<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\SoftDeletes;

class Task extends Model
{
    use HasFactory, SoftDeletes;

        protected $fillable = [
        'tenant_id',
        'project_id',
        'parent_id',
        'assignee_id',
        'reporter_id',
        'title',
        'description',
        'status',
        'priority',
        'start_date',
        'due_date',
        'progress',
        'estimated_hours',
        'completed_at',
        'order',
        ];

    protected $casts = [
        'start_date' => 'date',
        'due_date' => 'date',
        'completed_at' => 'datetime',
        'progress' => 'integer',
        'estimated_hours' => 'decimal:2',
        'order' => 'integer',
    ];

    // ─── Basic Relationships ───────────────────────────────────────────

    public function tenant()
    {
        return $this->belongsTo(Tenant::class);
    }

    public function project()
    {
        return $this->belongsTo(Project::class);
    }

    public function parent()
    {
        return $this->belongsTo(Task::class, 'parent_id');
    }

    public function children()
    {
        return $this->hasMany(Task::class, 'parent_id');
    }

    public function assignee()
    {
        return $this->belongsTo(User::class, 'assignee_id');
    }

    public function reporter()
    {
        return $this->belongsTo(User::class, 'reporter_id');
    }

    public function logs()
    {
        return $this->hasMany(TaskLog::class);
    }

    public function workLogs()
    {
        return $this->hasMany(WorkLog::class);
    }

    // ─── Dependency Relationships ──────────────────────────────────────

    /**
     * Tasks that this task depends on (predecessors).
     * e.g., "Task A depends on Task B" means B must finish before A starts.
     */
    public function dependencies()
    {
        return $this->belongsToMany(Task::class, 'task_dependencies', 'task_id', 'depends_on_task_id')
            ->withPivot('dependency_type')
            ->withTimestamps();
    }

    /**
     * Tasks that depend on this task (successors).
     * e.g., "Task A blocks Task C" means C cannot start until A finishes.
     */
    public function dependents()
    {
        return $this->belongsToMany(Task::class, 'task_dependencies', 'depends_on_task_id', 'task_id')
            ->withPivot('dependency_type')
            ->withTimestamps();
    }

    // ─── Scopes ────────────────────────────────────────────────────────

    public function scopeByStatus($query, $status)
    {
        return $query->where('status', $status);
    }

    public function scopeByPriority($query, $priority)
    {
        return $query->where('priority', $priority);
    }

    public function scopeTopLevel($query)
    {
        return $query->whereNull('parent_id');
    }

    public function scopeWithDependencies($query)
    {
        return $query->with(['dependencies', 'dependents', 'assignee', 'project']);
    }

    // ─── Accessors ─────────────────────────────────────────────────────

    public function getStatusLabelAttribute()
    {
        return [
            'pending' => __('task.status_pending'),
            'todo' => __('task.status_pending'),
            'in_progress' => __('task.status_in_progress'),
            'review' => __('task.status_review'),
            'done' => __('task.status_done'),
            'cancelled' => __('task.status_cancelled'),
        ][$this->status] ?? $this->status;
    }

    /**
     * Check if all dependency tasks are completed.
     */
    public function getCanStartAttribute(): bool
    {
        if ($this->dependencies->isEmpty()) {
            return true;
        }

        return $this->dependencies->every(fn ($dep) => $dep->status === 'done');
    }

    /**
     * Check if this task is blocked by incomplete dependencies.
     */
    public function getIsBlockedAttribute(): bool
    {
        return !$this->canStart;
    }

    /**
     * Get the blocking tasks (incomplete dependencies).
     */
    public function getBlockingTasksAttribute()
    {
        return $this->dependencies->filter(fn ($dep) => $dep->status !== 'done');
    }

    /**
     * Calculate duration in days.
     */
    public function getDurationDaysAttribute(): ?int
    {
        if (!$this->start_date || !$this->due_date) {
            return null;
        }
        return $this->start_date->diffInDays($this->due_date) + 1;
    }
}