import { Either, type IEither, isObject } from "@emprespresso/pengueno";
import { type FetchCodeJob, isJob, type Job } from "@emprespresso/ci-model";

export interface PipelineStage {
  readonly parallelJobs: Array<Job>;
}
export const isPipelineStage = (t: unknown): t is PipelineStage =>
  isObject(t) &&
  "parallelJobs" in t &&
  Array.isArray(t.parallelJobs) &&
  t.parallelJobs.every((j) => isJob(j));

export interface Pipeline {
  readonly serialJobs: Array<PipelineStage>;
  serialize(): string;
}
export const isPipeline = (t: unknown): t is Pipeline =>
  isObject(t) &&
  "serialJobs" in t &&
  Array.isArray(t.serialJobs) &&
  t.serialJobs.every((p) => isPipelineStage(p));

export interface PipelineBuilder {
  addStage(stage: PipelineStage): PipelineBuilder;
  build(): Pipeline;
}

export class PipelineImpl implements Pipeline {
  constructor(public readonly serialJobs: Array<PipelineStage>) {}

  public serialize() {
    return JSON.stringify(this.serialJobs);
  }

  public static from(s: string): IEither<Error, Pipeline> {
    return Either.fromFailable<Error, unknown>(() => JSON.parse(s))
      .flatMap<Pipeline>((eitherPipelineJson) =>
        isPipeline(eitherPipelineJson)
          ? Either.right(eitherPipelineJson)
          : Either.left(new Error("oh noes D: its a bad pipewine :((")),
      )
      .mapRight((pipeline) => new PipelineImpl(pipeline.serialJobs));
  }
}

abstract class BasePipelineBuilder implements PipelineBuilder {
  protected readonly stages: Array<PipelineStage> = [];

  public addStage(stage: PipelineStage): PipelineBuilder {
    this.stages.push(stage);
    return this;
  }

  public build() {
    return new PipelineImpl(this.stages);
  }
}

export class DefaultGitHookPipelineBuilder extends BasePipelineBuilder {
  constructor(
    private readonly remoteUrl = Deno.env.get("remote")!,
    rev = Deno.env.get("rev")!,
    private readonly ref = Deno.env.get("ref")!,
  ) {
    super();

    this.addStage({
      parallelJobs: [
        <FetchCodeJob>{
          type: "fetch_code",
          arguments: {
            remoteUrl,
            checkout: rev,
            path: this.getSourceDestination(),
          },
        },
      ],
    });
  }

  public getSourceDestination() {
    return this.remoteUrl.split("/").at(-1) ?? "src";
  }

  public getBranch(): string | undefined {
    const branchRefPrefix = "refs/heads/";
    return this.ref.split(branchRefPrefix).at(1);
  }
}