import { useEffect, useMemo, useState } from "react";
import { useAuthContext } from "@/providers/auth-context";
import { getPrimaryUserRole, isAdminUser } from "@/lib/auth/user-utils";
import { useDropdownOptionsByCategory } from "@/domain/settings/dropdown-options/use-cases/use-dropdown-options-by-category";
import type { Service, ServiceInput, ServiceWorkOrderType } from "@/domain/services/types/service";
import {
  useCreateService,
  useCompletionDocTemplates,
  useDeactivateService,
  useServices,
  useUpdateService,
} from "@/domain/services/use-cases/use-services";

export type ServiceStatus = "all" | "active" | "inactive";
export type ServiceForm = Omit<ServiceInput, "completionDocTemplateId"> & {
  completionDocTemplateId: string | number | null;
};

export const EMPTY_SERVICE_FORM: ServiceForm = {
  name: "",
  trade: "",
  iconKey: "",
  requiresCompletionDocument: false,
  completionDocTemplateId: null,
  supportedWorkOrderTypes: ["PM", "Reactive", "Emergency"],
};

export const DEFAULT_ICON_BY_TRADE: Record<string, string> = {
  HVAC: "droplets",
  Plumbing: "droplets",
  Electrical: "zap",
  "General Building": "hammer",
};

export function buildServiceInput(form: ServiceForm): {
  input: ServiceInput | null;
  error: string;
} {
  const name = form.name.trim();
  if (!name || !form.trade || !form.iconKey) {
    return { input: null, error: "Service Name, Trade, and Icon are required." };
  }
  if (!form.supportedWorkOrderTypes.length) {
    return { input: null, error: "Select at least one Work Order Type." };
  }
  if (form.requiresCompletionDocument && form.completionDocTemplateId == null) {
    return {
      input: null,
      error: "Select a completion document template when the document is required.",
    };
  }
  const templateId = form.completionDocTemplateId;
  return {
    input: {
      ...form,
      name,
      completionDocTemplateId: templateId == null || templateId === "" ? null : Number(templateId),
    },
    error: "",
  };
}

function emptyForm(): ServiceForm {
  return {
    ...EMPTY_SERVICE_FORM,
    supportedWorkOrderTypes: [...EMPTY_SERVICE_FORM.supportedWorkOrderTypes],
  };
}

function formFromService(service: Service): ServiceForm {
  return {
    name: service.name,
    trade: service.trade,
    iconKey: service.iconKey,
    requiresCompletionDocument: service.requiresCompletionDocument,
    completionDocTemplateId: service.completionDocTemplate?.id ?? null,
    supportedWorkOrderTypes: [...service.supportedWorkOrderTypes],
  };
}

export function useServicesRegistryController() {
  const { user } = useAuthContext();
  const role = getPrimaryUserRole(user?.userRoles).toLowerCase();
  const canManage = isAdminUser(user?.userRoles) || role === "scheduler";
  const canDeactivate = isAdminUser(user?.userRoles);
  const [status, setStatus] = useState<ServiceStatus>("active");
  const [search, setSearch] = useState("");
  const [selected, setSelected] = useState<Service | null>(null);
  const [editorMode, setEditorMode] = useState<"add" | "edit" | null>(null);
  const [form, setForm] = useState<ServiceForm>(emptyForm);
  const [iconTouched, setIconTouched] = useState(false);
  const [formError, setFormError] = useState("");
  const [deactivateTarget, setDeactivateTarget] = useState<Service | null>(null);

  const queryStatus = status === "active" ? true : status === "inactive" ? false : undefined;
  const servicesQuery = useServices(queryStatus);
  const { data: trades = [] } = useDropdownOptionsByCategory("Trade");
  const { data: templates = [] } = useCompletionDocTemplates();
  const createService = useCreateService();
  const updateService = useUpdateService();
  const deactivateService = useDeactivateService();

  const filteredServices = useMemo(() => {
    const needle = search.trim().toLowerCase();
    if (!needle) return servicesQuery.data ?? [];
    return (servicesQuery.data ?? []).filter(
      (service) =>
        service.name.toLowerCase().includes(needle) || service.trade.toLowerCase().includes(needle),
    );
  }, [search, servicesQuery.data]);

  useEffect(() => {
    if (!iconTouched && form.trade) {
      setForm((current) => ({
        ...current,
        iconKey: DEFAULT_ICON_BY_TRADE[current.trade] ?? "wrench",
      }));
    }
  }, [form.trade, iconTouched]);

  const openCreate = () => {
    setSelected(null);
    setForm(emptyForm());
    setIconTouched(false);
    setFormError("");
    setEditorMode("add");
  };

  const openEdit = (service: Service) => {
    setSelected(service);
    setForm(formFromService(service));
    setIconTouched(true);
    setFormError("");
    setEditorMode("edit");
  };

  const closeEditor = () => {
    if (!createService.isPending && !updateService.isPending) setEditorMode(null);
  };

  const updateForm = <K extends keyof ServiceForm>(key: K, value: ServiceForm[K]) => {
    if (key === "trade") setIconTouched(false);
    setFormError("");
    setForm((current) => ({ ...current, [key]: value }));
  };

  const toggleType = (type: ServiceWorkOrderType) => {
    setForm((current) => {
      const supported = current.supportedWorkOrderTypes.includes(type)
        ? current.supportedWorkOrderTypes.filter((item) => item !== type)
        : [...current.supportedWorkOrderTypes, type];
      return { ...current, supportedWorkOrderTypes: supported };
    });
  };

  const save = () => {
    const validation = buildServiceInput(form);
    if (!validation.input) {
      setFormError(validation.error);
      return;
    }
    const input = validation.input;
    if (editorMode === "add") {
      createService.mutate(input, {
        onSuccess: (created) => {
          setEditorMode(null);
          setSelected(created);
        },
      });
    } else if (editorMode === "edit" && selected) {
      updateService.mutate(
        { id: selected.id, input },
        {
          onSuccess: (updated) => {
            setEditorMode(null);
            setSelected(updated);
          },
        },
      );
    }
  };

  const confirmDeactivate = () => {
    if (!deactivateTarget) return;
    deactivateService.mutate(deactivateTarget.id, {
      onSuccess: () => {
        setDeactivateTarget(null);
        setSelected(null);
      },
    });
  };

  return {
    canManage,
    canDeactivate,
    status,
    setStatus,
    search,
    setSearch,
    selected,
    setSelected,
    editorMode,
    form,
    formError,
    trades,
    templates,
    filteredServices,
    services: servicesQuery.data ?? [],
    isLoading: servicesQuery.isLoading,
    error: servicesQuery.error,
    openCreate,
    openEdit,
    closeEditor,
    updateForm,
    toggleType,
    save,
    deactivateTarget,
    setDeactivateTarget,
    confirmDeactivate,
    isSaving: createService.isPending || updateService.isPending,
    isDeactivating: deactivateService.isPending,
  };
}