src/lib/orchestration/director-prompt.ts

/**
 * Director Prompt Builder
 *
 * Constructs the system prompt for the director agent that decides
 * which agent should respond next in a multi-agent conversation.
 */

import type { AgentConfig } from '@/lib/orchestration/registry/types';
import { createLogger } from '@/lib/logger';
import { buildPrompt, PROMPT_IDS } from '@/lib/prompts';
import type { WhiteboardActionRecord, AgentTurnSummary } from './types';

const log = createLogger('DirectorPrompt');

/**
 * Build the system prompt for the director agent
 *
 * @param agents - Available agent configurations
 * @param conversationSummary - Condensed summary of recent conversation
 * @param agentResponses - Agents that have already responded this round
 * @param turnCount - Current turn number in this round
 */
export function buildDirectorPrompt(
  agents: AgentConfig[],
  conversationSummary: string,
  agentResponses: AgentTurnSummary[],
  turnCount: number,
  discussionContext?: { topic: string; prompt?: string } | null,
  triggerAgentId?: string | null,
  whiteboardLedger?: WhiteboardActionRecord[],
  userProfile?: { nickname?: string; bio?: string },
  whiteboardOpen?: boolean,
): string {
  const agentList = agents
    .map((a) => `- id: "${a.id}", name: "${a.name}", role: ${a.role}, priority: ${a.priority}`)
    .join('\n');

  const respondedList =
    agentResponses.length > 0
      ? agentResponses
          .map((r) => {
            const wbSummary = summarizeAgentWhiteboardActions(r.whiteboardActions);
            const wbPart = wbSummary ? ` | Whiteboard: ${wbSummary}` : '';
            return `- ${r.agentName} (${r.agentId}): "${r.contentPreview}" [${r.actionCount} actions${wbPart}]`;
          })
          .join('\n')
      : 'None yet.';

  const isDiscussion = !!discussionContext;

  const discussionSection = isDiscussion
    ? `\n# Discussion Mode
Topic: "${discussionContext!.topic}"${discussionContext!.prompt ? `\nPrompt: "${discussionContext!.prompt}"` : ''}${triggerAgentId ? `\nInitiator: "${triggerAgentId}"` : ''}
This is a student-initiated discussion, not a Q&A session.\n`
    : '';

  const rule1 = isDiscussion
    ? `1. The discussion initiator${triggerAgentId ? ` ("${triggerAgentId}")` : ''} should speak first to kick off the topic. Then the teacher responds to guide the discussion. After that, other students may add their perspectives.`
    : "1. The teacher (role: teacher, highest priority) should usually speak first to address the user's question or topic.";

  const studentProfileSection =
    userProfile?.nickname || userProfile?.bio
      ? `
# Student Profile
Student name: ${userProfile.nickname || 'Unknown'}
${userProfile.bio ? `Background: ${userProfile.bio}` : ''}
`
      : '';

  const vars = {
    agentList,
    respondedList,
    conversationSummary,
    discussionSection,
    whiteboardSection: buildWhiteboardStateForDirector(whiteboardLedger),
    studentProfileSection,
    rule1,
    turnCountPlusOne: turnCount + 1,
    whiteboardOpenText: whiteboardOpen
      ? 'OPEN (slide canvas is hidden — spotlight/laser will not work)'
      : 'CLOSED (slide canvas is visible)',
  };

  const prompt = buildPrompt(PROMPT_IDS.DIRECTOR, vars);
  if (!prompt) {
    throw new Error('director prompt template failed to load');
  }
  return prompt.system;
}

/**
 * Summarize a single agent's whiteboard actions into a compact description.
 */
function summarizeAgentWhiteboardActions(actions: WhiteboardActionRecord[]): string {
  if (!actions || actions.length === 0) return '';

  const parts: string[] = [];
  for (const a of actions) {
    switch (a.actionName) {
      case 'wb_draw_text': {
        const content = String(a.params.content || '').slice(0, 30);
        parts.push(`drew text "${content}${content.length >= 30 ? '...' : ''}"`);
        break;
      }
      case 'wb_draw_shape':
        parts.push(`drew shape(${a.params.type || 'rectangle'})`);
        break;
      case 'wb_draw_chart': {
        const labels = Array.isArray(a.params.labels)
          ? a.params.labels
          : (a.params.data as Record<string, unknown>)?.labels;
        const chartType = a.params.chartType || a.params.type || 'bar';
        parts.push(
          `drew chart(${chartType}${labels ? `, labels: [${(labels as string[]).slice(0, 4).join(',')}]` : ''})`,
        );
        break;
      }
      case 'wb_draw_latex': {
        const latex = String(a.params.latex || '').slice(0, 30);
        parts.push(`drew formula "${latex}${latex.length >= 30 ? '...' : ''}"`);
        break;
      }
      case 'wb_draw_table': {
        const data = a.params.data as unknown[][] | undefined;
        const rows = data?.length || 0;
        const cols = (data?.[0] as unknown[])?.length || 0;
        parts.push(`drew table(${rows}×${cols})`);
        break;
      }
      case 'wb_draw_line': {
        const pts = a.params.points as string[] | undefined;
        const hasArrow = pts?.includes('arrow') ? ' arrow' : '';
        parts.push(`drew${hasArrow} line`);
        break;
      }
      case 'wb_draw_code': {
        const lang = String(a.params.language || '');
        const codeFileName = a.params.fileName ? ` "${a.params.fileName}"` : '';
        parts.push(`drew code block${codeFileName} (${lang})`);
        break;
      }
      case 'wb_edit_code': {
        const op = a.params.operation || 'edit';
        parts.push(`edited code (${op})`);
        break;
      }
      case 'wb_clear':
        parts.push('CLEARED whiteboard');
        break;
      case 'wb_delete':
        parts.push(`deleted element "${a.params.elementId}"`);
        break;
      case 'wb_open':
      case 'wb_close':
        // Skip open/close from summary — they're structural, not content
        break;
    }
  }
  return parts.join(', ');
}

/**
 * Replay the whiteboard ledger to compute current element count and contributors.
 */
export function summarizeWhiteboardForDirector(ledger: WhiteboardActionRecord[]): {
  elementCount: number;
  contributors: string[];
} {
  let elementCount = 0;
  const contributorSet = new Set<string>();

  for (const record of ledger) {
    if (record.actionName === 'wb_clear') {
      elementCount = 0;
      // Don't reset contributors — they still participated
    } else if (record.actionName === 'wb_delete') {
      elementCount = Math.max(0, elementCount - 1);
    } else if (record.actionName.startsWith('wb_draw_')) {
      elementCount++;
      contributorSet.add(record.agentName);
    }
  }

  return {
    elementCount,
    contributors: Array.from(contributorSet),
  };
}

/**
 * Build the whiteboard state section for the director prompt.
 * Returns empty string if there are no whiteboard actions.
 */
function buildWhiteboardStateForDirector(ledger?: WhiteboardActionRecord[]): string {
  if (!ledger || ledger.length === 0) return '';

  const { elementCount, contributors } = summarizeWhiteboardForDirector(ledger);
  const crowdedWarning =
    elementCount > 5
      ? '\n⚠ The whiteboard is getting crowded. Consider routing to an agent that will organize or clear it rather than adding more.'
      : '';

  return `
# Whiteboard State
Elements on whiteboard: ${elementCount}
Contributors: ${contributors.length > 0 ? contributors.join(', ') : 'none'}${crowdedWarning}
`;
}

/**
 * Parse the director's decision from its response
 *
 * @param content - Raw LLM response content
 * @returns Parsed decision with nextAgentId and shouldEnd flag
 */
export function parseDirectorDecision(content: string): {
  nextAgentId: string | null;
  shouldEnd: boolean;
} {
  try {
    // Try to extract JSON from the response
    const jsonMatch = content.match(/\{[\s\S]*?"next_agent"[\s\S]*?\}/);
    if (jsonMatch) {
      const parsed = JSON.parse(jsonMatch[0]);
      const nextAgent = parsed.next_agent;

      if (!nextAgent || nextAgent === 'END') {
        return { nextAgentId: null, shouldEnd: true };
      }

      return { nextAgentId: nextAgent, shouldEnd: false };
    }
  } catch (_e) {
    log.warn('[Director] Failed to parse decision:', content.slice(0, 200));
  }

  // Default: end the round if we can't parse
  return { nextAgentId: null, shouldEnd: true };
}