"use client";

import {
  type Context,
  createContext,
  createElement,
  type PropsWithChildren,
  use,
  useEffect,
  useMemo,
  useState,
} from "react";
import {
  type Bunja,
  type BunjaStore,
  createBunjaStore,
  createReadScopeFn,
  createScope,
  delayUnmount,
  type HashFn,
  type ReadScope,
  type Scope,
  type ScopeValuePair,
} from "./bunja.ts";

// @ts-ignore dev
// deno-lint-ignore no-process-global
const __DEV__ = process.env.NODE_ENV !== "production";

export const BunjaStoreContext: Context<BunjaStore> = createContext(
  createBunjaStore(),
);

export function BunjaStoreProvider(
  { children }: PropsWithChildren,
): React.JSX.Element {
  const [value] = useState(createBunjaStore);
  useEffect(() => () => value.dispose(), [value]);
  return createElement(BunjaStoreContext, { value, children });
}

export const scopeContextMap: Map<Scope<unknown>, Context<unknown>> = new Map();
export function bindScope<T>(scope: Scope<T>, context: Context<T>): void {
  scopeContextMap.set(scope as Scope<unknown>, context as Context<unknown>);
}

export function createScopeFromContext<T>(
  context: Context<T>,
  hash?: HashFn<T>,
): Scope<T> {
  const scope = createScope<T>(hash);
  bindScope(scope, context);
  return scope;
}

const defaultReadScope: ReadScope = <T>(scope: Scope<T>) => {
  const context = scopeContextMap.get(scope as Scope<unknown>)!;
  return use(context) as T;
};

export function useBunja<T>(
  bunja: Bunja<T>,
  scopeValuePairs?: ScopeValuePair<any>[],
): T {
  const store = use(BunjaStoreContext);
  const readScope = scopeValuePairs
    ? createReadScopeFn(scopeValuePairs, defaultReadScope)
    : defaultReadScope;
  if (__DEV__) {
    const { value, mount, deps, bunjaInstance } = store.get(bunja, readScope);
    useEffect(delayUnmount(mount), deps);
    useMemo(
      () => ({ bunja, scopeValuePairs, bunjaInstance }),
      [bunja, scopeValuePairs, bunjaInstance],
    );
    return value;
  } else {
    const { value, mount, deps } = store.get(bunja, readScope);
    useEffect(delayUnmount(mount), deps);
    return value;
  }
}