/**
 * v1.8.2 — duplicate dose-slot cleanup integration tests.
 *
 * Pins the one-time boot-backfill that collapses pre-fix duplicate slot
 * rows: a twice-daily med ends up with a 07:00 pending REMINDER row AND
 * a 07:00 taken WEB/API row for the same dose slot (the two
 * `scheduledFor` instants drifting by up to a minute). The cleanup keeps
 * the winner (taken > skipped > pending), soft-deletes the losers,
 * normalises the winner's `scheduledFor` to the canonical slot instant,
 * leaves PRN / off-slot rows untouched, and is a no-op on a second run.
 *
 * Coverage map:
 *   1. Duplicate 07:00 pair collapses to the taken row; loser tombstoned;
 *      the clean 19:00 row is untouched; compliance rollup self-corrects.
 *   2. A PRN med's multiple rows are never collapsed.
 *   3. A second run is a no-op (idempotent).
 *   4. taken > skipped tie-break keeps the taken row.
 *   5. Boot discovery only matches users that actually hold duplicates.
 */
import { beforeEach, describe, expect, it, vi } from "vitest";

import { getPrismaClient, truncateAllTables } from "./setup";

import {
  dedupeUserIntakeSlots,
  enqueueBootTimeIntakeSlotDedup,
} from "@/lib/medications/intake-slot-dedup";
import {
  applyCanonicalSlotWrite,
  resolveSlotInstantForWrite,
} from "@/lib/medications/scheduling/slot-upsert";
import { localHmAsUtc } from "@/lib/tz/local-day";

const TEST_USER_ID = "user-intake-slot-dedup";
const OTHER_USER_ID = "user-intake-slot-dedup-clean";

vi.mock("@/lib/db-compat", () => ({
  ensureDbCompatibility: vi.fn().mockResolvedValue(undefined),
}));

beforeEach(async () => {
  const prisma = getPrismaClient();
  await truncateAllTables(prisma);
  await prisma.user.create({
    data: {
      id: TEST_USER_ID,
      username: "intake-dedup",
      email: "intake-dedup@example.test",
      timezone: "Europe/Berlin",
    },
  });
  await prisma.user.create({
    data: {
      id: OTHER_USER_ID,
      username: "intake-dedup-clean",
      email: "intake-dedup-clean@example.test",
      timezone: "Europe/Berlin",
    },
  });
});

/**
 * Anchor every fixture on a fixed historical day so the slot instants
 * are deterministic regardless of when the suite runs. 2026-03-10 is a
 * non-DST-boundary weekday in Europe/Berlin.
 */
const DAY = new Date("2026-03-10T12:00:00.000Z");

async function createTwiceDailyMed(): Promise<string> {
  const prisma = getPrismaClient();
  const med = await prisma.medication.create({
    data: {
      userId: TEST_USER_ID,
      name: "Bisoprolol",
      dose: "2.5mg",
      active: true,
      schedules: {
        create: {
          windowStart: "07:00",
          windowEnd: "07:00",
          timesOfDay: ["07:00", "19:00"],
          daysOfWeek: null,
          scheduleType: "SCHEDULED",
        },
      },
    },
  });
  return med.id;
}

describe("intake-slot-dedup — duplicate slot collapse", () => {
  it("collapses the 07:00 pending+taken pair to the taken row, leaves 19:00 untouched, corrects the rollup", async () => {
    const prisma = getPrismaClient();
    const medId = await createTwiceDailyMed();

    const slot0700 = localHmAsUtc(DAY, "Europe/Berlin", 7, 0);
    const slot1900 = localHmAsUtc(DAY, "Europe/Berlin", 19, 0);

    // 07:00 pending REMINDER row (server-minted, canonical instant).
    const pending = await prisma.medicationIntakeEvent.create({
      data: {
        userId: TEST_USER_ID,
        medicationId: medId,
        scheduledFor: slot0700,
        takenAt: null,
        skipped: false,
        source: "REMINDER",
      },
    });
    // 07:00 taken API row, drifted +1 minute (the iOS-vs-server drift).
    const taken = await prisma.medicationIntakeEvent.create({
      data: {
        userId: TEST_USER_ID,
        medicationId: medId,
        scheduledFor: new Date(slot0700.getTime() + 60_000),
        takenAt: new Date(slot0700.getTime() + 60_000),
        skipped: false,
        source: "API",
      },
    });
    // Clean 19:00 pending row — no duplicate.
    const evening = await prisma.medicationIntakeEvent.create({
      data: {
        userId: TEST_USER_ID,
        medicationId: medId,
        scheduledFor: slot1900,
        takenAt: null,
        skipped: false,
        source: "REMINDER",
      },
    });

    const summary = await dedupeUserIntakeSlots(TEST_USER_ID);

    expect(summary.slotsCollapsed).toBe(1);
    expect(summary.rowsSoftDeleted).toBe(1);

    // Exactly one live 07:00 row survives, and it is the taken one.
    const live0700 = await prisma.medicationIntakeEvent.findMany({
      where: {
        userId: TEST_USER_ID,
        medicationId: medId,
        deletedAt: null,
        scheduledFor: slot0700,
      },
    });
    expect(live0700).toHaveLength(1);
    expect(live0700[0]?.id).toBe(taken.id);
    expect(live0700[0]?.takenAt).not.toBeNull();
    // Winner normalised onto the canonical slot instant.
    expect(live0700[0]?.scheduledFor.toISOString()).toBe(
      slot0700.toISOString(),
    );

    // The loser (the pending REMINDER row) is soft-deleted, not removed.
    const loser = await prisma.medicationIntakeEvent.findUniqueOrThrow({
      where: { id: pending.id },
    });
    expect(loser.deletedAt).not.toBeNull();

    // The clean 19:00 row is untouched.
    const eveningRow = await prisma.medicationIntakeEvent.findUniqueOrThrow({
      where: { id: evening.id },
    });
    expect(eveningRow.deletedAt).toBeNull();
    expect(eveningRow.scheduledFor.toISOString()).toBe(slot1900.toISOString());

    // The compliance rollup reflects the corrected counts: the 07:00 day
    // now has scheduled=2 (07:00 taken + 19:00 pending), taken=1 — not the
    // inflated scheduled=3 the duplicate produced.
    const rollups = await prisma.medicationComplianceRollup.findMany({
      where: { userId: TEST_USER_ID, medicationId: medId },
    });
    expect(rollups).toHaveLength(1);
    expect(rollups[0]?.scheduled).toBe(2);
    expect(rollups[0]?.taken).toBe(1);
  });

  it("never collapses a PRN med's multiple rows", async () => {
    const prisma = getPrismaClient();
    const med = await prisma.medication.create({
      data: {
        userId: TEST_USER_ID,
        name: "Ibuprofen PRN",
        dose: "400mg",
        active: true,
        schedules: {
          create: {
            windowStart: "00:00",
            windowEnd: "00:00",
            timesOfDay: [],
            daysOfWeek: null,
            scheduleType: "PRN",
          },
        },
      },
    });

    // Two as-needed doses logged minutes apart — both must survive.
    const a = await prisma.medicationIntakeEvent.create({
      data: {
        userId: TEST_USER_ID,
        medicationId: med.id,
        scheduledFor: new Date("2026-03-10T09:00:00.000Z"),
        takenAt: new Date("2026-03-10T09:00:00.000Z"),
        skipped: false,
        source: "WEB",
      },
    });
    const b = await prisma.medicationIntakeEvent.create({
      data: {
        userId: TEST_USER_ID,
        medicationId: med.id,
        scheduledFor: new Date("2026-03-10T09:01:00.000Z"),
        takenAt: new Date("2026-03-10T09:01:00.000Z"),
        skipped: false,
        source: "WEB",
      },
    });

    const summary = await dedupeUserIntakeSlots(TEST_USER_ID);
    expect(summary.slotsCollapsed).toBe(0);
    expect(summary.rowsSoftDeleted).toBe(0);

    const live = await prisma.medicationIntakeEvent.findMany({
      where: { userId: TEST_USER_ID, medicationId: med.id, deletedAt: null },
    });
    expect(live.map((r) => r.id).sort()).toEqual([a.id, b.id].sort());
  });

  it("is a no-op on a second run (idempotent)", async () => {
    const prisma = getPrismaClient();
    const medId = await createTwiceDailyMed();
    const slot0700 = localHmAsUtc(DAY, "Europe/Berlin", 7, 0);

    await prisma.medicationIntakeEvent.create({
      data: {
        userId: TEST_USER_ID,
        medicationId: medId,
        scheduledFor: slot0700,
        takenAt: null,
        skipped: false,
        source: "REMINDER",
      },
    });
    await prisma.medicationIntakeEvent.create({
      data: {
        userId: TEST_USER_ID,
        medicationId: medId,
        scheduledFor: new Date(slot0700.getTime() + 60_000),
        takenAt: new Date(slot0700.getTime() + 60_000),
        skipped: false,
        source: "API",
      },
    });

    const first = await dedupeUserIntakeSlots(TEST_USER_ID);
    expect(first.slotsCollapsed).toBe(1);

    const second = await dedupeUserIntakeSlots(TEST_USER_ID);
    expect(second.slotsCollapsed).toBe(0);
    expect(second.rowsSoftDeleted).toBe(0);
    expect(second.rowsNormalised).toBe(0);

    const live = await prisma.medicationIntakeEvent.findMany({
      where: { userId: TEST_USER_ID, medicationId: medId, deletedAt: null },
    });
    expect(live).toHaveLength(1);
    expect(live[0]?.takenAt).not.toBeNull();
  });

  it("keeps the taken row over a skipped row in the same slot", async () => {
    const prisma = getPrismaClient();
    const medId = await createTwiceDailyMed();
    const slot0700 = localHmAsUtc(DAY, "Europe/Berlin", 7, 0);

    const skipped = await prisma.medicationIntakeEvent.create({
      data: {
        userId: TEST_USER_ID,
        medicationId: medId,
        scheduledFor: slot0700,
        takenAt: null,
        skipped: true,
        source: "WEB",
      },
    });
    const taken = await prisma.medicationIntakeEvent.create({
      data: {
        userId: TEST_USER_ID,
        medicationId: medId,
        scheduledFor: new Date(slot0700.getTime() + 30_000),
        takenAt: new Date(slot0700.getTime() + 30_000),
        skipped: false,
        source: "API",
      },
    });

    await dedupeUserIntakeSlots(TEST_USER_ID);

    const live = await prisma.medicationIntakeEvent.findMany({
      where: { userId: TEST_USER_ID, medicationId: medId, deletedAt: null },
    });
    expect(live).toHaveLength(1);
    expect(live[0]?.id).toBe(taken.id);

    const loser = await prisma.medicationIntakeEvent.findUniqueOrThrow({
      where: { id: skipped.id },
    });
    expect(loser.deletedAt).not.toBeNull();
  });
});

describe("intake write path — multi-dose wide window does not collapse", () => {
  // The LIVE twice-daily-Ramipril regression, end-to-end through the
  // DB-backed slot resolver + the canonical-slot upsert: two distinct
  // same-day doses on an 08:00 / 20:00 schedule with a WIDE 08:00–22:00
  // window must land as TWO separate live rows, not collapse onto one.
  async function createWideWindowTwiceDailyMed(): Promise<string> {
    const prisma = getPrismaClient();
    const med = await prisma.medication.create({
      data: {
        userId: TEST_USER_ID,
        name: "Ramipril",
        dose: "5mg",
        active: true,
        schedules: {
          create: {
            windowStart: "08:00",
            windowEnd: "22:00", // wide window — the pre-fix overlap trigger
            timesOfDay: ["08:00", "20:00"],
            daysOfWeek: null,
            scheduleType: "SCHEDULED",
          },
        },
      },
    });
    return med.id;
  }

  it("resolves morning and evening writes to two distinct canonical slots and lands two rows", async () => {
    const prisma = getPrismaClient();
    const medId = await createWideWindowTwiceDailyMed();

    const morningWrite = new Date("2026-03-10T07:05:00.000Z"); // 08:05 CET
    const eveningWrite = new Date("2026-03-10T19:03:00.000Z"); // 20:03 CET

    const morningSlot = await resolveSlotInstantForWrite({
      userId: TEST_USER_ID,
      medicationId: medId,
      userTz: "Europe/Berlin",
      incoming: morningWrite,
      client: prisma,
    });
    const eveningSlot = await resolveSlotInstantForWrite({
      userId: TEST_USER_ID,
      medicationId: medId,
      userTz: "Europe/Berlin",
      incoming: eveningWrite,
      client: prisma,
    });

    expect(morningSlot).not.toBeNull();
    expect(eveningSlot).not.toBeNull();
    // The two doses must resolve to two distinct canonical slot instants.
    expect(morningSlot?.toISOString()).not.toBe(eveningSlot?.toISOString());
    expect(morningSlot?.toISOString()).toBe(
      localHmAsUtc(DAY, "Europe/Berlin", 8, 0).toISOString(),
    );
    expect(eveningSlot?.toISOString()).toBe(
      localHmAsUtc(DAY, "Europe/Berlin", 20, 0).toISOString(),
    );

    // Apply the morning taken write.
    const morningResult = await applyCanonicalSlotWrite({
      client: prisma,
      userId: TEST_USER_ID,
      medicationId: medId,
      canonicalSlot: morningSlot!,
      takenAt: morningWrite,
      skipped: false,
      isExplicitTaken: true,
      isExplicitSkip: false,
      idempotencyKey: null,
      createSource: "WEB",
    });
    expect(morningResult.outcome).toBe("inserted");

    // Apply the evening taken write — must NOT collapse onto the morning
    // slot (the bug) and must land as its own row.
    const eveningResult = await applyCanonicalSlotWrite({
      client: prisma,
      userId: TEST_USER_ID,
      medicationId: medId,
      canonicalSlot: eveningSlot!,
      takenAt: eveningWrite,
      skipped: false,
      isExplicitTaken: true,
      isExplicitSkip: false,
      idempotencyKey: null,
      createSource: "WEB",
    });
    expect(eveningResult.outcome).toBe("inserted");
    expect(eveningResult.noDowngradeNoOp).toBe(false);

    // Two distinct live rows, one per dose slot.
    const live = await prisma.medicationIntakeEvent.findMany({
      where: { userId: TEST_USER_ID, medicationId: medId, deletedAt: null },
      orderBy: { scheduledFor: "asc" },
    });
    expect(live).toHaveLength(2);
    expect(live[0]?.takenAt).not.toBeNull();
    expect(live[1]?.takenAt).not.toBeNull();
    expect(live[0]?.scheduledFor.toISOString()).toBe(
      localHmAsUtc(DAY, "Europe/Berlin", 8, 0).toISOString(),
    );
    expect(live[1]?.scheduledFor.toISOString()).toBe(
      localHmAsUtc(DAY, "Europe/Berlin", 20, 0).toISOString(),
    );
  });
});

describe("intake write path — defaulted-now midday does not back-fill the morning slot", () => {
  // The phantom morning-dose regression, end-to-end through the DB-backed
  // resolver: a bulk/sync entry that carries ONLY `takenAt` (no client
  // `scheduledFor`) around midday must NOT snap onto the 07:00 slot of a
  // 07:00 / 19:00 med and stamp it taken. With `instantIsExplicit:false`
  // the resolver returns null (PRN) so the morning slot stays untouched.
  it("a takenAt-only 12:30 write resolves to null and leaves the 07:00 slot untaken", async () => {
    const prisma = getPrismaClient();
    const medId = await createTwiceDailyMed();

    const slot0700 = localHmAsUtc(DAY, "Europe/Berlin", 7, 0);

    // Server-minted pending 07:00 reminder row — the row the phantom take
    // would have stamped.
    const pending = await prisma.medicationIntakeEvent.create({
      data: {
        userId: TEST_USER_ID,
        medicationId: medId,
        scheduledFor: slot0700,
        takenAt: null,
        skipped: false,
        source: "REMINDER",
      },
    });

    // Bulk/sync entry: no `scheduledFor`, only `takenAt` at 12:30 local
    // (10:30Z in CET). This mirrors `intake/bulk` defaulting the instant
    // to `takenAt` with `instantIsExplicit: entry.scheduledFor !== undefined`.
    const middayTakenAt = new Date("2026-03-10T11:30:00.000Z"); // 12:30 CET
    const canonicalSlot = await resolveSlotInstantForWrite({
      userId: TEST_USER_ID,
      medicationId: medId,
      userTz: "Europe/Berlin",
      incoming: middayTakenAt,
      instantIsExplicit: false,
      client: prisma,
    });

    // The defaulted-now write does NOT snap onto the far 07:00 slot.
    expect(canonicalSlot).toBeNull();

    // The 07:00 reminder row stays untaken — no phantom morning dose.
    const morning = await prisma.medicationIntakeEvent.findUniqueOrThrow({
      where: { id: pending.id },
    });
    expect(morning.takenAt).toBeNull();
    expect(morning.skipped).toBe(false);
    expect(morning.deletedAt).toBeNull();
  });

  it("an EXPLICIT scheduledFor:07:00 write still snaps onto the 07:00 slot", async () => {
    const prisma = getPrismaClient();
    const medId = await createTwiceDailyMed();
    const slot0700 = localHmAsUtc(DAY, "Europe/Berlin", 7, 0);

    const explicitWrite = new Date("2026-03-10T06:00:00.000Z"); // 07:00 CET
    const canonicalSlot = await resolveSlotInstantForWrite({
      userId: TEST_USER_ID,
      medicationId: medId,
      userTz: "Europe/Berlin",
      incoming: explicitWrite,
      instantIsExplicit: true,
      client: prisma,
    });
    expect(canonicalSlot?.toISOString()).toBe(slot0700.toISOString());
  });
});

describe("intake-slot-dedup — boot discovery scoping", () => {
  it("returns 0 when no user holds a duplicate pair", async () => {
    const prisma = getPrismaClient();
    const med = await prisma.medication.create({
      data: {
        userId: OTHER_USER_ID,
        name: "Clean med",
        dose: "1mg",
        active: true,
        schedules: {
          create: {
            windowStart: "08:00",
            windowEnd: "08:00",
            timesOfDay: ["08:00"],
            scheduleType: "SCHEDULED",
          },
        },
      },
    });
    // A single clean row, no duplicate.
    await prisma.medicationIntakeEvent.create({
      data: {
        userId: OTHER_USER_ID,
        medicationId: med.id,
        scheduledFor: localHmAsUtc(DAY, "Europe/Berlin", 8, 0),
        takenAt: null,
        skipped: false,
        source: "REMINDER",
      },
    });

    // boss is not initialised in this unit context → enqueue helper
    // returns the no-boss zero result. We assert the discovery query path
    // by running the per-user pass directly below; the helper's
    // discovery SQL is exercised in the live worker boot.
    const result = await enqueueBootTimeIntakeSlotDedup();
    expect(result.error).toBeNull();
    expect(result.enqueued).toBe(0);

    // Per-user pass on the clean user is a no-op.
    const summary = await dedupeUserIntakeSlots(OTHER_USER_ID);
    expect(summary.slotsCollapsed).toBe(0);
  });
});