"""Characterization tests for the decomposed installer step orchestrators.

The 2026 decomposition turned the giant step functions into thin
orchestrators that call one named sub-function per concern. These tests pin
the call SEQUENCE of each orchestrator: a dropped, added, or reordered
sub-step call fails the test. They guard the wiring, not the sub-functions'
own behavior (those mutate the system and are exercised by the VM harness).

Method: sed-extract the orchestrator from the real `archsetup` (its body is
now just `display` + sub-function calls), source it with `display` silenced
and every sub-function replaced by a recorder that echoes its own name, run
it, and assert stdout is the expected ordered list.

Run from repo root:
    python3 -m unittest tests.installer-steps.test_orchestrators
"""

import os
import subprocess
import textwrap
import unittest


REPO_ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", ".."))
ARCHSETUP = os.path.join(REPO_ROOT, "archsetup")

# orchestrator -> exact ordered sub-step calls
ORCHESTRATORS = {
    "essential_services": [
        "configure_randomness", "configure_networking", "configure_power",
        "configure_ssh_server", "configure_fail2ban", "configure_firewall",
        "configure_service_discovery", "configure_job_scheduling",
        "configure_package_cache", "configure_snapshots",
        "configure_user_lingering",
    ],
    "prerequisites": [
        "bootstrap_pacman_keyring", "install_required_software",
        "configure_build_environment", "configure_package_mirrors",
    ],
    "developer_workstation": [
        "install_programming_languages", "install_editors",
        "install_android_utilities", "install_vpn_tools",
        "install_devops_utilities",
    ],
    "boot_ux": [
        "tighten_efi_permissions", "add_nvme_early_module",
        "configure_initramfs_hook", "configure_encrypted_autologin",
        "configure_tlp_power", "trim_firmware", "configure_grub",
    ],
    "user_customizations": [
        "clone_user_repos", "stow_dotfiles", "prune_waybar_battery",
        "refresh_desktop_caches", "configure_dconf_defaults",
        "finalize_dotfiles", "create_user_directories",
    ],
}


def run_orchestrator(func, stubs, extra_defs=""):
    """Source `func` from archsetup with `stubs` recording their names."""
    stub_defs = "\n".join(f"{s}() {{ echo {s}; }}" for s in stubs)
    script = textwrap.dedent(f"""\
        display() {{ :; }}
        {stub_defs}
        {extra_defs}
        source <(sed -n '/^{func}() {{/,/^}}/p' "{ARCHSETUP}")
        {func}
    """)
    result = subprocess.run(
        ["bash", "-c", script],
        capture_output=True, text=True, timeout=10,
    )
    return result


class OrchestratorSequence(unittest.TestCase):
    def test_each_orchestrator_calls_substeps_in_order(self):
        for func, expected in ORCHESTRATORS.items():
            with self.subTest(orchestrator=func):
                result = run_orchestrator(func, expected)
                self.assertEqual(result.returncode, 0, result.stderr)
                got = result.stdout.split()
                self.assertEqual(got, expected,
                                 f"{func} call sequence drifted")


class SnapshotDispatch(unittest.TestCase):
    """configure_snapshots branches on filesystem; pin each branch."""

    SUBS = ["configure_zfs_snapshots", "configure_btrfs_snapshots"]

    def test_zfs_root_runs_zfs_snapshots(self):
        result = run_orchestrator(
            "configure_snapshots", self.SUBS,
            extra_defs="is_zfs_root() { return 0; }\nis_btrfs_root() { return 1; }",
        )
        self.assertEqual(result.returncode, 0, result.stderr)
        self.assertEqual(result.stdout.split(), ["configure_zfs_snapshots"])

    def test_btrfs_root_runs_btrfs_snapshots(self):
        result = run_orchestrator(
            "configure_snapshots", self.SUBS,
            extra_defs="is_zfs_root() { return 1; }\nis_btrfs_root() { return 0; }",
        )
        self.assertEqual(result.returncode, 0, result.stderr)
        self.assertEqual(result.stdout.split(), ["configure_btrfs_snapshots"])

    def test_other_filesystem_runs_neither(self):
        result = run_orchestrator(
            "configure_snapshots", self.SUBS,
            extra_defs="is_zfs_root() { return 1; }\nis_btrfs_root() { return 1; }",
        )
        self.assertEqual(result.returncode, 0, result.stderr)
        self.assertEqual(result.stdout.split(), [])


if __name__ == "__main__":
    unittest.main()