import { describe, it, expect, vi, beforeEach } from "vitest";

vi.mock("./db", () => ({
  getDb: vi.fn(),
}));

import { getDb } from "./db";
import {
  listBalanceCategories,
  createBalanceCategory,
  updateBalanceCategory,
  deleteBalanceCategory,
  listBalanceAccounts,
  createBalanceAccount,
  updateBalanceAccount,
  archiveBalanceAccount,
  unarchiveBalanceAccount,
  listSnapshots,
  getSnapshotByDate,
  createSnapshot,
  updateSnapshot,
  deleteSnapshot,
  listLinesBySnapshot,
  upsertSnapshotLines,
  getPreviousSnapshot,
  BalanceServiceError,
} from "./balance.service";

const mockSelect = vi.fn();
const mockExecute = vi.fn();
const mockDb = { select: mockSelect, execute: mockExecute };

beforeEach(() => {
  vi.mocked(getDb).mockResolvedValue(mockDb as never);
  mockSelect.mockReset();
  mockExecute.mockReset();
});

// -----------------------------------------------------------------------------
// Categories
// -----------------------------------------------------------------------------

describe("listBalanceCategories", () => {
  it("orders by sort_order then key", async () => {
    mockSelect.mockResolvedValueOnce([]);
    await listBalanceCategories();
    const sql = mockSelect.mock.calls[0][0] as string;
    expect(sql).toContain("FROM balance_categories");
    expect(sql).toContain("ORDER BY sort_order, key");
  });
});

describe("createBalanceCategory", () => {
  it("rejects an empty key", async () => {
    await expect(
      createBalanceCategory({ key: "  ", i18n_key: "x", kind: "simple" })
    ).rejects.toBeInstanceOf(BalanceServiceError);
    expect(mockExecute).not.toHaveBeenCalled();
  });

  it("rejects an invalid kind", async () => {
    await expect(
      createBalanceCategory({
        key: "custom",
        i18n_key: "balance.category.custom",
        // @ts-expect-error testing runtime guard
        kind: "weird",
      })
    ).rejects.toBeInstanceOf(BalanceServiceError);
    expect(mockExecute).not.toHaveBeenCalled();
  });

  it("inserts with is_seed = 0 and returns lastInsertId", async () => {
    mockExecute.mockResolvedValueOnce({ lastInsertId: 42, rowsAffected: 1 });
    const id = await createBalanceCategory({
      key: "ferr",
      i18n_key: "balance.category.ferr",
      kind: "simple",
      sort_order: 35,
    });
    expect(id).toBe(42);
    const sql = mockExecute.mock.calls[0][0] as string;
    const params = mockExecute.mock.calls[0][1] as unknown[];
    expect(sql).toContain("INSERT INTO balance_categories");
    expect(sql).toContain("is_seed");
    expect(sql).toMatch(/0\)$/); // is_seed hardcoded to 0
    expect(params).toEqual(["ferr", "balance.category.ferr", "simple", 35]);
  });
});

describe("deleteBalanceCategory", () => {
  it("refuses to delete a seeded category", async () => {
    mockSelect.mockResolvedValueOnce([
      {
        id: 1,
        key: "cash",
        i18n_key: "balance.category.cash",
        kind: "simple",
        sort_order: 10,
        is_active: 1,
        is_seed: 1,
      },
    ]);
    await expect(deleteBalanceCategory(1)).rejects.toMatchObject({
      code: "category_seed_protected",
    });
    expect(mockExecute).not.toHaveBeenCalled();
  });

  it("refuses to delete a category with linked accounts", async () => {
    // 1st select = getBalanceCategory; 2nd select = COUNT(*) accounts linked
    mockSelect
      .mockResolvedValueOnce([
        {
          id: 8,
          key: "ferr",
          i18n_key: "balance.category.ferr",
          kind: "simple",
          sort_order: 35,
          is_active: 1,
          is_seed: 0,
        },
      ])
      .mockResolvedValueOnce([{ count: 2 }]);
    await expect(deleteBalanceCategory(8)).rejects.toMatchObject({
      code: "category_has_accounts",
    });
    expect(mockExecute).not.toHaveBeenCalled();
  });

  it("deletes a user-created category with no linked accounts", async () => {
    mockSelect
      .mockResolvedValueOnce([
        {
          id: 8,
          key: "ferr",
          i18n_key: "balance.category.ferr",
          kind: "simple",
          sort_order: 35,
          is_active: 1,
          is_seed: 0,
        },
      ])
      .mockResolvedValueOnce([{ count: 0 }]);
    mockExecute.mockResolvedValueOnce({ rowsAffected: 1 });
    await deleteBalanceCategory(8);
    expect(mockExecute).toHaveBeenCalledWith(
      "DELETE FROM balance_categories WHERE id = $1",
      [8]
    );
  });
});

describe("updateBalanceCategory", () => {
  it("renames a seeded category (allowed)", async () => {
    mockSelect.mockResolvedValueOnce([
      {
        id: 1,
        key: "cash",
        i18n_key: "balance.category.cash",
        kind: "simple",
        sort_order: 10,
        is_active: 1,
        is_seed: 1,
      },
    ]);
    mockExecute.mockResolvedValueOnce({ rowsAffected: 1 });
    await updateBalanceCategory(1, { i18n_key: "balance.category.cash_renamed" });
    const params = mockExecute.mock.calls[0][1] as unknown[];
    expect(params[0]).toBe("balance.category.cash_renamed");
  });

  it("rejects update on missing category", async () => {
    mockSelect.mockResolvedValueOnce([]);
    await expect(updateBalanceCategory(999, { sort_order: 5 })).rejects.toMatchObject({
      code: "category_not_found",
    });
  });
});

// -----------------------------------------------------------------------------
// Accounts
// -----------------------------------------------------------------------------

describe("listBalanceAccounts", () => {
  it("excludes archived accounts by default", async () => {
    mockSelect.mockResolvedValueOnce([]);
    await listBalanceAccounts();
    const sql = mockSelect.mock.calls[0][0] as string;
    expect(sql).toContain("a.is_active = 1");
    expect(sql).toContain("a.archived_at IS NULL");
  });

  it("includes archived accounts when requested", async () => {
    mockSelect.mockResolvedValueOnce([]);
    await listBalanceAccounts({ includeArchived: true });
    const sql = mockSelect.mock.calls[0][0] as string;
    expect(sql).not.toContain("archived_at IS NULL");
  });
});

describe("createBalanceAccount", () => {
  it("rejects empty name", async () => {
    await expect(
      createBalanceAccount({ balance_category_id: 1, name: "  " })
    ).rejects.toMatchObject({ code: "name_required" });
  });

  it("rejects non-CAD currency at the MVP", async () => {
    await expect(
      createBalanceAccount({
        balance_category_id: 1,
        name: "USD account",
        currency: "USD",
      })
    ).rejects.toMatchObject({ code: "currency_unsupported" });
    expect(mockExecute).not.toHaveBeenCalled();
  });

  it("rejects when the category does not exist", async () => {
    mockSelect.mockResolvedValueOnce([]); // getBalanceCategory returns null
    await expect(
      createBalanceAccount({ balance_category_id: 999, name: "Mystery" })
    ).rejects.toMatchObject({ code: "category_not_found" });
  });

  it("inserts with default CAD currency", async () => {
    mockSelect.mockResolvedValueOnce([
      {
        id: 1,
        key: "cash",
        i18n_key: "balance.category.cash",
        kind: "simple",
        sort_order: 10,
        is_active: 1,
        is_seed: 1,
      },
    ]);
    mockExecute.mockResolvedValueOnce({ lastInsertId: 7, rowsAffected: 1 });
    const id = await createBalanceAccount({
      balance_category_id: 1,
      name: "Encaisse Wealthsimple",
    });
    expect(id).toBe(7);
    const params = mockExecute.mock.calls[0][1] as unknown[];
    expect(params).toEqual([1, "Encaisse Wealthsimple", null, "CAD", null]);
  });
});

describe("updateBalanceAccount", () => {
  it("rejects when account does not exist", async () => {
    mockSelect.mockResolvedValueOnce([]);
    await expect(updateBalanceAccount(42, { name: "x" })).rejects.toMatchObject({
      code: "account_not_found",
    });
  });

  it("normalizes empty symbol to null", async () => {
    mockSelect.mockResolvedValueOnce([
      {
        id: 7,
        balance_category_id: 1,
        name: "Encaisse",
        symbol: "OLD",
        currency: "CAD",
        notes: null,
        is_active: 1,
        archived_at: null,
        created_at: "",
        updated_at: "",
      },
    ]);
    mockExecute.mockResolvedValueOnce({ rowsAffected: 1 });
    await updateBalanceAccount(7, { symbol: "  " });
    const params = mockExecute.mock.calls[0][1] as unknown[];
    expect(params[2]).toBeNull(); // symbol
  });
});

describe("archiveBalanceAccount / unarchiveBalanceAccount", () => {
  it("archives an existing account", async () => {
    mockSelect.mockResolvedValueOnce([
      {
        id: 7,
        balance_category_id: 1,
        name: "Encaisse",
        symbol: null,
        currency: "CAD",
        notes: null,
        is_active: 1,
        archived_at: null,
        created_at: "",
        updated_at: "",
      },
    ]);
    mockExecute.mockResolvedValueOnce({ rowsAffected: 1 });
    await archiveBalanceAccount(7);
    const sql = mockExecute.mock.calls[0][0] as string;
    expect(sql).toContain("archived_at = CURRENT_TIMESTAMP");
    expect(sql).toContain("is_active = 0");
  });

  it("unarchives an existing account", async () => {
    mockSelect.mockResolvedValueOnce([
      {
        id: 7,
        balance_category_id: 1,
        name: "Encaisse",
        symbol: null,
        currency: "CAD",
        notes: null,
        is_active: 0,
        archived_at: "2026-04-25 10:00:00",
        created_at: "",
        updated_at: "",
      },
    ]);
    mockExecute.mockResolvedValueOnce({ rowsAffected: 1 });
    await unarchiveBalanceAccount(7);
    const sql = mockExecute.mock.calls[0][0] as string;
    expect(sql).toContain("archived_at = NULL");
    expect(sql).toContain("is_active = 1");
  });
});

// -----------------------------------------------------------------------------
// Snapshots + lines (Issue #146 / Bilan #1b — simple kind only)
// -----------------------------------------------------------------------------

const FAKE_SNAPSHOT = {
  id: 5,
  snapshot_date: "2026-04-15",
  notes: null,
  created_at: "",
  updated_at: "",
};

describe("listSnapshots", () => {
  it("orders by snapshot_date DESC", async () => {
    mockSelect.mockResolvedValueOnce([]);
    await listSnapshots();
    const sql = mockSelect.mock.calls[0][0] as string;
    expect(sql).toContain("FROM balance_snapshots");
    expect(sql).toContain("ORDER BY snapshot_date DESC");
  });
});

describe("getSnapshotByDate", () => {
  it("rejects empty / invalid dates with snapshot_date_required", async () => {
    await expect(getSnapshotByDate("")).rejects.toMatchObject({
      code: "snapshot_date_required",
    });
    await expect(getSnapshotByDate("2026/04/15")).rejects.toMatchObject({
      code: "snapshot_date_required",
    });
    expect(mockSelect).not.toHaveBeenCalled();
  });

  it("returns the snapshot row when found", async () => {
    mockSelect.mockResolvedValueOnce([FAKE_SNAPSHOT]);
    const got = await getSnapshotByDate("2026-04-15");
    expect(got).toEqual(FAKE_SNAPSHOT);
    expect(mockSelect.mock.calls[0][1]).toEqual(["2026-04-15"]);
  });

  it("returns null when no row matches", async () => {
    mockSelect.mockResolvedValueOnce([]);
    expect(await getSnapshotByDate("2026-04-15")).toBeNull();
  });
});

describe("createSnapshot", () => {
  it("rejects an invalid date", async () => {
    await expect(
      createSnapshot({ snapshot_date: "  " })
    ).rejects.toMatchObject({ code: "snapshot_date_required" });
    expect(mockExecute).not.toHaveBeenCalled();
  });

  it("rejects a duplicate snapshot date with snapshot_date_taken", async () => {
    mockSelect.mockResolvedValueOnce([FAKE_SNAPSHOT]); // existing
    await expect(
      createSnapshot({ snapshot_date: "2026-04-15" })
    ).rejects.toMatchObject({ code: "snapshot_date_taken" });
    expect(mockExecute).not.toHaveBeenCalled();
  });

  it("inserts a new snapshot and returns its id", async () => {
    mockSelect.mockResolvedValueOnce([]); // no existing
    mockExecute.mockResolvedValueOnce({ lastInsertId: 12, rowsAffected: 1 });
    const id = await createSnapshot({
      snapshot_date: "2026-04-25",
      notes: "  monthly check  ",
    });
    expect(id).toBe(12);
    const params = mockExecute.mock.calls[0][1] as unknown[];
    expect(params).toEqual(["2026-04-25", "monthly check"]);
  });
});

describe("updateSnapshot", () => {
  it("rejects when snapshot does not exist", async () => {
    mockSelect.mockResolvedValueOnce([]);
    await expect(
      updateSnapshot(999, { notes: "x" })
    ).rejects.toMatchObject({ code: "snapshot_not_found" });
  });

  it("normalizes empty notes to null", async () => {
    mockSelect.mockResolvedValueOnce([FAKE_SNAPSHOT]);
    mockExecute.mockResolvedValueOnce({ rowsAffected: 1 });
    await updateSnapshot(5, { notes: "  " });
    const params = mockExecute.mock.calls[0][1] as unknown[];
    expect(params[0]).toBeNull();
  });
});

describe("deleteSnapshot", () => {
  it("rejects when snapshot does not exist", async () => {
    mockSelect.mockResolvedValueOnce([]);
    await expect(deleteSnapshot(999)).rejects.toMatchObject({
      code: "snapshot_not_found",
    });
  });

  it("deletes when found (lines cascade via FK)", async () => {
    mockSelect.mockResolvedValueOnce([FAKE_SNAPSHOT]);
    mockExecute.mockResolvedValueOnce({ rowsAffected: 1 });
    await deleteSnapshot(5);
    expect(mockExecute).toHaveBeenCalledWith(
      "DELETE FROM balance_snapshots WHERE id = $1",
      [5]
    );
  });
});

describe("listLinesBySnapshot", () => {
  it("orders by id and filters by snapshot_id", async () => {
    mockSelect.mockResolvedValueOnce([]);
    await listLinesBySnapshot(5);
    const sql = mockSelect.mock.calls[0][0] as string;
    expect(sql).toContain("FROM balance_snapshot_lines");
    expect(sql).toContain("WHERE snapshot_id = $1");
    expect(sql).toContain("ORDER BY id");
    expect(mockSelect.mock.calls[0][1]).toEqual([5]);
  });
});

describe("upsertSnapshotLines (simple kind)", () => {
  it("rejects when the parent snapshot is missing", async () => {
    mockSelect.mockResolvedValueOnce([]);
    await expect(
      upsertSnapshotLines(99, [{ account_id: 1, value: 1000 }])
    ).rejects.toMatchObject({ code: "snapshot_not_found" });
    expect(mockExecute).not.toHaveBeenCalled();
  });

  it("rejects non-finite values with snapshot_value_invalid", async () => {
    mockSelect.mockResolvedValueOnce([FAKE_SNAPSHOT]);
    await expect(
      upsertSnapshotLines(5, [
        { account_id: 1, value: 1000 },
        // @ts-expect-error testing runtime guard
        { account_id: 2, value: "not a number" },
      ])
    ).rejects.toMatchObject({ code: "snapshot_value_invalid" });
    // Validation happens up-front, before any mutation
    expect(mockExecute).not.toHaveBeenCalled();
  });

  it("rejects NaN and Infinity", async () => {
    mockSelect.mockResolvedValueOnce([FAKE_SNAPSHOT]);
    await expect(
      upsertSnapshotLines(5, [{ account_id: 1, value: NaN }])
    ).rejects.toMatchObject({ code: "snapshot_value_invalid" });

    mockSelect.mockResolvedValueOnce([FAKE_SNAPSHOT]);
    await expect(
      upsertSnapshotLines(5, [{ account_id: 1, value: Infinity }])
    ).rejects.toMatchObject({ code: "snapshot_value_invalid" });
  });

  it("clears existing lines, inserts each line with NULL quantity/unit_price, and bumps updated_at", async () => {
    mockSelect.mockResolvedValueOnce([FAKE_SNAPSHOT]);
    mockExecute
      .mockResolvedValueOnce({ rowsAffected: 1 }) // delete
      .mockResolvedValueOnce({ lastInsertId: 100, rowsAffected: 1 }) // insert 1
      .mockResolvedValueOnce({ lastInsertId: 101, rowsAffected: 1 }) // insert 2
      .mockResolvedValueOnce({ rowsAffected: 1 }); // update updated_at
    await upsertSnapshotLines(5, [
      { account_id: 1, value: 1234.56 },
      { account_id: 2, value: 0 },
    ]);
    // 1st call = DELETE
    expect(mockExecute.mock.calls[0][0]).toContain(
      "DELETE FROM balance_snapshot_lines"
    );
    // Inserts use literal NULL for quantity/unit_price (simple kind invariant)
    const insertSql = mockExecute.mock.calls[1][0] as string;
    expect(insertSql).toContain("INSERT INTO balance_snapshot_lines");
    expect(insertSql).toMatch(/VALUES\s*\(\s*\$1,\s*\$2,\s*NULL,\s*NULL,\s*\$3/);
    expect(insertSql).toContain("'manual'");
    // First insert params
    expect(mockExecute.mock.calls[1][1]).toEqual([5, 1, 1234.56]);
    // Second insert params (zero is allowed)
    expect(mockExecute.mock.calls[2][1]).toEqual([5, 2, 0]);
    // Final call = UPDATE updated_at on parent snapshot
    expect(mockExecute.mock.calls[3][0]).toContain(
      "UPDATE balance_snapshots"
    );
    expect(mockExecute.mock.calls[3][0]).toContain("updated_at");
  });

  it("clears all lines when called with an empty array", async () => {
    mockSelect.mockResolvedValueOnce([FAKE_SNAPSHOT]);
    mockExecute
      .mockResolvedValueOnce({ rowsAffected: 3 }) // delete only
      .mockResolvedValueOnce({ rowsAffected: 1 }); // bump updated_at
    await upsertSnapshotLines(5, []);
    // Only DELETE + UPDATE updated_at — no INSERTs
    expect(mockExecute).toHaveBeenCalledTimes(2);
  });
});

describe("getPreviousSnapshot", () => {
  it("returns the most recent snapshot strictly before referenceDate", async () => {
    mockSelect.mockResolvedValueOnce([
      { ...FAKE_SNAPSHOT, snapshot_date: "2026-03-15" },
    ]);
    const got = await getPreviousSnapshot("2026-04-15");
    expect(got?.snapshot_date).toBe("2026-03-15");
    const sql = mockSelect.mock.calls[0][0] as string;
    expect(sql).toContain("snapshot_date < $1");
    expect(sql).toContain("ORDER BY snapshot_date DESC");
    expect(sql).toContain("LIMIT 1");
  });

  it("returns null when no earlier snapshot exists", async () => {
    mockSelect.mockResolvedValueOnce([]);
    expect(await getPreviousSnapshot("2026-04-15")).toBeNull();
  });

  it("rejects an invalid reference date", async () => {
    await expect(getPreviousSnapshot("nope")).rejects.toMatchObject({
      code: "snapshot_date_required",
    });
  });
});