import { useCallback, useEffect, useState } from 'react';
import { useAtelierClient } from '../lib/api';
import type { Adapter, ProviderStatus } from '../lib/api';

/**
 * Every provider, and the verbs that change them.
 *
 * Owned here rather than inside useGenerateManager because two things need the same list and it must
 * not exist twice: the dropdown at the top of the panel, and the form below it whose model choices are
 * derived from whichever providers actually have a key. Adding one used to mean reloading the page
 * before the form noticed.
 */
export const useProviders = () => {
  const client = useAtelierClient();
  const [providers, setProviders] = useState<ProviderStatus[]>([]);
  const [adapters, setAdapters] = useState<Adapter[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [busy, setBusy] = useState(false);
  const [refreshing, setRefreshing] = useState(false);

  const refresh = useCallback(async () => {
    try {
      const [rows, catalogue] = await Promise.all([client.listProviders(), client.listAdapters()]);
      setProviders(rows);
      setAdapters(catalogue);
      setError(null);
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
    } finally {
      setLoading(false);
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  useEffect(() => {
    void refresh();
  }, [refresh]);

  const guard = async (action: () => Promise<ProviderStatus[]>) => {
    setBusy(true);
    try {
      setProviders(await action());
      setError(null);
      return true;
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
      return false;
    } finally {
      setBusy(false);
    }
  };

  /**
   * Create, then set the key if one was typed.
   *
   * Two calls because they are two things on the server: a provider row is public configuration, a key
   * is an encrypted secret that is never sent back. A provider added without a key is legitimate — the
   * key may live in the environment — so the second call is skipped rather than required.
   */
  const add = async (adapter: string, model: string, apiKey?: string) =>
    guard(async () => {
      const rows = await client.createProvider(adapter, model);
      const created = rows.find((row) => row.adapter === adapter && row.model === model);
      if (!apiKey?.trim() || !created) return rows;
      return client.updateProvider(created.id, { apiKey: apiKey.trim() });
    });

  /**
   * Re-read the catalogue from the vendor, then re-read our copy of it.
   *
   * Separate busy flag from `busy`: this one is a live fetch against OpenAI and takes seconds, where
   * everything else here is a local database write. Sharing one flag would grey out the whole dialog
   * for the length of a network round trip to a third party.
   */
  const refreshCatalogue = async (provider?: string) => {
    setRefreshing(true);
    try {
      await client.refreshCatalogue(provider);
      setAdapters(await client.listAdapters());
      setError(null);
      return true;
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
      return false;
    } finally {
      setRefreshing(false);
    }
  };

  return {
    providers,
    adapters,
    loading,
    busy,
    refreshing,
    refreshCatalogue,
    error,
    refresh,
    add,
    setKey: (id: string, apiKey: string) => guard(() => client.updateProvider(id, { apiKey: apiKey.trim() })),
    /** The one a generation will use when the request names only a model. */
    makeDefault: (id: string) => guard(() => client.updateProvider(id, { isDefault: true, enabled: true })),
    remove: (id: string) => guard(() => client.deleteProvider(id)),
    modelsFor: (adapter: string) => adapters.find((entry) => entry.name === adapter)?.models ?? [],
    adapterFor: (adapter: string) => adapters.find((entry) => entry.name === adapter),
  };
};

export type ProvidersManager = ReturnType<typeof useProviders>;