/**
 * Chat Mode Resolution Logic
 * 
 * Determines which chat mode (collector, extraction_review, vision, mvp, marketing, general)
 * should be active based on project state.
 */

import { getAdminDb } from '@/lib/firebase/admin';
import type { ChatMode } from '@/lib/ai/chat-modes';

/**
 * Resolve the appropriate chat mode for a project
 * 
 * Logic:
 * 1. No knowledge_items → collector_mode
 * 2. Has knowledge but no extractions → collector_mode (needs to run extraction)
 * 3. Has extractions but no canonicalProductModel → extraction_review_mode
 * 4. Has canonicalProductModel but no mvpPlan → vision_mode
 * 5. Has mvpPlan but no marketingPlan → mvp_mode
 * 6. Has marketingPlan → marketing_mode
 * 7. Otherwise → general_chat_mode
 * 
 * @param projectId - Firestore project ID
 * @returns The appropriate chat mode
 */
export async function resolveChatMode(projectId: string): Promise<ChatMode> {
  try {
    const adminDb = getAdminDb();

    // Load project data
    const projectSnapshot = await adminDb.collection('projects').doc(projectId).get();
    if (!projectSnapshot.exists) {
      throw new Error(`Project ${projectId} not found`);
    }

    const projectData = projectSnapshot.data() ?? {};
    const phaseData = (projectData.phaseData ?? {}) as Record<string, any>;

    // Check for knowledge_items (top-level collection)
    const knowledgeSnapshot = await adminDb
      .collection('knowledge_items')
      .where('projectId', '==', projectId)
      .limit(1)
      .get();

    const hasKnowledge = !knowledgeSnapshot.empty;

    // Check for chat_extractions (top-level collection)
    const extractionsSnapshot = await adminDb
      .collection('chat_extractions')
      .where('projectId', '==', projectId)
      .limit(1)
      .get();

    const hasExtractions = !extractionsSnapshot.empty;

    // Apply resolution logic
    // PRIORITY: Check explicit phase transitions FIRST (overrides knowledge checks)
    if (projectData.currentPhase === 'extraction_review' || projectData.currentPhase === 'analyzed') {
      return 'extraction_review_mode';
    }
    
    if (projectData.currentPhase === 'vision') {
      return 'vision_mode';
    }
    
    if (projectData.currentPhase === 'mvp') {
      return 'mvp_mode';
    }
    
    if (projectData.currentPhase === 'marketing') {
      return 'marketing_mode';
    }

    if (!hasKnowledge) {
      return 'collector_mode';
    }

    if (hasKnowledge && !hasExtractions) {
      return 'collector_mode'; // Has knowledge but needs extraction
    }

    // Fallback: Has extractions but no canonicalProductModel
    if (hasExtractions && !phaseData.canonicalProductModel) {
      return 'extraction_review_mode';
    }

    if (phaseData.canonicalProductModel && !phaseData.mvpPlan) {
      return 'vision_mode';
    }

    if (phaseData.mvpPlan && !phaseData.marketingPlan) {
      return 'mvp_mode';
    }

    if (phaseData.marketingPlan) {
      return 'marketing_mode';
    }

    return 'general_chat_mode';
  } catch (error) {
    console.error('[Chat Mode Resolver] Failed to resolve mode:', error);
    // Default to collector on error
    return 'collector_mode';
  }
}

/**
 * Get a summary of knowledge_items for context building
 */
export async function summarizeKnowledgeItems(
  projectId: string
): Promise<{
  totalCount: number;
  bySourceType: Record<string, number>;
  recentTitles: string[];
}> {
  try {
    const adminDb = getAdminDb();
    const snapshot = await adminDb
      .collection('knowledge_items')
      .where('projectId', '==', projectId)
      .orderBy('createdAt', 'desc')
      .limit(20)
      .get();

    const totalCount = snapshot.size;
    const bySourceType: Record<string, number> = {};
    const recentTitles: string[] = [];

    snapshot.docs.forEach((doc) => {
      const data = doc.data();
      const sourceType = data.sourceType ?? 'unknown';
      bySourceType[sourceType] = (bySourceType[sourceType] ?? 0) + 1;

      if (data.title && recentTitles.length < 5) {
        recentTitles.push(data.title);
      }
    });

    return { totalCount, bySourceType, recentTitles };
  } catch (error) {
    console.error('[Chat Mode Resolver] Failed to summarize knowledge:', error);
    return { totalCount: 0, bySourceType: {}, recentTitles: [] };
  }
}

/**
 * Get a summary of chat_extractions for context building
 */
export async function summarizeExtractions(
  projectId: string
): Promise<{
  totalCount: number;
  avgConfidence: number;
  avgCompletion: number;
}> {
  try {
    const adminDb = getAdminDb();
    const snapshot = await adminDb
      .collection('chat_extractions')
      .where('projectId', '==', projectId)
      .get();

    if (snapshot.empty) {
      return { totalCount: 0, avgConfidence: 0, avgCompletion: 0 };
    }

    let sumConfidence = 0;
    let sumCompletion = 0;
    let count = 0;

    snapshot.docs.forEach((doc) => {
      const data = doc.data();
      sumConfidence += data.overallConfidence ?? 0;
      sumCompletion += data.overallCompletion ?? 0;
      count++;
    });

    return {
      totalCount: count,
      avgConfidence: count > 0 ? sumConfidence / count : 0,
      avgCompletion: count > 0 ? sumCompletion / count : 0,
    };
  } catch (error) {
    console.error('[Chat Mode Resolver] Failed to summarize extractions:', error);
    return { totalCount: 0, avgConfidence: 0, avgCompletion: 0 };
  }
}