"""CLI entry point for zkac-node."""

from __future__ import annotations

import argparse
import base64
import json
import sys

from . import client, store
from .paths import user_dir


def _is_loopback_host(host: str) -> bool:
    value = host.strip().lower()
    return value in {"127.0.0.1", "::1", "localhost"}


# ── user ──────────────────────────────────────────────────────────────

def _cmd_user_create(args):
    path = store.create_user(args.userid)
    ident = store.load_identity(args.userid)
    print(f"created user {args.userid!r}")
    print(f"  issuance public key: {ident['issuance_pk'].hex()}")
    print(f"  p2p transport public key: {ident['transport_pk'].hex()}")
    print(f"  (share this key out-of-band to receive credentials)")
    print(f"  stored in {path}")


def _cmd_user_list(_args):
    users = store.list_users()
    if not users:
        print("no users found")
        return
    for u in users:
        print(u)


def _cmd_user_show(args):
    ident = store.load_identity(args.userid)
    contact = store.export_contact_bundle(args.userid, peer=args.peer)
    print(f"user: {args.userid}")
    print(f"  issuance pk: {ident['issuance_pk'].hex()}")
    print(f"  p2p transport pk: {ident['transport_pk'].hex()}")
    print("  share contact:")
    print(f"    {contact}")
    if args.peer:
        print(f"  contact peer endpoint: {args.peer}")

    owned = [
        {"registry_id": r, **store.load_admin(args.userid, r)}
        for r in store.list_admin_registries(args.userid)
    ]
    if owned:
        print(f"  registries owned: {len(owned)}")
        for r in owned:
            print(f"    {r['registry_id']}  @ {r.get('server', '?')}  roles={r.get('roles', [])}")

    creds = store.list_credentials(args.userid)
    if creds:
        print(f"  credentials: {len(creds)}")
        for reg_hex, role in creds:
            print(f"    {reg_hex[:16]}… / {role}")


# ── serve ─────────────────────────────────────────────────────────────

def _cmd_serve(args):
    from .server import serve
    data_dir = args.data_dir
    if data_dir is None:
        data_dir = str(user_dir(args.userid) / "server")
    serve(
        data_dir,
        args.host,
        args.port,
        max_connections=args.max_connections,
        idle_timeout_s=args.idle_timeout,
        listen_backlog=args.listen_backlog,
        allow_non_loopback=args.allow_non_loopback,
    )


# ── server pin ───────────────────────────────────────────────────────

def _cmd_server_pin(args):
    pk_bytes = bytes.fromhex(args.key)
    store.pin_server(args.userid, args.server, base64.b64encode(pk_bytes).decode())
    print(f"pinned {args.server} for {args.userid} -> {args.key[:16]}…")


# ── registry ──────────────────────────────────────────────────────────

def _cmd_registry_create(args):
    roles = [r.strip() for r in args.roles.split(",")]
    rid = client.create_registry(args.userid, args.server, roles)
    print(f"registry created: {rid}")
    print(f"  roles: {', '.join(roles)}")


def _cmd_registry_update(args):
    add = [r.strip() for r in args.add_roles.split(",")]
    client.update_registry(args.userid, args.server, args.registry, add)
    print(f"registry updated: {args.registry[:16]}…")
    print(f"  added roles: {', '.join(add)}")


def _cmd_registry_get(args):
    info = client.get_registry(args.userid, args.server, args.registry)
    print(f"registry: {args.registry}")
    print(f"  state bytes: {len(info.get('state_bytes_b64', ''))} chars (b64)")


def _cmd_registry_list(args):
    regs = client.list_own_registries(args.userid)
    if not regs:
        print("no registries")
        return
    for r in regs:
        print(f"  {r['registry_id']}  @ {r['server']}  roles={r['roles']}")


def _cmd_registry_revoke(args):
    if args.all and args.role:
        raise RuntimeError("use either --role or --all, not both")
    if not args.all and not args.role:
        raise RuntimeError("missing target: pass --role <name> or --all")
    client.revoke_registry(
        args.userid,
        args.server,
        args.registry,
        role_name=None if args.all else args.role,
    )
    if args.all:
        print(f"registry revoked: {args.registry[:16]}…")
        print("  bumped epoch for all roles")
    else:
        print(f"registry revoked: {args.registry[:16]}…")
        print(f"  bumped epoch for role: {args.role}")


# ── grant ─────────────────────────────────────────────────────────────

def _cmd_grant(args):
    parsed = store.parse_contact_bundle(args.to)
    to = parsed["issuance_pk_hex"]
    peer_key = parsed["transport_pk_hex"]
    grant_token = parsed.get("grant_token_b64")
    peer = parsed.get("peer")
    if not grant_token:
        raise RuntimeError(
            "contact bundle is missing grant pairing token. "
            "Ask recipient to regenerate bundle with current CLI."
        )
    if not peer:
        raise RuntimeError(
            "contact bundle is missing peer endpoint. "
            "Ask recipient to regenerate with: zkac-node user show <userid> --peer <host:port>"
        )

    result = client.grant_p2p(
        args.userid, args.server, args.registry, args.role, to, grant_token, peer, peer_key,
    )
    print(f"granted {args.role!r} to {to[:16]}…")
    print(f"  delivery: direct p2p ({result['peer']})")


# ── credentials ─────────────────────────────────────────────────────

def _cmd_credentials_list(args):
    local = store.list_credentials(args.userid)
    print("local credentials:")
    if not local:
        print("  (none)")
    for reg_hex, role in local:
        print(f"  {reg_hex}:{role}")

    owned = store.list_admin_registries(args.userid)
    print("\nowner admin capability:")
    if not owned:
        print("  (none)")
    else:
        for reg_hex in owned:
            print(f"  {reg_hex}:__admin__ (reserved owner role)")


def _cmd_p2p_listen(args):
    if not _is_loopback_host(args.host):
        if not args.allow_non_loopback:
            raise RuntimeError(
                "refusing to bind p2p-listen outside loopback. "
                "Use --allow-non-loopback only when exposure is intentional."
            )
        print(f"warning: binding p2p-listen outside loopback: {args.host}:{args.port}", file=sys.stderr)
    print(f"listening for p2p grant on {args.host}:{args.port}")
    result = client.receive_p2p(args.userid, args.host, args.port, timeout_s=args.timeout)
    print("received credential")
    print(f"  registry: {result['registry_id']}")
    print(f"  role:     {result['role']}")


# ── auth ──────────────────────────────────────────────────────────────

def _cmd_auth(args):
    resp = client.authenticate(
        args.userid, args.registry, args.role, server=args.server,
    )
    print(json.dumps(resp, indent=2))


def _cmd_net_check(args):
    resp = client.net_check(
        args.target,
        timeout_s=args.timeout,
        handshake=args.handshake,
        userid=args.userid,
        server_key_hex=args.key,
    )
    if resp.get("ok"):
        print("network check: ok")
        print(f"  target: {resp['target']}")
        print(f"  via:    {resp['via']}")
        if args.handshake:
            print("  handshake: ok")
        return
    print("network check: failed")
    print(f"  target: {resp['target']}")
    print(f"  via:    {resp['via']}")
    print(f"  error:  {resp.get('error', 'unknown')}")
    sys.exit(2)


# ── argparse ─────────────────────────────────────────────────────────

def main():
    p = argparse.ArgumentParser(prog="zkac-node")
    sub = p.add_subparsers(dest="group", required=True)

    # user
    user_p = sub.add_parser("user", help="manage local user identities")
    user_sub = user_p.add_subparsers(dest="action", required=True)

    c = user_sub.add_parser("create", help="generate a new user identity")
    c.add_argument("userid")
    c.set_defaults(func=_cmd_user_create)

    c = user_sub.add_parser("list", help="list all local users")
    c.set_defaults(func=_cmd_user_list)

    c = user_sub.add_parser("show", help="show user keys + registries + credentials")
    c.add_argument("userid")
    c.add_argument("--peer", default=None, help="optional recipient p2p host:port to embed in contact bundle")
    c.set_defaults(func=_cmd_user_show)

    # serve
    c = sub.add_parser("serve", help="run as a ZKAC server node")
    c.add_argument("userid", help="user whose ~/.zkac/<userid>/server/ holds server state (unless --data-dir)")
    c.add_argument("--data-dir", default=None, help="override server data directory")
    c.add_argument("--host", default="127.0.0.1")
    c.add_argument("--port", type=int, default=9800)
    c.add_argument("--max-connections", type=int, default=64, help="max concurrent client connections")
    c.add_argument("--idle-timeout", type=float, default=45.0, help="per-connection idle timeout seconds")
    c.add_argument("--listen-backlog", type=int, default=64, help="TCP listen backlog")
    c.add_argument(
        "--allow-non-loopback",
        action="store_true",
        help="allow --host values outside loopback (default blocks non-loopback binds)",
    )
    c.set_defaults(func=_cmd_serve)

    # server pin
    srv_p = sub.add_parser("server", help="manage server pins")
    srv_sub = srv_p.add_subparsers(dest="action", required=True)

    c = srv_sub.add_parser("pin", help="pin a server's public key for a user")
    c.add_argument("userid")
    c.add_argument("server", help="host:port")
    c.add_argument("--key", required=True, help="server public key (hex)")
    c.set_defaults(func=_cmd_server_pin)

    # registry
    reg_p = sub.add_parser("registry", help="manage registries")
    reg_sub = reg_p.add_subparsers(dest="action", required=True)

    c = reg_sub.add_parser("create", help="create a new registry on a server")
    c.add_argument("userid")
    c.add_argument("server", help="host:port")
    c.add_argument("--roles", required=True, help="comma-separated role names")
    c.set_defaults(func=_cmd_registry_create)

    c = reg_sub.add_parser("update", help="add roles to a registry you own")
    c.add_argument("userid")
    c.add_argument("server", help="host:port")
    c.add_argument("--registry", required=True)
    c.add_argument("--add-roles", required=True, help="comma-separated new roles")
    c.set_defaults(func=_cmd_registry_update)

    c = reg_sub.add_parser("get", help="fetch registry state from server")
    c.add_argument("userid")
    c.add_argument("server", help="host:port")
    c.add_argument("--registry", required=True)
    c.set_defaults(func=_cmd_registry_get)

    c = reg_sub.add_parser("list", help="list locally owned registries")
    c.add_argument("userid")
    c.set_defaults(func=_cmd_registry_list)

    c = reg_sub.add_parser("revoke", help="revoke credentials by bumping role epoch(s)")
    c.add_argument("userid")
    c.add_argument("server", help="host:port")
    c.add_argument("--registry", required=True)
    c.add_argument("--role", default=None, help="revoke a single role by bumping its epoch")
    c.add_argument("--all", action="store_true", help="revoke all roles by bumping all epochs")
    c.set_defaults(func=_cmd_registry_revoke)

    # grant
    c = sub.add_parser("grant", help="issue a credential to a recipient (admin)")
    c.add_argument("userid")
    c.add_argument("--server", required=True, help="host:port")
    c.add_argument("--registry", required=True)
    c.add_argument("--role", required=True)
    c.add_argument("--to", required=True, help="recipient contact bundle")
    c.set_defaults(func=_cmd_grant)

    # credentials
    cred_p = sub.add_parser("credentials", help="local credentials")
    cred_sub = cred_p.add_subparsers(dest="action", required=True)
    c = cred_sub.add_parser("list", help="show local credentials")
    c.add_argument("userid")
    c.set_defaults(func=_cmd_credentials_list)

    # direct p2p receive
    c = sub.add_parser("p2p-listen", help="listen for one direct p2p credential grant")
    c.add_argument("userid")
    c.add_argument("--host", default="127.0.0.1")
    c.add_argument("--port", type=int, default=9810)
    c.add_argument("--timeout", type=float, default=60.0, help="max wait for authenticated sender")
    c.add_argument(
        "--allow-non-loopback",
        action="store_true",
        help="allow --host values outside loopback (default blocks non-loopback binds)",
    )
    c.set_defaults(func=_cmd_p2p_listen)

    # auth
    c = sub.add_parser("auth", help="authenticate with a credential")
    c.add_argument("userid")
    c.add_argument("--registry", required=True)
    c.add_argument("--role", required=True)
    c.add_argument("--server", default=None, help="host:port (optional if known from registry)")
    c.set_defaults(func=_cmd_auth)

    # network diagnostics
    net_p = sub.add_parser("net", help="network diagnostics")
    net_sub = net_p.add_subparsers(dest="action", required=True)
    c = net_sub.add_parser("check", help="test TCP reachability (direct or SOCKS5 proxy)")
    c.add_argument("target", help="host:port (supports .b32.i2p via SOCKS5)")
    c.add_argument("--timeout", type=float, default=8.0, help="connect timeout in seconds")
    c.add_argument("--handshake", action="store_true", help="also run anonymous ZKAC handshake")
    c.add_argument("--userid", default=None, help="client userid to load pinned server key for --handshake")
    c.add_argument("--key", default=None, help="server public key hex for --handshake")
    c.set_defaults(func=_cmd_net_check)

    args = p.parse_args()
    if not hasattr(args, "func"):
        p.print_help()
        sys.exit(1)
    args.func(args)


if __name__ == "__main__":
    main()