# Copyright (c) 2026 Krzysztof Rudnicki. MIT licence.
"""Writing the command history: one row per attempt, and what it cost.

Shares the ``Store`` connection exactly as ``EventStore`` does, so a command
and the message that triggered it are committed by the same connection in
the same order they happened.

The column set is pinned by ``test_command_events`` for the reason
``message_events``' is: this table sits beside a public repository that
leaked real names once, and a column added quietly is how the next one would
arrive. Nothing here holds free text. ``command`` is a registry name,
``args`` is a resolved token, ``item_id`` is a public identifier and
``error_class`` is an exception's class name.
"""

from __future__ import annotations

from dataclasses import dataclass, field
from typing import TYPE_CHECKING, Final

if TYPE_CHECKING:
    import sqlite3
    from collections.abc import Sequence

    from signal_bot.analytics.probe import UpstreamCall

OUTCOME_OK: Final = "ok"
OUTCOME_COOLDOWN: Final = "refused_cooldown"
OUTCOME_DAILY: Final = "refused_daily"
OUTCOME_VOTE: Final = "refused_vote"
OUTCOME_ERROR: Final = "error"
OUTCOME_UNKNOWN: Final = "unknown_word"

SOURCE_LIVE: Final = "live"
SOURCE_JOURNAL: Final = "journald"
SOURCE_DAILY: Final = "daily_uses"

# What ``args`` holds when a command took arguments that resolve to nothing
# nameable. Never the words themselves: a user-typed argument column is the
# exact shape that put real names in this repository once.
ARGS_PRESENT: Final = "+args"


@dataclass(frozen=True, slots=True)
class CommandEvent:
    """One attempt to run one command, whether or not it ran."""

    group_id: str
    user_uuid: str
    command: str
    outcome: str
    invoked_at_ms: int
    day: str
    local_hour: int
    weekday: int
    args: str = ""
    item_id: str | None = None
    error_class: str = ""
    # None rather than 0: a backfilled row has no duration, and zero
    # milliseconds is a lie that reads as data and would drag a p50 down.
    # The lesson is already written into backfill.UNKNOWN_HOUR's comment.
    handler_ms: int | None = None
    send_ms: int | None = None
    source: str = SOURCE_LIVE
    calls: Sequence[UpstreamCall] = field(default_factory=tuple)


class CommandEventStore:
    """Reads and writes the command history. Shares the Store's connection."""

    def __init__(self, conn: sqlite3.Connection) -> None:
        """Wrap an open connection whose schema has already been applied."""
        self._conn = conn

    @property
    def connection(self) -> sqlite3.Connection:
        """The shared connection, for the query modules in this package."""
        return self._conn

    def record(self, event: CommandEvent) -> None:
        """Append one attempt and the upstream calls it made.

        ``ON CONFLICT DO NOTHING`` against the natural key is what makes a
        signal-cli redelivery harmless, the same property ``message_events``
        gets from its primary key -- ``invoked_at_ms`` is the envelope's own
        timestamp, so a replayed frame collides with the row it already
        wrote instead of adding a second one.

        It is also what makes the backfill re-runnable, which is why the
        backfill needs no delete-then-rebuild pass and cannot lose rows to
        a journal that has since been vacuumed.
        """
        self._conn.execute(
            """
            INSERT INTO command_events (
                group_id, user_uuid, command, args, item_id, outcome,
                error_class, invoked_at_ms, day, local_hour, weekday,
                handler_ms, send_ms, source
            ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
            ON CONFLICT(group_id, user_uuid, command, invoked_at_ms, source)
            DO NOTHING
            """,
            (
                event.group_id,
                event.user_uuid,
                event.command,
                event.args,
                event.item_id,
                event.outcome,
                event.error_class,
                event.invoked_at_ms,
                event.day,
                event.local_hour,
                event.weekday,
                event.handler_ms,
                event.send_ms,
                event.source,
            ),
        )
        self._record_calls(event)
        self._conn.commit()

    def _record_calls(self, event: CommandEvent) -> None:
        """Append the upstream calls one invocation made.

        Keyed on (group, timestamp, seq) rather than on the parent's rowid.
        ``lastrowid`` is unusable here: ``ON CONFLICT DO NOTHING`` leaves it
        holding whatever the previous successful insert returned, so a
        replayed frame would file its calls under an unrelated invocation.
        """
        for seq, call in enumerate(event.calls):
            self._conn.execute(
                """
                INSERT INTO upstream_calls (
                    group_id, invoked_at_ms, command, host, status,
                    duration_ms, seq
                ) VALUES (?, ?, ?, ?, ?, ?, ?)
                ON CONFLICT(group_id, invoked_at_ms, seq) DO NOTHING
                """,
                (
                    event.group_id,
                    event.invoked_at_ms,
                    event.command,
                    call.host,
                    call.status,
                    call.ms,
                    seq,
                ),
            )