"""Registry ops — k3d mode (local dev cluster).

Uses k3d's built-in registry or falls back to a plain Docker registry container.
"""
from __future__ import annotations

from pathlib import Path

from ._services_common import (
    _LogFn,
    _docker,
    _k3d,
    _log,
    _to_bool,
)


def _patch_k3d_registry_mirrors(
    registry_name: str,
    port: str,
    cluster_name: str = "knoe-dev-cluster",
    *,
    env: dict | None = None,
    log: _LogFn | None = None,
) -> None:
    """Write containerd mirror config for the k3d registry onto every cluster node.

    k3d nodes resolve `k3d-NAME.localhost:PORT` as 127.0.0.1 (loopback) which
    has nothing listening.  The registries.yaml mirror tells containerd to use the
    Docker-network DNS name of the registry container (`http://k3d-NAME:PORT`)
    instead, which works because all k3d containers share the same Docker network.

    After patching, each affected node is restarted so containerd picks up the new
    config.  This is idempotent — if the mirror entry is already present the node
    is left untouched.
    """
    import subprocess as _sp

    docker_name = f"k3d-{registry_name}"
    host_alias = f"{docker_name}.localhost:{port}"
    endpoint = f"http://{docker_name}:{port}"

    registries_yaml = (
        "mirrors:\n"
        f'  "{host_alias}":\n'
        "    endpoint:\n"
        f'      - "{endpoint}"\n'
    )

    node_result = _sp.run(
        ["k3d", "node", "list", "-o", "json"],
        capture_output=True,
        text=True,
        timeout=15,
    )
    import json

    try:
        nodes = json.loads(node_result.stdout or "[]")
    except Exception:
        nodes = []

    node_containers = [
        n.get("name") or ""
        for n in nodes
        if isinstance(n, dict)
        and n.get("role", "") not in ("loadbalancer", "registry")
        and (n.get("runtimeLabels") or {}).get("k3d.cluster") == cluster_name
    ]
    if not node_containers:
        # Fallback: get containers by Docker label (two separate queries for server+agent)
        for role in ("server", "agent"):
            r = _sp.run(
                ["docker", "ps", "--filter", f"label=k3d.cluster={cluster_name}",
                 "--filter", f"label=k3d.role={role}", "--format", "{{.Names}}"],
                capture_output=True, text=True, timeout=15,
            )
            node_containers += [n.strip() for n in r.stdout.splitlines() if n.strip()]

    cfg_path = "/etc/rancher/k3s/registries.yaml"
    restarted = []
    for container in node_containers:
        if not container:
            continue
        # Check if mirror is already configured
        check = _sp.run(
            ["docker", "exec", container, "cat", cfg_path],
            capture_output=True, text=True, timeout=10,
        )
        if check.returncode == 0 and host_alias in (check.stdout or ""):
            _log(log, f"[REGISTRY] Mirror already configured on {container}")
            continue
        _log(log, f"[REGISTRY] Patching containerd mirror config on {container}")
        _sp.run(
            ["docker", "exec", container, "mkdir", "-p", "/etc/rancher/k3s"],
            capture_output=True, timeout=10,
        )
        _sp.run(
            ["docker", "exec", "-i", container, "sh", "-c", f"cat > {cfg_path}"],
            input=registries_yaml, capture_output=True, text=True, timeout=15,
        )
        restarted.append(container)

    for container in restarted:
        _log(log, f"[REGISTRY] Restarting {container} to apply mirror config")
        _sp.run(["docker", "restart", container], capture_output=True, text=True, timeout=60)

    if restarted:
        import time
        _log(log, "[REGISTRY] Waiting for cluster nodes to recover after restart...")
        time.sleep(10)


def _k3d_registry_running(raw_list: str, name: str) -> bool:
    """Return True only if a line whose NAME ends with `name` has STATUS=running."""
    for line in raw_list.splitlines():
        parts = line.split()
        if not parts:
            continue
        # k3d may prefix the name with "k3d-"; match the suffix.
        if parts[0].endswith(name) and parts[-1].lower() == "running":
            return True
    return False


def _ensure_k3d_registry(*, env: dict | None = None, log: _LogFn | None = None) -> None:
    name = str((env or {}).get("K3D_REGISTRY_NAME") or "knoe-registry")
    port = str((env or {}).get("REGISTRY_PORT") or "5000")
    legacy_name = "prole-registry"

    listed = _k3d(["registry", "list"], env=env, timeout=60)
    raw = listed.stdout if listed.returncode == 0 else ""

    # Remove legacy prole-registry that may be squatting on the port.
    if legacy_name in raw:
        _log(log, f"[REGISTRY] Removing legacy k3d registry {legacy_name}")
        _k3d(["registry", "delete", legacy_name], env=env, timeout=60)
        listed = _k3d(["registry", "list"], env=env, timeout=60)
        raw = listed.stdout if listed.returncode == 0 else ""

    cluster_name = str((env or {}).get("K3D_CLUSTER_NAME") or "knoe-dev-cluster")

    if name in raw:
        if _k3d_registry_running(raw, name):
            _log(log, f"[REGISTRY] k3d registry {name} already running")
            _patch_k3d_registry_mirrors(name, port, cluster_name, env=env, log=log)
            return
        # Exists but not running (e.g. "created" — port was unavailable).
        _log(log, f"[REGISTRY] k3d registry {name} exists but not running; recreating")
        _k3d(["registry", "delete", name], env=env, timeout=60)

    _log(log, f"[REGISTRY] Creating k3d registry {name} on port {port}")
    created = _k3d(["registry", "create", name, "--port", f"{port}:{port}"], env=env, timeout=180)
    if created.returncode == 0:
        _patch_k3d_registry_mirrors(name, port, cluster_name, env=env, log=log)
        return

    # fallback docker registry
    _log(log, "[REGISTRY] k3d registry creation failed; trying docker registry fallback")
    running = _docker(["ps", "--format", "{{.Names}}"], env=env, timeout=30)
    if running.returncode == 0 and name in running.stdout.splitlines():
        return
    _docker(["rm", "-f", name], env=env, timeout=30)
    _docker(
        [
            "run",
            "-d",
            "--restart=always",
            "-p",
            f"{port}:5000",
            "--name",
            name,
            "registry:2",
        ],
        env=env,
        timeout=120,
        check=True,
    )


def initialize(
    *,
    namespace: str | None = None,
    env: dict | None = None,
    project_root: str | Path = ".",
    log: _LogFn | None = None,
    mode: str | None = None,
) -> None:
    update(namespace=namespace, env=env, project_root=project_root, log=log, mode=mode)


def start(
    *,
    namespace: str | None = None,
    env: dict | None = None,
    project_root: str | Path = ".",
    log: _LogFn | None = None,
    mode: str | None = None,
) -> None:
    update(namespace=namespace, env=env, project_root=project_root, log=log, mode=mode)


def update(
    *,
    namespace: str | None = None,
    env: dict | None = None,
    project_root: str | Path = ".",
    log: _LogFn | None = None,
    mode: str | None = None,
) -> None:
    _ensure_k3d_registry(env=env, log=log)


def stop(
    *,
    namespace: str | None = None,
    env: dict | None = None,
    mode: str | None = None,
    log: _LogFn | None = None,
) -> None:
    name = str((env or {}).get("K3D_REGISTRY_NAME") or "knoe-registry")
    _log(log, f"[REGISTRY] Removing k3d registry {name}")
    _k3d(["registry", "delete", name], env=env, timeout=120)
    _docker(["rm", "-f", name], env=env, timeout=30)


def restart(
    *,
    namespace: str | None = None,
    env: dict | None = None,
    mode: str | None = None,
    log: _LogFn | None = None,
) -> None:
    update(namespace=namespace, env=env, mode=mode, log=log)


def status(
    *,
    namespace: str | None = None,
    env: dict | None = None,
    mode: str | None = None,
) -> bool:
    name = str((env or {}).get("K3D_REGISTRY_NAME") or "knoe-registry")
    reg = _k3d(["registry", "list"], env=env, timeout=30)
    return _to_bool(reg.returncode == 0 and name in reg.stdout)