from django.shortcuts import render, get_object_or_404, redirect
from django.contrib.auth.decorators import login_required
from django.urls import reverse
from django.utils import timezone
from django.template import Template, Context
from processes.models import ProcessInstance, StepInstance
from .models import ContractTemplate, ContractInstance
from _helpers.utils import jalali_converter2


def build_contract_context(instance: ProcessInstance) -> dict:
    representative = instance.representative
    profile = getattr(representative, 'profile', None)
    well = instance.well
    return {
        'customer_full_name': representative.get_full_name() if representative else '',
        'national_code': profile.national_code if profile else '',
        'address': profile.address if profile else '',
        'phone': profile.phone_number_1 if profile else '',
        'phone2': profile.phone_number_2 if profile else '',
        'water_subscription_number': well.water_subscription_number if well else '',
        'electricity_subscription_number': well.electricity_subscription_number if well else '',
        'water_meter_serial_number': well.water_meter_serial_number if well else '',
        'well_power': well.well_power if well else '',
        'request_code': instance.code,
        'today': jalali_converter2(timezone.now()),
    }


@login_required
def contract_step(request, instance_id, step_id):
    instance = get_object_or_404(ProcessInstance, id=instance_id)
    # Resolve step navigation
    step = get_object_or_404(instance.process.steps, id=step_id)
    previous_step = instance.process.steps.filter(order__lt=step.order).last()
    next_step = instance.process.steps.filter(order__gt=step.order).first()
    template_obj = ContractTemplate.objects.first()
    if not template_obj:
        return render(request, 'contracts/contract_missing.html', {'instance': instance})

    ctx = build_contract_context(instance)
    rendered = Template(template_obj.body).render(Context(ctx))

    contract, _ = ContractInstance.objects.get_or_create(
        process_instance=instance,
        defaults={
            'template': template_obj,
            'rendered_body': rendered,
            'created_by': request.user,
        }
    )
    # keep latest rendering if template changed (optional)
    contract.template = template_obj
    contract.rendered_body = rendered
    contract.save()

    # If user submits to go next, mark this step completed and go to next
    if request.method == 'POST':
        StepInstance.objects.update_or_create(
            process_instance=instance,
            step=step,
            defaults={'status': 'completed', 'completed_at': timezone.now()}
        )
        if next_step:
            instance.current_step = next_step
            instance.save()
            return redirect('processes:step_detail', instance_id=instance.id, step_id=next_step.id)
        return redirect('processes:request_list')

    return render(request, 'contracts/contract_step.html', {
        'instance': instance,
        'step': step,
        'contract': contract,
        'template': template_obj,
        'previous_step': previous_step,
        'next_step': next_step,
    })


@login_required
def contract_print(request, instance_id):
    instance = get_object_or_404(ProcessInstance, id=instance_id)
    contract = get_object_or_404(ContractInstance, process_instance=instance)
    return render(request, 'contracts/contract_print.html', {
        'instance': instance,
        'contract': contract,
    })