# Juicebox SDK Patterns - Advanced Pattern Implementations

## Pagination Helper

Juicebox search uses cursor-based pagination. This async generator transparently fetches all pages, yielding profiles one at a time.

```typescript
// lib/paginator.ts
import { JuiceboxClient } from "./juicebox-client";
import { SearchParams, Profile } from "../types/juicebox";

export async function* paginateSearch(
  client: JuiceboxClient,
  params: Omit<SearchParams, "cursor">,
  options?: { maxPages?: number; pageSize?: number }
): AsyncGenerator<Profile, void, undefined> {
  const pageSize = options?.pageSize ?? 50;
  const maxPages = options?.maxPages ?? Infinity;
  let cursor: string | undefined;
  let page = 0;

  do {
    const response = await client.search({
      ...params,
      limit: pageSize,
      cursor,
    });

    for (const profile of response.profiles) {
      yield profile;
    }

    cursor = response.cursor;
    page++;

    if (page >= maxPages) {
      console.log(`Reached max pages (${maxPages}). Stopping pagination.`);
      break;
    }
  } while (cursor);
}

// Convenience: collect all results into an array
export async function collectAll(
  client: JuiceboxClient,
  params: Omit<SearchParams, "cursor">,
  maxResults = 500
): Promise<Profile[]> {
  const results: Profile[] = [];

  for await (const profile of paginateSearch(client, params)) {
    results.push(profile);
    if (results.length >= maxResults) break;
  }

  return results;
}
```

## Result Monad for Error Handling

Instead of try/catch everywhere, use a `Result<T, E>` type that makes errors explicit in function signatures and enables composable pipelines.

```typescript
// lib/result.ts
export type Result<T, E = Error> =
  | { ok: true; value: T }
  | { ok: false; error: E };

export function ok<T>(value: T): Result<T, never> {
  return { ok: true, value };
}

export function err<E>(error: E): Result<never, E> {
  return { ok: false, error };
}

export async function tryAsync<T>(fn: () => Promise<T>): Promise<Result<T, Error>> {
  try {
    return ok(await fn());
  } catch (e) {
    return err(e instanceof Error ? e : new Error(String(e)));
  }
}

export function map<T, U, E>(result: Result<T, E>, fn: (v: T) => U): Result<U, E> {
  return result.ok ? ok(fn(result.value)) : result;
}

export function flatMap<T, U, E>(
  result: Result<T, E>,
  fn: (v: T) => Result<U, E>
): Result<U, E> {
  return result.ok ? fn(result.value) : result;
}

// Usage with Juicebox client
import { JuiceboxClient, JuiceboxApiError } from "./juicebox-client";

export async function safeSearch(
  client: JuiceboxClient,
  params: SearchParams
): Promise<Result<SearchResponse, JuiceboxApiError | Error>> {
  return tryAsync(() => client.search(params));
}

export async function safeGetProfile(
  client: JuiceboxClient,
  id: string
): Promise<Result<Profile, JuiceboxApiError | Error>> {
  return tryAsync(() => client.getProfile(id));
}
```

## Builder Pattern for Complex Search Queries

For complex search criteria across multiple dimensions, a fluent builder prevents query string bugs and validates constraints at build time.

```typescript
// lib/search-builder.ts
import { SearchParams } from "../types/juicebox";

export class SearchBuilder {
  private params: Partial<SearchParams> = {};
  private queryParts: string[] = [];

  role(role: string): this {
    this.queryParts.push(role);
    return this;
  }

  withSkills(...skills: string[]): this {
    if (skills.length > 0) {
      this.queryParts.push(`skills:(${skills.join(" OR ")})`);
    }
    this.params.skills = skills;
    return this;
  }

  inLocation(location: string): this {
    this.params.location = location;
    return this;
  }

  atCompany(company: string): this {
    this.params.company = company;
    return this;
  }

  withTitle(title: string): this {
    this.params.title = title;
    return this;
  }

  limit(n: number): this {
    if (n < 1 || n > 100) {
      throw new Error("Limit must be between 1 and 100");
    }
    this.params.limit = n;
    return this;
  }

  offset(n: number): this {
    if (n < 0) throw new Error("Offset must be >= 0");
    this.params.offset = n;
    return this;
  }

  build(): SearchParams {
    if (this.queryParts.length === 0) {
      throw new Error("Search query is empty. Call .role() or add query terms first.");
    }
    return {
      query: this.queryParts.join(" AND "),
      ...this.params,
    };
  }

  // Static factory for common searches
  static candidateSearch(role: string, skills: string[], location?: string): SearchParams {
    const builder = new SearchBuilder().role(role).withSkills(...skills).limit(50);
    if (location) builder.inLocation(location);
    return builder.build();
  }
}
```

## Extended Examples

### Paginated Candidate Collection

```typescript
import { JuiceboxClient } from "./lib/juicebox-client";
import { paginateSearch, collectAll } from "./lib/paginator";

const client = new JuiceboxClient({
  username: process.env.JUICEBOX_USERNAME!,
  apiToken: process.env.JUICEBOX_API_TOKEN!,
});

// Stream profiles one at a time (memory efficient)
for await (const profile of paginateSearch(client, {
  query: "ML engineer PyTorch distributed training",
  limit: 50,
})) {
  console.log(`${profile.name} (${profile.experience_years}yr) — ${profile.company}`);
}

// Or collect into an array with a cap
const allProfiles = await collectAll(
  client,
  { query: "engineering manager", location: "New York" },
  200 // stop after 200 results
);
console.log(`Collected ${allProfiles.length} profiles`);
```

### Enrichment with Result Monad Pipeline

```typescript
import { JuiceboxClient, JuiceboxApiError } from "./lib/juicebox-client";
import { tryAsync, map, ok, err, Result } from "./lib/result";

const client = new JuiceboxClient({
  username: process.env.JUICEBOX_USERNAME!,
  apiToken: process.env.JUICEBOX_API_TOKEN!,
});

// Search, then enrich — each step returns Result
const searchResult = await tryAsync(() =>
  client.search({ query: "VP Engineering fintech", limit: 10 })
);

if (!searchResult.ok) {
  console.error("Search failed:", searchResult.error.message);
  process.exit(1);
}

const profileIds = searchResult.value.profiles.map((p) => p.id);
const enrichResult = await tryAsync(() =>
  client.enrichProfiles(profileIds, ["email", "phone"])
);

if (enrichResult.ok) {
  console.log(`Enriched ${enrichResult.value.profiles.length} profiles`);
  console.log(`Credits remaining: ${enrichResult.value.credits_remaining}`);
  enrichResult.value.profiles.forEach((p) =>
    console.log(`  ${p.name}: ${p.email ?? "no email"} | ${p.phone ?? "no phone"}`)
  );
} else {
  console.error("Enrichment failed:", enrichResult.error.message);
}
```

### Singleton Pattern for Shared Client

```typescript
// lib/singleton.ts
import { JuiceboxClient } from "./juicebox-client";

let instance: JuiceboxClient | null = null;

export function getJuiceboxClient(): JuiceboxClient {
  if (!instance) {
    const username = process.env.JUICEBOX_USERNAME;
    const apiToken = process.env.JUICEBOX_API_TOKEN;
    if (!username || !apiToken) {
      throw new Error(
        "JUICEBOX_USERNAME and JUICEBOX_API_TOKEN must be set in environment"
      );
    }
    instance = new JuiceboxClient({ username, apiToken });
  }
  return instance;
}
```
