<?php

namespace Modules\ApprovalWorkflow\Models;

use App\Models\User;
use App\Traits\HasPublicIdentifier;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\Relations\MorphTo;
use Modules\ApprovalWorkflow\Enums\ApprovalChainStatus;

class ApprovalChain extends Model
{
    use HasPublicIdentifier;

    protected $fillable = [
        'approvable_type',
        'approvable_id',
        'type',
        'status',
        'notes',
        'initiated_by',
        'completed_at',
    ];

    protected function casts(): array
    {
        return [
            'status' => ApprovalChainStatus::class,
            'completed_at' => 'datetime',
        ];
    }

    public function approvable(): MorphTo
    {
        return $this->morphTo();
    }

    public function initiator(): BelongsTo
    {
        return $this->belongsTo(User::class, 'initiated_by')->withoutGlobalScopes();
    }

    public function steps(): HasMany
    {
        return $this->hasMany(ApprovalStep::class)->orderBy('order');
    }

    public function currentStep(): ?ApprovalStep
    {
        return $this->steps()->where('status', 'pending')->first();
    }

    public function isFullyApproved(): bool
    {
        return $this->steps()->where('status', '!=', 'approved')->doesntExist();
    }

    public function transitionTo(ApprovalChainStatus $newStatus): void
    {
        $allowed = $this->status->allowedTransitions();
        if (!in_array($newStatus, $allowed)) {
            throw new \InvalidArgumentException(
                "Cannot transition chain from {$this->status->label()} to {$newStatus->label()}"
            );
        }

        $updates = ['status' => $newStatus];
        if (in_array($newStatus, [ApprovalChainStatus::Approved, ApprovalChainStatus::Rejected])) {
            $updates['completed_at'] = now();
        }

        $this->update($updates);
    }
}