import { Link2, RefreshCw, ShieldCheck, UserRoundPlus } from "lucide-react";
import { useCallback, useEffect, useState } from "react";
import { ActionToolbar,
  Button,
  DocumentationHelpLink,
  DismissibleAlert,
  LoadingIndicator,
  PageScrollViewport,
  SelectionList,
  SelectionListItem,
  SelectionListItemContent,
  StatePanel,
  StatusBadge,
  hasScope,
  i18nMessage,
  useGuardedNavigate,
  usePlatformLanguage,
  WorkspaceFrame,
  type PlatformRouteContext
} from "@govoplan/core-webui";
import { listFormInstances, type FormInstance } from "../../api/formsRuntime";
import { FORMS_RUNTIME_DOCUMENTATION, FORMS_RUNTIME_I18N } from "./interfacePatterns";
import IntakeProfilesDialog from "./IntakeProfilesDialog";
import AssistedIntakeDialog from "./AssistedIntakeDialog";
import StatusAccessPoliciesDialog from "./StatusAccessPoliciesDialog";


const OPEN_STATUSES = ["started", "draft", "submitted", "validated", "needs_review"];

export default function FormsRuntimePage({ settings, auth }: PlatformRouteContext) {
  const navigate = useGuardedNavigate();
  const { language } = usePlatformLanguage();
  const [items, setItems] = useState<FormInstance[]>([]);
  const [total, setTotal] = useState(0);
  const [status, setStatus] = useState("open");
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState("");
  const [intakeOpen, setIntakeOpen] = useState(false);
  const [assistedOpen, setAssistedOpen] = useState(false);
  const [statusAccessOpen, setStatusAccessOpen] = useState(false);
  const canAdmin = hasScope(auth, "forms_runtime:workspace:admin");
  const canAssist = hasScope(auth, "forms_runtime:submission:assist")
    || hasScope(auth, "forms_runtime:workspace:write");

  const load = useCallback((signal?: AbortSignal) => {
    setLoading(true);
    setError("");
    return listFormInstances(settings, {
      statuses: status === "open" ? OPEN_STATUSES : status ? [status] : undefined,
      limit: 200
    }, signal).
      then((result) => {
        setItems(result.instances);
        setTotal(result.total);
      }).
      finally(() => setLoading(false));
  }, [settings, status]);

  useEffect(() => {
    const controller = new AbortController();
    load(controller.signal).catch((reason) => {
      if ((reason as Error).name !== "AbortError") {
        setError(reason instanceof Error ? reason.message : "Forms could not be loaded.");
      }
    });
    return () => controller.abort();
  }, [load]);

  return (
    <main className="forms-runtime-page">
      <WorkspaceFrame className="forms-runtime-shell" label="Forms runtime" interfaceId="forms-runtime.workspace" helpContextId="forms-runtime.page.workspace" helpModuleId="forms-runtime">
        <ActionToolbar surface="panel-header" className="forms-runtime-toolbar">
          <Button onClick={() => void load()} disabled={loading} disabledReason={loading ? FORMS_RUNTIME_I18N.loading : undefined}>
            <RefreshCw size={16} aria-hidden="true" />
            Refresh
          </Button>
          {canAdmin &&
            <Button onClick={() => setIntakeOpen(true)}>
              <Link2 size={16} aria-hidden="true" />
              Public intake
            </Button>
          }
          {canAdmin &&
            <Button onClick={() => setStatusAccessOpen(true)}>
              <ShieldCheck size={16} aria-hidden="true" />
              Status access
            </Button>
          }
          {canAssist &&
            <Button onClick={() => setAssistedOpen(true)}>
              <UserRoundPlus size={16} aria-hidden="true" />
              Assisted intake
            </Button>
          }
          <label>
            <span>Status</span>
            <select value={status} onChange={(event) => setStatus(event.target.value)}>
              <option value="open">Open</option>
              <option value="">All</option>
              <option value="draft">Draft</option>
              <option value="submitted">Submitted</option>
              <option value="needs_review">Needs review</option>
              <option value="accepted">Accepted</option>
              <option value="rejected">Rejected</option>
              <option value="handed_off">Handed off</option>
              <option value="archived">Archived</option>
            </select>
          </label>
          <span className="forms-runtime-count">{i18nMessage("i18n:govoplan-forms-runtime.form_count", { total })}</span>
          <DocumentationHelpLink reference={FORMS_RUNTIME_DOCUMENTATION} />
        </ActionToolbar>
        <PageScrollViewport className="forms-runtime-list-viewport">
          {error &&
            <DismissibleAlert tone="danger" resetKey={error}>
              {error}
            </DismissibleAlert>
          }
          {loading && <LoadingIndicator label="Loading forms" />}
          {!loading && !error && items.length === 0 &&
            <StatePanel size="compact" description="No matching Forms." />
          }
          {!loading && items.length > 0 &&
            <SelectionList variant="navigation" label="Forms">
              {items.map((item) =>
                <SelectionListItem
                  key={item.instance_id}
                  selected={false}
                  onClick={() => navigate(`/forms-runtime/${encodeURIComponent(item.instance_id)}`)}>
                  <SelectionListItemContent title={item.definition_ref.label ?? humanize(item.definition_ref.object_id)} description={`Revision ${item.definition_ref.version ?? "-"} · ${formatDateTime(item.recorded_at, language)}`} />
                  <StatusBadge status={isOpen(item.status) ? "active" : "inactive"} label={stateLabel(item.status)} />
                </SelectionListItem>
              )}
            </SelectionList>
          }
        </PageScrollViewport>
      </WorkspaceFrame>
      <IntakeProfilesDialog open={intakeOpen} settings={settings} onClose={() => setIntakeOpen(false)} />
      <StatusAccessPoliciesDialog open={statusAccessOpen} settings={settings} onClose={() => setStatusAccessOpen(false)} />
      <AssistedIntakeDialog
        open={assistedOpen}
        settings={settings}
        language={language}
        onClose={() => setAssistedOpen(false)}
        onStarted={(instanceId) => {
          setAssistedOpen(false);
          navigate(`/forms-runtime/${encodeURIComponent(instanceId)}`);
        }}
      />
    </main>
  );
}

function isOpen(status: string): boolean {
  return OPEN_STATUSES.includes(status);
}

function formatDateTime(value: string, locale?: string): string {
  return new Intl.DateTimeFormat(locale, { dateStyle: "medium", timeStyle: "short" }).format(new Date(value));
}

function humanize(value: string): string {
  return value.replace(/[_:.-]+/g, " ").replace(/\b\w/g, (letter) => letter.toUpperCase());
}

function stateLabel(value: string): string {
  return `i18n:govoplan-forms-runtime.state_${value}`;
}