"""A run's play recap in words (#5329, #5330): what the runs list says under a
run's status and what the run page says beside each host.

A run's `results` is {hosts: {name: {ok, changed, unreachable, failed,
skipped}}, failures: [...]}, parsed from the play recap. Model-free, so it is
unit-tested without a database.
"""
from __future__ import annotations

NAMES_SHOWN = 2


def _n(counts: dict | None, key: str) -> int:
    return int((counts or {}).get(key) or 0)


def _names(names: list[str]) -> str:
    """"a", "a and b", "a, b and 3 more"."""
    if len(names) <= NAMES_SHOWN:
        return " and ".join(names)
    return f"{', '.join(names[:NAMES_SHOWN])} and {len(names) - NAMES_SHOWN} more"


def run_recap(results: dict | None, check: bool = False) -> list[tuple[str, str | None]]:
    """A run's outcome across its hosts as (text, tone) parts, the worst
    first: "failed on web-1" (crit), "db-2 unreachable" (crit), "3 hosts",
    "2 changed" ("would change" for a dry run, which changed nothing).
    Empty when the run left no recap (it is still going, or died first)."""
    hosts = (results or {}).get("hosts") or {}
    if not hosts:
        return []
    failed = sorted(h for h, c in hosts.items() if _n(c, "failed"))
    unreachable = sorted(h for h, c in hosts.items() if _n(c, "unreachable") and h not in failed)
    changed = sum(1 for c in hosts.values() if _n(c, "changed"))
    parts: list[tuple[str, str | None]] = []
    if failed:
        parts.append((f"failed on {_names(failed)}", "crit"))
    if unreachable:
        parts.append((f"{_names(unreachable)} unreachable", "crit"))
    parts.append((f"{len(hosts)} host{'s' if len(hosts) != 1 else ''}", None))
    if changed:
        parts.append((f"{changed} would change" if check else f"{changed} changed", None))
    elif not failed and not unreachable:
        parts.append(("nothing to change" if check else "nothing changed", "muted"))
    return parts


def host_recap(counts: dict | None, check: bool = False) -> list[tuple[str, str | None]]:
    """One host's task counts as (text, tone) parts, zeros left out and the
    worst first: "unreachable", "1 failed", "3 ok", "1 changed", "2 skipped"."""
    parts: list[tuple[str, str | None]] = []
    if _n(counts, "unreachable"):
        parts.append(("unreachable", "crit"))
    if _n(counts, "failed"):
        parts.append((f"{_n(counts, 'failed')} failed", "crit"))
    if _n(counts, "ok"):
        parts.append((f"{_n(counts, 'ok')} ok", None))
    if _n(counts, "changed"):
        word = "would change" if check else "changed"
        parts.append((f"{_n(counts, 'changed')} {word}", None))
    if _n(counts, "skipped"):
        parts.append((f"{_n(counts, 'skipped')} skipped", "muted"))
    return parts