/* What a full wipe has to leave behind: nothing the learner did.

   The reported failure was that "Reset everything" did not clear learned
   words. It did delete them — and then also deleted the `seed.known` guard,
   so the next boot re-seeded ~47 cards from the known-words list and the
   deck looked untouched. The seed is gone now; these tests pin the wipe so
   a future seed cannot reintroduce the same shape. */

import { describe, it, expect, beforeEach, afterEach } from "vitest";
import { SqliteWasmDb } from "@app/db/sqlite-wasm-core.js";
import { migrate } from "@app/db/migrate.js";
import {
  editCard,
  editChatTurn,
  editMeta,
  editReset,
  editStudyLog,
  insertBand,
  seedCard,
  type LemmaRow,
} from "@app/db/writes.js";
import { newCard, markKnown } from "@lib/srs.js";
import type { Db } from "@app/db/types.js";

let db: Db;
beforeEach(async () => {
  db = await SqliteWasmDb.open({ memory: true });
  await migrate(db);
});
afterEach(async () => {
  await db.close();
});

const lemma = (id: number, headword: string): LemmaRow => ({
  id,
  headword,
  pos: "noun",
  freq_rank: id,
  level: null,
  gloss_en: `gloss ${id}`,
  gloss_ko: "",
  unit_band: 0,
  source: "curated",
});

const count = async (tbl: string): Promise<number> =>
  (await db.get<{ n: number }>(`SELECT COUNT(*) AS n FROM ${tbl}`))!.n;

async function aLearnerWithHistory(): Promise<void> {
  await insertBand(db, [lemma(1, "물"), lemma(2, "책"), lemma(3, "가다")], []);
  await editCard(db, 1, markKnown(10));
  await editCard(db, 2, newCard());
  await editStudyLog(db, 10, { reviews: 4, correct: 3 });
  await editChatTurn(db, "user", "Start unit 1.1.");
  await editChatTurn(db, "assistant", "좋아요.");
  await editMeta(db, "prefs.focus", "particles");
  await editMeta(db, "grammar.learned", '["p1"]');
  await db.run("INSERT INTO progress (unit_id, confidence, updated_at) VALUES ('1.1', 40, 1)");
}

describe("editReset('everything')", () => {
  it("leaves no cards, no study log, no transcript, no progress", async () => {
    await aLearnerWithHistory();
    await editReset(db, "everything");

    for (const tbl of ["card", "study_log", "chat", "progress", "peek"]) {
      expect(await count(tbl), `${tbl} should be empty after a full wipe`).toBe(0);
    }
  });

  it("clears the learner's preferences, grammar flags and notes", async () => {
    await aLearnerWithHistory();
    await editReset(db, "everything");

    const left = await db.all<{ k: string }>(
      "SELECT k FROM meta WHERE k LIKE 'prefs.%' OR k LIKE 'grammar.%' OR k LIKE 'trainer.%'",
    );
    expect(left).toEqual([]);
  });

  it("keeps the dictionary, which is reference data and not the learner's", async () => {
    await aLearnerWithHistory();
    await editReset(db, "everything");
    expect(await count("lemma")).toBe(3);
  });

  it("tombstones what it deleted, so a sync cannot restore it", async () => {
    await aLearnerWithHistory();
    await editReset(db, "everything");

    const graves = await db.all<{ tbl: string }>("SELECT DISTINCT tbl FROM tombstone");
    const tables = graves.map((g) => g.tbl).sort();
    expect(tables).toContain("card");
    expect(tables).toContain("chat");
    expect(tables).toContain("progress");
    expect(tables).toContain("study_log");
  });

  it("does not survive a reboot: nothing reseeds the deck", async () => {
    await aLearnerWithHistory();
    await editReset(db, "everything");
    // Re-running the migrations is what a restart does.
    await migrate(db);
    expect(await count("card")).toBe(0);
  });
});

describe("editReset('roadmap')", () => {
  it("clears the roadmap and transcript but keeps the deck and history", async () => {
    await aLearnerWithHistory();
    await editReset(db, "roadmap");

    expect(await count("progress")).toBe(0);
    expect(await count("chat")).toBe(0);
    expect(await count("card")).toBe(2);
    expect(await count("study_log")).toBe(1);
  });
});

describe("migration 5 — the known-words seed is gone", () => {
  it("removes an existing install's seeded cards and keeps graded ones", async () => {
    await insertBand(db, [lemma(1, "물"), lemma(2, "책")], []);
    await seedCard(db, 1, markKnown(10)); // what the seed used to write
    await editCard(db, 2, newCard()); // something the learner actually did
    await db.run("INSERT INTO meta (k, v, updated_at) VALUES ('seed.known', '47', 0)");

    // Wind the recorded version back to 4 so migrate() really runs 5.
    await db.run("INSERT OR REPLACE INTO meta (k, v, updated_at) VALUES ('schema_version','4',0)");
    const { from, to } = await migrate(db);
    expect(from).toBe(4);
    expect(to).toBe(5);

    const rows = await db.all<{ lemma_id: number }>("SELECT lemma_id FROM card");
    expect(rows.map((r) => r.lemma_id)).toEqual([2]);
    expect(await db.get("SELECT v FROM meta WHERE k = 'seed.known'")).toBeUndefined();
  });
});