use std::sync::Arc;
use std::sync::atomic::{AtomicU32, Ordering};

use ntex::web;
use regex::Regex;
use serde_json::Value;
use url::Url;
use wreq::Version;

use crate::util::requester::Requester;

const BASE_URL: &str = "https://www.pornhd3x.tv";
const SOURCE_SECRET: &str = "98126avrbi6m49vd7shxkn985";
const SOURCE_COOKIE_PREFIX: &str = "826avrbi6m49vd7shxkn985m";
const SOURCE_COOKIE_SUFFIX: &str = "k06twz87wwxtp3dqiicks2df";

#[derive(Debug, Clone)]
pub struct Pornhd3xProxy {
    source_counter: Arc<AtomicU32>,
}

impl Pornhd3xProxy {
    pub fn new() -> Self {
        Self {
            source_counter: Arc::new(AtomicU32::new(0)),
        }
    }

    fn normalize_detail_request(endpoint: &str) -> Option<(String, Option<String>)> {
        let endpoint = endpoint.trim().trim_start_matches('/');
        if endpoint.is_empty() {
            return None;
        }

        let (detail_part, quality) = match endpoint.split_once("/__quality__/") {
            Some((detail, quality)) => {
                (detail, Some(quality.replace("%20", " ").trim().to_string()))
            }
            None => (endpoint, None),
        };

        let detail_url =
            if detail_part.starts_with("http://") || detail_part.starts_with("https://") {
                detail_part.to_string()
            } else {
                format!("https://{}", detail_part.trim_start_matches('/'))
            };

        Self::is_allowed_detail_url(&detail_url)
            .then_some((detail_url, quality.filter(|value| !value.is_empty())))
    }

    fn is_allowed_detail_url(url: &str) -> bool {
        let Some(url) = Url::parse(url).ok() else {
            return false;
        };
        if url.scheme() != "https" {
            return false;
        }
        let Some(host) = url.host_str() else {
            return false;
        };
        (host == "www.pornhd3x.tv" || host == "pornhd3x.tv") && url.path().starts_with("/movies/")
    }

    fn normalize_url(raw: &str) -> String {
        let value = raw.trim();
        if value.is_empty() {
            return String::new();
        }
        if value.starts_with("//") {
            return format!("https:{value}");
        }
        if value.starts_with('/') {
            return format!("{BASE_URL}{value}");
        }
        if value.starts_with("http://") {
            return value.replacen("http://", "https://", 1);
        }
        value.to_string()
    }

    fn extract_episode_id(html: &str) -> Option<String> {
        Regex::new(r#"(?is)(?:id=["']uuid["'][^>]*value=["']|episode-id=["'])([A-Za-z0-9]+)"#)
            .ok()?
            .captures(html)
            .and_then(|captures| captures.get(1))
            .map(|value| value.as_str().to_string())
    }

    fn build_source_cookie_name(episode_id: &str) -> String {
        format!("{SOURCE_COOKIE_PREFIX}{episode_id}{SOURCE_COOKIE_SUFFIX}")
    }

    fn build_source_hash(episode_id: &str, nonce: &str) -> String {
        format!(
            "{:x}",
            md5::compute(format!("{episode_id}{nonce}{SOURCE_SECRET}"))
        )
    }

    fn next_source_request(&self) -> (u32, String) {
        let count = self.source_counter.fetch_add(1, Ordering::Relaxed) + 1;
        let nonce = format!("{:06x}", count % 0xFF_FFFF);
        (count, nonce)
    }

    async fn fetch_sources(
        &self,
        requester: &mut Requester,
        referer: &str,
        episode_id: &str,
    ) -> Option<Value> {
        let (count, nonce) = self.next_source_request();
        let source_url = format!(
            "{BASE_URL}/ajax/get_sources/{episode_id}/{hash}?count={count}&mobile=true",
            hash = Self::build_source_hash(episode_id, &nonce),
        );
        let existing_cookie = requester.cookie_header_for_url(&source_url);
        let cookie_value = format!("{}={nonce}", Self::build_source_cookie_name(episode_id));
        let combined_cookie = match existing_cookie {
            Some(existing) if !existing.trim().is_empty() => format!("{existing}; {cookie_value}"),
            _ => cookie_value,
        };

        let response = requester
            .get_with_headers(
                &source_url,
                vec![
                    ("Cookie".to_string(), combined_cookie),
                    ("Referer".to_string(), referer.to_string()),
                    ("X-Requested-With".to_string(), "XMLHttpRequest".to_string()),
                    (
                        "Accept".to_string(),
                        "application/json, text/javascript, */*; q=0.01".to_string(),
                    ),
                ],
                Some(Version::HTTP_11),
            )
            .await
            .ok()?;

        serde_json::from_str::<Value>(&response).ok()
    }

    fn select_source_url(payload: &Value, quality: Option<&str>) -> Option<String> {
        let sources = payload
            .get("playlist")
            .and_then(Value::as_array)
            .into_iter()
            .flatten()
            .flat_map(|playlist| {
                playlist
                    .get("sources")
                    .and_then(Value::as_array)
                    .into_iter()
                    .flatten()
            })
            .collect::<Vec<_>>();

        if let Some(quality) = quality {
            let quality = quality.trim().to_ascii_lowercase();
            for source in &sources {
                let label = source
                    .get("label")
                    .and_then(Value::as_str)
                    .unwrap_or_default()
                    .trim()
                    .to_ascii_lowercase();
                if label == quality {
                    let file = source.get("file").and_then(Value::as_str)?;
                    return Some(Self::normalize_url(file));
                }
            }
        }

        for source in sources {
            let Some(file) = source.get("file").and_then(Value::as_str) else {
                continue;
            };
            let url = Self::normalize_url(file);
            if !url.is_empty() {
                return Some(url);
            }
        }

        None
    }
}

impl crate::proxies::Proxy for Pornhd3xProxy {
    async fn get_video_url(&self, url: String, requester: web::types::State<Requester>) -> String {
        let Some((detail_url, quality)) = Self::normalize_detail_request(&url) else {
            return String::new();
        };

        let mut requester = requester.get_ref().clone();
        let detail_html = match requester.get(&detail_url, Some(Version::HTTP_11)).await {
            Ok(text) => text,
            Err(_) => return String::new(),
        };
        let Some(episode_id) = Self::extract_episode_id(&detail_html) else {
            return String::new();
        };
        let Some(payload) = self
            .fetch_sources(&mut requester, &detail_url, &episode_id)
            .await
        else {
            return String::new();
        };

        Self::select_source_url(&payload, quality.as_deref()).unwrap_or_default()
    }
}

#[cfg(test)]
mod tests {
    use super::Pornhd3xProxy;

    #[test]
    fn normalizes_detail_endpoint_and_quality() {
        let (url, quality) = Pornhd3xProxy::normalize_detail_request(
            "www.pornhd3x.tv/movies/example-video/__quality__/720p",
        )
        .expect("proxy target should parse");

        assert_eq!(url, "https://www.pornhd3x.tv/movies/example-video");
        assert_eq!(quality.as_deref(), Some("720p"));
    }

    #[test]
    fn extracts_episode_id_from_detail_markup() {
        let html = r#"
            <input id="uuid" value="49Q27JL3HCPVNJQN">
            <a class="btn-eps" episode-id="OTHER"></a>
        "#;

        assert_eq!(
            Pornhd3xProxy::extract_episode_id(html).as_deref(),
            Some("49Q27JL3HCPVNJQN")
        );
    }
}