"""
Workload deploy and pod/deployment readiness fixtures for CI/tests_v2.
"""

import logging
import time
from pathlib import Path

import pytest
import yaml
from kubernetes import utils as k8s_utils
from kubernetes.client.rest import ApiException

from lib.base import READINESS_TIMEOUT
from lib.utils import patch_namespace_in_docs

logger = logging.getLogger(__name__)


def wait_for_deployment_replicas(k8s_apps, namespace: str, name: str, timeout: int = 120) -> None:
    """
    Poll until the deployment has ready_replicas >= spec.replicas.
    Raises TimeoutError with diagnostic details on failure.
    """
    deadline = time.monotonic() + timeout
    last_dep = None
    attempts = 0
    while time.monotonic() < deadline:
        try:
            dep = k8s_apps.read_namespaced_deployment(name=name, namespace=namespace)
        except Exception as e:
            logger.debug("Deployment %s/%s poll attempt %s failed: %s", namespace, name, attempts, e)
            time.sleep(2)
            attempts += 1
            continue
        last_dep = dep
        ready = dep.status.ready_replicas or 0
        desired = dep.spec.replicas or 1
        if ready >= desired:
            logger.debug("Deployment %s/%s ready (%s/%s)", namespace, name, ready, desired)
            return
        logger.debug("Deployment %s/%s not ready yet: %s/%s", namespace, name, ready, desired)
        time.sleep(2)
        attempts += 1
    diag = ""
    if last_dep is not None and last_dep.status:
        diag = f" ready_replicas={last_dep.status.ready_replicas}, desired={last_dep.spec.replicas}"
    raise TimeoutError(
        f"Deployment {namespace}/{name} did not become ready within {timeout}s.{diag}"
    )


def deployment_exists(k8s_apps, namespace: str, name: str) -> bool:
    """Return True if the named deployment exists in the namespace, False on 404."""
    try:
        k8s_apps.read_namespaced_deployment(name=name, namespace=namespace)
        return True
    except ApiException as e:
        if e.status == 404:
            return False
        raise


def wait_for_no_deployment(k8s_apps, namespace: str, name: str, timeout: int = 45) -> None:
    """Poll until the named deployment is gone from the namespace; raise if it persists."""
    deadline = time.monotonic() + timeout
    while time.monotonic() < deadline:
        if not deployment_exists(k8s_apps, namespace, name):
            return
        time.sleep(1)
    raise AssertionError(
        f"Deployment {name} still present in namespace={namespace} after {timeout}s"
    )


def service_exists(k8s_core, namespace: str, name: str) -> bool:
    """Return True if the named service exists in the namespace, False on 404."""
    try:
        k8s_core.read_namespaced_service(name=name, namespace=namespace)
        return True
    except ApiException as e:
        if e.status == 404:
            return False
        raise


def wait_for_no_service(k8s_core, namespace: str, name: str, timeout: int = 45) -> None:
    """Poll until the named service is gone from the namespace; raise if it persists."""
    deadline = time.monotonic() + timeout
    while time.monotonic() < deadline:
        if not service_exists(k8s_core, namespace, name):
            return
        time.sleep(1)
    raise AssertionError(
        f"Service {name} still present in namespace={namespace} after {timeout}s"
    )


def wait_for_present_deployment_count(
    k8s_apps, namespaces, name: str, expected: int, timeout: int = 45
) -> list:
    """
    Poll until exactly `expected` of the given namespaces still contain the named deployment.
    Returns the namespaces where it is still present. Useful for delete_count assertions.
    """
    deadline = time.monotonic() + timeout
    # Snapshot once so a one-shot iterable (e.g. generator) is not exhausted by the
    # first poll, which would make every subsequent iteration see an empty list.
    ns_list = list(namespaces)
    present = list(ns_list)
    while time.monotonic() < deadline:
        present = [n for n in ns_list if deployment_exists(k8s_apps, n, name)]
        if len(present) == expected:
            return present
        time.sleep(1)
    raise AssertionError(
        f"Expected {expected} namespace(s) with {name} present, "
        f"found {len(present)}: {present}"
    )


def deploy_manifest_to_namespace(
    k8s_client,
    k8s_apps,
    manifest,
    namespace: str,
    deployment_name: str,
    *,
    repo_root=None,
    timeout: int = READINESS_TIMEOUT,
) -> None:
    """
    Apply a manifest file into `namespace` (overriding each doc's namespace) and wait for the
    named deployment to become ready. `manifest` may be absolute or relative to repo_root.
    Reusable by any scenario that needs to seed a namespace with a target workload.
    """
    path = Path(manifest)
    if not path.is_absolute() and repo_root is not None:
        path = Path(repo_root) / path
    docs = patch_namespace_in_docs(list(yaml.safe_load_all(path.read_text())), namespace)
    try:
        k8s_utils.create_from_yaml(k8s_client, yaml_objects=docs, namespace=namespace)
    except k8s_utils.FailToCreateError as e:
        msgs = [str(exc) for exc in e.api_exceptions]
        raise RuntimeError(
            f"Failed to create resources in namespace={namespace}: {'; '.join(msgs)}"
        ) from e
    wait_for_deployment_replicas(k8s_apps, namespace, deployment_name, timeout=timeout)


@pytest.fixture
def wait_for_pods_running(k8s_core):
    """
    Poll until all matching pods are Running and all containers ready.
    Uses exponential backoff: 1s, 2s, 4s, ... capped at 10s.
    Raises TimeoutError with diagnostic details on failure.
    """

    def _wait(namespace: str, label_selector: str, timeout: int = READINESS_TIMEOUT):
        deadline = time.monotonic() + timeout
        interval = 1.0
        max_interval = 10.0
        last_list = None
        while time.monotonic() < deadline:
            try:
                pod_list = k8s_core.list_namespaced_pod(
                    namespace=namespace,
                    label_selector=label_selector,
                )
            except Exception:
                time.sleep(min(interval, max_interval))
                interval = min(interval * 2, max_interval)
                continue
            last_list = pod_list
            items = pod_list.items or []
            if not items:
                time.sleep(min(interval, max_interval))
                interval = min(interval * 2, max_interval)
                continue
            all_running = all(
                (p.status and p.status.phase == "Running") for p in items
            )
            if not all_running:
                time.sleep(min(interval, max_interval))
                interval = min(interval * 2, max_interval)
                continue
            all_ready = True
            for p in items:
                if not p.status or not p.status.container_statuses:
                    all_ready = False
                    break
                for cs in p.status.container_statuses:
                    if not getattr(cs, "ready", False):
                        all_ready = False
                        break
            if all_ready:
                return
            time.sleep(min(interval, max_interval))
            interval = min(interval * 2, max_interval)

        diag = ""
        if last_list and last_list.items:
            p = last_list.items[0]
            diag = f" e.g. pod {p.metadata.name}: phase={getattr(p.status, 'phase', None)}"
        raise TimeoutError(
            f"Pods in {namespace} with label {label_selector} did not become ready within {timeout}s.{diag}"
        )

    return _wait


@pytest.fixture(scope="function")
def deploy_workload(test_namespace, k8s_client, wait_for_pods_running, repo_root, tmp_path):
    """
    Helper that applies a manifest into the test namespace and waits for pods.
    Yields a callable: deploy(manifest_path_or_content, label_selector, *, is_path=True)
    which applies the manifest, waits for readiness, and returns the namespace name.
    """

    def _deploy(manifest_path_or_content, label_selector, *, is_path=True, timeout=READINESS_TIMEOUT):
        try:
            if is_path:
                path = Path(manifest_path_or_content)
                if not path.is_absolute():
                    path = repo_root / path
                with open(path) as f:
                    docs = list(yaml.safe_load_all(f))
            else:
                docs = list(yaml.safe_load_all(manifest_path_or_content))
            docs = patch_namespace_in_docs(docs, test_namespace)
            k8s_utils.create_from_yaml(
                k8s_client,
                yaml_objects=docs,
                namespace=test_namespace,
            )
        except k8s_utils.FailToCreateError as e:
            msgs = [str(exc) for exc in e.api_exceptions]
            raise RuntimeError(f"Failed to create resources: {'; '.join(msgs)}") from e
        logger.info("Workload applied in namespace=%s, waiting for pods with selector=%s", test_namespace, label_selector)
        wait_for_pods_running(test_namespace, label_selector, timeout=timeout)
        logger.info("Pods ready in namespace=%s", test_namespace)
        return test_namespace

    return _deploy