import { useState } from "react";
import { useTranslation } from "react-i18next";
import { Plus, Trash2, Pencil } from "lucide-react";
import type { Provider } from "@/lib/types";
import { useProviders, useProviderMutations } from "@/lib/queries";
import { useToast } from "@/components/toast";
import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { ProviderForm, type ProviderSubmitInput } from "@/components/ProviderForm";

export default function Providers() {
  const { t } = useTranslation();
  const { data, isLoading, isError } = useProviders("claude");
  const mutations = useProviderMutations();
  const { show } = useToast();
  const [editing, setEditing] = useState<{ provider: Provider | null } | null>(null);
  const [lastAppliedEnv, setLastAppliedEnv] = useState<Record<string, string> | null>(null);

  const providers = data?.items ?? [];

  const submitForm = (input: ProviderSubmitInput) => {
    const target = editing?.provider ?? null;
    const onSuccess = () => {
      show(target ? t("providers.updated") : t("providers.created"));
      setEditing(null);
    };
    const onError = (err: Error) => show(err.message, "error");
    if (target) {
      mutations.update.mutate({ id: target.id, input }, { onSuccess, onError });
    } else {
      mutations.create.mutate(input, { onSuccess, onError });
    }
  };

  const apply = (provider: Provider) => {
    mutations.apply.mutate(
      { id: provider.id, target: "claude" },
      {
        onSuccess: (result) => {
          setLastAppliedEnv(result.env ?? null);
          show(`${t("providers.activated")}: ${provider.name}`);
        },
        onError: (err: Error) => show(err.message, "error"),
      },
    );
  };

  if (isLoading) return <div className="text-sm text-zinc-500">{t("common.loading")}</div>;
  if (isError) return <div className="text-sm text-red-600">{t("common.error")}</div>;

  return (
    <div className="flex flex-col gap-5">
      <div className="flex items-center justify-between">
        <h2 className="text-lg font-semibold">{t("providers.title")}</h2>
        <Button size="sm" onClick={() => setEditing({ provider: null })}>
          <Plus size={14} aria-hidden />
          {t("providers.add")}
        </Button>
      </div>

      {editing && (
        <ProviderForm
          target="claude"
          editing={editing.provider}
          pending={mutations.create.isPending || mutations.update.isPending}
          onSubmit={submitForm}
          onCancel={() => setEditing(null)}
        />
      )}

      {lastAppliedEnv && (
        <Card>
          <CardHeader>
            <CardTitle>{t("providers.appliedEnv")}</CardTitle>
          </CardHeader>
          <CardContent>
            <ul className="grid grid-cols-2 gap-1 font-mono text-xs text-zinc-600">
              {Object.entries(lastAppliedEnv)
                .filter(([key]) => key.startsWith("ANTHROPIC_"))
                .sort(([a], [b]) => a.localeCompare(b))
                .map(([key, value]) => (
                  <li key={key}>
                    <span className="text-zinc-400">{key}</span> = {value}
                  </li>
                ))}
            </ul>
          </CardContent>
        </Card>
      )}

      {providers.length === 0 ? (
        <Card>
          <CardContent className="py-8 text-center text-sm text-zinc-500">
            {t("providers.empty")}
          </CardContent>
        </Card>
      ) : (
        <div className="flex flex-col gap-3">
          {providers.map((provider) => (
            <Card key={provider.id}>
              <CardContent className="flex items-center gap-4 py-4">
                <div className="min-w-0 flex-1">
                  <div className="flex items-center gap-2">
                    <span className="text-sm font-medium">{provider.name}</span>
                    {provider.enabled_for_claude && (
                      <Badge tone="success">{t("providers.activated")}</Badge>
                    )}
                    {provider.preset && <Badge>{provider.preset}</Badge>}
                  </div>
                  <div className="truncate text-xs text-zinc-500">{provider.base_url}</div>
                </div>
                <div className="flex shrink-0 gap-2">
                  <Button variant="outline" size="sm" onClick={() => apply(provider)}>
                    {t("providers.activate")}
                  </Button>
                  <Button
                    variant="ghost"
                    size="icon"
                    aria-label={t("common.edit")}
                    onClick={() => setEditing({ provider })}
                  >
                    <Pencil size={14} aria-hidden />
                  </Button>
                  <Button
                    variant="ghost"
                    size="icon"
                    aria-label={t("common.delete")}
                    onClick={() => {
                      if (window.confirm(t("providers.deleteConfirm"))) {
                        mutations.remove.mutate(provider.id, {
                          onSuccess: () => show(t("providers.deleted")),
                          onError: (err: Error) => show(err.message, "error"),
                        });
                      }
                    }}
                  >
                    <Trash2 size={14} aria-hidden />
                  </Button>
                </div>
              </CardContent>
            </Card>
          ))}
        </div>
      )}
    </div>
  );
}