use crate::routes::posts;
use std::collections::HashMap;
use xml::escape::escape_str_pcdata;

pub struct RssEntry {
    pub title: String,
    pub link: String,
    pub description: Option<String>,
    pub created_at: String,
    pub author: String,
    pub guid: String,
}

impl From<posts::Post> for RssEntry {
    fn from(post: posts::Post) -> Self {
        let web_url =
            std::env::var("BASE_URI_WEB").expect("Environment variable BASE_URI_WEB not found");
        let post_url = format!("{}{}{}", web_url, "/posts/", post.post_id.to_string());
        let author_full_name = format!("{} {}", post.first_name.unwrap(), post.last_name.unwrap());

        Self {
            title: post.title.clone(),
            link: post_url.clone(),
            description: Some(post.body.clone()),
            created_at: post
                .created_at
                .expect("No timestamp was available")
                .to_rfc2822(),
            author: author_full_name,
            guid: post_url.clone(),
        }
    }
}

impl RssEntry {
    pub fn to_item(&self) -> String {
        format!(
            r#"
            <item>
                <title><![CDATA[{}]]></title>
                <description><![CDATA[{}]]></description>
                <pubDate>{}</pubDate>
                <link>{}</link>
                <guid isPermaLink="true">{}</guid>
            </item>
            "#,
            self.title,
            self.description.clone().unwrap_or_default(),
            self.created_at,
            self.guid,
            self.guid
        )
    }
}

pub fn generate_rss(
    title: &str,
    description: &str,
    link: &str,
    posts: &HashMap<String, posts::Post>,
) -> String {
    let values = posts.clone().into_values();
    let rss_entries = values
        .map(|p| p.into())
        .map(|r: RssEntry| r.to_item())
        .collect::<String>();

    let safe_title = escape_str_pcdata(title);
    let safe_description = escape_str_pcdata(description);

    // TODO: change the atom link in this string - it's not correct
    // change it when we know the URL
    format!(
        r#"<?xml version="1.0" encoding="UTF-8"?>
            <rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
                <channel>
                  <title>{safe_title}</title>
                    <description>{safe_description}</description>
                    <link>{link}</link>
                    <language>en-us</language>
                    <ttl>60</ttl>
                    <generator>Kyouma 1.0.0-SE</generator>
                    <atom:link href="https://wyattjmiller.com/posts.xml" rel="self" type="application/rss+xml" />
                    {}
                </channel>
            </rss>"#,
        rss_entries
    )
}