"""scripts/backup/ps-backup.sh with a fake `docker` on PATH.

No Docker and no database: the fake answers `docker ps`, `docker exec ... pg_dump`, `pg_dumpall` and
`pg_restore --list`, and records every call. Runs on Linux (CI, docker-1) and on Windows when a
Git Bash or Cygwin bash with cygpath is installed; skipped otherwise.
"""

from __future__ import annotations

import os
import re
import shutil
import stat
import subprocess
import sys
from pathlib import Path

import pytest

REPO = Path(__file__).resolve().parents[2]
BACKUP = REPO / "scripts" / "backup" / "ps-backup.sh"
RESTORE = REPO / "scripts" / "backup" / "ps-restore.sh"
WINDOWS = sys.platform == "win32"

FAKE_DOCKER = r"""#!/usr/bin/env bash
# Fake docker for the backup script tests. Behaviour comes from FAKE_* variables.
printf '%s\n' "$*" >> "$FAKE_DOCKER_LOG"
cmd="$1"; shift
case "$cmd" in
  ps)
    if [[ -n "${FAKE_PS_IDS+x}" ]]; then
      [[ -n "$FAKE_PS_IDS" ]] && printf '%s\n' $FAKE_PS_IDS
    else
      echo pgfake
    fi
    exit 0 ;;
  exec)
    [[ "$1" == "-i" ]] && shift
    container="$1"; shift
    tool="$1"; shift
    case "$tool" in
      pg_dump)
        [[ "$container" == "${FAKE_DUMP_FAIL_CONTAINER:-none}" ]] && { echo "pg_dump: error: fake" >&2; exit 1; }
        [[ -n "${FAKE_DUMP_EMPTY:-}" ]] && exit 0
        printf 'PGDMP fake dump of %s\n' "$container"
        exit 0 ;;
      pg_dumpall)
        printf 'CREATE ROLE ps_app;\nALTER ROLE ps_app WITH LOGIN;\n'
        exit 0 ;;
      pg_restore)
        input="$(cat)"
        [[ -n "${FAKE_RESTORE_FAIL:-}" ]] && { echo "pg_restore: error: input file is too short" >&2; exit 1; }
        [[ "$input" == PGDMP* ]] || { echo "pg_restore: error: not a dump" >&2; exit 1; }
        printf ';\n; Archive created at 2026-10-21\n;\n215; 1259 16390 TABLE public packets ps_migrate\n'
        printf '3801; 0 16390 TABLE DATA public packets ps_migrate\n'
        exit 0 ;;
    esac ;;
esac
echo "fake docker: unexpected call: $cmd $*" >&2
exit 99
"""


def _find_bash() -> str | None:
    if not WINDOWS:
        return shutil.which("bash")
    candidates = [
        r"C:\Program Files\Git\bin\bash.exe",
        r"C:\Program Files\Git\usr\bin\bash.exe",
        shutil.which("bash") or "",
    ]
    for c in candidates:
        if not c or not Path(c).exists() or "system32" in c.lower():
            continue
        try:
            out = subprocess.run(
                [c, "-c", "cygpath -u 'C:\\' && command -v find stat mktemp"],
                capture_output=True,
                text=True,
                timeout=30,
            )
        except OSError:
            continue
        if out.returncode == 0:
            return c
    return None


BASH = _find_bash()
pytestmark = pytest.mark.skipif(BASH is None, reason="no usable bash (Linux bash, or Git Bash with cygpath)")


def _posix(p: Path) -> str:
    if not WINDOWS:
        return str(p)
    assert BASH is not None
    out = subprocess.run([BASH, "-c", 'cygpath -u "$1"', "_", str(p)], capture_output=True, text=True, check=True)
    return out.stdout.strip()


@pytest.fixture()
def fake(tmp_path: Path) -> dict[str, object]:
    bindir = tmp_path / "bin"
    bindir.mkdir()
    docker = bindir / "docker"
    docker.write_text(FAKE_DOCKER, encoding="utf-8", newline="\n")
    docker.chmod(docker.stat().st_mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)
    log = tmp_path / "docker.log"
    log.touch()
    env = {k: v for k, v in os.environ.items() if not k.startswith("FAKE_")}
    env["FAKE_DOCKER_LOG"] = _posix(log)
    env["DOCKER"] = _posix(docker)
    env["PATH"] = str(bindir) + os.pathsep + env.get("PATH", "")
    env.pop("KEEP", None)
    env.pop("PS_BACKUP_CONFIG", None)
    return {"env": env, "log": log, "tmp": tmp_path}


def run_backup(fake: dict[str, object], *args: str, **extra_env: str) -> subprocess.CompletedProcess[str]:
    env = dict(fake["env"])  # type: ignore[call-overload]
    env.update(extra_env)
    assert BASH is not None
    return subprocess.run([BASH, _posix(BACKUP), *args], capture_output=True, text=True, env=env, timeout=120)


def stack_args(name: str, folder: Path, container: str = "project:packetstation-test") -> list[str]:
    return ["--stack", name, container, "packetstation", _posix(folder)]


def dumps(folder: Path) -> list[str]:
    return sorted(p.name for p in folder.glob("ps-*.dump"))


def no_partials(folder: Path) -> bool:
    return not [p for p in folder.iterdir() if p.name.endswith(".partial")]


MARKER = re.compile(r"^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}Z (ps-\d{8}T\d{6}Z\.dump)(.*)$")


def test_success_writes_dump_globals_and_marker(fake: dict[str, object]) -> None:
    folder = fake["tmp"] / "backups"  # type: ignore[operator]
    res = run_backup(fake, *stack_args("test", folder))
    assert res.returncode == 0, res.stderr
    names = dumps(folder)
    assert len(names) == 1
    dump = folder / names[0]
    assert dump.read_text().startswith("PGDMP")
    globals_file = folder / names[0].replace(".dump", ".globals.sql")
    assert "CREATE ROLE" in globals_file.read_text()
    m = MARKER.match((folder / "last-success").read_text().strip())
    assert m and m.group(1) == names[0]
    assert not (folder / "last-failure").exists()
    assert no_partials(folder)
    if not WINDOWS:
        assert stat.S_IMODE(dump.stat().st_mode) == 0o600
        assert stat.S_IMODE(globals_file.stat().st_mode) == 0o600
        assert stat.S_IMODE((folder / "last-success").stat().st_mode) == 0o644
    calls = fake["log"].read_text()  # type: ignore[attr-defined]
    assert "label=com.docker.compose.project=packetstation-test" in calls
    assert "exec pgfake pg_dump -U postgres -d packetstation -Fc" in calls
    assert "pg_dumpall -U postgres --globals-only --no-role-passwords" in calls
    assert "exec -i pgfake pg_restore --list" in calls


def test_rotation_keeps_seven(fake: dict[str, object]) -> None:
    folder = fake["tmp"] / "backups"  # type: ignore[operator]
    folder.mkdir()
    old = [f"ps-202601{d:02d}T020000Z" for d in range(1, 9)]  # 8 older dumps
    for base in old:
        (folder / f"{base}.dump").write_text("PGDMP old")
        (folder / f"{base}.globals.sql").write_text("-- old")
    (folder / "ps-20251231T020000Z.globals.sql").write_text("-- orphan globals")
    res = run_backup(fake, *stack_args("test", folder))
    assert res.returncode == 0, res.stderr
    names = dumps(folder)
    assert len(names) == 7
    # The newest six old ones and today's stay; the two oldest go with their globals.
    assert names[:6] == [f"{b}.dump" for b in old[2:]]
    assert not (folder / f"{old[0]}.globals.sql").exists()
    assert not (folder / f"{old[1]}.globals.sql").exists()
    assert not (folder / "ps-20251231T020000Z.globals.sql").exists()
    assert sorted(p.name for p in folder.glob("*.globals.sql")) == [n.replace(".dump", ".globals.sql") for n in names]


def test_keep_is_configurable(fake: dict[str, object]) -> None:
    folder = fake["tmp"] / "backups"  # type: ignore[operator]
    folder.mkdir()
    for d in range(1, 5):
        (folder / f"ps-202601{d:02d}T020000Z.dump").write_text("PGDMP old")
    res = run_backup(fake, "--keep", "2", *stack_args("test", folder))
    assert res.returncode == 0, res.stderr
    assert len(dumps(folder)) == 2


def test_failed_restore_list_writes_last_failure(fake: dict[str, object]) -> None:
    folder = fake["tmp"] / "backups"  # type: ignore[operator]
    folder.mkdir()
    (folder / "ps-20260101T020000Z.dump").write_text("PGDMP old")
    (folder / "last-success").write_text("2026-01-01T02:00:05Z ps-20260101T020000Z.dump\n")
    res = run_backup(fake, *stack_args("test", folder), FAKE_RESTORE_FAIL="1")
    assert res.returncode != 0
    failure = (folder / "last-failure").read_text().strip()
    m = MARKER.match(failure)
    assert m, failure
    assert "pg_restore --list" in m.group(2)
    # Nothing new kept, nothing half-written, the old success left alone.
    assert dumps(folder) == ["ps-20260101T020000Z.dump"]
    assert not list(folder.glob("ps-*.globals.sql"))
    assert no_partials(folder)
    assert (folder / "last-success").read_text().startswith("2026-01-01")
    assert "FAILED" in res.stderr


def test_failed_pg_dump_and_empty_dump(fake: dict[str, object]) -> None:
    folder = fake["tmp"] / "backups"  # type: ignore[operator]
    res = run_backup(fake, *stack_args("test", folder, container="pgdirect"), FAKE_DUMP_FAIL_CONTAINER="pgdirect")
    assert res.returncode != 0
    assert "pg_dump failed" in (folder / "last-failure").read_text()
    assert dumps(folder) == []
    assert no_partials(folder)

    res = run_backup(fake, *stack_args("test", folder, container="pgdirect"), FAKE_DUMP_EMPTY="1")
    assert res.returncode != 0
    assert "pg_dump wrote nothing" in (folder / "last-failure").read_text()
    assert not (folder / "last-success").exists()


def test_no_container_for_project(fake: dict[str, object]) -> None:
    folder = fake["tmp"] / "backups"  # type: ignore[operator]
    res = run_backup(fake, *stack_args("test", folder), FAKE_PS_IDS="")
    assert res.returncode != 0
    assert "no running postgres container" in (folder / "last-failure").read_text()

    res = run_backup(fake, *stack_args("test", folder), FAKE_PS_IDS="aaa bbb")
    assert res.returncode != 0
    assert "more than one postgres container" in (folder / "last-failure").read_text()


def test_one_stack_fails_the_other_still_runs(fake: dict[str, object]) -> None:
    good = fake["tmp"] / "good"  # type: ignore[operator]
    bad = fake["tmp"] / "bad"  # type: ignore[operator]
    res = run_backup(
        fake,
        *stack_args("bad", bad, container="pgbad"),
        *stack_args("good", good, container="pggood"),
        FAKE_DUMP_FAIL_CONTAINER="pgbad",
    )
    assert res.returncode == 1
    assert (bad / "last-failure").exists() and not (bad / "last-success").exists()
    assert (good / "last-success").exists() and not (good / "last-failure").exists()
    assert len(dumps(good)) == 1


def test_config_file_and_stack_selection(fake: dict[str, object]) -> None:
    tmp: Path = fake["tmp"]  # type: ignore[assignment]
    a, b = tmp / "a", tmp / "b"
    conf = tmp / "backup.conf"
    conf.write_text(
        "# name container database folder\n"
        f"alpha  pga  packetstation  {_posix(a)}\n"
        "\n"
        f"beta   pgb  packetstation  {_posix(b)}\n",
        encoding="utf-8",
        newline="\n",
    )
    res = run_backup(fake, "--config", _posix(conf), "beta")
    assert res.returncode == 0, res.stderr
    assert not a.exists()
    assert len(dumps(b)) == 1

    res = run_backup(fake, "--config", _posix(conf), "gamma")
    assert res.returncode == 2

    res = run_backup(fake, "--config", _posix(tmp / "missing.conf"))
    assert res.returncode == 2


def test_scripts_are_strict_and_parse() -> None:
    assert BASH is not None
    for script in (BACKUP, RESTORE):
        text = script.read_text(encoding="utf-8")
        assert "\r" not in text
        assert "set -euo pipefail" in text
        assert "umask 077" in text
        res = subprocess.run([BASH, "-n", _posix(script)], capture_output=True, text=True)
        assert res.returncode == 0, res.stderr