"""Flask web management panel for WinDHCPD."""

from __future__ import annotations

import logging
import threading
from typing import Optional

from flask import Flask, jsonify, request, render_template

from ..config import Config, StaticBinding
from ..lease import Lease, LeaseDB
from ..server import DHCPd

log = logging.getLogger("dhcpd.web")

app = Flask(__name__)

# ── global state (set by run.py) ────────────────────────────────────────
_server: Optional[DHCPd] = None
_config: Optional[Config] = None
_db: Optional[LeaseDB] = None


def init(srv: DHCPd, cfg: Config, db: LeaseDB) -> None:
    global _server, _config, _db
    _server = srv
    _config = cfg
    _db = db


def run(host: str, port: int) -> None:
    log.info("Web panel on http://%s:%d", host, port)
    app.run(host=host, port=port, threaded=True, debug=False)


# ── routes ──────────────────────────────────────────────────────────────

def _safe_db() -> LeaseDB:
    return _db  # type: ignore


@app.route("/")
def index():
    cfg = _config  # type: ignore
    db = _safe_db()
    srv = _server  # type: ignore
    leases = db.list_all() if db else []
    scopes = cfg.scopes if cfg else []
    return render_template("index.html",
                           scopes=scopes,
                           leases=leases,
                           stats=srv.stats if srv else {},
                           bindings=cfg.bindings if cfg else [],
                           count_active=db.count_active() if db else 0,
                           count_total=db.count() if db else 0,
                           )


@app.route("/api/leases")
def api_leases():
    db = _safe_db()
    leases = db.list_all() if db else []
    return jsonify([l.to_json() for l in leases])


@app.route("/api/leases/<mac>/release", methods=["POST"])
def api_release(mac: str):
    db = _safe_db()
    if db:
        db.release(mac)
    return jsonify({"ok": True})


@app.route("/api/leases/prune", methods=["POST"])
def api_prune():
    db = _safe_db()
    n = 0
    if db:
        n = db.prune_expired()
    return jsonify({"pruned": n})


@app.route("/api/scopes")
def api_scopes():
    cfg = _config  # type: ignore
    out = []
    for sc in cfg.scopes:
        out.append({
            "name": sc.name,
            "network": sc.network,
            "start_ip": str(sc.start_ip),
            "end_ip": str(sc.end_ip),
            "subnet_mask": sc.subnet_mask,
            "router": sc.router,
            "dns_servers": sc.dns_servers,
            "lease_seconds": sc.lease_seconds,
            "enable": sc.enable,
        })
    return jsonify(out)


@app.route("/api/stats")
def api_stats():
    srv = _server  # type: ignore
    db = _safe_db()
    stats: dict = {}
    if srv:
        stats.update(srv.stats)
    if db:
        stats["leases_total"] = db.count()
        stats["leases_active"] = db.count_active()
    return jsonify(stats)


@app.route("/api/bindings")
def api_bindings():
    cfg = _config  # type: ignore
    return jsonify([{"mac": b.mac_display, "ip": b.ip,
                     "scope": b.scope_name, "hostname": b.hostname}
                    for b in cfg.bindings])