import {
  type GlobalSettings,
  GlobalSettings as GlobalSettingsSchema,
  type GlobalSettingsUpdate,
  mergeSettings,
} from "@umt/contracts";
import { LoaderCircle } from "lucide-react";
import { type ReactNode, useState } from "react";
import { toast } from "sonner";
import { useSettings, useUpdateSettings } from "~/api/settings.ts";
import { ErrorState, LoadingState } from "~/components/console/empty-state.tsx";
import { zodFieldErrors } from "~/components/console/form-field.tsx";
import { Button } from "~/components/ui/button.tsx";
import { errorMessage } from "~/lib/api.ts";
import { FieldControl, type FieldSpec, type FormValues } from "./resource-section.tsx";
import { SettingsBlock } from "./settings-block.tsx";

// 全局设置的一节:一组字段,独立保存(PATCH 对应 key);
// 校验 = 合并现值后用 contracts GlobalSettings 整体校验(含"恢复水位 < 硬阈值"等交叉规则)。

export type CardSpec = {
  /** 锚点 id(分区内唯一) */
  anchor: string;
  title: string;
  description?: ReactNode;
  fields: FieldSpec[];
  fromSettings: (s: GlobalSettings) => FormValues;
  toPatch: (v: FormValues, s: GlobalSettings) => GlobalSettingsUpdate;
  extra?: (s: GlobalSettings) => ReactNode;
};

export function SettingsCard({
  spec,
  settings,
  section,
}: {
  spec: CardSpec;
  settings: GlobalSettings;
  section: string;
}) {
  const update = useUpdateSettings();
  const [values, setValues] = useState<FormValues>(() => spec.fromSettings(settings));
  const [errors, setErrors] = useState<Record<string, string>>({});
  const initial = spec.fromSettings(settings);
  const dirty = Object.keys(values).some((k) => values[k] !== initial[k]);

  const save = async (e: React.FormEvent) => {
    e.preventDefault();
    const patch = spec.toPatch(values, settings);
    const parsed = GlobalSettingsSchema.safeParse(mergeSettings(settings, patch));
    if (!parsed.success) {
      const fe = zodFieldErrors(parsed.error.issues);
      // 交叉校验(refine)落在分组上:挂到本节同组的第一个字段
      for (const [k, m] of Object.entries(fe)) {
        if (!spec.fields.some((f) => f.name === k))
          fe[spec.fields.find((f) => k.startsWith(f.name.split(".")[0] ?? ""))?.name ?? k] ??= m;
      }
      setErrors(fe);
      return;
    }
    setErrors({});
    try {
      const next = await update.mutateAsync(patch);
      setValues(spec.fromSettings(next));
      toast.success(`${spec.title}已保存`);
    } catch (err) {
      toast.error(errorMessage(err, "保存失败"));
    }
  };

  return (
    <SettingsBlock
      section={section}
      anchor={spec.anchor}
      title={spec.title}
      description={spec.description}
      dirty={dirty}
    >
      <form onSubmit={save} noValidate>
        <div className="grid gap-x-4 gap-y-1 sm:grid-cols-2">
          {spec.fields
            .filter((f) => !f.visible || f.visible(values))
            .map((f) => (
              <FieldControl
                key={f.name}
                spec={f}
                value={values[f.name]}
                error={errors[f.name]}
                hint={f.hint}
                disabled={update.isPending}
                onChange={(v) => setValues((s) => ({ ...s, [f.name]: v }))}
              />
            ))}
        </div>
        {spec.extra?.(settings)}
        <div className="mt-2 flex items-center gap-2">
          <Button type="submit" size="sm" disabled={update.isPending || !dirty}>
            {update.isPending ? <LoaderCircle className="animate-spin" /> : null}
            保存
          </Button>
          {dirty ? (
            <Button
              type="button"
              variant="ghost"
              size="sm"
              onClick={() => {
                setValues(spec.fromSettings(settings));
                setErrors({});
              }}
            >
              还原
            </Button>
          ) : null}
        </div>
      </form>
    </SettingsBlock>
  );
}

/** 读取全局设置后再渲染(加载 / 出错占位) */
export function SettingsGate({ children }: { children: (s: GlobalSettings) => ReactNode }) {
  const q = useSettings();
  if (q.isPending) return <LoadingState rows={6} />;
  if (q.isError) return <ErrorState error={q.error} onRetry={() => q.refetch()} />;
  return <>{children(q.data)}</>;
}

/** 数字 → 表单字符串(null 为空) */
export const n = (v: number | null | undefined) => (v === null || v === undefined ? "" : String(v));