sie per
 * Freigabe-Link einsehen kann. Neue Änderungen nach dem Versand
 * erzeugen eine neue Version (version_no = max+1, status = draft).
 *
 * @property int $id
 * @property int $offer_id
 * @property int $version_no
 * @property string $status
 * @property Carbon|null $valid_until
 * @property float $total_price
 * @property string|null $headline
 * @property string|null $intro_text
 * @property string|null $itinerary_text
 * @property string|null $closing_text
 * @property int|null $template_id
 * @property string|null $pdf_path
 * @property bool $pdf_archived
 * @property Carbon|null $sent_at
 * @property Carbon|null $accepted_at
 * @property string|null $accepted_via
 * @property array|null $template_document_ids
 * @property int $created_by
 * @property Carbon $created_at
 * @property Carbon $updated_at
 * @property-read Offer $offer
 * @property-read OfferTemplate|null $template
 * @property-read Collection|OfferItem[] $items
 * @property-read Collection|OfferFile[] $files
 * @property-read User $creator
 */
class OfferVersion extends Model
{
    use HasFactory;

    public const STATUS_DRAFT      = 'draft';
    public const STATUS_SENT       = 'sent';
    public const STATUS_ACCEPTED   = 'accepted';
    public const STATUS_DECLINED   = 'declined';
    public const STATUS_EXPIRED    = 'expired';
    public const STATUS_SUPERSEDED = 'superseded';

    public const ACCEPTED_VIA_LINK  = 'customer_link';
    public const ACCEPTED_VIA_ADMIN = 'admin';
    public const ACCEPTED_VIA_MAIL  = 'email';

    protected $table = 'offer_versions';

    protected $fillable = [
        'offer_id',
        'version_no',
        'status',
        'valid_until',
        'total_price',
        'headline',
        'intro_text',
        'itinerary_text',
        'closing_text',
        'template_id',
        'pdf_path',
        'pdf_archived',
        'sent_at',
        'accepted_at',
        'accepted_via',
        'template_document_ids',
        'created_by',
    ];

    protected $casts = [
        'offer_id'              => 'int',
        'version_no'            => 'int',
        'valid_until'           => 'date',
        'total_price'           => 'decimal:2',
        'template_id'           => 'int',
        'pdf_archived'          => 'bool',
        'sent_at'               => 'datetime',
        'accepted_at'           => 'datetime',
        'template_document_ids' => 'array',
        'created_by'            => 'int',
    ];

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

    public function template(): BelongsTo
    {
        return $this->belongsTo(OfferTemplate::class, 'template_id');
    }

    public function items(): HasMany
    {
        return $this->hasMany(OfferItem::class)->orderBy('position');
    }

    public function files(): HasMany
    {
        return $this->hasMany(OfferFile::class);
    }

    public function creator(): BelongsTo
    {
        return $this->belongsTo(User::class, 'created_by');
    }

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