import { randomUUID } from "node:crypto";
import type { CallAttempt, CallAttemptStatus, Prisma } from "@b2bcall/database";
import { computeNextAttemptAt } from "./retry-rules";
import { ewmaUpdate } from "./ewma";

export interface CreateAttemptParams {
  tenantId: string;
  campaignId: string;
  leadId: string;
  simulated: boolean;
}

export async function createCallAttempt(
  tx: Prisma.TransactionClient,
  params: CreateAttemptParams,
): Promise<CallAttempt> {
  return tx.callAttempt.create({
    data: {
      tenantId: params.tenantId,
      campaignId: params.campaignId,
      leadId: params.leadId,
      simulated: params.simulated,
      status: "RESERVED",
    },
  });
}

export async function setAttemptStatus(
  tx: Prisma.TransactionClient,
  attemptId: string,
  status: CallAttemptStatus,
  extra: Partial<Pick<CallAttempt, "originationUuid" | "ringingAt" | "answeredAt" | "bridgedAt" | "agentId">> = {},
): Promise<void> {
  await tx.callAttempt.update({ where: { id: attemptId }, data: { status, ...extra } });
}

export function newOriginationUuid(): string {
  return randomUUID();
}

export type TerminalOutcome = "COMPLETED" | "BUSY" | "NO_ANSWER" | "FAILED" | "ABANDONED";

export interface CompleteAttemptParams {
  attemptId: string;
  tenantId: string;
  campaignId: string;
  leadId: string;
  outcome: TerminalOutcome;
  reachedQueue: boolean;
  answerDelaySeconds?: number;
  talkTimeSeconds?: number;
  hangupCause?: string;
  agentId?: string;
}

const OUTCOME_TO_STATUS: Record<TerminalOutcome, CallAttemptStatus> = {
  COMPLETED: "COMPLETED",
  BUSY: "BUSY",
  NO_ANSWER: "NO_ANSWER",
  FAILED: "FAILED",
  ABANDONED: "ABANDONED",
};

/**
 * Fecha uma tentativa: grava o CallAttempt terminal, atualiza a EWMA da
 * campanha (agente.md secao 75) e decide o próximo passo do Lead — nunca
 * retry infinito (secao 86): `attemptCount >= maxAttempts` vira
 * MAX_ATTEMPTS, terminal, nunca mais selecionado. Leads que ainda vão
 * tentar de novo voltam pra READY (não BUSY/NO_ANSWER/etc como status
 * consultável — a razão especifica fica em `lastResult`; READY é o único
 * jeito da query de reserva achar o lead de novo depois de
 * `nextAttemptAt`).
 */
export async function completeAttempt(
  tx: Prisma.TransactionClient,
  params: CompleteAttemptParams,
  campaignMaxAttempts: number,
): Promise<void> {
  const now = new Date();

  await tx.callAttempt.update({
    where: { id: params.attemptId },
    data: {
      status: OUTCOME_TO_STATUS[params.outcome],
      talkTimeSeconds: params.talkTimeSeconds,
      hangupCause: params.hangupCause,
      agentId: params.agentId,
      endedAt: now,
    },
  });

  const stats = await tx.campaignStats.findUniqueOrThrow({ where: { campaignId: params.campaignId } });
  const wasAnswered = params.outcome === "COMPLETED" || params.outcome === "ABANDONED";
  const data: Prisma.CampaignStatsUpdateInput = {
    answerProbability: ewmaUpdate(stats.answerProbability, wasAnswered ? 1 : 0),
  };
  if (wasAnswered && params.answerDelaySeconds != null) {
    data.averageAnswerDelay = ewmaUpdate(stats.averageAnswerDelay, params.answerDelaySeconds);
  }
  if (params.talkTimeSeconds != null) {
    data.averageTalkTime = ewmaUpdate(stats.averageTalkTime, params.talkTimeSeconds);
  }
  if (params.reachedQueue) {
    data.abandonRate = ewmaUpdate(stats.abandonRate, params.outcome === "ABANDONED" ? 1 : 0);
  }
  await tx.campaignStats.update({ where: { campaignId: params.campaignId }, data });

  const lead = await tx.lead.findUniqueOrThrow({ where: { id: params.leadId } });
  const attemptCount = lead.attemptCount + 1;

  if (params.outcome === "COMPLETED") {
    await tx.lead.update({
      where: { id: params.leadId },
      data: { status: "COMPLETED", attemptCount, lastAttemptAt: now, lastResult: params.outcome },
    });
    return;
  }

  if (attemptCount >= campaignMaxAttempts) {
    await tx.lead.update({
      where: { id: params.leadId },
      data: { status: "MAX_ATTEMPTS", attemptCount, lastAttemptAt: now, lastResult: params.outcome },
    });
    return;
  }

  await tx.lead.update({
    where: { id: params.leadId },
    data: {
      status: "READY",
      attemptCount,
      lastAttemptAt: now,
      lastResult: params.outcome,
      nextAttemptAt: computeNextAttemptAt(params.outcome, now),
    },
  });
}