/**
 * vibe-registry core —— 万物皆注册的类型基石
 *
 * 设计要点(v0.5):
 *  - 注册项类型封闭 + id 即引用键
 *  - 所有注册项可带 demo 预览数据(预览即真实)
 *  - 纯 TS、零依赖、不接 UI(渲染内核后续接)
 */

export type RegistryKind = 'layout' | 'widget' | 'action' | 'schema' | 'theme'

/** 布局渲染函数签名(React 无关,render 层传入类型;避免 core 依赖 React) */
export interface LayoutRenderProps<S extends string = string> {
  readonly slots: readonly S[]
  /** slot → 已填充的 ReactNode 数组 */
  readonly blocks: Record<string, readonly unknown[]>
  /** 页面声明本身(含 title 等元信息) */
  readonly page: { readonly layout: string; readonly title?: string }
}

/** 布局骨架:页面级结构。渲染内核据 slots 填充 blocks。 */
export interface LayoutRegistryEntry {
  readonly kind: 'layout'
  /** 简易 id,如 'admin' —— 用户/agent 只需说这个 id */
  readonly id: string
  /** 布局所含槽位顺序,渲染时 blocks 依 slot 填入 */
  readonly slots: readonly string[]
  /** 描述,供画廊/agent 展示 */
  readonly description: string
  /** 布局渲染实现(slots → 页面骨架)。可选:缺省用画廊的通用骨架 */
  readonly render?: (props: LayoutRenderProps) => unknown
  /** demo 数据(预览即真实,与实装共用渲染内核) */
  readonly preview?: LayoutPreview
}

export interface LayoutPreview {
  /** 标题文本,画廊首页展示 */
  readonly title: string
  /** 缩略示意:每个 slot 放什么 demo block(id 或描述) */
  readonly demoBlocks?: ReadonlyArray<{
    readonly slot: string
    readonly widget: string
    readonly props?: Record<string, unknown>
  }>
}

/** 业务组件注册项(映射到已有 UI 库,不重造原子组件) */
export interface WidgetRegistryEntry {
  readonly kind: 'widget'
  readonly id: string
  /** 渲染组件(React 组件;render 层消费,core 不依赖 React 类型) */
  readonly component?: unknown
  /** 关联字段/列 schema id(可选) */
  readonly schemaId?: string
  readonly description?: string
}

/** 行为注册项:可复用的事件语义(泛型:payload/结果类型随注册保留,不丢业务语义) */
export interface ActionRegistryEntry<P = unknown, R = unknown> {
  readonly kind: 'action'
  readonly id: string
  readonly handler: (payload: P, ctx: unknown) => R | Promise<R>
  readonly description?: string
}

/** 数据/字段注册项:表单字段、表格列 */
export interface SchemaRegistryEntry {
  readonly kind: 'schema'
  readonly id: string
  readonly fields?: readonly unknown[]
  readonly description?: string
}

export type RegistryEntry =
  | LayoutRegistryEntry
  | WidgetRegistryEntry
  | ActionRegistryEntry
  | SchemaRegistryEntry

/** 注册表集合:kind → id → entry(单一事实来源) */
export type RegistryStore = {
  readonly layouts: ReadonlyMap<string, LayoutRegistryEntry>
  readonly widgets: ReadonlyMap<string, WidgetRegistryEntry>
  readonly actions: ReadonlyMap<string, ActionRegistryEntry>
  readonly schemas: ReadonlyMap<string, SchemaRegistryEntry>
}

/* ── 注册与查询 ─────────────────────────────────────────────── */

export type RegisterFn<K extends RegistryKind, E extends { readonly kind: K; readonly id: string }> =
  (entry: E) => E

export interface RegistryApi {
  readonly store: RegistryStore
  registerLayout: RegisterFn<'layout', LayoutRegistryEntry>
  registerWidget: RegisterFn<'widget', WidgetRegistryEntry>
  registerAction: <P, R>(entry: ActionRegistryEntry<P, R>) => ActionRegistryEntry<P, R>
  registerSchema: RegisterFn<'schema', SchemaRegistryEntry>
  /** 校验:给定引用集合,返回未注册的 id 清单(空 = 通过) */
  validateRefs: (refs: ReadonlyArray<{ readonly kind: RegistryKind; readonly id: string }>) => string[]
  /** 画廊用的清单:全部已注册项(dev 用) */
  listAll: () => RegistryEntry[]
}

/** 创建注册表(单例由 createRegistry 返回) */
export function createRegistry(): RegistryApi {
  const layouts = new Map<string, LayoutRegistryEntry>()
  const widgets = new Map<string, WidgetRegistryEntry>()
  const actions = new Map<string, ActionRegistryEntry>()
  const schemas = new Map<string, SchemaRegistryEntry>()

  function register<K extends RegistryKind, E extends { readonly kind: K; readonly id: string }>(
    map: Map<string, RegistryEntry>,
    entry: E,
  ): E {
    const existed = map.get(entry.id)
    if (existed) {
      throw new Error(`[vibe-registry] 注册冲突:${entry.kind} '${entry.id}' 已存在(万物皆注册,id 唯一)`)
    }
    map.set(entry.id, entry as RegistryEntry)
    return entry
  }

  return {
    store: { layouts, widgets, actions, schemas },
    registerLayout: (e) => register(layouts, e),
    registerWidget: (e) => register(widgets, e),
    registerAction: <P, R>(entry: ActionRegistryEntry<P, R>) => {
      if (actions.has(entry.id)) {
        throw new Error(`[vibe-registry] 注册冲突:action '${entry.id}' 已存在(万物皆注册,id 唯一)`)
      }
      actions.set(entry.id, entry as ActionRegistryEntry)
      return entry
    },
    registerSchema: (e) => register(schemas, e),
    validateRefs(refs) {
      const missing: string[] = []
      for (const r of refs) {
        const map = r.kind === 'layout' ? layouts : r.kind === 'widget' ? widgets : r.kind === 'action' ? actions : schemas
        if (!map.has(r.id)) missing.push(`${r.kind}:${r.id}`)
      }
      return missing
    },
    listAll() {
      return [...layouts.values(), ...widgets.values(), ...actions.values(), ...schemas.values()]
    },
  }
}

/* ── 全局注册表(单例,项目内 import 即用) ────────────────────── */

const globalRegistry = createRegistry()
export const registerLayout: RegistryApi['registerLayout'] = (e) => globalRegistry.registerLayout(e)
export const registerWidget: RegistryApi['registerWidget'] = (e) => globalRegistry.registerWidget(e)
export const registerAction: RegistryApi['registerAction'] = (e) => globalRegistry.registerAction(e)
export const registerSchema: RegistryApi['registerSchema'] = (e) => globalRegistry.registerSchema(e)
export const registry: RegistryApi = globalRegistry