import { HydrationState } from "./hydration/index.ts";

export function createPipeline<Params, Skeleton, View, Context>(
  skeletonFn: (
    input: SkeletonFnInput<Context, Params>,
  ) => Promise<Skeleton> | Skeleton,
  hydrationFn: (
    input: HydrationFnInput<Context, Params, Skeleton>,
  ) => Promise<HydrationState>,
  rulesFn: (input: RulesFnInput<Context, Params, Skeleton>) => Skeleton,
  presentationFn: (
    input: PresentationFnInput<Context, Params, Skeleton>,
  ) => View,
) {
  return async (params: Params, ctx: Context) => {
    const skeleton = await skeletonFn({ ctx, params });
    const hydration = await hydrationFn({ ctx, params, skeleton });
    const appliedRules = rulesFn({ ctx, params, skeleton, hydration });
    return presentationFn({ ctx, params, skeleton: appliedRules, hydration });
  };
}

export type SkeletonFnInput<Context, Params> = {
  ctx: Context;
  params: Params;
};

export type HydrationFnInput<Context, Params, Skeleton> = {
  ctx: Context;
  params: Params;
  skeleton: Skeleton;
};

export type RulesFnInput<Context, Params, Skeleton> = {
  ctx: Context;
  params: Params;
  skeleton: Skeleton;
  hydration: HydrationState;
};

export type PresentationFnInput<Context, Params, Skeleton> = {
  ctx: Context;
  params: Params;
  skeleton: Skeleton;
  hydration: HydrationState;
};

export function noRules<S>(input: { skeleton: S }) {
  return input.skeleton;
}