"""Pure-Python tests for the bulk-edit data path. The Textual modal itself
is exercised manually; here we lock in the semantics of the per-row diff
overlay so a regression in the loop is caught."""

from pathlib import Path

import pytest

from common_cents.db import Database
from common_cents.screens._spending_bulk_form import _split_tags


@pytest.fixture
def db(tmp_path: Path) -> Database:
    return Database(tmp_path / "test.db")


def _seed(db: Database, *rows) -> list[int]:
    for r in rows:
        db.add_spending(*r)
    return [row["id"] for row in db.get_spending()]


def _apply_diff(db: Database, ids: list[int], diff: dict) -> int:
    """Mirror BulkEditScreen._write so the overlay logic can be tested headlessly."""
    tag_ids: list[int] | None = None
    if "tag_names" in diff:
        tag_ids = [db.get_or_create_metadata("tag", n) for n in diff["tag_names"]]
    updated = 0
    for sid in ids:
        row = db.get_spending_by_id(sid)
        if row is None:
            continue
        new_date = diff.get("date", row["date"])
        new_category = diff.get("category", row["category_name"])
        new_merchant = diff["merchant"] if "merchant" in diff else row["merchant_name"]
        new_notes = diff["notes"] if "notes" in diff else row["notes"]
        new_tags = (
            tag_ids
            if tag_ids is not None
            else db.get_spending_metadata_ids(sid, "tag")
        )
        db.update_spending(
            sid,
            new_date,
            row["cents"],
            new_category,
            new_merchant,
            new_notes,
            new_tags,
        )
        updated += 1
    return updated


def test_split_tags_strips_and_drops_empty():
    assert _split_tags("a, b ,  ,c") == ["a", "b", "c"]
    assert _split_tags("") == []
    assert _split_tags("   ") == []


def test_bulk_recategorize_preserves_other_fields(db):
    ids = _seed(
        db,
        ("2026-05-01", 1500, "Food", "Whole Foods", "lunch", []),
        ("2026-05-02", 2500, "Food", "Trader Joes", None, []),
    )
    _apply_diff(db, ids, {"category": "Groceries"})
    rows = db.get_spending()
    assert {r["category"] for r in rows} == {"Groceries"}
    # merchants and notes preserved
    by_date = {r["date"]: r for r in rows}
    assert by_date["2026-05-01"]["merchant"] == "Whole Foods"
    assert by_date["2026-05-01"]["notes"] == "lunch"
    assert by_date["2026-05-02"]["merchant"] == "Trader Joes"


def test_bulk_clear_merchant_and_notes(db):
    ids = _seed(
        db,
        ("2026-05-01", 1500, "Food", "X", "n1", []),
        ("2026-05-02", 2500, "Food", "Y", "n2", []),
    )
    _apply_diff(db, ids, {"merchant": None, "notes": None})
    for row in db.get_spending():
        assert row["merchant"] is None
        assert row["notes"] is None


def test_bulk_replace_tags_overwrites_existing(db):
    food_id = db.add_metadata("tag", "lunch")
    ids = _seed(
        db,
        ("2026-05-01", 1500, "Food", None, None, [food_id]),
        ("2026-05-02", 2500, "Food", None, None, []),
    )
    _apply_diff(db, ids, {"tag_names": ["work", "client"]})
    for sid in ids:
        names = sorted(
            t["name"]
            for t in db.get_metadata("tag")
            if t["id"] in db.get_spending_metadata_ids(sid, "tag")
        )
        assert names == ["client", "work"]


def test_bulk_clear_tags(db):
    work_id = db.add_metadata("tag", "work")
    ids = _seed(
        db,
        ("2026-05-01", 1500, "Food", None, None, [work_id]),
    )
    _apply_diff(db, ids, {"tag_names": []})
    assert db.get_spending_metadata_ids(ids[0], "tag") == []


def test_bulk_skips_missing_id(db):
    ids = _seed(
        db,
        ("2026-05-01", 1500, "Food", None, None, []),
    )
    n = _apply_diff(db, [*ids, 99999], {"category": "Travel"})
    assert n == 1  # the bogus id is skipped, not raised
    assert db.get_spending()[0]["category"] == "Travel"