import os
import re
import smbclient

from db_py import (
    clear_tests,
    get_all_tests,
    mark_completed,
    set_coe_pair,
    set_p3p_pair,
    upsert_test,
)
from parser import (
    parse_elapsed_time,
    parse_result_filename,
    parse_target_filename,
    parse_timestamp,
    parse_tput_rssi,
)


_SMB_SESSIONS = set()


def _normalize_input_path(path_value):
    if not path_value:
        return path_value

    path = str(path_value).strip()

    # Accept //server/share style and normalize to UNC for smbclient.
    if path.startswith("//"):
        return "\\\\" + path.lstrip("/").replace("/", "\\")

    # Accept /<ipv4>/<share>/... and normalize to UNC for Linux-hosted inputs.
    if re.match(r"^/\d{1,3}(?:\.\d{1,3}){3}/[^/]+", path):
        return "\\\\" + path.lstrip("/").replace("/", "\\")

    return path


def _is_unc_path(path):
    return isinstance(path, str) and path.startswith("\\\\")


def _extract_unc_server(path):
    if not _is_unc_path(path):
        return None
    rest = path[2:]
    return rest.split("\\", 1)[0] if rest else None


def _register_smb_session_if_needed(path):
    if not _is_unc_path(path):
        return

    server = _extract_unc_server(path)
    if not server or server in _SMB_SESSIONS:
        return

    username = os.getenv("SMB_USERNAME", "").strip()
    password = os.getenv("SMB_PASSWORD", "")
    domain = os.getenv("SMB_DOMAIN", "").strip()

    if username and domain and "\\" not in username and "@" not in username:
        username = f"{domain}\\{username}"

    if username:
        smbclient.register_session(server, username=username, password=password)
    else:
        smbclient.register_session(server)

    _SMB_SESSIONS.add(server)


def _iter_dir_entries(path):
    path = _normalize_input_path(path)
    if _is_unc_path(path):
        _register_smb_session_if_needed(path)
        return list(smbclient.scandir(path))
    return list(os.scandir(path))


def _join_path(path, name):
    if _is_unc_path(path):
        base = path.rstrip("\\")
        return f"{base}\\{name}"
    return os.path.join(path, name)


def _read_text_lines(path):
    path = _normalize_input_path(path)
    if _is_unc_path(path):
        _register_smb_session_if_needed(path)
        with smbclient.open_file(path, mode="r", encoding="utf-8", errors="ignore") as fh:
            for line in fh:
                yield line
        return

    with open(path, "r", encoding="utf-8", errors="ignore") as fh:
        for line in fh:
            yield line


def scan_results_only(results_dir, results_dir_ref=None):
    """Re-scan only the results directories without clearing or re-scanning targets."""
    results_dir = _normalize_input_path(results_dir)
    results_dir_ref = _normalize_input_path(results_dir_ref)

    if not results_dir:
        return

    print(f"[scanner] results-only scan dir     : {results_dir}")
    if results_dir_ref:
        print(f"[scanner] results-only scan dir ref : {results_dir_ref}")

    scan_results(results_dir)
    if results_dir_ref:
        scan_results(results_dir_ref)
    update_p2p_coe_pairs()
    update_p3p_throttle_pairs()


def full_scan(target_dir, results_dir, results_dir_ref=None):
    target_dir = _normalize_input_path(target_dir)
    results_dir = _normalize_input_path(results_dir)
    results_dir_ref = _normalize_input_path(results_dir_ref)

    clear_tests()
    if not target_dir or not results_dir:
        return

    print(f"[scanner] target dir      : {target_dir}")
    print(f"[scanner] results dir     : {results_dir}")
    if results_dir_ref:
        print(f"[scanner] results dir ref : {results_dir_ref}")

    scan_targets(target_dir)
    scan_results(results_dir)
    if results_dir_ref:
        scan_results(results_dir_ref)
    update_p2p_coe_pairs()
    update_p3p_throttle_pairs()


def update_p2p_coe_pairs():
    pair_fields = [
        "device",
        "rotation",
        "test_point",
        "rssi",
        "station",
        "band",
        "channel",
        "bandwidth",
        "direction",
    ]

    tests = get_all_tests()
    coe_by_key = {}

    for test in tests:
        if test.get("interference") != "COE":
            continue

        key = tuple(test.get(field) for field in pair_fields)
        device = test.get("device")
        test_id = test.get("test_id")
        if not device or not test_id:
            continue

        coe_by_key.setdefault(key, []).append(f"{device}_{test_id}")

    updated = 0
    for test in tests:
        if test.get("interference") != "P2P":
            continue

        key = tuple(test.get(field) for field in pair_fields)
        pairs = sorted(set(coe_by_key.get(key, [])))
        set_coe_pair(test.get("id"), pairs)
        updated += 1

    print(f"[scanner] coe_pair updated for {updated} P2P test(s)")

def update_p3p_throttle_pairs():
    tests = get_all_tests()

    p3p_lookup = {}
    for test in tests:
        if test.get("interference") != "P3P":
            continue

        device = test.get("device")
        test_id = test.get("test_id")
        if not device or not test_id:
            continue

        p3p_lookup.setdefault(f"{str(device).upper()}_{str(test_id).upper()}", []).append(test)

    def _pair_test_id(test_id, throttled):
        if not test_id or not throttled:
            return None

        upper_id = str(test_id).upper()
        upper_throttled = str(throttled).upper()

        if upper_throttled == "TH":
            return re.sub("TH", "UT", upper_id, count=1)
        if upper_throttled == "UT":
            return re.sub("UT", "TH", upper_id, count=1)
        return None

    updated = 0
    for test in tests:
        if test.get("interference") != "P3P":
            continue

        device = test.get("device")
        test_id = test.get("test_id")
        pair_test_id = _pair_test_id(test_id, test.get("throttled"))

        pairs = []
        if device and pair_test_id:
            lookup_key = f"{str(device).upper()}_{str(pair_test_id).upper()}"
            matches = p3p_lookup.get(lookup_key, [])
            for match in matches:
                match_device = match.get("device")
                match_test_id = match.get("test_id")
                if match_device and match_test_id:
                    pairs.append(f"{match_device}_{match_test_id}")

        set_p3p_pair(test.get("id"), sorted(set(pairs)))
        updated += 1

    print(f"[scanner] p3p_pair updated for {updated} P3P test(s)")


def scan_targets(target_dir):
    target_dir = _normalize_input_path(target_dir)

    try:
        parent_entries = [
            entry.name
            for entry in _iter_dir_entries(target_dir)
            if entry.is_dir()
        ]
    except OSError as exc:
        print(f"[scanner] Cannot read target dir: {exc}")
        return

    print(f"[scanner] subdirectories found: {len(parent_entries)}")

    for parent_name in parent_entries:
        parent_path = _join_path(target_dir, parent_name)
        try:
            files = [
                entry.name
                for entry in _iter_dir_entries(parent_path)
                if entry.is_file()
                and not entry.name.startswith("GLOBAL")
                and entry.name.endswith(".ini")
            ]
        except OSError as exc:
            print(f"[scanner] Cannot read parent dir {parent_name}: {exc}")
            continue

        print(f"[scanner]   {parent_name} -> {len(files)} target test file(s)")

        for filename in files:
            parsed = parse_target_filename(filename, parent_name)
            if not parsed["test_id"]:
                print(f"[scanner] skip (no test_id): {parent_name}/{filename}")
                continue

            print(
                f"[scanner] found: {parent_name}/{filename}  ->  test_id={parsed['test_id']}"
            )
            upsert_test(
                {
                    "id": parsed["id"],
                    "test_id": parsed["test_id"],
                    "parent_dir": parent_name,
                    "filename": filename,
                    "interference": parsed["interference"],
                    "device": parsed["device"],
                    "rotation": parsed["rotation"],
                    "test_point": parsed["test_point"],
                    "station": parsed["station"],
                    "band": parsed["band"],
                    "channel": parsed["channel"],
                    "bandwidth": parsed["bandwidth"],
                    "rssi": parsed["rssi"],
                    "direction": parsed["direction"],
                    "throttled": parsed["throttled"],
                }
            )


def scan_results(results_dir):
    results_dir = _normalize_input_path(results_dir)

    try:
        entries = [
            entry.name
            for entry in _iter_dir_entries(results_dir)
            if entry.is_dir()
        ]
    except OSError as exc:
        print(f"[scanner] Cannot read results dir: {exc}")
        return

    print(f"[scanner] results: {len(entries)} result dir(s) found")
    for dir_name in entries:
        process_result_dir(results_dir, dir_name)


def process_result_dir(results_dir, result_dir_name):
    results_dir = _normalize_input_path(results_dir)

    parsed = parse_result_filename(result_dir_name)
    test_id = parsed["test_id"]
    device = parsed["device"]
    if not test_id or not device:
        return

    result_dir_path = _join_path(results_dir, result_dir_name)

    try:
        log_files = [
            entry.name
            for entry in _iter_dir_entries(result_dir_path)
            if entry.is_file()
            and entry.name.endswith(".txt")
            and test_id in entry.name
        ]
    except OSError as exc:
        print(f"[scanner] Cannot read result dir {result_dir_name}: {exc}")
        return

    if not log_files:
        print(f"[scanner] completed (no log yet): {test_id}")
        mark_completed(test_id, device, None, None)
        return

    latest_log = sorted(log_files)[-1]
    log_path = _join_path(result_dir_path, latest_log)
    completed_at = parse_timestamp(latest_log)
    data = extract_log_data(log_path)

    print(
        f"[scanner] completed: {test_id}  device={device}  "
        f"duration={data['duration_seconds']}s  stations={len(data['tputResults'])}  at={completed_at}"
    )
    mark_completed(
        test_id,
        device,
        completed_at,
        data["duration_seconds"],
        data["tputResults"],
    )


def parse_deleted_result_dir_name(dir_name):
    segments = re.split(r"[_\-]", dir_name)
    test_id = next((s for s in segments if re.match(r"^R\d+[A-Z0-9]+$", s, re.IGNORECASE)), None)
    device = next((s for s in segments if re.match(r"^CGW\d+$", s, re.IGNORECASE)), None)
    return test_id, device


def extract_log_data(log_file_path):
    elapsed_regex = re.compile(r"\[.*?INFO\]\s+Elapsed time\s*:\s*([\d]+:[\d]{2}:[\d]{2}\.[\d]+)")
    tput_regex = re.compile(
        r"\[.*?INFO\]\s+STA(\d+) over angles >> AVG IxChariot TPUT: (\d+) Mbps, AVG DL RSSI: (-?\d+) dBm, AVG UL RSSI: (-?\d+) dBm"
    )

    result = {"duration_seconds": None, "tputResults": []}
    try:
        for line in _read_text_lines(log_file_path):
            time_match = elapsed_regex.search(line)
            if time_match:
                result["duration_seconds"] = parse_elapsed_time(time_match.group(1))
                continue

            if tput_regex.search(line):
                parsed = parse_tput_rssi(line)
                if parsed:
                    result["tputResults"].append(parsed)
    except OSError as exc:
        print(f"[scanner] Cannot read log file {log_file_path}: {exc}")

    return result