#!/usr/bin/env python3
# -*- coding: utf-8 -*-

"""
Общие вспомогательные функции HTML Report.

В этом модуле не должно быть SQL-запросов.

Только:

    • форматирование
    • HTML escaping
    • работа с файлами
    • чтение CSV
    • чтение gps_track.nmea
    • вычисления
"""

from __future__ import annotations

import csv
import html
import os

from datetime import datetime, timezone
from pathlib import Path
from zoneinfo import ZoneInfo

from .config import TIMEZONE


# ============================================================
# HTML
# ============================================================


def esc(value) -> str:
    """
    Безопасный вывод значения в HTML.
    """

    if value is None:
        return ""

    return html.escape(str(value))


# ============================================================
# Значение по умолчанию
# ============================================================


def safe(value, default="-"):

    if value is None:
        return default

    if value == "":
        return default

    return value


# ============================================================
# Размер файла
# ============================================================


def format_size(size):

    if size is None:
        return "-"

    size = float(size)

    units = [
        "B",
        "KB",
        "MB",
        "GB",
        "TB"
    ]

    for unit in units:

        if size < 1024:

            return f"{size:.1f} {unit}"

        size /= 1024

    return f"{size:.1f} PB"


def file_size(path):

    path = Path(path)

    if not path.exists():

        return "-"

    return format_size(
        path.stat().st_size
    )


# ============================================================
# Дата / время
# ============================================================


def parse_datetime(text):
    if not text:
        return None

    try:
        dt = datetime.fromisoformat(text)

        #
        # Старые записи проекта хранят UTC
        # как naive datetime.
        #
        if dt.tzinfo is None:
            dt = dt.replace(
                tzinfo=timezone.utc
            )

        return dt

    except Exception:
        return None


def format_datetime(
    text,
    output_format="%d.%m.%Y %H:%M:%S"
):
    dt = parse_datetime(text)

    if dt is None:
        return safe(text)

    display_timezone = ZoneInfo(TIMEZONE)

    return dt.astimezone(
        display_timezone
    ).strftime(
        output_format
    )


def format_duration(start, end):

    start = parse_datetime(start)

    end = parse_datetime(end)

    if start is None:

        return "-"

    if end is None:

        return "-"

    delta = end - start

    seconds = int(
        delta.total_seconds()
    )

    hours = seconds // 3600

    minutes = (
        seconds % 3600
    ) // 60

    seconds = seconds % 60

    return (
        f"{hours:02}:{minutes:02}:{seconds:02}"
    )


# Совместимость со старым кодом
duration = format_duration

# ============================================================
# CSV
# ============================================================


def read_csv(filename):

    filename = Path(filename)

    if not filename.exists():

        return []

    with open(
        filename,
        newline="",
        encoding="utf-8",
        errors="ignore"
    ) as f:

        reader = csv.DictReader(f)

        return list(reader)


# ============================================================
# Текстовый файл
# ============================================================


def read_lines(filename):

    filename = Path(filename)

    if not filename.exists():

        return []

    with open(
        filename,
        encoding="utf-8",
        errors="ignore"
    ) as f:

        return [
            line.rstrip()
            for line in f
        ]


# ============================================================
# gps_track.nmea
# ============================================================


def read_nmea(filename):

    """
    Читает gps_track.nmea.

    Формат строки:

    2026-07-16T12:47:51.938726;$GPRMC,...

    Возвращает:

    [
        (
            datetime,
            "$GPRMC,..."
        ),
        ...
    ]
    """

    result = []

    filename = Path(filename)

    if not filename.exists():

        return result

    with open(
        filename,
        encoding="utf-8",
        errors="ignore"
    ) as f:

        for line in f:

            line = line.strip()

            if not line:

                continue

            if ";" not in line:

                continue

            timestamp, sentence = line.split(
                ";",
                1
            )

            dt = parse_datetime(
                timestamp
            )

            if dt is None:

                continue

            result.append(
                (
                    dt,
                    sentence
                )
            )

    return result


# ============================================================
# Каталог
# ============================================================


def list_directories(path):

    path = Path(path)

    if not path.exists():

        return []

    return sorted(

        [
            item

            for item in path.iterdir()

            if item.is_dir()
        ]

    )


# ============================================================
# Список файлов
# ============================================================


def list_files(path):

    path = Path(path)

    if not path.exists():

        return []

    return sorted(

        [
            item

            for item in path.iterdir()

            if item.is_file()
        ]

    )


# ============================================================
# Проверка существования
# ============================================================


def exists(path):

    return Path(path).exists()


# ============================================================
# Имя файла
# ============================================================


def filename(path):

    return Path(path).name


# ============================================================
# Имя каталога
# ============================================================


def dirname(path):

    return Path(path).parent.name


# ============================================================
# Последнее изменение
# ============================================================


def modified(path):
    path = Path(path)

    if not path.exists():
        return "-"

    display_timezone = ZoneInfo(TIMEZONE)

    return datetime.fromtimestamp(
        path.stat().st_mtime,
        timezone.utc,
    ).astimezone(
        display_timezone
    ).strftime(
        "%d.%m.%Y %H:%M:%S"
    )


# ============================================================
# Количество строк файла
# ============================================================


def line_count(filename):

    filename = Path(filename)

    if not filename.exists():

        return 0

    with open(
        filename,
        encoding="utf-8",
        errors="ignore"
    ) as f:

        return sum(
            1
            for _ in f
        )