from __future__ import annotations

import asyncio
from pathlib import Path
from typing import AsyncGenerator
from urllib.parse import urlparse

import structlog

from src.models import SimplifyCommand
from src.models.constants import ARTICLE_NAME_INDEX, MIN_WIKI_PATH_PARTS, WIKI_PATH_INDEX


class FileSource:
    def __init__(self, file_path: str) -> None:
        self.file_path = Path(file_path)
        self.logger = structlog.get_logger().bind(source="file", path=str(self.file_path))

    async def read_urls(
        self, *, force_reprocess: bool = False
    ) -> AsyncGenerator[SimplifyCommand, None]:
        if not self.file_path.exists():
            msg = f"Файл с URL не найден: {self.file_path}"
            raise FileNotFoundError(msg)

        self.logger.info("Начинаем чтение URL из файла")

        content = await asyncio.to_thread(self._read_file_sync)

        seen_urls = set()
        valid_count = 0
        invalid_count = 0

        for line_num, original_line in enumerate(content.splitlines(), 1):
            line = original_line.strip()

            if not line or line.startswith("#"):
                continue

            if not self._is_valid_wikipedia_url(line):
                self.logger.warning("Невалидный URL", line_number=line_num, url=line)
                invalid_count += 1
                continue

            if line in seen_urls:
                self.logger.debug("Дубликат URL пропущен", line_number=line_num, url=line)
                continue

            seen_urls.add(line)
            valid_count += 1

            yield SimplifyCommand(url=line, force_reprocess=force_reprocess)

        self.logger.info(
            "Завершено чтение URL",
            valid_count=valid_count,
            invalid_count=invalid_count,
            total_unique=len(seen_urls),
        )

    def _read_file_sync(self) -> str:
        return self.file_path.read_text(encoding="utf-8")

    def _is_valid_wikipedia_url(self, url: str) -> bool:
        try:
            self.logger.info("Начинаем проверку URL", raw_url=url)

            parsed = urlparse(url)
            self.logger.info(
                "Разобранный URL", scheme=parsed.scheme, netloc=parsed.netloc, path=parsed.path
            )

            if parsed.scheme not in ("http", "https"):
                self.logger.info("Отклонено: неподдерживаемая схема", scheme=parsed.scheme, url=url)
                return False

            if "ruwiki" not in parsed.netloc:
                self.logger.info(
                    "Отклонено: домен не содержит 'ruwiki'", netloc=parsed.netloc, url=url
                )
                return False

            path_parts = parsed.path.split("/")
            self.logger.info("Части пути", path_parts=path_parts)

            if len(path_parts) < MIN_WIKI_PATH_PARTS:
                self.logger.info(
                    "Отклонено: слишком мало сегментов в пути", parts=path_parts, url=url
                )
                return False

            if path_parts[WIKI_PATH_INDEX] != "wiki":
                self.logger.info(
                    "Отклонено: неверный сегмент пути",
                    expected="wiki",
                    actual=path_parts[WIKI_PATH_INDEX],
                    url=url,
                )
                return False

            article_name = path_parts[ARTICLE_NAME_INDEX]
            self.logger.info("Извлечено имя статьи", article_name=article_name, url=url)

            if not article_name or article_name in ("Main_Page", "Заглавная_страница"):
                self.logger.info(
                    "Отклонено: некорректное имя статьи", article_name=article_name, url=url
                )
                return False

            self.logger.info("URL прошёл все проверки", url=url)
            return True

        except Exception as e:
            self.logger.info("Ошибка при проверке URL", error=str(e), url=url)
            return False

    async def count_urls(self) -> int:
        count = 0
        async for _ in self.read_urls():
            count += 1
        return count