#!/usr/bin/env python3
import argparse
import datetime as dt
import json
import os
import re
import socket
import ssl
import subprocess
import sys
import time
import urllib.parse
import urllib.request


DOMAIN_RE = re.compile(r"^(?=.{1,253}$)(?!-)[A-Za-z0-9-]{1,63}(?<!-)(\.(?!-)[A-Za-z0-9-]{1,63}(?<!-))+$")
IPV4_RE = re.compile(r"^(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(?:\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}$")


def utc_now_iso():
    return dt.datetime.now(dt.timezone.utc).replace(microsecond=0).isoformat().replace("+00:00", "Z")


def read_json_file(path, default=None):
    if default is None:
        default = {}
    if not os.path.exists(path):
        return default
    with open(path, "r", encoding="utf-8") as f:
        return json.load(f)


def write_json_file(path, data):
    os.makedirs(os.path.dirname(path), exist_ok=True)
    with open(path, "w", encoding="utf-8") as f:
        json.dump(data, f, ensure_ascii=True, indent=2)


def write_text_file(path, data):
    os.makedirs(os.path.dirname(path), exist_ok=True)
    with open(path, "w", encoding="utf-8") as f:
        f.write(data)


def build_url(base_url, params):
    if not params:
        return base_url
    parsed = urllib.parse.urlparse(base_url)
    current = urllib.parse.parse_qs(parsed.query)
    for k, v in params.items():
        current[k] = [str(v)]
    query = urllib.parse.urlencode(current, doseq=True)
    return urllib.parse.urlunparse(parsed._replace(query=query))


def fetch_api_json(cfg):
    api = cfg["api"]
    url = build_url(api["url"], api.get("params", {}))
    method = api.get("method", "GET").upper()
    headers = api.get("headers", {})
    timeout = int(api.get("timeout_sec", 10))
    body_obj = api.get("body")
    body = None
    if body_obj is not None:
        body = json.dumps(body_obj).encode("utf-8")
        headers = {**headers, "Content-Type": "application/json"}

    req = urllib.request.Request(url=url, data=body, headers=headers, method=method)
    with urllib.request.urlopen(req, timeout=timeout) as resp:
        raw = resp.read().decode("utf-8", errors="replace")
    return json.loads(raw)


def flatten_values(value):
    out = []
    if isinstance(value, str):
        out.append(value)
    elif isinstance(value, list):
        for item in value:
            out.extend(flatten_values(item))
    elif isinstance(value, dict):
        for item in value.values():
            out.extend(flatten_values(item))
    return out


def get_by_json_path(data, path):
    cur = data
    for part in path.split("."):
        if isinstance(cur, dict) and part in cur:
            cur = cur[part]
        else:
            return None
    return cur


def get_values_by_path(data, path):
    parts = path.split(".")

    def walk(cur, idx):
        if idx >= len(parts):
            return [cur]

        part = parts[idx]
        if part.endswith("[]"):
            key = part[:-2]
            if isinstance(cur, dict):
                arr = cur.get(key)
            else:
                arr = None
            if not isinstance(arr, list):
                return []

            out = []
            for item in arr:
                out.extend(walk(item, idx + 1))
            return out

        if isinstance(cur, dict) and part in cur:
            return walk(cur[part], idx + 1)
        return []

    return walk(data, 0)


def parse_domains(payload, parser_cfg):
    domains = []

    for p in parser_cfg.get("field_paths", []):
        values = get_values_by_path(payload, p)
        domains.extend(flatten_values(values))

    for p in parser_cfg.get("json_paths", []):
        v = get_by_json_path(payload, p)
        if v is not None:
            domains.extend(flatten_values(v))

    if not domains:
        regex_s = parser_cfg.get("regex", r"[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}")
        text = json.dumps(payload, ensure_ascii=True)
        domains.extend(re.findall(regex_s, text))

    clean = []
    seen = set()
    for d in domains:
        d = d.strip().lower().rstrip(".")
        if (DOMAIN_RE.match(d) or IPV4_RE.match(d)) and d not in seen:
            seen.add(d)
            clean.append(d)
    return clean


def parse_created_time(s):
    if not s:
        return None
    try:
        return dt.datetime.strptime(str(s).strip(), "%Y-%m-%d %H:%M:%S").replace(tzinfo=dt.timezone.utc)
    except Exception:
        return None


def parse_scored_records(payload, scoring_cfg):
    if not scoring_cfg.get("enabled", False):
        return []

    records_path = scoring_cfg.get("records_path", "data.good[]")
    ip_field = scoring_cfg.get("ip_field", "ip")
    created_time_field = scoring_cfg.get("created_time_field", "createdTime")
    score_fields = scoring_cfg.get("score_fields", ["avgScore", "ydScore", "dxScore", "ltScore"])

    raw_records = get_values_by_path(payload, records_path)
    out = []
    for r in raw_records:
        if not isinstance(r, dict):
            continue
        domain = str(r.get(ip_field, "")).strip().lower().rstrip(".")
        if not domain:
            continue
        created = parse_created_time(r.get(created_time_field))
        scores = []
        for f in score_fields:
            v = r.get(f)
            try:
                scores.append(float(v))
            except Exception:
                scores.append(float("inf"))
        out.append(
            {
                "domain": domain,
                "created_at": created,
                "created_raw": r.get(created_time_field),
                "scores": scores,
            }
        )
    return out


def rank_scored_records(records, scoring_cfg):
    if not records:
        return []

    within_hours = float(scoring_cfg.get("within_hours", 24))
    prefer_lower = bool(scoring_cfg.get("prefer_lower", True))
    use_api_order = bool(scoring_cfg.get("use_api_order", False))

    now = dt.datetime.now(dt.timezone.utc)
    cutoff = now - dt.timedelta(hours=within_hours)

    recent = [r for r in records if r.get("created_at") is not None and r["created_at"] >= cutoff]
    candidates = recent if recent else records

    if use_api_order:
        seen = set()
        ordered = []
        for r in candidates:
            d = r["domain"]
            if d in seen:
                continue
            seen.add(d)
            ordered.append(r)
        return ordered

    def key_lower(r):
        return tuple(r["scores"] + [r["domain"]])

    def key_higher(r):
        return tuple([-x if x != float("inf") else float("inf") for x in r["scores"]] + [r["domain"]])

    ranked = sorted(candidates, key=key_lower if prefer_lower else key_higher)
    return ranked


def apply_filter(domains, filter_cfg):
    include_suffixes = [s.lower() for s in filter_cfg.get("include_suffixes", []) if s]
    exclude_regex = [re.compile(x) for x in filter_cfg.get("exclude_regex", []) if x]

    out = []
    for d in domains:
        if include_suffixes and not any(d.endswith(s) for s in include_suffixes):
            continue
        if any(rx.search(d) for rx in exclude_regex):
            continue
        out.append(d)
    return out


def single_tls_check(domain, timeout_ms, port, tls_verify=True):
    start = time.perf_counter()
    timeout_sec = max(0.2, timeout_ms / 1000.0)
    try:
        infos = socket.getaddrinfo(domain, port, proto=socket.IPPROTO_TCP)
        if not infos:
            return False, None, "dns_empty"

        af, socktype, proto, _, sockaddr = infos[0]
        with socket.socket(af, socktype, proto) as sock:
            sock.settimeout(timeout_sec)
            sock.connect(sockaddr)
            if tls_verify:
                ctx = ssl.create_default_context()
            else:
                ctx = ssl._create_unverified_context()
            with ctx.wrap_socket(sock, server_hostname=domain) as ssock:
                ssock.do_handshake()

        elapsed = int((time.perf_counter() - start) * 1000)
        return True, elapsed, "ok"
    except Exception as e:
        return False, None, str(e)


def check_domains(domains, hc_cfg):
    attempts = int(hc_cfg.get("attempts", 2))
    timeout_ms = int(hc_cfg.get("timeout_ms", 1800))
    port = int(hc_cfg.get("port", 443))
    tls_verify = bool(hc_cfg.get("tls_verify", True))

    results = []
    for d in domains:
        ok_count = 0
        latencies = []
        errors = []
        for _ in range(attempts):
            ok, latency, err = single_tls_check(d, timeout_ms, port, tls_verify=tls_verify)
            if ok:
                ok_count += 1
                latencies.append(latency)
            else:
                errors.append(err)

        success_ratio = ok_count / attempts if attempts else 0.0
        avg_latency = int(sum(latencies) / len(latencies)) if latencies else 999999
        results.append(
            {
                "domain": d,
                "success_ratio": success_ratio,
                "avg_latency_ms": avg_latency,
                "ok_count": ok_count,
                "attempts": attempts,
                "errors": errors[:3],
            }
        )

    results.sort(key=lambda x: (-x["success_ratio"], x["avg_latency_ms"], x["domain"]))
    return results


def render_v2ray(template_file, output_file, token, domain):
    if not template_file or not output_file:
        return False
    if not os.path.exists(template_file):
        return False
    with open(template_file, "r", encoding="utf-8") as f:
        tpl = f.read()
    rendered = tpl.replace(token, domain)
    os.makedirs(os.path.dirname(output_file), exist_ok=True)
    with open(output_file, "w", encoding="utf-8") as f:
        f.write(rendered)
    return True


def run_notify(cmd, domain, status):
    if not cmd:
        return
    env = os.environ.copy()
    env["AUTODOMAIN"] = domain
    env["AUTODOMAIN_STATUS"] = status
    subprocess.run(cmd, shell=True, check=False, env=env)


def choose_domain(filtered_domains, check_results, top_n, ranked_scored):
    if ranked_scored:
        domains_by_score = [x["domain"] for x in ranked_scored]

        if check_results:
            check_map = {x["domain"]: x for x in check_results}
            top = []
            for d in domains_by_score:
                if d in check_map and check_map[d]["success_ratio"] > 0:
                    top.append(check_map[d])
                if len(top) >= top_n:
                    break
            if top:
                return top[0]["domain"], top

            score_only = [{"domain": x["domain"], "scores": x["scores"], "created_raw": x["created_raw"]} for x in ranked_scored[:top_n]]
            return score_only[0]["domain"], score_only

        top_scored = [{"domain": x["domain"], "scores": x["scores"], "created_raw": x["created_raw"]} for x in ranked_scored[:top_n]]
        if top_scored:
            return top_scored[0]["domain"], top_scored

    if check_results:
        top = [x for x in check_results if x["success_ratio"] > 0][:top_n]
        if top:
            return top[0]["domain"], top
        return None, check_results[:top_n]
    if filtered_domains:
        return filtered_domains[0], [{"domain": x} for x in filtered_domains[:top_n]]
    return None, []


def main():
    ap = argparse.ArgumentParser(description="Auto select VMess preferred domain")
    ap.add_argument("--config", default="config.json", help="Path to config JSON")
    args = ap.parse_args()

    config_path_abs = os.path.abspath(args.config)
    if not os.path.exists(config_path_abs):
        print(json.dumps({"status": "error", "error": f"config file not found: {config_path_abs}"}, ensure_ascii=True), file=sys.stderr)
        sys.exit(1)

    cfg = read_json_file(config_path_abs)
    output_cfg = cfg.get("output", {})
    runtime_dir_cfg = output_cfg.get("runtime_dir", "./runtime")
    if os.path.isabs(runtime_dir_cfg):
        runtime_dir = runtime_dir_cfg
    else:
        runtime_dir = os.path.normpath(os.path.join(os.path.dirname(config_path_abs), runtime_dir_cfg))
    v2_cfg = cfg.get("v2ray", {})
    notify_cfg = cfg.get("notify", {})

    current_domain_file = os.path.join(runtime_dir, output_cfg.get("current_domain_file", "current_domain.txt"))
    current_domain_json = os.path.join(runtime_dir, output_cfg.get("current_domain_json", "current_domain.json"))
    state_file = os.path.join(runtime_dir, output_cfg.get("state_file", "state.json"))
    substore_vars_file = os.path.join(runtime_dir, output_cfg.get("substore_vars_file", "substore_vars.json"))

    state = read_json_file(state_file, default={})
    last_good = state.get("last_good_domain", "")

    try:
        payload = fetch_api_json(cfg)
        parsed = parse_domains(payload, cfg.get("parser", {}))
        filtered = apply_filter(parsed, cfg.get("domain_filter", {}))

        scored_records = parse_scored_records(payload, cfg.get("scoring", {}))
        scored_records = [r for r in scored_records if r["domain"] in set(filtered)]
        ranked_scored = rank_scored_records(scored_records, cfg.get("scoring", {}))

        check_results = []
        if cfg.get("healthcheck", {}).get("enabled", True):
            check_results = check_domains(filtered, cfg.get("healthcheck", {}))

        top_n = int(cfg.get("selection", {}).get("top_n", 3))
        selected, top_candidates = choose_domain(filtered, check_results, top_n, ranked_scored)

        status = "ok"
        if not selected and last_good:
            selected = last_good
            status = "fallback_last_good"
        if not selected:
            raise RuntimeError("No valid domain available from API and no fallback in state")

        write_text_file(current_domain_file, selected + "\n")

        current_json = {
            "domain": selected,
            "updated_at": utc_now_iso(),
            "status": status,
            "source_count": len(parsed),
            "checked_count": len(check_results),
            "top_candidates": top_candidates,
        }
        write_json_file(current_domain_json, current_json)
        write_json_file(
            substore_vars_file,
            {
                "AUTO_DOMAIN": selected,
                "UPDATED_AT": current_json["updated_at"],
                "STATUS": status,
            },
        )

        rendered = render_v2ray(
            template_file=v2_cfg.get("template_file", ""),
            output_file=v2_cfg.get("output_file", ""),
            token=v2_cfg.get("replace_token", "__AUTO_DOMAIN__"),
            domain=selected,
        )

        new_state = {
            "updated_at": current_json["updated_at"],
            "last_good_domain": selected,
            "status": status,
            "source_count": len(parsed),
            "checked_count": len(check_results),
            "rendered_v2ray": rendered,
        }
        write_json_file(state_file, new_state)

        run_notify(notify_cfg.get("command", ""), selected, status)
        print(json.dumps(current_json, ensure_ascii=True))

    except Exception as e:
        now = utc_now_iso()
        err_state = {
            "updated_at": now,
            "status": "error",
            "error": str(e),
            "last_good_domain": last_good,
        }
        write_json_file(state_file, err_state)

        if last_good:
            write_text_file(current_domain_file, last_good + "\n")
            write_json_file(
                current_domain_json,
                {
                    "domain": last_good,
                    "updated_at": now,
                    "status": "error_use_last_good",
                    "error": str(e),
                },
            )
            run_notify(notify_cfg.get("command", ""), last_good, "error_use_last_good")
            print(json.dumps({"status": "error_use_last_good", "error": str(e)}, ensure_ascii=True))
            return

        print(json.dumps({"status": "error", "error": str(e)}, ensure_ascii=True), file=sys.stderr)
        sys.exit(1)


if __name__ == "__main__":
    main()