use crate::DbPool;
use crate::api::ClientVersion;
use crate::providers::{
    Provider, build_proxy_url, report_provider_error, requester_or_default, strip_url_scheme,
};
use crate::status::*;
use crate::util::time::parse_time_to_seconds;
use crate::videos::{ServerOptions, VideoItem};

use async_trait::async_trait;
use chrono::NaiveDate;
use error_chain::error_chain;
use htmlentity::entity::{ICodedDataTrait, decode};
use regex::Regex;
use scraper::{ElementRef, Html, Selector};
use serde::Deserialize;
use std::collections::HashSet;
use wreq::Version;

pub const CHANNEL_METADATA: crate::providers::ProviderChannelMetadata =
    crate::providers::ProviderChannelMetadata {
        group_id: "amateur-homemade",
        tags: &["amateur", "homemade", "interracial"],
    };

const BASE_URL: &str = "https://www.clapdat.com";
const SEARCH_URL: &str = "https://search.clapdat.com/indexes/videos/search";
const SEARCH_KEY: &str = "36ce9a190ca0e797debc3f0a2a311749dbd76262c389531c3a37e9dd74ab9df5";
const CHANNEL_ID: &str = "clapdat";

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

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

#[derive(Debug, Clone)]
enum Target {
    Trending,
    Recent,
    Search { query: String },
    Tag { slug: String },
    User { username: String },
}

#[derive(Debug, Clone)]
struct StubVideo {
    id: String,
    title: String,
    url: String,
    thumb: String,
    duration: u32,
}

#[derive(Debug, Deserialize)]
struct SearchResponse {
    #[serde(default)]
    hits: Vec<SearchHit>,
}

#[derive(Debug, Deserialize)]
struct SearchHit {
    #[serde(rename = "_id", default)]
    id: String,
    #[serde(default)]
    title: String,
    #[serde(default)]
    slug: String,
    #[serde(default)]
    image: String,
}

impl ClapdatProvider {
    pub fn new() -> Self {
        Self {
            url: BASE_URL.to_string(),
        }
    }

    fn build_channel(&self, _clientversion: ClientVersion) -> Channel {
        Channel {
            id: CHANNEL_ID.to_string(),
            name: "ClapDat".to_string(),
            description: "ClapDat trending/recent feeds with tag and uploader shortcuts."
                .to_string(),
            premium: false,
            favicon: "https://www.google.com/s2/favicons?sz=64&domain=clapdat.com".to_string(),
            status: "active".to_string(),
            categories: vec![],
            options: vec![ChannelOption {
                id: "sort".to_string(),
                title: "Sort".to_string(),
                description: "Trending or latest ClapDat feed.".to_string(),
                systemImage: "list.number".to_string(),
                colorName: "blue".to_string(),
                options: vec![
                    FilterOption {
                        id: "trending".to_string(),
                        title: "Trending".to_string(),
                    },
                    FilterOption {
                        id: "new".to_string(),
                        title: "Recent".to_string(),
                    },
                ],
                multiSelect: false,
            }],
            nsfw: true,
            cacheDuration: Some(1800),
            ytdlpCommand: Some("yt-dlp --impersonate chrome-120".to_string())
        }
    }

    fn resolve_target(&self, query: &str, sort: &str) -> Target {
        let q = query.trim();
        if let Some(value) = q.strip_prefix("tag:").or_else(|| q.strip_prefix('#')) {
            let slug = value.trim().to_lowercase().replace(' ', "-");
            if !slug.is_empty() {
                return Target::Tag { slug };
            }
        }

        if let Some(value) = q
            .strip_prefix("user:")
            .or_else(|| q.strip_prefix("uploader:"))
        {
            let username = value.trim().to_lowercase().replace(' ', "-");
            if !username.is_empty() {
                return Target::User { username };
            }
        }

        if !q.is_empty() {
            return Target::Search {
                query: q.to_string(),
            };
        }

        match sort {
            "recent" | "new" | "latest" => Target::Recent,
            _ => Target::Trending,
        }
    }

    fn listing_url(&self, target: &Target, page: u16) -> Option<String> {
        let page = page.max(1);
        match target {
            Target::Trending => Some(if page == 1 {
                self.url.clone()
            } else {
                format!("{}/trending/{page}", self.url)
            }),
            Target::Recent => Some(if page == 1 {
                self.url.clone()
            } else {
                format!("{}/recent/{page}", self.url)
            }),
            Target::Tag { slug } => Some(if page == 1 {
                format!("{}/tag/{slug}", self.url)
            } else {
                format!("{}/tag/{slug}/{page}", self.url)
            }),
            Target::User { username } => Some(if page == 1 {
                format!("{}/user/{username}", self.url)
            } else {
                format!("{}/user/{username}/{page}", self.url)
            }),
            Target::Search { .. } => None,
        }
    }

    fn selector(value: &str) -> Result<Selector> {
        Selector::parse(value).map_err(|error| Error::from(format!("selector `{value}`: {error}")))
    }

    fn regex(value: &str) -> Result<Regex> {
        Regex::new(value).map_err(|error| Error::from(format!("regex `{value}`: {error}")))
    }

    fn normalize_text(value: &str) -> String {
        decode(value.as_bytes())
            .to_string()
            .unwrap_or_else(|_| value.to_string())
            .replace('\u{a0}', " ")
            .split_whitespace()
            .collect::<Vec<_>>()
            .join(" ")
            .trim()
            .to_string()
    }

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

    fn extract_video_id(url: &str) -> Option<String> {
        let re = Regex::new(r"-([a-z0-9]+)(?:/|$)").ok()?;
        re.captures(url)
            .and_then(|caps| caps.get(1).map(|m| m.as_str().to_string()))
    }

    fn parse_duration(value: &str) -> u32 {
        parse_time_to_seconds(value)
            .and_then(|seconds| u32::try_from(seconds).ok())
            .unwrap_or(0)
    }

    fn parse_card(
        &self,
        card: &ElementRef<'_>,
        link_sel: &Selector,
        img_sel: &Selector,
    ) -> Option<StubVideo> {
        let link = card.select(link_sel).next()?;
        let href = link.value().attr("href")?;
        let url = self.normalize_url(href);
        let id = Self::extract_video_id(&url)?;

        let title = card
            .select(&Self::selector("h3").ok()?)
            .next()
            .map(|node| Self::normalize_text(&node.text().collect::<Vec<_>>().join(" ")))
            .unwrap_or_default();
        if title.is_empty() {
            return None;
        }

        let duration_text = card
            .select(&Self::selector("span").ok()?)
            .filter_map(|node| {
                let value = Self::normalize_text(&node.text().collect::<Vec<_>>().join(" "));
                if value.contains(':') {
                    Some(value)
                } else {
                    None
                }
            })
            .next()
            .unwrap_or_default();

        let thumb = card
            .select(img_sel)
            .filter_map(|img| {
                // Collect the attributes we are looking for
                img.value()
                    .attr("src")
                    .or_else(|| img.value().attr("data-src"))
            })
            .nth(1) // Skips the first match (index 0) and takes the second match (index 1)
            .map(|value| self.normalize_url(value))
            .unwrap_or_default();

        Some(StubVideo {
            id,
            title,
            url,
            thumb,
            duration: Self::parse_duration(&duration_text),
        })
    }

    fn parse_listing_html(&self, html: &str) -> Result<Vec<StubVideo>> {
        let doc = Html::parse_document(html);
        let card_sel = Self::selector("div.video-card")?;
        let link_sel = Self::selector("a[href*='/video/']")?;
        let img_sel = Self::selector("img")?;
        let mut out = Vec::new();
        let mut seen = HashSet::new();

        for card in doc.select(&card_sel) {
            if let Some(stub) = self.parse_card(&card, &link_sel, &img_sel) {
                if seen.insert(stub.id.clone()) {
                    out.push(stub);
                }
            }
        }

        Ok(out)
    }

    fn parse_home_section_html(&self, html: &str, section_id: &str) -> Result<Vec<StubVideo>> {
        let doc = Html::parse_document(html);
        let section_sel = Self::selector(&format!("section#{section_id}"))?;
        let card_sel = Self::selector("div.video-card")?;
        let link_sel = Self::selector("a[href*='/video/']")?;
        let img_sel = Self::selector("img")?;
        let mut out = Vec::new();
        let mut seen = HashSet::new();

        if let Some(section) = doc.select(&section_sel).next() {
            for card in section.select(&card_sel) {
                if let Some(stub) = self.parse_card(&card, &link_sel, &img_sel) {
                    if seen.insert(stub.id.clone()) {
                        out.push(stub);
                    }
                }
            }
        }

        Ok(out)
    }

    fn html_headers(&self) -> Vec<(String, String)> {
        vec![
            ("accept".to_string(), "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8".to_string()),
            ("accept-language".to_string(), "en-US,en;q=0.8".to_string()),
            ("user-agent".to_string(), "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36".to_string()),
            ("referer".to_string(), self.url.clone()),
        ]
    }

    async fn fetch_html(&self, options: &ServerOptions, url: &str) -> Result<String> {
        let mut requester = requester_or_default(options, CHANNEL_ID, "fetch_html");
        requester
            .get_with_headers(url, self.html_headers(), Some(Version::HTTP_11))
            .await
            .map_err(|error| Error::from(format!("request failed for {url}: {error}")))
    }

    async fn search_videos(
        &self,
        options: &ServerOptions,
        query: &str,
        page: u16,
        per_page: usize,
    ) -> Result<Vec<StubVideo>> {
        let mut requester = requester_or_default(options, CHANNEL_ID, "search_videos");
        let offset = page.saturating_sub(1) as usize * per_page;
        let query_encoded =
            url::form_urlencoded::byte_serialize(query.as_bytes()).collect::<String>();
        let search_url = format!("{SEARCH_URL}?q={query_encoded}&limit={per_page}&offset={offset}");
        let auth_header = format!("Bearer {SEARCH_KEY}");
        let headers = vec![
            ("accept".to_string(), "application/json".to_string()),
            ("authorization".to_string(), auth_header),
            (
                "user-agent".to_string(),
                "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36".to_string(),
            ),
        ];

        let text = requester
            .get_with_headers(&search_url, headers, Some(Version::HTTP_11))
            .await
            .map_err(|error| Error::from(format!("search request failed: {error}")))?;

        let parsed: SearchResponse = serde_json::from_str(&text)?;
        Ok(parsed
            .hits
            .into_iter()
            .filter_map(|hit| {
                let slug = hit.slug.trim();
                if hit.id.is_empty() || slug.is_empty() || hit.title.trim().is_empty() {
                    return None;
                }
                Some(StubVideo {
                    id: hit.id,
                    title: Self::normalize_text(&hit.title),
                    url: format!("{}/video/{}", self.url, slug),
                    thumb: hit.image,
                    duration: 0,
                })
            })
            .collect())
    }

    fn extract_detail_metadata(
        &self,
        html: &str,
    ) -> (
        Vec<String>,
        Option<String>,
        Option<String>,
        Option<String>,
        Option<u64>,
    ) {
        let uploader_name =
            Self::regex(r#"<a href="/user/([^"]+)"[^>]*>[^<]*<img[^>]*>\s*<p[^>]*>([^<]+)</p>"#)
                .ok()
                .and_then(|re| re.captures(html))
                .and_then(|caps| {
                    let slug = caps.get(1)?.as_str().to_string();
                    let name = Self::normalize_text(caps.get(2)?.as_str());
                    if name.is_empty() {
                        return None;
                    }
                    Some((name, slug))
                });

        let uploader = uploader_name.as_ref().map(|v| v.0.clone());
        let uploader_url = uploader_name
            .as_ref()
            .map(|v| format!("{}/user/{}", self.url, v.1));
        let uploader_id = uploader_name
            .as_ref()
            .map(|v| format!("{CHANNEL_ID}:{}", v.1));

        let uploaded_at =
            Self::regex(r#"<p class="s-1he9h8j">([A-Za-z]{3}\s+\d{1,2},\s+\d{4})</p>"#)
                .ok()
                .and_then(|re| re.captures(html))
                .and_then(|caps| caps.get(1).map(|m| m.as_str().to_string()))
                .and_then(|value| NaiveDate::parse_from_str(&value, "%b %e, %Y").ok())
                .and_then(|date| date.and_hms_opt(0, 0, 0))
                .and_then(|dt| u64::try_from(dt.and_utc().timestamp()).ok());

        let tag_re = Self::regex(r#"<a href="/tag/[^"]+"[^>]*>([^<]+)</a>"#).ok();
        let tags = tag_re
            .map(|re| {
                re.captures_iter(html)
                    .filter_map(|caps| caps.get(1).map(|m| Self::normalize_text(m.as_str())))
                    .filter(|t| !t.is_empty())
                    .collect::<Vec<_>>()
            })
            .unwrap_or_default();

        (tags, uploader, uploader_url, uploader_id, uploaded_at)
    }

    async fn enrich_video(&self, options: &ServerOptions, stub: StubVideo) -> VideoItem {
        let proxy_url = build_proxy_url(&options, CHANNEL_ID, &strip_url_scheme(&stub.url));
        let mut item = VideoItem::new(
            stub.id,
            stub.title,
            proxy_url,
            CHANNEL_ID.to_string(),
            stub.thumb,
            stub.duration,
        );

        if let Ok(detail_html) = self.fetch_html(options, &stub.url).await {
            let (tags, uploader, uploader_url, uploader_id, uploaded_at) =
                self.extract_detail_metadata(&detail_html);

            if !tags.is_empty() {
                item.tags = Some(tags);
            }
            if let Some(value) = uploader {
                item = item.uploader(value);
            }
            if let Some(value) = uploader_url {
                item = item.uploader_url(value);
            }
            if let Some(value) = uploader_id {
                item.uploaderId = Some(value);
            }
            if let Some(value) = uploaded_at {
                item.uploadedAt = Some(value);
            }
        }

        item
    }
}

#[async_trait]
impl Provider for ClapdatProvider {
    async fn get_videos(
        &self,
        _cache: crate::util::cache::VideoCache,
        _pool: DbPool,
        sort: String,
        query: Option<String>,
        page: String,
        per_page: String,
        options: ServerOptions,
    ) -> Vec<VideoItem> {
        let page_num = page.parse::<u16>().unwrap_or(1).max(1);
        let per_page_num = per_page.parse::<usize>().unwrap_or(20).clamp(1, 60);
        let sort_value = if sort.trim().is_empty() {
            options.sort.as_deref().unwrap_or("trending").to_string()
        } else {
            sort
        };
        let query_value = query.unwrap_or_default();
        let target = self.resolve_target(&query_value, &sort_value);

        let stubs = match &target {
            Target::Search { query } => match self
                .search_videos(&options, query, page_num, per_page_num)
                .await
            {
                Ok(items) => items,
                Err(error) => {
                    report_provider_error(CHANNEL_ID, "search_videos", &error.to_string()).await;
                    vec![]
                }
            },
            _ => {
                let Some(url) = self.listing_url(&target, page_num) else {
                    return vec![];
                };
                match self.fetch_html(&options, &url).await {
                    Ok(html) => {
                        let parsed = match (&target, page_num) {
                            (Target::Trending, 1) => {
                                self.parse_home_section_html(&html, "trending-videos")
                            }
                            (Target::Recent, 1) => {
                                self.parse_home_section_html(&html, "recent-videos")
                            }
                            _ => self.parse_listing_html(&html),
                        };
                        match parsed {
                            Ok(items) => items,
                            Err(error) => {
                                report_provider_error(
                                    CHANNEL_ID,
                                    "parse_listing_html",
                                    &error.to_string(),
                                )
                                .await;
                                vec![]
                            }
                        }
                    }
                    Err(error) => {
                        report_provider_error(CHANNEL_ID, "fetch_html", &error.to_string()).await;
                        vec![]
                    }
                }
            }
        };

        let mut output = Vec::with_capacity(stubs.len());
        for stub in stubs.into_iter().take(per_page_num) {
            output.push(self.enrich_video(&options, stub).await);
        }
        output
    }

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