<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

class Task extends Model
{
    use HasFactory;

    protected $fillable = [
        'title',
        'description',
        'priority',
        'status',
        'due_date',
        'assigned_to',
        'created_by',
        'notes',
        'completed_at',
    ];

    protected $casts = [
        'due_date' => 'date',
        'completed_at' => 'datetime',
    ];

    /**
     * Priority levels
     */
    const PRIORITY_LOW = 'low';
    const PRIORITY_MEDIUM = 'medium';
    const PRIORITY_HIGH = 'high';
    const PRIORITY_URGENT = 'urgent';

    /**
     * Status values
     */
    const STATUS_PENDING = 'pending';
    const STATUS_IN_PROGRESS = 'in_progress';
    const STATUS_COMPLETED = 'completed';
    const STATUS_CANCELLED = 'cancelled';

    /**
     * Get all priority options
     */
    public static function getPriorities(): array
    {
        return [
            self::PRIORITY_LOW => 'Low',
            self::PRIORITY_MEDIUM => 'Medium',
            self::PRIORITY_HIGH => 'High',
            self::PRIORITY_URGENT => 'Urgent',
        ];
    }

    /**
     * Get all status options
     */
    public static function getStatuses(): array
    {
        return [
            self::STATUS_PENDING => 'Pending',
            self::STATUS_IN_PROGRESS => 'In Progress',
            self::STATUS_COMPLETED => 'Completed',
            self::STATUS_CANCELLED => 'Cancelled',
        ];
    }

    /**
     * Get the user this task is assigned to
     */
    public function assignee(): BelongsTo
    {
        return $this->belongsTo(User::class, 'assigned_to');
    }

    /**
     * Get the user who created this task
     */
    public function creator(): BelongsTo
    {
        return $this->belongsTo(User::class, 'created_by');
    }

    /**
     * Scope for filtering by status
     */
    public function scopeStatus($query, string $status)
    {
        return $query->where('status', $status);
    }

    /**
     * Scope for filtering by priority
     */
    public function scopePriority($query, string $priority)
    {
        return $query->where('priority', $priority);
    }

    /**
     * Scope for filtering by assigned user
     */
    public function scopeAssignedTo($query, int $userId)
    {
        return $query->where('assigned_to', $userId);
    }

    /**
     * Scope for filtering by creator
     */
    public function scopeCreatedBy($query, int $userId)
    {
        return $query->where('created_by', $userId);
    }

    /**
     * Scope for overdue tasks
     */
    public function scopeOverdue($query)
    {
        return $query->where('due_date', '<', now())
            ->whereNotIn('status', [self::STATUS_COMPLETED, self::STATUS_CANCELLED]);
    }

    /**
     * Scope for tasks due today
     */
    public function scopeDueToday($query)
    {
        return $query->whereDate('due_date', today());
    }

    /**
     * Check if task is overdue
     */
    public function isOverdue(): bool
    {
        return $this->due_date && 
               $this->due_date->isPast() && 
               !in_array($this->status, [self::STATUS_COMPLETED, self::STATUS_CANCELLED]);
    }

    /**
     * Mark task as completed
     */
    public function markAsCompleted(): bool
    {
        return $this->update([
            'status' => self::STATUS_COMPLETED,
            'completed_at' => now(),
        ]);
    }
}