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

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

import logging

from flask import Blueprint, jsonify, request

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

logger = logging.getLogger(__name__)
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:
        logger.error("Failed to read DHCP config: %s", 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:
        logger.error("Failed to save DHCP config: %s", 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:
        logger.error("Failed to patch DHCP config: %s", exc)
        return _error(str(exc), 500)


@bp.route("/apply", methods=["POST"])
def apply_bp():
    try:
        apply_config()
        logger.info("dnsmasq config applied via API")
        return _ok(None)
    except RuntimeError as exc:
        logger.error("Failed to apply dnsmasq config: %s", exc)
        return _error(str(exc), 500)


# ---------------------------------------------------------------------------
# Status
# ---------------------------------------------------------------------------


@bp.route("/status", methods=["GET"])
def status_bp():
    try:
        from lib.dnsmasq import get_status as dnsmasq_status

        return _ok(dnsmasq_status())
    except RuntimeError as exc:
        logger.error("Failed to get DHCP status: %s", exc)
        return _error(str(exc), 500)


# ---------------------------------------------------------------------------
# DHCP ranges
# ---------------------------------------------------------------------------


@bp.route("/ranges", methods=["POST"])
def add_range_bp():
    body = request.get_json(silent=True) or {}
    iface = body.get("interface", "").strip() or None
    start = body.get("start", "").strip()
    end = body.get("end", "").strip()
    lease_time = body.get("lease_time", "12h")
    if not start or not end:
        return _error("'start' and 'end' are required", 400)
    try:
        set_dhcp_range(
            iface if iface else "",
            start,
            end,
            lease_time=lease_time,
        )
        logger.info("DHCP range added via API: %s-%s", start, end)
        return _ok(None)
    except RuntimeError as exc:
        logger.error("Failed to add DHCP range: %s", exc)
        return _error(str(exc), 500)


@bp.route("/ranges", methods=["DELETE"])
def remove_range_bp():
    body = request.get_json(silent=True) or {}
    iface = body.get("interface", "").strip() or ""
    start = body.get("start", "").strip()
    end = body.get("end", "").strip()
    if not start or not end:
        return _error("'start' and 'end' are required", 400)
    try:
        remove_dhcp_range(iface, start, end)
        logger.info("DHCP range removed via API: %s-%s", start, end)
        return _ok(None)
    except RuntimeError as exc:
        logger.error("Failed to remove DHCP range: %s", exc)
        return _error(str(exc), 500)


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


@bp.route("/leases", methods=["GET"])
def leases_bp():
    try:
        return _ok(get_lease_table())
    except RuntimeError as exc:
        logger.error("Failed to read lease table: %s", 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)
        logger.info("Static lease added via API: %s -> %s", mac, ip)
        return _ok({"mac": mac, "ip": ip, "hostname": hostname})
    except RuntimeError as exc:
        logger.error("Failed to add static lease: %s", exc)
        return _error(str(exc), 500)


@bp.route("/static-lease/<mac>", methods=["DELETE"])
def remove_static_lease_bp(mac):
    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)
        logger.info("Static lease removed via API: %s", mac)
        return _ok(None)
    except RuntimeError as exc:
        logger.error("Failed to remove static lease: %s", 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)
        logger.info("DNS record added via API: %s -> %s", name, address)
        return _ok({"name": name, "address": address, "hostname": hostname})
    except RuntimeError as exc:
        logger.error("Failed to add DNS record: %s", exc)
        return _error(str(exc), 500)


@bp.route("/dns-record/<name>", methods=["DELETE"])
def remove_dns_record_bp(name):
    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)
        logger.info("DNS record removed via API: %s", name)
        return _ok(None)
    except RuntimeError as exc:
        logger.error("Failed to remove DNS record: %s", exc)
        return _error(str(exc), 500)