import Dependencies = require('../dependencies');

// TODO: ProcessStringResult and Context should be template types so that the
// consumer can strongly type their data.
export type ProcessStringResult<Data = {}> = Record<'output', string> & Data;

export interface Context {
  processString(contents: string, relativePath: string): string | ProcessStringResult | Promise<string | ProcessStringResult>;
  postProcess(v: ProcessStringResult, relativePath: string): ProcessStringResult | Promise<ProcessStringResult>;
  cacheKey?(): string;
  cacheKeyProcessString?(contents: string, relativePath: string): string;
}

export interface InstrumentationSchema {
  persistentCacheHit: number;
  persistentCachePrime: number;
}

export interface Strategy {
  init(ctx: Context): void;
  processString(ctx: Context, contents: string, relativePath: string, forceInvalidation: boolean, instrumentation: InstrumentationSchema):  string | ProcessStringResult | Promise<string | ProcessStringResult>;
  initialDependencies(rootFS: Dependencies.FSFacade, inputEncoding: string): Dependencies
  sealDependencies(dependencies: Dependencies): void;
}