use std::fmt;
use std::marker::PhantomData;
use std::collections::HashMap;
use serde::de::{self, Visitor};
use serde::{Deserialize, Deserializer};
use quick_xml::Reader;
use quick_xml::events::Event;
extern crate reqwest;
extern crate quick_xml;
extern crate serde_json;

// contains more info that i won't add for search results, maybe non_exhaustive? not sure
#[derive(Deserialize, Debug)]
pub struct SearchResult {
    pub id: i32,
    pub name: String
}

impl fmt::Display for SearchResult {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        formatter.write_str(&format!("{}: {}", self.id, &self.name))
    }
}

#[derive(Deserialize, Debug)]
pub struct SearchResultMetadata {
    pub hits: String
}

#[derive(Deserialize, Debug)]
pub struct HentaiInfo {
    pub state: HentaiState
}

#[derive(Deserialize, Debug)]
pub struct HentaiState {
    pub data: HentaiData
}

#[derive(Deserialize, Debug)]
pub struct HentaiData {
    pub video: HentaiDataVideo
}

#[derive(Deserialize, Debug)]
pub struct HentaiDataVideo {
    pub hentai_video: HentaiVideo,
    pub videos_manifest: VideosManifest
}

#[derive(Deserialize, Debug)]
pub struct HentaiVideo {
    pub id: i32,
    pub slug: String,
    pub name: String,
    #[serde(deserialize_with = "remove_html")]
    pub description: String,
    pub views: usize,
    pub is_hard_subtitled: bool,
    pub duration_in_ms: i32,
    pub is_censored: bool,
    pub likes: usize,
    pub dislikes: usize,
    pub hentai_tags: Vec<HentaiTag>
}

impl fmt::Display for HentaiInfo {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        let video = &self.state.data.video.hentai_video;
        let mut text = format!("ID: {}\nSlug: {}\nName: {}\nViews: {}\nLikes: {}\nDislikes: {}\nCensored: {}\nHardsubbed: {}\n",
            video.id,
            &video.slug,
            &video.name,
            video.views,
            video.likes,
            video.dislikes,
            match video.is_censored {
                true => "Yes",
                false => "No"
            },
            match video.is_hard_subtitled {
                true => "Yes",
                false => "No"
            }
        );
        let servers = &self.state.data.video.videos_manifest.servers;
        if !servers.is_empty() {
            let mut string_servers = HashMap::new();
            for server in servers {
                let mut tmp_string_servers = string_servers.clone();
                for stream in &server.streams {
                    if !stream.url.is_empty() && !tmp_string_servers.contains_key(&stream.height) {
                        tmp_string_servers.insert(&stream.height, stream.filesize_mbs);
                    }
                }
                string_servers.extend(tmp_string_servers);
            }
            if !string_servers.is_empty() {
                let mut int_servers = HashMap::with_capacity(string_servers.len());
                for (i, j) in &string_servers {
                    match i.parse::<i32>() {
                        Ok(i) => int_servers.insert(i, j),
                        Err(_) => {
                            int_servers.clear();
                            break;
                        }
                    };
                }
                text.push_str(&format!("Resolution: {}\n",
                    match int_servers.is_empty() {
                        true => {
                            let mut keys: Vec<&&String> = string_servers.keys().collect();
                            keys.sort();
                            keys.iter().map(|&i| format!("{} ({}MB)", i, string_servers.get(i).unwrap())).collect::<Vec<_>>().join(", ")
                        },
                        false => {
                            let mut keys: Vec<&i32> = int_servers.keys().collect();
                            keys.sort();
                            keys.iter().map(|i| format!("{} ({}MB)", i, int_servers.get(i).unwrap())).collect::<Vec<_>>().join(", ")
                        }
                    }
                ));
            }
        }
        if video.duration_in_ms > 0 {
            let mut seconds = video.duration_in_ms / 1000;
            let mut minutes = seconds / 60;
            if minutes > 0 {
                seconds -= minutes * 60;
            }
            let hours = minutes / 60;
            if hours > 0 {
                minutes -= hours * 60;
                seconds -= hours * 60 * 60;
            }
            let mut duration = String::new();
            if hours > 0 {
                duration.push_str(&format!("{}:", hours));
            }
            if minutes > 0 {
                duration.push_str(&format!("{}:", minutes));
            }
            duration.push_str(&seconds.to_string());
            text.push_str(&format!("Duration: {}\n", &duration));
        }
        formatter.write_str(&format!("{}Tags: {}\nDescription: {}", &text, video.hentai_tags.iter().map(|i| i.text.as_str()).collect::<Vec<_>>().join(", "), &video.description))
    }
}

#[derive(Deserialize, Debug)]
pub struct HentaiTag {
    pub id: i32,
    pub text: String
}

#[derive(Deserialize, Debug)]
pub struct VideosManifest {
    pub servers: Vec<VideoServer>
}

#[derive(Deserialize, Debug)]
pub struct VideoServer {
    pub is_permanent: bool,
    pub streams: Vec<VideoStream>
}

#[derive(Deserialize, Debug)]
pub struct VideoStream {
    pub height: String,
    pub url: String,
    pub filesize_mbs: i32
}

fn remove_html<'de, D>(deserializer: D) -> Result<String, D::Error>
where
    D: Deserializer<'de>
{
    struct RemoveHTML<T>(PhantomData<fn() -> T>);

    impl<'de> Visitor<'de> for RemoveHTML<String>
    {
        type Value = String;

        fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
            formatter.write_str("HTML string")
        }

        fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
        where
            E: de::Error
        {
//          https://brokenco.de/2020/08/03/serde-deserialize-with-string.html
            let mut to_return = String::new();
            let mut reader = Reader::from_str(&value);
            reader.check_end_names(false);
            let mut buf = Vec::new();
            loop {
                match reader.read_event(&mut buf) {
                    Ok(Event::Text(e)) => to_return.push_str(&e.unescape_and_decode(&reader).map_err(de::Error::custom)?),
                    Ok(Event::Eof) => break,
                    Err(err) => panic!("Error at position {}: {:?}", reader.buffer_position(), err),
                    _ => ()
                };
                buf.clear();
            }
            Ok(to_return)
        }
    }

    deserializer.deserialize_any(RemoveHTML(PhantomData))
}

#[derive(Debug)]
pub enum Error {
    Reqwest(reqwest::Error),
    QuickXML(quick_xml::Error),
    SerdeJSON(serde_json::Error),
}

impl From<reqwest::Error> for Error {
    #[inline]
    fn from(error: reqwest::Error) -> Error {
        Error::Reqwest(error)
    }
}

impl From<quick_xml::Error> for Error {
    #[inline]
    fn from(error: quick_xml::Error) -> Error {
        Error::QuickXML(error)
    }
}

impl From<serde_json::Error> for Error {
    #[inline]
    fn from(error: serde_json::Error) -> Error {
        Error::SerdeJSON(error)
    }
}

impl fmt::Display for Error {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        formatter.write_str(
            &match self {
                Error::Reqwest(err) => format!("reqwest error: {}", err),
                Error::QuickXML(err) => format!("quick-xml error: {}", err),
                Error::SerdeJSON(err) => format!("serde_json error: {}", err),
            }
        )
    }
}