/**
 * Search-box.ai
 * Author: Simon-Pierre Boucher
 * Contact: contact@spboucher.ai
 * File: packages/agent/src/orchestrator.ts
 * Description: Single-agent research loop — Claude decides strategy, the app enforces safety.
 */

import type Anthropic from "@anthropic-ai/sdk";
import { getModels, orchestratorTurn } from "@search-box/anthropic";
import type { ResearchState } from "@search-box/research";
import { budgetExceeded, newBudgetUsage, type Budgets } from "@search-box/shared";
import { ORCHESTRATOR_SYSTEM, PROMPT_VERSION } from "./prompts.js";
import { TOOLS, executeTool, type ToolContext } from "./tools.js";

export interface OrchestrationResult {
  finishedReason: "model_finished" | "budget" | "no_tools" | "max_turns";
  readinessSummary: string | null;
}

/**
 * Runs the agentic research loop until the model calls finish_research,
 * budgets run out, or the model stops calling tools.
 */
export async function runOrchestration(
  state: ResearchState,
  question: string,
  budgets: Budgets
): Promise<OrchestrationResult> {
  const models = getModels();
  const usage = newBudgetUsage();
  const ctx: ToolContext = { state, budgets, usage, finished: { value: null } };

  const system: Anthropic.TextBlockParam[] = [
    {
      type: "text",
      text: ORCHESTRATOR_SYSTEM,
      cache_control: { type: "ephemeral" }
    }
  ];

  const messages: Anthropic.MessageParam[] = [
    {
      role: "user",
      content: `Research question: ${question}\n\nBudgets for this session: up to ${budgets.maxSearches} searches, ${budgets.maxScrapes} page fetches, ${budgets.maxModelTurns} reasoning turns. Begin.`
    }
  ];

  let warnedBudget = false;

  while (true) {
    usage.modelTurns++;
    if (usage.modelTurns > budgets.maxModelTurns) {
      return { finishedReason: "max_turns", readinessSummary: ctx.finished.value };
    }

    const response = await orchestratorTurn({
      model: models.orchestrator,
      system,
      messages,
      tools: TOOLS
    });

    if (response.stop_reason === "refusal") {
      throw new Error("model declined the request (safety refusal)");
    }

    // Echo assistant content back verbatim (thinking blocks included).
    messages.push({ role: "assistant", content: response.content });

    const toolUses = response.content.filter(
      (b): b is Anthropic.ToolUseBlock => b.type === "tool_use"
    );

    if (toolUses.length === 0) {
      // Model concluded in prose without finish_research — accept as done.
      return { finishedReason: "no_tools", readinessSummary: ctx.finished.value };
    }

    const toolResults: Anthropic.ToolResultBlockParam[] = [];
    for (const tu of toolUses) {
      const outcome = await executeTool(tu.name, tu.input, ctx);
      toolResults.push({
        type: "tool_result",
        tool_use_id: tu.id,
        content: outcome.result,
        is_error: outcome.isError
      });
    }

    const content: Anthropic.ContentBlockParam[] = [...toolResults];

    if (ctx.finished.value !== null) {
      return { finishedReason: "model_finished", readinessSummary: ctx.finished.value };
    }

    // Budget enforcement: warn once, then hard-stop on the following turn.
    const exceeded = budgetExceeded(budgets, usage);
    if (exceeded) {
      if (warnedBudget) {
        return { finishedReason: "budget", readinessSummary: ctx.finished.value };
      }
      warnedBudget = true;
      content.push({
        type: "text",
        text: `[system] ${exceeded}. Stop gathering: record any remaining claim updates now and call finish_research in this next turn.`
      });
    }

    messages.push({ role: "user", content });
  }
}

export { PROMPT_VERSION };