package com.example.datacollect.repository;

import com.example.datacollect.model.Article;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class ArticleRepository {
    private static final Logger logger = LoggerFactory.getLogger(ArticleRepository.class);
    private final List<Article> articles = new ArrayList<>();

    // 新增：根据索引获取文章（防御索引越界）
    public Article get(int index) {
        logger.debug("Getting article at index: {}", index);
        if (index < 0 || index >= articles.size()) {
            String errorMsg = "Index out of bounds: index=" + index + ", size=" + articles.size();
            logger.error(errorMsg);
            throw new IndexOutOfBoundsException(errorMsg);
        }
        return articles.get(index);
    }

    public void add(Article article) {
        logger.debug("Adding article: {}", article);
        if (article == null) {
            String errorMsg = "Article cannot be null";
            logger.error(errorMsg);
            throw new IllegalArgumentException(errorMsg);
        }
        // 新增：防御重复添加（可选）
        if (articles.contains(article)) {
            logger.warn("Article already exists: {}", article);
            return;
        }
        articles.add(article);
        logger.info("Added article: {}", article.getTitle());
    }

    // ★ 新增：批量添加方法以及注意防御 null
    public void addAll(List<Article> articles) {
        logger.debug("Adding batch articles, size: {}", articles == null ? "null" : articles.size());
        if (articles == null) {
            String errorMsg = "Articles list cannot be null";
            logger.error(errorMsg);
            throw new IllegalArgumentException(errorMsg);
        }
        if (articles.isEmpty()) {
            logger.warn("Articles list is empty, skip addAll");
            return;
        }
        int addedCount = 0;
        for (Article article : articles) {
            if (article == null) {
                logger.error("Skipping null article in batch add");
                continue; // 或抛出异常，根据业务选择
            }
            if (!this.articles.contains(article)) {
                this.articles.add(article);
                addedCount++;
            }
        }
        logger.info("Batch added {} articles (skipped duplicates/null)", addedCount);
    }

    public List<Article> getAll() {
        List<Article> unmodifiableList = Collections.unmodifiableList(articles);
        logger.debug("Getting all articles, size: {}", unmodifiableList.size());
        return unmodifiableList;
    }

    public int size() {
        int size = articles.size();
        logger.debug("Repository size: {}", size);
        return size;
    }

    // 新增：清空前校验 + 日志
    public void clear() {
        logger.warn("Clearing all articles (current size: {})", articles.size());
        if (articles.isEmpty()) {
            logger.info("Repository is already empty, skip clear");
            return;
        }
        articles.clear();
        logger.info("Cleared all articles successfully");
    }

    // 新增：检查是否包含指定URL的文章（防御检查）
    public boolean containsUrl(String url) {
        logger.debug("Checking if repository contains url: {}", url);
        if (url == null || url.isBlank()) {
            logger.error("URL cannot be null/blank");
            throw new IllegalArgumentException("URL cannot be null or blank");
        }
        return articles.stream().anyMatch(article -> url.equals(article.getUrl()));
    }
}