use std::sync::LazyLock;

use super::StructuredPrinter;
use super::TagHandler;

use crate::common::get_tag_attr;
use crate::dummy::IdentityHandler;
use crate::markup5ever_rcdom;

use markup5ever_rcdom::Handle;
use regex::Regex;

/// Pattern that detects iframes with Youtube embedded videos<br/>
/// Examples:
/// * `https://www.youtube.com/embed/zE-dmXZp3nU?wmode=opaque`
/// * `https://www.youtube-nocookie.com/embed/5yo6exIypkY`
/// * `https://www.youtube.com/embed/TXm6IXrbQuM`
static YOUTUBE_PATTERN: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r"www\.youtube(?:-nocookie)?\.com/embed/([-\w]+)").unwrap());
/// Pattern that detects iframes with Instagram embedded photos<br/>
/// Examples:
/// * `https://www.instagram.com/p/B1BKr9Wo8YX/embed/`
/// * `https://www.instagram.com/p/BpKjlo-B4uI/embed/`
static INSTAGRAM_PATTERN: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r"www\.instagram\.com/p/([-\w]+)/embed").unwrap());
/// Patter that detects iframes with VKontakte embedded videos<br/>
/// Examples:
/// * `https://vk.com/video_ext.php?oid=-49423435&id=456245092&hash=e1611aefe899c4f8`
/// * `https://vk.com/video_ext.php?oid=-76477496&id=456239454&hash=ebfdc2d386617b97`
static VK_PATTERN: LazyLock<Regex> = LazyLock::new(|| {
    Regex::new(r"vk\.com/video_ext\.php\?oid=(-?\d+)&id=(\d+)&hash=(.*)").unwrap()
});
#[allow(dead_code)]
static YANDEX_MUSIC_TRACK_PATTERN: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r"https://music.yandex.ru/iframe/#track/(\d+)/(\d+)").unwrap());
#[allow(dead_code)]
static YANDEX_MUSIC_ALBUM_PATTERN: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r"https://music.yandex.ru/iframe/#album/(\d+)").unwrap());

#[derive(Default)]
pub struct IframeHandler;

impl TagHandler for IframeHandler {
    fn handle(&mut self, tag: &Handle, printer: &mut StructuredPrinter) {
        printer.insert_newline();
        printer.insert_newline();

        let src = get_tag_attr(tag, "src");
        //let width = get_tag_attr(tag, "width");
        //let height = get_tag_attr(tag, "height");

        if src.is_none() {
            return;
        }

        let src = src.unwrap();

        if let Some(capture) = YOUTUBE_PATTERN.captures(&src) {
            let media_id = capture.get(1).map_or("", |m| m.as_str());
            printer.append_str(&format!("[![Embedded YouTube video](https://img.youtube.com/vi/{mid}/0.jpg)](https://www.youtube.com/watch?v={mid})", mid = media_id));
            return;
        }

        if let Some(capture) = INSTAGRAM_PATTERN.captures(&src) {
            let media_id = capture.get(1).map_or("", |m| m.as_str());
            printer.append_str(&format!("[![Embedded Instagram post](https://www.instagram.com/p/{mid}/media/?size=m)](https://www.instagram.com/p/{mid}/embed/)", mid = media_id));
            return;
        }

        if let Some(capture) = VK_PATTERN.captures(&src) {
            let owner_id = capture.get(1).map_or("", |m| m.as_str());
            let video_id = capture.get(2).map_or("", |m| m.as_str());
            let _hash = capture.get(3).map_or("", |m| m.as_str());
            printer.append_str(&format!("[![Embedded VK video](https://st.vk.com/images/icons/video_empty_2x.png)](https://vk.com/video{oid}_{vid})", oid = owner_id, vid = video_id));
            return;
        }

        // not found, use generic implementation
        let mut identity = IdentityHandler;
        identity.handle(tag, printer);
    }

    fn after_handle(&mut self, printer: &mut StructuredPrinter) {
        printer.insert_newline();
        printer.insert_newline();
    }

    fn skip_descendants(&self) -> bool {
        true
    }
}
