use std::{
    sync::{Arc, LazyLock},
    time::Duration,
};

use anyhow::Context;
use reqwest::Url;
use scraper::{Html, Selector};
use tokio::sync::RwLock;
use tracing::instrument;

use super::{
    Media,
    cached::{MediaCache, cache_or_fetch, try_cache_or_fetch},
};

pub async fn fetch() -> anyhow::Result<Media> {
    static FIRST_ENTRY_SEL: LazyLock<Selector> =
        LazyLock::new(|| Selector::parse(".journal_entry:first-child").unwrap());
    static NAME_SEL: LazyLock<Selector> =
        LazyLock::new(|| Selector::parse(".game-name a").unwrap());
    static IMAGE_SEL: LazyLock<Selector> = LazyLock::new(|| Selector::parse(".card-img").unwrap());
    static PLATFORM_SEL: LazyLock<Selector> =
        LazyLock::new(|| Selector::parse(".journal-platform").unwrap());
    static URL_SEL: LazyLock<Selector> =
        LazyLock::new(|| Selector::parse("a:has(.fa-arrow-right)").unwrap());

    let page_url = Url::parse("https://backloggd.com/u/cherryfunk/journal")
        .context("wrote invalid Backloggd URL")?;
    let html = reqwest::get(page_url.clone())
        .await
        .context("failed to fetch Backloggd page")?
        .text()
        .await
        .context("failed to get HTML text")?;
    let document = Html::parse_document(&html);

    let first_entry = document
        .select(&FIRST_ENTRY_SEL)
        .next()
        .context("couldn't find any journal entries")?;
    let name = first_entry
        .select(&NAME_SEL)
        .next()
        .context("couldn't find name element")?
        .text()
        .next()
        .context("name element didn't have any text")?
        .to_owned();
    let image = first_entry
        .select(&IMAGE_SEL)
        .next()
        .context("couldn't find image element")?
        .attr("src")
        .context("image element didn't have src attribute")?
        .to_owned();
    let platform = first_entry
        .select(&PLATFORM_SEL)
        .next()
        .context("couldn't find platform element")?
        .text()
        .next()
        .context("platform element didn't have any text")?
        .to_owned();
    let url = first_entry
        .select(&URL_SEL)
        .next()
        .context("couldn't find log URL element")?
        .attr("href")
        .context("log anchor didn't have a URL")?
        .to_owned();
    let url = page_url.join(&url).context("log URL was invalid")?;

    Ok(Media {
        name,
        image,
        context: platform,
        url: url.into(),
    })
}

static CACHE: LazyLock<MediaCache> = LazyLock::new(|| Arc::new(RwLock::new(None)));
static TTL: Duration = Duration::from_secs(300);
#[instrument(name = "backlogged_try_cached_fetch")]
pub fn try_cached_fetch() -> Option<Media> {
    try_cache_or_fetch(&CACHE, TTL, fetch)
}
#[instrument(name = "backlogged_cached_fetch")]
pub async fn cached_fetch() -> Option<Media> {
    cache_or_fetch(&CACHE, TTL, fetch).await
}