/**
 * Search-box.ai
 * Author: Simon-Pierre Boucher
 * Contact: contact@spboucher.ai
 * File: packages/anthropic/src/index.ts
 * Description: Anthropic Messages API adapter — singleton client, model config, streaming helpers.
 */

import Anthropic from "@anthropic-ai/sdk";

let client: Anthropic | null = null;

export function getAnthropic(): Anthropic {
  if (!client) {
    if (!process.env.ANTHROPIC_API_KEY) throw new Error("ANTHROPIC_API_KEY is not set");
    client = new Anthropic({ maxRetries: 3 });
  }
  return client;
}

export interface ModelConfig {
  orchestrator: string;
  researcher: string;
  verifier: string;
  synthesis: string;
}

const DEFAULT_MODEL = "claude-opus-5";

export function getModels(): ModelConfig {
  return {
    orchestrator: process.env.CLAUDE_ORCHESTRATOR_MODEL || DEFAULT_MODEL,
    researcher: process.env.CLAUDE_RESEARCHER_MODEL || DEFAULT_MODEL,
    verifier: process.env.CLAUDE_VERIFIER_MODEL || DEFAULT_MODEL,
    synthesis: process.env.CLAUDE_SYNTHESIS_MODEL || DEFAULT_MODEL
  };
}

/**
 * One orchestrator turn (non-streaming). Uses streaming under the hood via
 * the SDK helper so long turns don't hit HTTP timeouts.
 */
export async function orchestratorTurn(params: {
  model: string;
  system: Anthropic.TextBlockParam[];
  messages: Anthropic.MessageParam[];
  tools: Anthropic.ToolUnion[];
  maxTokens?: number;
}): Promise<Anthropic.Message> {
  const stream = getAnthropic().messages.stream({
    model: params.model,
    max_tokens: params.maxTokens ?? 16000,
    output_config: { effort: "medium" },
    system: params.system,
    messages: params.messages,
    tools: params.tools
  });
  return stream.finalMessage();
}

/**
 * Streaming synthesis call. Invokes `onDelta` per text token; resolves with
 * the final message once complete.
 */
export async function synthesisStream(params: {
  model: string;
  system: Anthropic.TextBlockParam[];
  messages: Anthropic.MessageParam[];
  maxTokens?: number;
  onDelta: (delta: string) => void | Promise<void>;
}): Promise<Anthropic.Message> {
  const stream = getAnthropic().messages.stream({
    model: params.model,
    max_tokens: params.maxTokens ?? 24000,
    output_config: { effort: "medium" },
    system: params.system,
    messages: params.messages
  });
  stream.on("text", (delta) => {
    void params.onDelta(delta);
  });
  return stream.finalMessage();
}

export type { Anthropic };