import { useState } from "react";
import { adminAddLlmProvider } from "../../../lib/api";
import type { AdminLlmProvider, LlmProviderRequest } from "../../../lib/types";
import { useAuditStore } from "../../audit";
import { Button, Surface } from "../../../components/primitives";
import {
  ApiKeyAndBudgetField,
  ContextWindowField,
  MultimodalField,
  PersonaRoutesEditor,
  ReasoningField,
  initPersonaRoutes,
  personaRouteProblem,
  routesToMaps,
} from "./LlmProviderRouting";
import type { CatalogHint, PersonaRouteDraft } from "./LlmProviderRouting";

/** Add/edit form for one LLM provider group. The group list hands in an
 *  `initial` group to edit (remounted via key) or null to add a new one. The
 *  backend merges the request over the stored group, so blank optional fields
 *  (apiKey / maxTokens / contextWindow) are simply omitted and keep their
 *  stored value. */

interface FormState {
  name: string;
  provider: string;
  model: string;
  baseUrl: string;
  apiKey: string;
  multimodal: boolean;
  maxTokens: string;
  /** 模型上下文窗口（token）；空串 = 未声明（不提交该键，保留已存窗口）。 */
  contextWindow: string;
  /** 推理开关形状；空串 = 未声明（等同 auto）。 */
  reasoning: string;
  /** per-persona 路由行（persona → 模型 / 协议覆盖）。 */
  personaRoutes: PersonaRouteDraft[];
}

type FieldSetter = <K extends keyof FormState>(key: K, value: FormState[K]) => void;

function initState(initial: AdminLlmProvider | null): FormState {
  return {
    name: initial?.id ?? "",
    provider: initial?.provider || "openai",
    model: initial?.model ?? "",
    baseUrl: initial?.baseUrl ?? "",
    apiKey: "",
    multimodal: initial?.multimodal ?? false,
    maxTokens: initial?.maxTokens ? String(initial.maxTokens) : "",
    contextWindow: initial?.contextWindow ? String(initial.contextWindow) : "",
    reasoning: initial?.reasoning?.kind ?? "",
    personaRoutes: initPersonaRoutes(initial),
  };
}

/** 把表单状态变成一个 provider 保存请求 —— 模块级纯函数，因此「保存」这条路径的
 *  语义不依赖组件内部状态。提交前的本地校验（两个数字字段的非负整数、按角色路由
 *  的行）都在这里发生：不通过就通过 onError 报红字并返回 null（一个请求都不发）。 */
function buildRequest(
  form: FormState,
  editing: boolean,
  initial: AdminLlmProvider | null,
  onError: (msg: string | null) => void,
): LlmProviderRequest | null {
  const budget = form.maxTokens.trim();
  if (budget !== "" && !/^\d+$/.test(budget)) {
    onError("maxTokens 必须为非负整数（留空 = 保持/默认）");
    return null;
  }
  const window = form.contextWindow.trim();
  if (window !== "" && !/^\d+$/.test(window)) {
    onError("contextWindow 必须为非负整数（留空 = 未声明，按 128 Ki token 保守估算）");
    return null;
  }
  const problem = personaRouteProblem(form.personaRoutes);
  if (problem) {
    onError(problem);
    return null;
  }
  const { personaModels, personaProviders } = routesToMaps(form.personaRoutes);
  const req: LlmProviderRequest = {
    provider: form.provider,
    baseUrl: form.baseUrl,
    model: form.model,
    multimodal: form.multimodal,
    // reasoning 整块给出：kind 空串 = 显式回到「未声明」，否则面板无法把
    // 已存形状改回去（缺省字段意味着「保留原值」）。
    reasoning: { kind: form.reasoning },
    // 两张路由表整表提交：面板删掉一行后要真的能从存储里删掉。
    personaModels,
    personaProviders,
  };
  if (editing && initial) req.id = initial.id;
  else if (form.name.trim()) req.id = form.name.trim();
  if (form.apiKey.trim()) req.apiKey = form.apiKey.trim();
  if (budget !== "") req.maxTokens = Number(budget);
  // 空串 = 不提交该键（缺省 = 保留已存窗口）；显式 `0` 与省略同义（都表示
  // 未声明），因此面板只在此处如实转发用户真的填了的那个数。
  if (window !== "") req.contextWindow = Number(window);
  return req;
}

/** The form fields; state lives in the form component below. */
function ProviderFields({
  form,
  set,
  editing,
  hint,
  reasoningKinds,
  personaProviderOptions,
  personaIds,
  personaListError,
}: {
  form: FormState;
  set: FieldSetter;
  editing: boolean;
  hint: CatalogHint | null;
  reasoningKinds: string[];
  personaProviderOptions: string[];
  personaIds: string[];
  personaListError: string | null;
}): React.ReactNode {
  return (
    <>
      <div className="grid grid-cols-1 gap-2 sm:grid-cols-2">
        <label className="block space-y-1">
          <span className="text-xs text-[var(--mu-text-lo)]">名称 / ID（留空自动生成）</span>
          <input
            value={form.name}
            onChange={(e) => set("name", e.target.value)}
            placeholder="deepseek"
            disabled={editing}
            className={inputCls}
          />
        </label>
        <label className="block space-y-1">
          <span className="text-xs text-[var(--mu-text-lo)]">协议 Provider</span>
          <select value={form.provider} onChange={(e) => set("provider", e.target.value)} className={inputCls}>
            <option value="openai">openai（OpenAI 兼容）</option>
            <option value="anthropic">anthropic（Anthropic Messages）</option>
          </select>
        </label>
      </div>
      <div className="grid grid-cols-1 gap-2 sm:grid-cols-2">
        <label className="block space-y-1">
          <span className="text-xs text-[var(--mu-text-lo)]">模型</span>
          <input value={form.model} onChange={(e) => set("model", e.target.value)} className={inputCls} />
        </label>
        <label className="block space-y-1">
          <span className="text-xs text-[var(--mu-text-lo)]">baseURL</span>
          <input value={form.baseUrl} onChange={(e) => set("baseUrl", e.target.value)} placeholder="https://api.example.com/v1" className={inputCls} />
        </label>
      </div>
      <ApiKeyAndBudgetField
        apiKey={form.apiKey}
        maxTokens={form.maxTokens}
        editing={editing}
        onApiKey={(v) => set("apiKey", v)}
        onMaxTokens={(v) => set("maxTokens", v)}
      />
      <ContextWindowField value={form.contextWindow} onChange={(v) => set("contextWindow", v)} />
      <MultimodalField checked={form.multimodal} hint={hint} onChange={(v) => set("multimodal", v)} />
      <ReasoningField
        value={form.reasoning}
        kinds={reasoningKinds}
        provider={form.provider}
        onChange={(v) => set("reasoning", v)}
      />
      <PersonaRoutesEditor
        routes={form.personaRoutes}
        knownIds={personaIds}
        personaListError={personaListError}
        providerOptions={personaProviderOptions}
        groupProvider={form.provider}
        onChange={(next) => set("personaRoutes", next)}
      />
    </>
  );
}

interface LlmProviderFormProps {
  initial: AdminLlmProvider | null;
  busy: boolean;
  setBusy: (v: boolean) => void;
  onResult: (msg: string) => void;
  onError: (msg: string | null) => void;
  onSaved: () => void;
  onCancel: () => void;
  /** 目录候选带进来的能力建议（可推翻）；null = 没有建议。 */
  hint: CatalogHint | null;
  /** reasoning.kind 的可选取值，由后端下发（缺省 = 后端未报告）。 */
  reasoningKinds: string[];
  /** personaProviders 的可选取值，由后端下发（缺省 = 后端未报告）。 */
  personaProviderOptions: string[];
  /** 已知 persona id，仅作为候选提示（可手填）。 */
  personaIds: string[];
  /** 角色清单取不到时的原因；null = 清单可用。 */
  personaListError: string | null;
}

/** Owns the field state and the save round-trip; the module supplies callbacks. */
export function LlmProviderForm({
  initial,
  busy,
  setBusy,
  onResult,
  onError,
  onSaved,
  onCancel,
  hint,
  reasoningKinds,
  personaProviderOptions,
  personaIds,
  personaListError,
}: LlmProviderFormProps): React.ReactNode {
  const editing = initial !== null;
  const [form, setForm] = useState<FormState>(() => initState(initial));
  const log = useAuditStore((s) => s.log);
  const set: FieldSetter = (key, value) => setForm((prev) => ({ ...prev, [key]: value }));

  const save = () => {
    const req = buildRequest(form, editing, initial, onError);
    if (!req) return;
    setBusy(true);
    onError(null);
    adminAddLlmProvider(req)
      .then((r) => {
        log("llm.addProvider", "ok");
        const budgetNote = r.provider.maxTokens ? ` · maxTokens ${r.provider.maxTokens}` : "";
        const windowNote = r.provider.contextWindow ? ` · contextWindow ${r.provider.contextWindow}` : "";
        onResult(`已保存到 models.json 并热更新：${r.provider.name} · ${r.provider.model}${budgetNote}${windowNote}${r.path ? `（${r.path}）` : ""}`);
        onSaved();
        if (editing) onCancel();
        else setForm(initState(null));
      })
      .catch((e: unknown) => {
        log("llm.addProvider", "error");
        onError(e instanceof Error ? e.message : "保存模型失败");
      })
      .finally(() => setBusy(false));
  };

  return (
    <Surface className="space-y-3">
      <div className="flex items-center gap-2">
        <h3 className="text-sm font-semibold">{editing ? `编辑模型组 · ${initial?.id}` : "新增模型（保存到 models.json，即刻热更新）"}</h3>
        {editing ? (
          <Button size="sm" variant="ghost" className="ml-auto" onClick={onCancel}>
            取消编辑
          </Button>
        ) : null}
      </div>
      <ProviderFields
        form={form}
        set={set}
        editing={editing}
        hint={hint}
        reasoningKinds={reasoningKinds}
        personaProviderOptions={personaProviderOptions}
        personaIds={personaIds}
        personaListError={personaListError}
      />
      <div className="flex items-center gap-2">
        <Button variant="primary" disabled={busy || !form.model || !form.baseUrl} onClick={save}>
          {editing ? "保存修改" : "保存模型"}
        </Button>
        <span className="text-xs text-[var(--mu-text-lo)]">
          {editing
            ? "只提交本表单填写的字段，未填字段保持原值（按角色路由与推理形状按当前表单内容整块提交）"
            : "保存后写入 models.json 并热更新运行中的 LLM provider"}
        </span>
      </div>
    </Surface>
  );
}

const inputCls =
  "w-full rounded-[var(--mu-radius)] bg-[var(--mu-surface-2)] px-3 py-2 text-sm outline-none focus:ring-1 focus:ring-[var(--mu-accent)] disabled:opacity-60";