# Copyright (c) 2026 Krzysztof Rudnicki. MIT licence.
"""Carrying the pre-0.1.0 counter into the event log."""

from __future__ import annotations

from typing import TYPE_CHECKING

from signal_bot.stats.backfill import (
    UNKNOWN_HOUR,
    backfilled_day,
    has_legacy_counter,
    seed_from_counter,
)
from signal_bot.stats.queries_day import day_rows, day_totals

if TYPE_CHECKING:
    from signal_bot.store import Store

GROUP = "group-a=="
OTHER = "group-b=="
DAY = "2026-08-30"

LEGACY = """
CREATE TABLE message_counts (
    group_id     TEXT NOT NULL,
    uuid         TEXT NOT NULL,
    display_name TEXT NOT NULL,
    count        INTEGER NOT NULL DEFAULT 0,
    PRIMARY KEY (group_id, uuid)
);
"""


def give_legacy_counter(store: Store, rows: list[tuple[str, str, str, int]]) -> None:
    """Recreate the pre-0.1.0 table and fill it, as a real old database has."""
    store.events.connection.executescript(LEGACY)
    store.events.connection.executemany(
        "INSERT INTO message_counts (group_id, uuid, display_name, count) VALUES (?, ?, ?, ?)",
        rows,
    )
    store.events.connection.commit()


def test_a_fresh_database_has_no_legacy_counter(store: Store) -> None:
    """0.1.0 stopped declaring the table, so a new file never has one."""
    assert has_legacy_counter(store) is False


def test_an_old_database_is_detected(store: Store) -> None:
    give_legacy_counter(store, [(GROUP, "u1", "Ala", 3)])
    assert has_legacy_counter(store) is True


def test_counts_become_events_on_the_named_day(store: Store) -> None:
    give_legacy_counter(
        store,
        [(GROUP, "u1", "Ala", 3), (GROUP, "u2", "kuhy", 2), (OTHER, "u1", "Ala", 1)],
    )
    seeded = seed_from_counter(store, DAY)

    assert seeded == {GROUP: 5, OTHER: 1}
    rows = day_rows(store.events, GROUP, DAY)
    assert [(r.display_name, r.messages) for r in rows] == [("Ala", 3), ("kuhy", 2)]
    assert day_totals(rows).messages == 5


def test_the_seeded_day_is_marked_per_group(store: Store) -> None:
    """Marked, so records and hour statistics can leave it out."""
    give_legacy_counter(store, [(GROUP, "u1", "Ala", 1), (OTHER, "u2", "kuhy", 1)])
    seed_from_counter(store, DAY)
    assert backfilled_day(store, GROUP) == DAY
    assert backfilled_day(store, OTHER) == DAY


def test_an_unseeded_group_is_not_marked(store: Store) -> None:
    give_legacy_counter(store, [(GROUP, "u1", "Ala", 1)])
    seed_from_counter(store, DAY)
    assert backfilled_day(store, OTHER) is None


def test_zero_counts_are_skipped(store: Store) -> None:
    """A row at zero is somebody who was reset, not somebody who spoke."""
    give_legacy_counter(store, [(GROUP, "u1", "Ala", 0)])
    assert seed_from_counter(store, DAY) == {}
    assert day_rows(store.events, GROUP, DAY) == []
    assert backfilled_day(store, GROUP) is None


def test_seeded_people_are_known_to_the_roster(store: Store) -> None:
    """Otherwise they would show as unnamed strangers in the first report."""
    give_legacy_counter(store, [(GROUP, "u1", "Ala", 2)])
    seed_from_counter(store, DAY)
    assert [p.display_name for p in store.events.roster(GROUP, ["u1"])] == ["Ala"]


def test_seeded_events_carry_no_invented_detail(store: Store) -> None:
    """No hours, no lengths, no media -- the counter knew none of them.

    The hour is -1 rather than any real hour. It was noon once, and
    favourite_hour then told all seven people they wrote most at midday: 319
    synthetic noons outweighed every genuine evening.
    """
    give_legacy_counter(store, [(GROUP, "u1", "Ala", 2)])
    seed_from_counter(store, DAY)
    rows = store.events.connection.execute(
        "SELECT local_hour, char_len, media_count, is_command FROM message_events"
    ).fetchall()
    assert len(rows) == 2
    for row in rows:
        assert row["local_hour"] == UNKNOWN_HOUR
        assert (row["char_len"], row["media_count"], row["is_command"]) == (0, 0, 0)


def test_seeding_twice_does_not_double_the_totals(store: Store) -> None:
    """The synthetic keys are deterministic, so a rerun is absorbed."""
    give_legacy_counter(store, [(GROUP, "u1", "Ala", 3)])
    seed_from_counter(store, DAY)
    seed_from_counter(store, DAY)
    assert day_totals(day_rows(store.events, GROUP, DAY)).messages == 3