import { eq, and, desc, gte } from "drizzle-orm";
import { agents, agentMetrics, agentHistory, agentAccessControl, type Agent, type InsertAgent, type AgentMetric, type InsertAgentMetric } from "../drizzle/schema";
import { getDb } from "./db";
import { nanoid } from "nanoid";

/**
 * Создать нового агента
 */
export async function createAgent(userId: number, data: InsertAgent): Promise<Agent | null> {
  const db = await getDb();
  if (!db) return null;

  try {
    const result = await db.insert(agents).values({
      ...data,
      userId,
    });

    const agentId = result[0].insertId;
    const created = await db.select().from(agents).where(eq(agents.id, Number(agentId))).limit(1);
    return created[0] || null;
  } catch (error) {
    console.error("[DB] Failed to create agent:", error);
    throw error;
  }
}

/**
 * Получить агента по ID
 */
export async function getAgentById(agentId: number): Promise<Agent | null> {
  const db = await getDb();
  if (!db) return null;

  try {
    const result = await db.select().from(agents).where(eq(agents.id, agentId)).limit(1);
    return result[0] || null;
  } catch (error) {
    console.error("[DB] Failed to get agent:", error);
    return null;
  }
}

/**
 * Получить все агенты пользователя
 */
export async function getUserAgents(userId: number): Promise<Agent[]> {
  const db = await getDb();
  if (!db) return [];

  try {
    return await db.select().from(agents).where(eq(agents.userId, userId));
  } catch (error) {
    console.error("[DB] Failed to get user agents:", error);
    return [];
  }
}

/**
 * Обновить конфигурацию агента
 */
export async function updateAgent(agentId: number, updates: Partial<InsertAgent>): Promise<Agent | null> {
  const db = await getDb();
  if (!db) return null;

  try {
    await db.update(agents).set(updates).where(eq(agents.id, agentId));
    return getAgentById(agentId);
  } catch (error) {
    console.error("[DB] Failed to update agent:", error);
    throw error;
  }
}

/**
 * Удалить агента
 */
export async function deleteAgent(agentId: number): Promise<boolean> {
  const db = await getDb();
  if (!db) return false;

  try {
    await db.delete(agents).where(eq(agents.id, agentId));
    return true;
  } catch (error) {
    console.error("[DB] Failed to delete agent:", error);
    return false;
  }
}

/**
 * Сохранить метрику запроса
 */
export async function saveMetric(agentId: number, data: Omit<InsertAgentMetric, "agentId">): Promise<AgentMetric | null> {
  const db = await getDb();
  if (!db) return null;

  try {
    const requestId = nanoid();
    const result = await db.insert(agentMetrics).values({
      ...data,
      agentId,
      requestId,
    });

    const metricId = result[0].insertId;
    const created = await db.select().from(agentMetrics).where(eq(agentMetrics.id, Number(metricId))).limit(1);
    return created[0] || null;
  } catch (error) {
    console.error("[DB] Failed to save metric:", error);
    throw error;
  }
}

/**
 * Получить метрики агента за последние N часов
 */
export async function getAgentMetrics(agentId: number, hoursBack: number = 24): Promise<AgentMetric[]> {
  const db = await getDb();
  if (!db) return [];

  try {
    const since = new Date(Date.now() - hoursBack * 60 * 60 * 1000);
    return await db
      .select()
      .from(agentMetrics)
      .where(and(eq(agentMetrics.agentId, agentId), gte(agentMetrics.createdAt, since)))
      .orderBy(desc(agentMetrics.createdAt));
  } catch (error) {
    console.error("[DB] Failed to get agent metrics:", error);
    return [];
  }
}

/**
 * Получить статистику агента
 */
export async function getAgentStats(agentId: number, hoursBack: number = 24) {
  const db = await getDb();
  if (!db) return null;

  try {
    const metrics = await getAgentMetrics(agentId, hoursBack);

    const totalRequests = metrics.length;
    const successRequests = metrics.filter((m) => m.status === "success").length;
    const errorRequests = metrics.filter((m) => m.status === "error").length;
    const avgProcessingTime = metrics.length > 0 ? metrics.reduce((sum, m) => sum + m.processingTimeMs, 0) / metrics.length : 0;
    const totalTokens = metrics.reduce((sum, m) => sum + (m.totalTokens || 0), 0);
    const avgTokensPerRequest = metrics.length > 0 ? totalTokens / metrics.length : 0;

    return {
      totalRequests,
      successRequests,
      errorRequests,
      successRate: totalRequests > 0 ? (successRequests / totalRequests) * 100 : 0,
      avgProcessingTime: Math.round(avgProcessingTime),
      totalTokens,
      avgTokensPerRequest: Math.round(avgTokensPerRequest),
      period: `${hoursBack}h`,
    };
  } catch (error) {
    console.error("[DB] Failed to get agent stats:", error);
    return null;
  }
}

/**
 * Получить историю запросов агента
 */
export async function getAgentHistory(agentId: number, limit: number = 50) {
  const db = await getDb();
  if (!db) return [];

  try {
    return await db
      .select()
      .from(agentHistory)
      .where(eq(agentHistory.agentId, agentId))
      .orderBy(desc(agentHistory.createdAt))
      .limit(limit);
  } catch (error) {
    console.error("[DB] Failed to get agent history:", error);
    return [];
  }
}

/**
 * Получить управление доступами для агента
 */
export async function getAgentAccessControl(agentId: number) {
  const db = await getDb();
  if (!db) return [];

  try {
    return await db.select().from(agentAccessControl).where(eq(agentAccessControl.agentId, agentId));
  } catch (error) {
    console.error("[DB] Failed to get agent access control:", error);
    return [];
  }
}

/**
 * Обновить управление доступами для инструмента
 */
export async function updateToolAccess(agentId: number, tool: string, updates: Partial<typeof agentAccessControl.$inferInsert>) {
  const db = await getDb();
  if (!db) return null;

  try {
    const existing = await db
      .select()
      .from(agentAccessControl)
      .where(and(eq(agentAccessControl.agentId, agentId), eq(agentAccessControl.tool, tool)))
      .limit(1);

    if (existing.length > 0) {
      await db
        .update(agentAccessControl)
        .set(updates)
        .where(and(eq(agentAccessControl.agentId, agentId), eq(agentAccessControl.tool, tool)));
    } else {
      await db.insert(agentAccessControl).values({
        agentId,
        tool,
        ...updates,
      });
    }

    const result = await db
      .select()
      .from(agentAccessControl)
      .where(and(eq(agentAccessControl.agentId, agentId), eq(agentAccessControl.tool, tool)))
      .limit(1);

    return result[0] || null;
  } catch (error) {
    console.error("[DB] Failed to update tool access:", error);
    throw error;
  }
}