"""Generic, recipe-agnostic lifecycle assertions + op helpers (Phase 1d, plan §2.1).

These are THE default for each lifecycle op: when a recipe ships no `test_<op>.py` overlay, the
generic tier (tests/_generic/test_<op>.py) runs these against the single shared deployment the
orchestrator brought up. The lifecycle OPERATIONS (upgrade/backup/restore) live here too — owned by
the shared harness, not copy-pasted per recipe (DG7 DRY) — so overlays are assertions-only and may
reuse these by composition (`from harness import generic; generic.assert_serving(...)`).

Design + precedence: machine-docs/DECISIONS.md (Phase 1d).
"""

from __future__ import annotations

import glob
import os
import re
import socket
import ssl
import time

from . import lifecycle

# A recipe is backup-capable iff a compose file carries a truthy backupbot.backup label.
_BACKUPBOT_RE = re.compile(r"backupbot\.backup\b[^\n]*\btrue\b", re.IGNORECASE)


def _recipe_dir(recipe: str) -> str:
    return os.path.expanduser(f"~/.abra/recipes/{recipe}")


def backup_capable(recipe: str, meta: dict | None = None) -> bool:
    """Whether the harness should run the backup/restore tiers (else they are a clean N/A skip, DG3).

    `recipe_meta.BACKUP_CAPABLE` (bool) overrides; otherwise auto-detect by scanning the recipe's
    compose*.yml for a truthy `backupbot.backup` label (the Co-op Cloud backup convention)."""
    if meta and "BACKUP_CAPABLE" in meta:
        return bool(meta["BACKUP_CAPABLE"])
    for path in glob.glob(os.path.join(_recipe_dir(recipe), "compose*.yml")):
        try:
            with open(path) as fh:
                if _BACKUPBOT_RE.search(fh.read()):
                    return True
        except OSError:
            continue
    return False


def served_cert(domain: str, port: int = 443) -> tuple[bool, str]:
    """CA-verified TLS handshake to `domain` (via the gateway passthrough to cc-ci's Traefik).
    Returns (verified, detail) with CN+SAN on success, or the failure reason.

    Scope (per Adversary finding F1d-1): this is an INFRA TLS sanity check — it proves the served
    wildcard cert is publicly trusted, unexpired, and hostname-valid (so it would fail if the
    operator's LE wildcard lapsed/was mis-rotated — a real concern, plan §4.0 renewal). It does NOT
    distinguish a routed app from an un-routed host: Traefik's file provider serves the wildcard for
    the WHOLE `*.ci.commoninternet.net` zone, so any in-zone subdomain verifies whether or not an app
    is deployed. The app-vs-Traefik-fallback proof is `services_converged` + a non-404 status in
    `assert_serving`, not this."""
    ctx = ssl.create_default_context()  # verifies chain against system CAs + checks hostname
    try:
        with (
            socket.create_connection((domain, port), timeout=20) as sock,
            ctx.wrap_socket(sock, server_hostname=domain) as ssock,
        ):
            cert = ssock.getpeercert()
    except ssl.SSLCertVerificationError as e:
        return (False, f"cert did not verify (Traefik default/self-signed?): {e}")
    except (OSError, ssl.SSLError) as e:
        return (False, f"TLS handshake error: {e}")
    cn = next(
        (v for rdn in cert.get("subject", ()) for k, v in rdn if k == "commonName"),
        "",
    )
    sans = [v for typ, v in cert.get("subjectAltName", ()) if typ == "DNS"]
    return (True, f"CN={cn} SAN={sans}")


def assert_serving(domain: str, meta: dict) -> None:
    """The single generic "is the app really serving?" assertion (DG1).

    The app-vs-Traefik-fallback proof is steps 1+2 (both load-bearing, verified by the Adversary):
      1. every service in the stack converged (the app's OWN containers are N/N — an un-routed host
         has no app service, so this is False for a non-deployment);
      2. a real HTTP(S) response with a status in HEALTH_OK — which EXCLUDES 404, so a Traefik
         unmatched-router fallback (404) fails, as does a routed-but-dead backend (502/503);
      3. the body (from the SAME request as the status — no race) is not Traefik's default 404 page;
      4. an INFRA TLS sanity check (served_cert): the served wildcard cert is trusted+unexpired. This
         does NOT distinguish the app from an un-routed host (Traefik serves the wildcard zone-wide,
         F1d-1) — it only catches a lapsed/mis-rotated cert.

    Steps 1–2 are BOUNDED POLLS (no bare sleep), so a state-mutating op (upgrade/restore) that leaves
    the app briefly reconverging settles, while a persistent failure still fails within the timeout."""
    deadline = time.time() + meta["DEPLOY_TIMEOUT"]
    while time.time() < deadline and not lifecycle.services_converged(domain):
        time.sleep(5)
    assert lifecycle.services_converged(domain), f"{domain}: services did not converge"

    path = meta["HEALTH_PATH"]
    ok = tuple(meta["HEALTH_OK"])
    deadline = time.time() + meta["HTTP_TIMEOUT"]
    served = False
    status, body = 0, ""
    while time.time() < deadline:
        status, body = lifecycle.http_fetch(domain, path)
        if status in ok and not (status == 200 and "404 page not found" in body):
            served = True
            break
        time.sleep(5)
    assert served, (
        f"{domain}{path}: not serving — last HTTP {status} (Traefik 404 fallback, "
        "unhealthy backend, or default-404 body)"
    )

    # Infra TLS sanity only (F1d-1): catches a lapsed/mis-rotated wildcard cert; does NOT prove the
    # app is routed (Traefik serves the wildcard zone-wide). The serving proof is steps 1–2 above.
    verified, detail = served_cert(domain)
    assert verified, f"{domain}: served wildcard cert is not trusted/valid — {detail}"
    assert "commoninternet.net" in detail.lower(), f"{domain}: served cert unexpected — {detail}"


def do_upgrade(domain: str, target: str | None, meta: dict) -> None:
    """UPGRADE op (in place on the shared deployment): abra app upgrade -> target, then assert it
    reconverges + still serves AND that the deployment actually MOVED (version label and/or image
    changed). The move assertion guards against a vacuous no-op upgrade silently passing — the exact
    F1d-2 failure where a mis-pinned base deployed LATEST so 'upgrade to latest' changed nothing."""
    before = lifecycle.deployed_identity(domain)
    lifecycle.upgrade_app(domain, version=target)
    assert_serving(domain, meta)
    after = lifecycle.deployed_identity(domain)
    moved = (before[0] and after[0] and before[0] != after[0]) or (
        before[1] and after[1] and before[1] != after[1]
    )
    assert moved, (
        f"{domain}: upgrade did not move the deployment "
        f"(version {before[0]}->{after[0]}, image {before[1]}->{after[1]}) — "
        "not a real previous->target upgrade (DG2 must be non-vacuous)"
    )


_SNAPSHOT_ID_RE = re.compile(r'"snapshot_id"\s*:\s*"([0-9a-f]{8,})"')


def parse_snapshot_id(backup_output: str) -> str | None:
    """The snapshot id from `abra app backup create` output (restic JSON summary line). This IS the
    backup artifact identity (DG3) — read from the create output because `abra app backup snapshots`
    requires a TTY and is awkward to script."""
    m = _SNAPSHOT_ID_RE.search(backup_output)
    return m.group(1) if m else None


def do_backup(domain: str) -> str:
    """BACKUP op: create a backup, then assert a snapshot artifact was produced (returns its id)."""
    out = lifecycle.backup_app(domain)
    snap_id = parse_snapshot_id(out)
    assert snap_id, (
        f"{domain}: backup produced no snapshot artifact "
        "(no snapshot_id in `abra app backup create` output)"
    )
    return snap_id


def do_restore(domain: str, meta: dict) -> None:
    """RESTORE op: restore the latest snapshot, then assert the app is healthy + serving again
    (assert_serving polls, so the post-restore reconverge settles)."""
    lifecycle.restore_app(domain)
    assert_serving(domain, meta)