use crate::DbPool;
use crate::api::ClientVersion;
use crate::providers::{Provider, report_provider_error, requester_or_default};
use crate::status::*;
use crate::util::cache::VideoCache;
use crate::util::parse_abbreviated_number;
use crate::util::time::parse_time_to_seconds;
use crate::videos::{ServerOptions, VideoItem};
use async_trait::async_trait;
use error_chain::error_chain;
use htmlentity::entity::{ICodedDataTrait, decode};
use regex::Regex;
use std::collections::HashSet;

pub const CHANNEL_METADATA: crate::providers::ProviderChannelMetadata =
    crate::providers::ProviderChannelMetadata {
        group_id: "mainstream-tube",
        tags: &["tube", "viral", "mixed"],
    };

error_chain! {
    foreign_links {
        Io(std::io::Error);
        HttpRequest(wreq::Error);
    }
}

#[derive(Debug, Clone)]
pub struct ViralxxxpornProvider {
    url: String,
}

impl ViralxxxpornProvider {
    pub fn new() -> Self {
        Self {
            url: "https://viralxxxporn.com".to_string(),
        }
    }

    fn build_channel(&self, _clientversion: ClientVersion) -> Channel {
        Channel {
            id: "viralxxxporn".to_string(),
            name: "Viralxxxporn".to_string(),
            description: "Latest viral porn videos.".to_string(),
            premium: false,
            favicon: "https://www.google.com/s2/favicons?sz=64&domain=viralxxxporn.com".to_string(),
            status: "active".to_string(),
            categories: vec![],
            options: vec![],
            nsfw: true,
            cacheDuration: Some(1800),
        }
    }

    fn build_latest_url(&self, page: u32) -> String {
        format!(
            "{}/latest-updates/?mode=async&function=get_block&block_id=list_videos_latest_videos_list&sort_by=post_date&from={page}",
            self.url
        )
    }

    fn build_latest_headers(&self) -> Vec<(String, String)> {
        vec![(
            "Referer".to_string(),
            format!("{}/latest-updates/", self.url),
        )]
    }

    fn build_search_path_query(query: &str, separator: &str) -> String {
        query.split_whitespace().collect::<Vec<_>>().join(separator)
    }

    fn build_search_url(&self, query: &str, page: u32) -> String {
        let query_param = Self::build_search_path_query(query, "+");
        let path_query = Self::build_search_path_query(query, "-");
        format!(
            "{}/search/{path_query}/?mode=async&function=get_block&block_id=list_videos_videos_list_search_result&q={query_param}&from_videos={page}",
            self.url
        )
    }

    fn build_search_headers(&self, query: &str) -> Vec<(String, String)> {
        let path_query = Self::build_search_path_query(query, "-");
        vec![(
            "Referer".to_string(),
            format!("{}/search/{path_query}/", self.url),
        )]
    }

    async fn get(
        &self,
        cache: VideoCache,
        page: u32,
        options: ServerOptions,
    ) -> Result<Vec<VideoItem>> {
        let video_url = self.build_latest_url(page);
        let old_items = match cache.get(&video_url) {
            Some((time, items)) => {
                if time.elapsed().unwrap_or_default().as_secs() < 60 * 5 {
                    return Ok(items.clone());
                }
                items.clone()
            }
            None => vec![],
        };

        let mut requester = requester_or_default(
            &options,
            "viralxxxporn",
            "viralxxxporn.get.missing_requester",
        );
        let text = match requester
            .get_with_headers(&video_url, self.build_latest_headers(), None)
            .await
        {
            Ok(text) => text,
            Err(e) => {
                report_provider_error(
                    "viralxxxporn",
                    "get.request",
                    &format!("url={video_url}; error={e}"),
                )
                .await;
                return Ok(old_items);
            }
        };

        if text.trim().is_empty() {
            report_provider_error(
                "viralxxxporn",
                "get.empty_response",
                &format!("url={video_url}"),
            )
            .await;
            return Ok(old_items);
        }

        let video_items = self.get_video_items_from_html(text);
        if !video_items.is_empty() {
            cache.remove(&video_url);
            cache.insert(video_url.clone(), video_items.clone());
            return Ok(video_items);
        }

        Ok(old_items)
    }

    async fn query(
        &self,
        cache: VideoCache,
        page: u32,
        query: &str,
        options: ServerOptions,
    ) -> Result<Vec<VideoItem>> {
        let video_url = self.build_search_url(query, page);
        let old_items = match cache.get(&video_url) {
            Some((time, items)) => {
                if time.elapsed().unwrap_or_default().as_secs() < 60 * 5 {
                    return Ok(items.clone());
                }
                items.clone()
            }
            None => vec![],
        };

        let mut requester = requester_or_default(
            &options,
            "viralxxxporn",
            "viralxxxporn.query.missing_requester",
        );
        let text = match requester
            .get_with_headers(&video_url, self.build_search_headers(query), None)
            .await
        {
            Ok(text) => text,
            Err(e) => {
                report_provider_error(
                    "viralxxxporn",
                    "query.request",
                    &format!("url={video_url}; error={e}"),
                )
                .await;
                return Ok(old_items);
            }
        };

        if text.trim().is_empty() {
            report_provider_error(
                "viralxxxporn",
                "query.empty_response",
                &format!("url={video_url}"),
            )
            .await;
            return Ok(old_items);
        }

        let video_items = self.get_video_items_from_html(text);
        if !video_items.is_empty() {
            cache.remove(&video_url);
            cache.insert(video_url.clone(), video_items.clone());
            return Ok(video_items);
        }

        Ok(old_items)
    }

    fn extract_between<'a>(text: &'a str, start: &str, end: &str) -> Option<&'a str> {
        text.split(start).nth(1)?.split(end).next()
    }

    fn normalize_ws(text: &str) -> String {
        text.split_whitespace().collect::<Vec<_>>().join(" ")
    }

    fn decode_html(text: &str) -> String {
        decode(text.as_bytes())
            .to_string()
            .unwrap_or_else(|_| text.to_string())
    }

    fn first_non_empty_attr(segment: &str, attrs: &[&str]) -> Option<String> {
        attrs.iter().find_map(|attr| {
            Self::extract_between(segment, attr, "\"")
                .map(str::trim)
                .filter(|value| !value.is_empty())
                .map(ToString::to_string)
        })
    }

    fn extract_thumb_url(&self, segment: &str) -> String {
        let thumb_raw = Self::first_non_empty_attr(
            segment,
            &[
                "data-original=\"",
                "data-webp=\"",
                "data-src=\"",
                "poster=\"",
                "src=\"",
            ],
        )
        .unwrap_or_default();

        if thumb_raw.starts_with("data:image/") {
            return String::new();
        }

        self.normalize_url(&thumb_raw)
    }

    fn normalize_url(&self, url: &str) -> String {
        if url.starts_with("http://") || url.starts_with("https://") {
            return url.to_string();
        }
        if url.starts_with("//") {
            return format!("https:{url}");
        }
        if url.starts_with('/') {
            return format!("{}{}", self.url, url);
        }
        format!("{}/{}", self.url, url.trim_start_matches("./"))
    }

    fn extract_id_from_url(url: &str) -> String {
        let parts = url
            .trim_end_matches('/')
            .split('/')
            .filter(|part| !part.is_empty())
            .collect::<Vec<_>>();

        parts
            .windows(2)
            .find_map(|window| match window {
                ["video", id] | ["videos", id] => Some((*id).to_string()),
                _ => None,
            })
            .or_else(|| parts.last().map(|id| (*id).to_string()))
            .unwrap_or_default()
    }

    fn strip_tags(text: &str) -> String {
        let Ok(tag_re) = Regex::new(r"(?is)<[^>]+>") else {
            return text.to_string();
        };
        tag_re.replace_all(text, " ").to_string()
    }

    fn extract_duration_seconds(text: &str) -> Option<u32> {
        let colon_duration = Regex::new(r"\b(\d{1,2}:\d{2}(?::\d{2})?)\b")
            .ok()
            .and_then(|re| re.captures(text))
            .and_then(|caps| caps.get(1))
            .and_then(|m| parse_time_to_seconds(m.as_str()))
            .map(|seconds| seconds as u32);
        if colon_duration.is_some() {
            return colon_duration;
        }

        let minute = Regex::new(r"(?i)\b(\d{1,3})\s*(?:min|mins|minute|minutes)\b")
            .ok()
            .and_then(|re| re.captures(text))
            .and_then(|caps| caps.get(1))
            .and_then(|m| m.as_str().parse::<u32>().ok());
        let second = Regex::new(r"(?i)\b(\d{1,3})\s*(?:sec|secs|second|seconds)\b")
            .ok()
            .and_then(|re| re.captures(text))
            .and_then(|caps| caps.get(1))
            .and_then(|m| m.as_str().parse::<u32>().ok());

        match (minute, second) {
            (Some(min), Some(sec)) => Some(min * 60 + sec),
            (Some(min), None) => Some(min * 60),
            (None, Some(sec)) => Some(sec),
            (None, None) => None,
        }
    }

    fn extract_views(text: &str) -> Option<u32> {
        let with_label = Regex::new(r"(?i)\b([0-9]+(?:\.[0-9]+)?\s*[kmb]?)\s*views?\b")
            .ok()
            .and_then(|re| re.captures(text))
            .and_then(|caps| caps.get(1))
            .and_then(|m| parse_abbreviated_number(m.as_str().trim()));
        if with_label.is_some() {
            return with_label;
        }

        Regex::new(r"(?i)\b([0-9]+(?:\.[0-9]+)?\s*[kmb])\b")
            .ok()
            .and_then(|re| re.captures(text))
            .and_then(|caps| caps.get(1))
            .and_then(|m| parse_abbreviated_number(m.as_str().trim()))
    }

    fn parse_anchor_items(&self, html: &str) -> Vec<VideoItem> {
        let Ok(link_re) = Regex::new(
            r#"(?is)<a[^>]+href="(?P<href>(?:https?://[^"]+)?/video/(?P<id>\d+)/[^"]+)"[^>]*>(?P<body>.*?)</a>"#,
        ) else {
            return vec![];
        };
        let Ok(title_attr_re) = Regex::new(r#"(?is)\btitle="([^"]+)""#) else {
            return vec![];
        };
        let mut items = Vec::new();
        let mut seen = HashSet::new();

        for captures in link_re.captures_iter(html) {
            let Some(id) = captures.name("id").map(|m| m.as_str().to_string()) else {
                continue;
            };
            if !seen.insert(id.clone()) {
                continue;
            }

            let href = captures
                .name("href")
                .map(|m| self.normalize_url(m.as_str()))
                .unwrap_or_default();
            let body = captures
                .name("body")
                .map(|m| m.as_str())
                .unwrap_or_default();
            let Some(full_match) = captures.get(0) else {
                continue;
            };

            let seg_start = full_match.start().saturating_sub(600);
            let seg_end = (full_match.end() + 1800).min(html.len());
            let segment = html.get(seg_start..seg_end).unwrap_or(body);

            let title_from_attr = title_attr_re
                .captures(full_match.as_str())
                .and_then(|caps| caps.get(1))
                .map(|m| m.as_str().to_string())
                .unwrap_or_default();
            let title_from_body = Self::strip_tags(body);
            let title_source = if !title_from_attr.is_empty() {
                title_from_attr
            } else {
                title_from_body
            };
            let title = Self::normalize_ws(&Self::decode_html(&title_source));
            if title.is_empty() {
                continue;
            }

            let thumb = self.extract_thumb_url(segment);

            let text_segment = Self::normalize_ws(&Self::decode_html(&Self::strip_tags(segment)));
            let duration = Self::extract_duration_seconds(segment)
                .or_else(|| Self::extract_duration_seconds(&text_segment))
                .unwrap_or(0);
            let views = Self::extract_views(segment)
                .or_else(|| Self::extract_views(&text_segment))
                .unwrap_or(0);

            let mut item =
                VideoItem::new(id, title, href, "viralxxxporn".to_string(), thumb, duration);
            if views > 0 {
                item = item.views(views);
            }
            items.push(item);
        }

        items
    }

    fn get_video_items_from_html(&self, html: String) -> Vec<VideoItem> {
        if html.trim().is_empty() {
            return vec![];
        }

        let anchor_items = self.parse_anchor_items(&html);
        if !anchor_items.is_empty() {
            return anchor_items;
        }

        let mut items = Vec::new();
        let content = html
            .split("<div class=\"pagination\"")
            .next()
            .unwrap_or(&html)
            .split("class=\"pagination\"")
            .next()
            .unwrap_or(&html);

        let markers = [
            "<div class=\"thumb thumb_rel item  \">",
            "<div class=\"item  \">",
            "<div class=\"item thumb video_",
            "<article class=\"thumb",
            "<article class=\"item",
        ];

        for marker in markers {
            for segment in content.split(marker).skip(1) {
                let Some(video_url_raw) =
                    Self::first_non_empty_attr(segment, &["<a href=\"", "href=\""])
                else {
                    continue;
                };
                let video_url = self.normalize_url(&video_url_raw);
                let id = Self::extract_id_from_url(&video_url);
                if id.is_empty() {
                    continue;
                }

                let title_raw = Self::first_non_empty_attr(segment, &["\" title=\"", "alt=\""])
                    .or_else(|| {
                        Self::extract_between(segment, "<strong class=\"title\">", "<")
                            .map(ToString::to_string)
                    })
                    .unwrap_or_default();
                let title = decode(title_raw.as_bytes())
                    .to_string()
                    .unwrap_or(title_raw)
                    .trim()
                    .to_string();
                if title.is_empty() {
                    continue;
                }

                let thumb = self.extract_thumb_url(segment);

                let raw_duration = Self::extract_between(segment, "<div class=\"duration\">", "<")
                    .or_else(|| Self::extract_between(segment, "<div class=\"time\">", "<"))
                    .or_else(|| Self::extract_between(segment, "class=\"duration\">", "<"))
                    .or_else(|| Self::extract_between(segment, "class=\"time\">", "<"))
                    .unwrap_or_default()
                    .trim()
                    .to_string();
                let duration = parse_time_to_seconds(&raw_duration)
                    .map(|v| v as u32)
                    .or_else(|| Self::extract_duration_seconds(&raw_duration))
                    .unwrap_or(0);

                let views = Self::extract_between(segment, "<div class=\"views\">", "<")
                    .or_else(|| Self::extract_between(segment, "class=\"views\">", "<"))
                    .and_then(|value| parse_abbreviated_number(value.trim()))
                    .or_else(|| Self::extract_views(segment))
                    .unwrap_or(0);

                let mut item = VideoItem::new(
                    id,
                    title,
                    video_url,
                    "viralxxxporn".to_string(),
                    thumb,
                    duration,
                );
                if views > 0 {
                    item = item.views(views);
                }
                items.push(item);
            }

            if !items.is_empty() {
                return items;
            }
        }

        vec![]
    }
}

#[async_trait]
impl Provider for ViralxxxpornProvider {
    async fn get_videos(
        &self,
        cache: VideoCache,
        pool: DbPool,
        sort: String,
        query: Option<String>,
        page: String,
        per_page: String,
        options: ServerOptions,
    ) -> Vec<VideoItem> {
        let _ = pool;
        let _ = sort;
        let _ = per_page;
        let page = page.parse::<u32>().unwrap_or(1);

        let videos = match query {
            Some(q) if !q.trim().is_empty() => self.query(cache, page, &q, options).await,
            _ => self.get(cache, page, options).await,
        };

        match videos {
            Ok(videos) => videos,
            Err(e) => {
                report_provider_error(
                    "viralxxxporn",
                    "get_videos",
                    &format!("page={page}; error={e}"),
                )
                .await;
                vec![]
            }
        }
    }

    fn get_channel(&self, clientversion: ClientVersion) -> Option<Channel> {
        Some(self.build_channel(clientversion))
    }
}

#[cfg(test)]
mod tests {
    use super::ViralxxxpornProvider;

    #[test]
    fn builds_latest_url_with_expected_endpoint() {
        let provider = ViralxxxpornProvider::new();
        assert_eq!(
            provider.build_latest_url(3),
            "https://viralxxxporn.com/latest-updates/?mode=async&function=get_block&block_id=list_videos_latest_videos_list&sort_by=post_date&from=3"
        );
    }

    #[test]
    fn builds_search_url_and_referer_with_requested_encoding() {
        let provider = ViralxxxpornProvider::new();
        assert_eq!(
            provider.build_search_url("adriana chechik", 4),
            "https://viralxxxporn.com/search/adriana-chechik/?mode=async&function=get_block&block_id=list_videos_videos_list_search_result&q=adriana+chechik&from_videos=4"
        );
        assert_eq!(
            provider.build_search_headers("adriana chechik"),
            vec![(
                "Referer".to_string(),
                "https://viralxxxporn.com/search/adriana-chechik/".to_string()
            )]
        );
    }

    #[test]
    fn parses_common_kvs_item_markup() {
        let provider = ViralxxxpornProvider::new();
        let html = r#"
            <div class="item  ">
              <a href="/videos/336186/sample-video/" title="Sample &amp; Title">
                <img class="thumb lazy-load" data-original="https://cdn.example/thumb.jpg" />
              </a>
              <div class="duration">12:34</div>
              <div class="views">1.2M</div>
            </div>
            <div class="pagination"></div>
        "#;

        let items = provider.get_video_items_from_html(html.to_string());
        assert_eq!(items.len(), 1);
        assert_eq!(items[0].id, "336186");
        assert_eq!(items[0].title, "Sample & Title");
        assert_eq!(
            items[0].url,
            "https://viralxxxporn.com/videos/336186/sample-video/"
        );
        assert_eq!(items[0].thumb, "https://cdn.example/thumb.jpg");
        assert_eq!(items[0].duration, 754);
        assert_eq!(items[0].views, Some(1_200_000));
    }

    #[test]
    fn parses_anchor_only_async_markup() {
        let provider = ViralxxxpornProvider::new();
        let html = r#"
            <div class="list-videos">
              <a href="/video/336186/jax-slayher-teases-her-gorgeous-ebony-ass-in-steamy-video/" title="Jax Slayher Teases Her Gorgeous Ebony Ass In Steamy Video">
                <img src="https://cdn.example.com/thumb.jpg" />
                <span class="video-deck">720p 13 min 29K 99%</span>
              </a>
            </div>
        "#;

        let items = provider.get_video_items_from_html(html.to_string());
        assert_eq!(items.len(), 1);
        assert_eq!(items[0].id, "336186");
        assert_eq!(
            items[0].url,
            "https://viralxxxporn.com/video/336186/jax-slayher-teases-her-gorgeous-ebony-ass-in-steamy-video/"
        );
        assert_eq!(items[0].thumb, "https://cdn.example.com/thumb.jpg");
        assert_eq!(items[0].duration, 780);
        assert_eq!(items[0].views, Some(29_000));
    }

    #[test]
    fn prefers_real_thumb_url_over_base64_placeholder() {
        let provider = ViralxxxpornProvider::new();
        let html = r#"
            <div class=" th item  ">
              <div class="main-card">
                <a class="media" href="https://viralxxxporn.com/video/229322/adriana-chechik-kazumi-tease-wet-threesome-fuckfest-video-leaked-993ee5d/" title="Adriana Chechik Kazumi Tease Wet Threesome Fuckfest Video Leaked">
                  <img class="img lazy-load"
                    src="data:image/svg+xml;base64,AAAA"
                    data-original="https://imgcdn.viralxxxporn.com/contents/videos_screenshots/229000/229322/800x450/2.jpg"
                    data-webp="https://imgcdn.viralxxxporn.com/contents/videos_screenshots/229000/229322/800x450/2.jpg"
                    alt="Adriana Chechik Kazumi Tease Wet Threesome Fuckfest Video Leaked">
                  <div class="duration">25:15</div>
                </a>
                <div class="content">
                  <ul class="list">
                    <li><span>9.9K Views</span></li>
                  </ul>
                </div>
              </div>
            </div>
        "#;

        let items = provider.get_video_items_from_html(html.to_string());
        assert_eq!(items.len(), 1);
        assert_eq!(
            items[0].thumb,
            "https://imgcdn.viralxxxporn.com/contents/videos_screenshots/229000/229322/800x450/2.jpg"
        );
        assert_eq!(items[0].views, Some(9_900));
    }
}