package com.ruoyi.app.service;

import com.ruoyi.app.domain.AppBlogArticle;
import com.ruoyi.app.domain.AppResource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import java.util.List;

/**
 * Builds CDN image variants without persisting derived URLs in the database.
 */
@Component
public class ImageUrlService
{
    @Value("${app.image.cdn-domain:https://img.yidaima.cn}")
    private String cdnDomain;

    @Value("${app.image.article-card-operation:imageView2/1/w/600/h/375/format/webp/q/75/ignore-error/1}")
    private String articleCardOperation;

    @Value("${app.image.resource-card-operation:imageView2/1/w/500/h/400/format/webp/q/75/ignore-error/1}")
    private String resourceCardOperation;

    public void decorateArticles(List<AppBlogArticle> articles)
    {
        if (articles == null)
        {
            return;
        }
        for (AppBlogArticle article : articles)
        {
            decorateArticle(article);
        }
    }

    public AppBlogArticle decorateArticle(AppBlogArticle article)
    {
        if (article == null)
        {
            return null;
        }
        String originalUrl = normalizeOriginalUrl(article.getShowImg());
        article.setShowImg(originalUrl);
        article.setShowImgThumb(buildThumbnailUrl(originalUrl, articleCardOperation));
        decorateResource(article.getAppResource());
        return article;
    }

    public void decorateResources(List<AppResource> resources)
    {
        if (resources == null)
        {
            return;
        }
        for (AppResource resource : resources)
        {
            decorateResource(resource);
        }
    }

    public AppResource decorateResource(AppResource resource)
    {
        if (resource == null)
        {
            return null;
        }
        String originalUrl = normalizeOriginalUrl(resource.getShowImg());
        resource.setShowImg(originalUrl);
        resource.setShowImgThumb(buildThumbnailUrl(originalUrl, resourceCardOperation));
        return resource;
    }

    public String normalizeOriginalUrl(String originalUrl)
    {
        if (originalUrl == null)
        {
            return null;
        }
        String url = originalUrl.trim();
        String host = cdnHost();
        String httpPrefix = "http://" + host + "/";
        if (url.startsWith(httpPrefix))
        {
            return "https://" + url.substring("http://".length());
        }
        String protocolRelativePrefix = "//" + host + "/";
        if (url.startsWith(protocolRelativePrefix))
        {
            return "https:" + url;
        }
        return url;
    }

    private String buildThumbnailUrl(String originalUrl, String operation)
    {
        if (originalUrl == null || originalUrl.isEmpty())
        {
            return originalUrl;
        }
        String cdnPrefix = "https://" + cdnHost() + "/";
        if (!originalUrl.startsWith(cdnPrefix))
        {
            return originalUrl;
        }
        // Avoid corrupting signed or already processed URLs.
        if (originalUrl.indexOf('?') >= 0)
        {
            return originalUrl;
        }
        return originalUrl + "?" + operation;
    }

    private String cdnHost()
    {
        String value = cdnDomain == null ? "img.yidaima.cn" : cdnDomain.trim();
        if (value.startsWith("https://"))
        {
            value = value.substring("https://".length());
        }
        else if (value.startsWith("http://"))
        {
            value = value.substring("http://".length());
        }
        while (value.endsWith("/"))
        {
            value = value.substring(0, value.length() - 1);
        }
        return value;
    }
}