use url::Url;

use crate::resolver::{BoxFuture, ResolveContext, Resolver};
use crate::types::MessageEmbed;
use crate::{EmbedKind, UnfurlError};

pub struct RegistryResolver;

impl Resolver for RegistryResolver {
    fn matches(&self, url: &Url) -> bool {
        crate::resolve::parse(url.as_str()).is_some()
    }

    fn resolve<'a>(
        &'a self,
        context: &'a ResolveContext<'_>,
    ) -> BoxFuture<'a, Result<Vec<MessageEmbed>, UnfurlError>> {
        Box::pin(async move {
            let resolved = crate::resolve::parse(context.url.as_str())
                .ok_or_else(|| UnfurlError::InvalidUrl("unknown platform".into()))?;
            let mut embed = MessageEmbed::from_resolved(&resolved);
            if resolved.kind == EmbedKind::Link
                && let Ok((final_url, page)) = super::page::resolve_page_final(context).await
            {
                // 短链落地页命中可直接内嵌的平台时，升级成播放器但保留原始 URL。
                if final_url != context.url
                    && let Some(landing) = crate::resolve::parse(final_url.as_str())
                    && landing.kind != EmbedKind::Link
                {
                    let mut upgraded = MessageEmbed::from_resolved(&landing);
                    upgraded.url = Some(context.original_url.to_string());
                    crate::normalize::normalize(&mut upgraded);
                    return Ok(vec![upgraded]);
                }
                if let Some(page) = page {
                    embed.title = page.title.or(embed.title);
                    embed.description = page.description.or(embed.description);
                    if embed.image.is_none() {
                        embed.image = page.image;
                        embed.image_url = page.image_url;
                    }
                    embed.author = page.author.or(embed.author);
                    embed.provider = page.provider.or(embed.provider);
                    embed.site_name = page.site_name.or(embed.site_name);
                    if page.html.is_some() {
                        embed.html = page.html;
                        embed.embed_type = page.embed_type;
                        embed.html_width = page.html_width;
                        embed.html_height = page.html_height;
                        embed.src = page.src;
                        embed.height = page.height;
                        embed.kind = page.kind;
                    }
                }
            }
            crate::normalize::normalize(&mut embed);
            Ok(vec![embed])
        })
    }
}