AI next-best action

// src/agents/reengagement-strategist.ts
import { createAnthropic } from "@ai-sdk/anthropic";
import { generateText, tool } from "ai";
import { z } from "zod";
import type { JourneyContext, JourneyUser } from "@hogsend/engine";

const DecisionSchema = z.object({
  action: z.enum([
    "reengage_tip_a",
    "reengage_tip_b",
    "reengage_webinar",
    "suppress",
  ]),
  reason: z.string().describe("One sentence explaining the choice."),
});

export type Decision = z.infer<typeof DecisionSchema>;

export async function decideNextBestAction(
  user: JourneyUser,
  ctx: JourneyContext,
): Promise<Decision | null> {
  const anthropic = createAnthropic();

  const result = await generateText({
    model: anthropic("claude-opus-4-8"),
    maxSteps: 5,
    tools: {
      getRecentEvents: tool({
        description:
          "Fetch the user's recent events, newest first. Use this to understand " +
          "what the user has been doing and what they haven't tried.",
        parameters: z.object({
          limit: z.number().int().min(1).max(50).default(20),
        }),
        execute: async ({ limit }) => {
          const events = await ctx.history.events({ userId: user.id, limit });
          return events.map((e) => ({ event: e.event, occurredAt: e.occurredAt }));
        },
      }),

      decide: tool({
        description:
          "Commit to a re-engagement action for this user. Call this exactly " +
          "once after you've reviewed their history. Choose 'suppress' if " +
          "they've been recently active or already received a re-engagement email.",
        parameters: DecisionSchema,
        // No side effects — just capture the decision.
        execute: async (decision) => decision,
      }),
    },
    system:
      "You are a re-engagement strategist. Use getRecentEvents to understand " +
      "the user's history, then call decide once. " +
      "'reengage_tip_a' = quick practical win. " +
      "'reengage_tip_b' = advanced pattern for power users. " +
      "'reengage_webinar' = live session invite for users who prefer learning together. " +
      "'suppress' = user is active or doesn't need contact right now.",
    prompt: `Decide the best re-engagement action for user ${user.id} (${user.email}).`,
  });

  // Find the decide tool call in the steps — it fires exactly once.
  for (const step of result.steps) {
    for (const call of step.toolCalls ?? []) {
      if (call.toolName === "decide") {
        return DecisionSchema.parse(call.args);
      }
    }
  }

  return null; // model didn't commit — treated as suppress
}

// src/journeys/ai-reengagement.ts
import { defineJourney, sendEmail } from "@hogsend/engine";
import { hours } from "@hogsend/core";
import { decideNextBestAction } from "../agents/reengagement-strategist.js";
import { Events, Templates } from "./constants/index.js";

const TEMPLATE_MAP = {
  reengage_tip_a:   Templates.REENGAGE_TIP_A,
  reengage_tip_b:   Templates.REENGAGE_TIP_B,
  reengage_webinar: Templates.REENGAGE_WEBINAR,
} as const;

export const aiReengagement = defineJourney({
  meta: {
    id: "ai-reengagement",
    name: "AI Re-engagement — Next Best Action",
    enabled: true,
    trigger: { event: Events.DORMANT_30D },
    entryLimit: "once_per_period",
    entryPeriod: { days: 30 },
    suppress: hours(12),
    exitOn: [{ event: Events.USER_ACTIVATED }],
  },

  run: async (user, ctx) => {
    if (!(await ctx.guard.isSubscribed())) return;

    const decision = await decideNextBestAction(user, ctx);

    // null or suppress — the model chose silence. No send.
    if (!decision || decision.action === "suppress") return;

    await sendEmail({
      to: user.email,
      userId: user.id,
      journeyStateId: user.stateId,
      template: TEMPLATE_MAP[decision.action],
      journeyName: user.journeyName,
    });
  },
});

// src/journeys/constants/index.ts (additions)
export const Events = {
  // …existing…
  DORMANT_30D:    "user.dormant_30d",
  USER_ACTIVATED: "user.activated",
} as const;

export const Templates = {
  // …existing…
  REENGAGE_TIP_A:   "reengage/tip-a",
  REENGAGE_TIP_B:   "reengage/tip-b",
  REENGAGE_WEBINAR: "reengage/webinar",
} as const;

// src/journeys/index.ts
import { aiReengagement } from "./ai-reengagement.js";
export const journeys: DefinedJourney[] = [aiReengagement, /* …others… */];

// src/workflows/detect-dormancy.ts (excerpt)
// Runs on a daily cron; emits dormancy events for eligible users.
const dormantUsers = await db.query…;
for (const u of dormantUsers) {
  await hs.events.send({
    name: "user.dormant_30d",
    userId: u.id,
    eventProperties: { daysSinceActive: u.daysSinceActive },
    idempotencyKey: `dormant-${u.id}-${todayIso}`,
  });
}