3 files changed, 92 insertions, 0 deletions
diff --git a/model/pipeline/builder.ts b/model/pipeline/builder.ts
new file mode 100644
index 0000000..e95e89c
--- /dev/null
+++ b/model/pipeline/builder.ts
@@ -0,0 +1,53 @@
+import { Pipeline, PipelineStage } from '.';
+import { FetchCodeJob } from '../job';
+import { PipelineImpl } from './impl';
+
+export interface PipelineBuilder {
+    addStage(stage: PipelineStage): PipelineBuilder;
+    build(): Pipeline;
+}
+
+export 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 = process.env.remote!,
+        rev = process.env.rev!,
+        private readonly ref = process.env.ref!,
+    ) {
+        super();
+
+        this.addStage({
+            parallelJobs: [
+                <FetchCodeJob>{
+                    type: 'fetch_code.ts',
+                    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);
+    }
+}
diff --git a/model/pipeline/impl.ts b/model/pipeline/impl.ts
new file mode 100644
index 0000000..2e08d6e
--- /dev/null
+++ b/model/pipeline/impl.ts
@@ -0,0 +1,20 @@
+import { Either, IEither } from '@emprespresso/pengueno';
+import { isPipeline, Pipeline, PipelineStage } from '.';
+
+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));
+    }
+}
diff --git a/model/pipeline/index.ts b/model/pipeline/index.ts
new file mode 100644
index 0000000..adf902b
--- /dev/null
+++ b/model/pipeline/index.ts
@@ -0,0 +1,19 @@
+import { isObject } from '@emprespresso/pengueno';
+import { isJob, Job } from '../job';
+
+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 const isPipeline = (t: unknown): t is Pipeline =>
+    isObject(t) && 'serialJobs' in t && Array.isArray(t.serialJobs) && t.serialJobs.every((p) => isPipelineStage(p));
+
+export interface Pipeline {
+    readonly serialJobs: Array<PipelineStage>;
+    serialize(): string;
+}
+
+export * from './builder';
+export * from './impl';