/**
 * Drizzle Conversation Repository Adapter
 *
 * Implements ConversationRepository interface using Drizzle ORM.
 */

import { eq, and, asc, count, inArray } from 'drizzle-orm';
import { nanoid } from 'nanoid';
import type { DrizzleDatabase } from '../../index.js';
import { conversations, type Conversation } from '../../schema.js';
import type { ConversationRepository, CreateConversationData } from '../conversation-repository.js';

export class DrizzleConversationRepository implements ConversationRepository {
  constructor(private db: DrizzleDatabase) {}

  async create(data: CreateConversationData): Promise<Conversation> {
    const now = new Date();
    const id = nanoid();
    await this.db.insert(conversations).values({
      id,
      fromAgentId: data.fromAgentId,
      toAgentId: data.toAgentId,
      initiativeId: data.initiativeId ?? null,
      phaseId: data.phaseId ?? null,
      taskId: data.taskId ?? null,
      question: data.question,
      status: 'pending',
      createdAt: now,
      updatedAt: now,
    });
    return this.findById(id) as Promise<Conversation>;
  }

  async findById(id: string): Promise<Conversation | null> {
    const rows = await this.db
      .select()
      .from(conversations)
      .where(eq(conversations.id, id))
      .limit(1);
    return rows[0] ?? null;
  }

  async findPendingForAgent(toAgentId: string): Promise<Conversation[]> {
    return this.db
      .select()
      .from(conversations)
      .where(
        and(
          eq(conversations.toAgentId, toAgentId),
          eq(conversations.status, 'pending' as 'pending' | 'answered'),
        ),
      )
      .orderBy(asc(conversations.createdAt));
  }

  async answer(id: string, answer: string): Promise<Conversation | null> {
    await this.db
      .update(conversations)
      .set({
        answer,
        status: 'answered' as 'pending' | 'answered',
        updatedAt: new Date(),
      })
      .where(eq(conversations.id, id));
    return this.findById(id);
  }

  async countByFromAgentIds(agentIds: string[]): Promise<{ agentId: string; count: number }[]> {
    if (agentIds.length === 0) return [];
    const rows = await this.db
      .select({
        agentId: conversations.fromAgentId,
        count: count(),
      })
      .from(conversations)
      .where(inArray(conversations.fromAgentId, agentIds))
      .groupBy(conversations.fromAgentId);
    return rows.map(r => ({ agentId: r.agentId, count: Number(r.count) }));
  }

  async findByFromAgentId(agentId: string): Promise<Conversation[]> {
    return this.db
      .select()
      .from(conversations)
      .where(eq(conversations.fromAgentId, agentId))
      .orderBy(asc(conversations.createdAt))
      .limit(200);
  }
}