import { Trans, useLingui } from "@lingui/react/macro";
import type { SpaceMemoryConfig } from "@rakazo/contracts";
import {
  Button,
  Field,
  FieldLabel,
  NativeSelect,
  NativeSelectOption,
  Switch,
} from "@rakazo/ui-web";
import { useEffect, useId, useState } from "react";
import { rpc } from "../lib/rpc";
import { SpaceMemorySection } from "./KnowledgeSection";
import {
  defaultMemoryProviderSettings,
  MEMORY_PROVIDER_SETTINGS,
  type MemoryProviderConnectionDraft,
  memoryProviderSettings,
} from "./memory-providers/registry";

type MemoryScope = "isolated" | "shared";

function SharedScopeSwitch({
  value,
  disabled,
  onChange,
}: {
  value: MemoryScope;
  disabled: boolean;
  onChange: (scope: MemoryScope) => void;
}) {
  const labelId = useId();
  return (
    <div className="flex items-center justify-between gap-4">
      <span id={labelId} className="text-ui-body text-foreground">
        <Trans>Share between bots</Trans>
      </span>
      <Switch
        aria-labelledby={labelId}
        checked={value === "shared"}
        disabled={disabled}
        onCheckedChange={(checked) => onChange(checked ? "shared" : "isolated")}
      />
    </div>
  );
}

/**
 * What the agents remember first; the optional semantic-recall provider stays
 * behind Advanced because most people never need it.
 */
export function MemorySettingsOverlay({
  config,
  onConfigChange,
  onBusyChange,
}: {
  config: SpaceMemoryConfig | null | undefined;
  onConfigChange: (config: SpaceMemoryConfig | null) => void;
  onBusyChange?: (busy: boolean) => void;
}) {
  const { t } = useLingui();
  const providerSelectId = useId();
  const defaultRegistration = defaultMemoryProviderSettings();
  const [selectedProvider, setSelectedProvider] = useState(
    config?.provider ?? defaultRegistration.id,
  );
  const [defaultScope, setDefaultScope] = useState<MemoryScope>(
    config?.defaultMemoryScope ?? "isolated",
  );
  const [pending, setPending] = useState<"connect" | "disconnect" | "scope" | null>(null);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    if (config) {
      setSelectedProvider(config.provider);
      setDefaultScope(config.defaultMemoryScope);
      return;
    }
    if (config === null && !memoryProviderSettings(selectedProvider)) {
      setSelectedProvider(defaultRegistration.id);
    }
  }, [config, defaultRegistration.id, selectedProvider]);

  const registration = memoryProviderSettings(config?.provider ?? selectedProvider);
  const busy = pending !== null;

  useEffect(() => {
    return () => onBusyChange?.(false);
  }, [onBusyChange]);

  function markPending(next: "connect" | "disconnect" | "scope" | null) {
    setPending(next);
    onBusyChange?.(next !== null);
  }

  async function connect(draft: MemoryProviderConnectionDraft) {
    if (!registration) return false;
    setError(null);
    markPending("connect");
    try {
      const next = await rpc.memory.connectProvider({
        provider: registration.id,
        ...draft,
        defaultMemoryScope: defaultScope,
      });
      onConfigChange(next);
      return true;
    } catch (err) {
      setError(err instanceof Error ? err.message : t`Could not connect ${registration.name}`);
      return false;
    } finally {
      markPending(null);
    }
  }

  async function disconnect() {
    setError(null);
    markPending("disconnect");
    try {
      await rpc.memory.disconnectProvider();
      onConfigChange(null);
    } catch (err) {
      setError(err instanceof Error ? err.message : t`Could not disconnect memory provider`);
    } finally {
      markPending(null);
    }
  }

  async function updateDefaultScope(scope: MemoryScope) {
    if (scope === defaultScope) return;
    setError(null);
    markPending("scope");
    try {
      const next = await rpc.memory.setDefaultScope({ defaultMemoryScope: scope });
      onConfigChange(next);
    } catch (err) {
      setError(err instanceof Error ? err.message : t`Could not update the default memory scope`);
    } finally {
      markPending(null);
    }
  }

  return (
    <div data-testid="memory-settings" className="flex min-h-0 flex-1 flex-col overflow-hidden">
      <div className="rk-scroll min-h-0 flex-1 overflow-y-auto overscroll-contain px-6 pb-6 pt-5 sm:px-8 sm:pb-8">
        <SpaceMemorySection />

        <details data-testid="memory-advanced" className="group mt-8" open={Boolean(config)}>
          <summary className="flex cursor-pointer list-none items-center justify-between gap-3 text-ui-body text-muted-foreground">
            <span>
              <Trans>Advanced</Trans>
            </span>
            <span aria-hidden="true" className="transition-transform group-open:rotate-90">
              ›
            </span>
          </summary>

          <div className="mt-4">
            {error ? <p className="mb-4 text-sm text-destructive">{error}</p> : null}

            {config === undefined ? (
              <p className="text-sm text-muted-foreground">
                <Trans>Loading memory settings…</Trans>
              </p>
            ) : config ? (
              <div className="rounded-xl border border-border px-4 py-3">
                <div className="flex items-center justify-between gap-3">
                  <span className="min-w-0 truncate text-ui-body text-foreground">
                    {registration?.connectedLabel(config) ?? config.provider}
                  </span>
                  <Button
                    type="button"
                    variant="outline"
                    size="sm"
                    disabled={busy}
                    onClick={() => void disconnect()}
                  >
                    {pending === "disconnect" ? (
                      <Trans>Disconnecting…</Trans>
                    ) : (
                      <Trans>Disconnect</Trans>
                    )}
                  </Button>
                </div>
                <div className="mt-3">
                  <SharedScopeSwitch
                    value={defaultScope}
                    disabled={busy}
                    onChange={(scope) => void updateDefaultScope(scope)}
                  />
                </div>
              </div>
            ) : registration ? (
              <>
                {MEMORY_PROVIDER_SETTINGS.length > 1 ? (
                  <Field className="mb-4">
                    <FieldLabel htmlFor={providerSelectId}>
                      <Trans>Provider</Trans>
                    </FieldLabel>
                    <NativeSelect
                      id={providerSelectId}
                      className="w-full"
                      value={selectedProvider}
                      disabled={busy}
                      onChange={(event) => setSelectedProvider(event.target.value)}
                    >
                      {MEMORY_PROVIDER_SETTINGS.map((entry) => (
                        <NativeSelectOption key={entry.id} value={entry.id}>
                          {entry.name}
                        </NativeSelectOption>
                      ))}
                    </NativeSelect>
                  </Field>
                ) : null}

                <div className="mb-4">
                  <SharedScopeSwitch
                    value={defaultScope}
                    disabled={busy}
                    onChange={setDefaultScope}
                  />
                </div>

                <registration.SettingsForm busy={busy} onConnect={connect} />
              </>
            ) : (
              <p className="text-sm text-destructive">
                <Trans>The selected memory provider is not available in this build.</Trans>
              </p>
            )}
          </div>
        </details>
      </div>
    </div>
  );
}