import type { JobPublisher } from "@rakazo/adapter-kit";
import { routineJobKey, routineWakeupJob } from "@rakazo/adapter-kit";
import type { CoachRhythm } from "@rakazo/contracts";
import { COACH_RHYTHM_OFF } from "@rakazo/contracts";
import { nextCronDate } from "@rakazo/core";
import type { PrismaClient } from "@rakazo/db";
import { coachTimeZone, ensureMainConversation, findMainBotId } from "@rakazo/db";

export const COACH_KEYS = ["morning", "evening", "weekly"] as const;
export type CoachKey = (typeof COACH_KEYS)[number];

/**
 * The main bot's check-ins. Names show in the main bot's routine list; prompts are its task when
 * a check-in fires. Product text in English: the main bot answers in the user's language, and
 * its instructions name the coach tools it has.
 */
export const COACH_ROUTINES: Record<CoachKey, { name: string; prompt: string }> = {
  morning: {
    name: "Morning brief",
    prompt:
      "Morning check-in. Review the user's active goals and habits, and today's calendar if a calendar app is connected. Write today's brief: two to five short lines on what matters most today, and save it. Then post one short, friendly message with the gist. Leave out what is not relevant today.",
  },
  evening: {
    name: "Evening check-in",
    prompt:
      "Evening check-in. Log as check-ins what the user already told you about today. Then ask in one or two sentences how the day went and about habits not yet checked off. Keep it light, and do not ask when everything is already logged.",
  },
  weekly: {
    name: "Weekly review",
    prompt:
      "Weekly review. Look at the past week's check-ins and the progress on the user's active goals. Post a short summary: what moved, what stalled, and one concrete suggestion for next week. Offer to adjust, complete or drop goals, and change them only when the user agrees.",
  },
};

export interface CoachRhythmDeps {
  prisma: PrismaClient;
  jobs: Pick<JobPublisher, "enqueue" | "cancel">;
}

/** The cron for one check-in, or null when it is off. */
export function coachCron(key: CoachKey, rhythm: CoachRhythm): string | null {
  const slot = key === "weekly" ? rhythm.weekly : rhythm[key];
  if (!slot) return null;
  const time = typeof slot === "string" ? slot : slot.time;
  const [hour, minute] = time.split(":").map(Number);
  return `${minute} ${hour} * * ${typeof slot === "string" ? "*" : slot.day}`;
}

const pad = (value: string) => value.padStart(2, "0");

/** Reads a check-in back from its routine; a schedule edited into another shape reads as off. */
function rhythmSlot(key: CoachKey, crons: readonly string[]) {
  const match =
    crons.length === 1 ? /^(\d{1,2}) (\d{1,2}) \* \* (\*|[0-6])$/.exec(crons[0]!) : null;
  if (!match || Number(match[1]) > 59 || Number(match[2]) > 23) return null;
  const time = `${pad(match[2]!)}:${pad(match[1]!)}`;
  if (key === "weekly") return match[3] === "*" ? null : { day: Number(match[3]), time };
  return match[3] === "*" ? time : null;
}

function isCoachKey(value: string | null): value is CoachKey {
  return (COACH_KEYS as readonly string[]).includes(value ?? "");
}

/** The user's check-in times, read from the main bot's active coach routines. */
export async function getCoachRhythm(prisma: PrismaClient, userId: string): Promise<CoachRhythm> {
  const botId = await findMainBotId(prisma, userId);
  if (!botId) return { ...COACH_RHYTHM_OFF };
  const routines = await prisma.routine.findMany({
    where: { botId, userId, active: true, coachKey: { not: null } },
    select: { coachKey: true, crons: true },
  });
  const rhythm: CoachRhythm = { ...COACH_RHYTHM_OFF };
  for (const routine of routines) {
    if (!isCoachKey(routine.coachKey)) continue;
    const slot = rhythmSlot(routine.coachKey, routine.crons);
    if (routine.coachKey === "weekly") rhythm.weekly = slot as CoachRhythm["weekly"];
    else rhythm[routine.coachKey] = slot as string | null;
  }
  return rhythm;
}

/**
 * Makes the main bot's coach routines match `rhythm`: one routine per check-in that is on,
 * waking in the main conversation in the user's time zone. Check-ins that are off are deleted.
 * Calling it again with the same rhythm changes nothing.
 */
export async function setCoachRhythm(
  deps: CoachRhythmDeps,
  input: { userId: string; rhythm: CoachRhythm },
): Promise<CoachRhythm> {
  const { prisma, jobs } = deps;
  const { userId, rhythm } = input;
  const anyOn = COACH_KEYS.some((key) => coachCron(key, rhythm) !== null);
  const conversation = anyOn ? await ensureMainConversation(prisma, userId) : null;
  const botId = conversation?.leadBotId ?? (await findMainBotId(prisma, userId));
  if (!botId) return { ...COACH_RHYTHM_OFF };
  const existing = await prisma.routine.findMany({
    where: { botId, userId, coachKey: { not: null } },
  });
  const timezone = anyOn ? await coachTimeZone(prisma, userId) : "UTC";
  for (const key of COACH_KEYS) {
    const cron = coachCron(key, rhythm);
    const current = existing.find((routine) => routine.coachKey === key);
    if (!cron || !conversation) {
      if (current) {
        await prisma.routine.deleteMany({ where: { id: current.id } });
        await jobs.cancel(routineJobKey(current.id));
      }
      continue;
    }
    const { name, prompt } = COACH_ROUTINES[key];
    const unchanged =
      current?.active &&
      current.nextRunAt &&
      current.crons.length === 1 &&
      current.crons[0] === cron &&
      current.timezone === timezone &&
      current.threadId === conversation.threadId &&
      current.spaceId === conversation.spaceId &&
      current.name === name &&
      current.prompt === prompt;
    if (unchanged) continue;
    const nextRunAt = nextCronDate(cron, new Date(), timezone);
    const fields = {
      spaceId: conversation.spaceId,
      threadId: conversation.threadId,
      name,
      prompt,
      crons: [cron],
      timezone,
      active: true,
      notify: true,
      nextRunAt,
    };
    const saved = await prisma.routine.upsert({
      where: { botId_coachKey: { botId, coachKey: key } },
      create: { ...fields, botId, userId, coachKey: key },
      update: fields,
    });
    // The job reconciler re-arms an active routine whose wakeup could not be enqueued.
    await jobs.enqueue(routineWakeupJob(saved.id, nextRunAt));
  }
  return getCoachRhythm(prisma, userId);
}