from django.shortcuts import render, get_object_or_404, redirect
from django.contrib.auth.decorators import login_required
from django.contrib import messages
from django.http import JsonResponse
from django.views.decorators.http import require_POST
from .models import Process, ProcessInstance, StepInstance
from .forms import ProcessInstanceForm

@login_required
def process_list(request):
    """نمایش لیست فرآیندهای فعال"""
    processes = Process.objects.filter(is_active=True)
    return render(request, 'processes/process_list.html', {
        'processes': processes
    })

@login_required
def process_detail(request, process_id):
    """نمایش جزئیات فرآیند"""
    process = get_object_or_404(Process, id=process_id, is_active=True)
    return render(request, 'processes/process_detail.html', {
        'process': process
    })

@login_required
def start_process(request, process_id):
    """شروع فرآیند جدید"""
    process = get_object_or_404(Process, id=process_id, is_active=True)
    
    if request.method == 'POST':
        form = ProcessInstanceForm(request.POST)
        if form.is_valid():
            instance = form.save(commit=False)
            instance.process = process
            instance.requester = request.user
            instance.save()
            
            # ایجاد نمونه‌های مرحله
            for step in process.steps.all():
                StepInstance.objects.create(
                    process_instance=instance,
                    step=step
                )
            
            # تنظیم مرحله اول به عنوان مرحله فعلی
            first_step = process.steps.first()
            if first_step:
                instance.current_step = first_step
                instance.status = 'in_progress'
                instance.save()
            
            messages.success(request, f'فرآیند {process.name} با موفقیت شروع شد.')
            return redirect('processes:instance_detail', instance_id=instance.id)
    else:
        form = ProcessInstanceForm()
    
    return render(request, 'processes/start_process.html', {
        'process': process,
        'form': form
    })

@login_required
def instance_detail(request, instance_id):
    """نمایش جزئیات نمونه فرآیند"""
    instance = get_object_or_404(ProcessInstance, id=instance_id)
    return render(request, 'processes/instance_detail.html', {
        'instance': instance
    })

@login_required
def my_processes(request):
    """نمایش فرآیندهای کاربر"""
    my_instances = ProcessInstance.objects.filter(requester=request.user)
    assigned_steps = StepInstance.objects.filter(assigned_to=request.user, status='in_progress')
    
    return render(request, 'processes/my_processes.html', {
        'my_instances': my_instances,
        'assigned_steps': assigned_steps
    })