"""
webui/api/dhcp.py - DHCP/DNS (dnsmasq) management API blueprint.

Exposed at /api/dhcp/* and delegates all operations to lib.dnsmasq.
"""

from flask import Blueprint, jsonify, request

from lib.dnsmasq import (
    add_dns_record,
    add_static_lease,
    apply_config,
    get_config,
    get_lease_table,
    remove_dns_record,
    remove_static_lease,
    save_config,
)

bp = Blueprint("dhcp", __name__)


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------


def _error(msg, code=400):
    return jsonify({"ok": False, "error": msg}), code


def _ok(data=None):
    return jsonify({"ok": True, "data": data})


def _deep_merge(base, overrides):
    result = dict(base)
    for k, v in overrides.items():
        if k in result and isinstance(result[k], dict) and isinstance(v, dict):
            result[k] = _deep_merge(result[k], v)
        else:
            result[k] = v
    return result


# ---------------------------------------------------------------------------
# Config
# ---------------------------------------------------------------------------


@bp.route("/config", methods=["GET"])
def get_config_bp():
    try:
        return _ok(get_config())
    except RuntimeError as exc:
        return _error(str(exc), 500)


@bp.route("/config", methods=["POST"])
def post_config():
    body = request.get_json(silent=True) or {}
    if not isinstance(body, dict):
        return _error("Request body must be a JSON object", 400)
    try:
        save_config(body)
        return _ok(None)
    except RuntimeError as exc:
        return _error(str(exc), 500)


@bp.route("/config", methods=["PATCH"])
def patch_config():
    body = request.get_json(silent=True) or {}
    if not isinstance(body, dict):
        return _error("Request body must be a JSON object", 400)
    try:
        current = get_config()
        merged = _deep_merge(current, body)
        save_config(merged)
        return _ok(None)
    except RuntimeError as exc:
        return _error(str(exc), 500)


@bp.route("/apply", methods=["POST"])
def apply_bp():
    try:
        apply_config()
        return _ok(None)
    except RuntimeError as exc:
        return _error(str(exc), 500)


# ---------------------------------------------------------------------------
# Leases
# ---------------------------------------------------------------------------


@bp.route("/leases", methods=["GET"])
def leases_bp():
    try:
        return _ok(get_lease_table())
    except RuntimeError as exc:
        return _error(str(exc), 500)


# ---------------------------------------------------------------------------
# Static leases
# ---------------------------------------------------------------------------


@bp.route("/static-lease", methods=["POST"])
def add_static_lease_bp():
    body = request.get_json(silent=True) or {}
    mac = body.get("mac", "").strip()
    ip = body.get("ip", "").strip()
    hostname = body.get("hostname")
    if not mac or not ip:
        return _error("'mac' and 'ip' are required", 400)
    try:
        add_static_lease(mac, ip, hostname)
        return _ok({"mac": mac, "ip": ip, "hostname": hostname})
    except RuntimeError as exc:
        return _error(str(exc), 500)


@bp.route("/static-lease", methods=["DELETE"])
def remove_static_lease_bp():
    mac = request.args.get("mac", "").strip()
    if not mac:
        return _error("Query parameter 'mac' is required", 400)
    current = get_config()
    found = any(
        lease["mac"].lower() == mac.lower()
        for lease in current.get("dhcp", {}).get("static_leases", [])
    )
    if not found:
        return _error(f"No static lease found for MAC '{mac}'", 404)
    try:
        remove_static_lease(mac)
        return _ok(None)
    except RuntimeError as exc:
        return _error(str(exc), 500)


# ---------------------------------------------------------------------------
# DNS records
# ---------------------------------------------------------------------------


@bp.route("/dns-record", methods=["POST"])
def add_dns_record_bp():
    body = request.get_json(silent=True) or {}
    name = body.get("name", "").strip()
    address = body.get("address", "").strip()
    hostname = body.get("hostname")
    if not name or not address:
        return _error("'name' and 'address' are required", 400)
    try:
        add_dns_record(name, address, hostname)
        return _ok({"name": name, "address": address, "hostname": hostname})
    except RuntimeError as exc:
        return _error(str(exc), 500)


@bp.route("/dns-record", methods=["DELETE"])
def remove_dns_record_bp():
    name = request.args.get("name", "").strip()
    if not name:
        return _error("Query parameter 'name' is required", 400)
    current = get_config()
    found = any(
        r["name"] == name for r in current.get("dns", {}).get("custom_records", [])
    )
    if not found:
        return _error(f"No DNS record found for '{name}'", 404)
    try:
        remove_dns_record(name)
        return _ok(None)
    except RuntimeError as exc:
        return _error(str(exc), 500)