from django.shortcuts import render, get_object_or_404, redirect
from django.urls import reverse

from .models import RotaSchedule, Worker
from .forms import WorkerForm, LeaveForm, RotaScheduleForm
from .services import run_rota_async
from .forms import ShiftForm
from django.views.decorators.http import require_http_methods
from django.template.loader import render_to_string
from django.http import HttpResponse, HttpResponseBadRequest


def index(request):
	rotas = RotaSchedule.objects.all().order_by("-created_at")
	return render(request, "rota/index.html", {"rotas": rotas})


def rota_detail(request, rota_id):
	rota = get_object_or_404(RotaSchedule, pk=rota_id)
	if request.method == "POST":
		# trigger a background run
		run = run_rota_async(rota.id)
		return redirect(reverse("rota:rota_run_detail", args=(run.id,)))

	return render(request, "rota/rota_detail.html", {"rota": rota})


def rota_create(request):
	if request.method == "POST":
		form = RotaScheduleForm(request.POST)
		if form.is_valid():
			rota = form.save()
			return redirect("rota:rota_detail", rota_id=rota.id)
	else:
		form = RotaScheduleForm()

	return render(request, "rota/rota_form.html", {"form": form})


def worker_create(request):
	if request.method == "POST":
		form = WorkerForm(request.POST)
		if form.is_valid():
			worker = form.save()
			return redirect("/")
	else:
		form = WorkerForm()

	return render(request, "rota/worker_form.html", {"form": form})


def worker_detail(request, worker_id):
	worker = get_object_or_404(Worker, pk=worker_id)
	if request.method == "POST":
		form = LeaveForm(request.POST)
		if form.is_valid():
			leave = form.save(commit=False)
			leave.worker = worker
			leave.save()
			return redirect("rota:worker_detail", worker_id=worker.id)
	else:
		form = LeaveForm()

	return render(request, "rota/worker_detail.html", {"worker": worker, "form": form})


@require_http_methods(["GET", "POST"])
def worker_edit(request, rota_id, worker_id):
	rota = get_object_or_404(RotaSchedule, pk=rota_id)
	worker = get_object_or_404(Worker, pk=worker_id)

	if request.method == "POST":
		form = WorkerForm(request.POST, instance=worker)
		if form.is_valid():
			form.save()
			# Return updated worker list OOB and close modal
			worker_list_html = render_to_string("rota/partials/worker_list.html", {"rota": rota}, request=request)
			resp = (
				f'<div id="worker-list" hx-swap-oob="true">{worker_list_html}</div>'
				+ '<div id="modal" hx-swap-oob="true"></div>'
			)
			response = HttpResponse(resp)
			response["HX-Trigger"] = "closeModal"
			return response

		# invalid: return form modal with errors
		modal_html = render_to_string(
			"rota/partials/worker_form_modal.html",
			{"form": form, "form_action": request.path, "rota": rota},
			request=request,
		)
		return HttpResponse(modal_html)

	# GET: populate form and return modal
	form = WorkerForm(instance=worker)
	modal_html = render_to_string(
		"rota/partials/worker_form_modal.html",
		{"form": form, "form_action": request.path, "rota": rota},
		request=request,
	)
	return HttpResponse(modal_html)


@require_http_methods(["GET", "POST"])
def worker_delete(request, rota_id, worker_id):
	rota = get_object_or_404(RotaSchedule, pk=rota_id)
	worker = get_object_or_404(Worker, pk=worker_id)

	if request.method == "POST":
		# remove assignment between worker and rota
		try:
			from .models import Assignment

			Assignment.objects.filter(worker=worker, rota=rota).delete()
		except Exception:
			try:
				rota.workers.remove(worker)
			except Exception:
				return HttpResponseBadRequest("Unable to remove worker from rota")

		rota = get_object_or_404(RotaSchedule, pk=rota_id)
		worker_list_html = render_to_string("rota/partials/worker_list.html", {"rota": rota}, request=request)
		resp = (
			f'<div id="worker-list" hx-swap-oob="true">{worker_list_html}</div>'
			+ '<div id="modal" hx-swap-oob="true"></div>'
		)
		response = HttpResponse(resp)
		response["HX-Trigger"] = "closeModal"
		return response

	# GET: confirmation modal
	modal_html = render_to_string(
		"rota/partials/worker_confirm_delete.html",
		{"rota": rota, "worker": worker},
		request=request,
	)
	return HttpResponse(modal_html)


def rota_run_detail(request, run_id):
	from .models import RotaRun

	run = get_object_or_404(RotaRun, pk=run_id)
	return render(request, "rota/rota_run_detail.html", {"run": run})


def rota_run_export_html(request, run_id):
	from .models import RotaRun

	run = get_object_or_404(RotaRun, pk=run_id)
	return render(request, "rota/rota_run_export.html", {"run": run})


def rota_run_export_download(request, run_id):
	from .models import RotaRun

	run = get_object_or_404(RotaRun, pk=run_id)
	html = render_to_string("rota/rota_run_export.html", {"run": run}, request=request)
	response = HttpResponse(html, content_type="text/html; charset=utf-8")
	filename = f"rota_run_{run.id}_export.html"
	response["Content-Disposition"] = f'attachment; filename="{filename}"'
	return response


def rota_export_builder(request, rota_id):
	"""Build a `RotaBuilder` for the given `RotaSchedule` and return its HTML export.

	Query parameters:
	- solve=1 : attempt to solve the model (may require solver binaries and can be slow)
	- solver=<name> : solver name passed to `build_and_solve`
	"""
	rota = get_object_or_404(RotaSchedule, pk=rota_id)

	try:
		rb = rota.to_rota_builder()
	except Exception as exc:
		return HttpResponseBadRequest(f"Unable to construct RotaBuilder: {exc}")

	solve = request.GET.get("solve") == "1"
	solver = request.GET.get("solver", "appsi_highs")

	try:
		# Build model (and optionally solve) - keep defaults safe
		rb.build_and_solve(solve=solve, solver=solver)
	except Exception as exc:
		# Return error message in the page so it's visible in browser
		content = f"<html><body><h1>Error running builder</h1><pre>{exc}</pre></body></html>"
		return HttpResponse(content, status=500, content_type="text/html")

	html = rb.get_worker_timetable_html(include_html_tag=True)
	return HttpResponse(html, content_type="text/html; charset=utf-8")


@require_http_methods(["GET", "POST"])
def shift_add(request, rota_id):
	"""HTMX endpoint to render a shift form or accept submission to append a shift to the rota."""
	rota = get_object_or_404(RotaSchedule, pk=rota_id)

	if request.method == "POST":
		form = ShiftForm(request.POST)
		if form.is_valid():
			data = form.cleaned_data
			shift_dict = {
				"sites": data["sites"],
				"name": data["name"],
				"length": float(data["length"]),
				"days": data["days"],
				"workers_required": int(data["workers_required"]),
				"assign_as_block": bool(data["assign_as_block"]),
			}

			current = rota.shifts or []
			current.append(shift_dict)
			rota.shifts = current
			rota.save()

			# Return out-of-band swap: update shift-list and clear modal
			shift_list_html = render_to_string("rota/partials/shift_list.html", {"rota": rota}, request=request)
			# wrap shift list for OOB swap and clear form/modal containers
			resp = (
				f'<div id="shift-list" hx-swap-oob="true">{shift_list_html}</div>'
				+ '<div id="shift-form" hx-swap-oob="true"></div>'
				+ '<div id="modal" hx-swap-oob="true"></div>'
				)
			response = HttpResponse(resp)
			response["HX-Trigger"] = "closeModal"
			return response

		# invalid: return modal with form and errors
		modal_html = render_to_string("rota/partials/shift_form_modal.html", {"form": form, "rota": rota, "form_action": request.path}, request=request)
		return HttpResponse(modal_html)

	else:
		form = ShiftForm()
		modal_html = render_to_string("rota/partials/shift_form_modal.html", {"form": form, "rota": rota, "form_action": request.path}, request=request)
		return HttpResponse(modal_html)


@require_http_methods(["GET", "POST"])
def shift_edit(request, rota_id, idx):
	rota = get_object_or_404(RotaSchedule, pk=rota_id)
	try:
		shift = rota.shifts[idx]
	except Exception:
		return HttpResponseBadRequest("Shift not found")

	if request.method == "POST":
		form = ShiftForm(request.POST)
		if form.is_valid():
			data = form.cleaned_data
			shift_dict = {
				"sites": data["sites"],
				"name": data["name"],
				"length": float(data["length"]),
				"days": data["days"],
				"workers_required": int(data["workers_required"]),
				"assign_as_block": bool(data["assign_as_block"]),
			}
			current = rota.shifts or []
			current[idx] = shift_dict
			rota.shifts = current
			rota.save()

			shift_list_html = render_to_string("rota/partials/shift_list.html", {"rota": rota}, request=request)
			resp = (
				f'<div id="shift-list" hx-swap-oob="true">{shift_list_html}</div>'
				+ '<div id="shift-form" hx-swap-oob="true"></div>'
				+ '<div id="modal" hx-swap-oob="true"></div>'
				)
			response = HttpResponse(resp)
			response["HX-Trigger"] = "closeModal"
			return response

		modal_html = render_to_string("rota/partials/shift_form_modal.html", {"form": form, "rota": rota, "form_action": request.path}, request=request)
		return HttpResponse(modal_html)

	# GET: populate form with existing shift
	initial = {
		"name": shift.get("name"),
		"sites": ",".join(shift.get("sites") or []),
		"length": shift.get("length"),
		"days": shift.get("days"),
		"workers_required": shift.get("workers_required"),
		"assign_as_block": shift.get("assign_as_block", False),
	}
	form = ShiftForm(initial=initial)
	modal_html = render_to_string("rota/partials/shift_form_modal.html", {"form": form, "rota": rota, "form_action": request.path}, request=request)
	return HttpResponse(modal_html)


@require_http_methods(["GET", "POST"])
def shift_delete(request, rota_id, idx):
	rota = get_object_or_404(RotaSchedule, pk=rota_id)
	try:
		shift = rota.shifts[idx]
	except Exception:
		return HttpResponseBadRequest("Shift not found")

	if request.method == "POST":
		current = rota.shifts or []
		try:
			current.pop(idx)
		except Exception:
			return HttpResponseBadRequest("Invalid index")
		rota.shifts = current
		rota.save()
		shift_list_html = render_to_string("rota/partials/shift_list.html", {"rota": rota}, request=request)
		resp = (
			f'<div id="shift-list" hx-swap-oob="true">{shift_list_html}</div>'
			+ '<div id="shift-form" hx-swap-oob="true"></div>'
			+ '<div id="modal" hx-swap-oob="true"></div>'
			)
		response = HttpResponse(resp)
		response["HX-Trigger"] = "closeModal"
		return response

	# GET: confirmation modal
	modal_html = render_to_string("rota/partials/shift_confirm_delete.html", {"rota": rota, "idx": idx, "shift": shift}, request=request)
	return HttpResponse(modal_html)