use futures_util::StreamExt;
use indicatif::{MultiProgress, ProgressBar, ProgressStyle};
use reqwest::Client;
use std::{
    cmp::min,
    collections::HashMap,
    fs::{copy, read_dir, remove_file, rename, File},
    io::Write,
};
use tokio::task::JoinSet;

use crate::{
    cache::{copy_cached_version, get_cached_versions},
    config::Cfg,
    db::{mods_get_info, userlist_add_disabled_versions},
    error::{ErrorType, MLError, MLE},
    modrinth::Version,
    List, PROGRESS_CHARS, STYLE_BAR_BYTE, STYLE_BAR_POS, STYLE_SPINNER,
};

pub async fn download_versions(
    list: List,
    config: Cfg,
    versions: Vec<Version>,
    progress: &MultiProgress,
    progress_before: &ProgressBar,
) -> MLE<()> {
    let cached = get_cached_versions(&config.cache);

    let mut js = JoinSet::new();

    let style_spinner = ProgressStyle::with_template(STYLE_SPINNER).unwrap();

    let all = progress.insert_before(
        progress_before,
        ProgressBar::new(versions.len().try_into().unwrap()),
    );
    all.set_style(
        ProgressStyle::with_template(STYLE_BAR_POS)
            .unwrap()
            .progress_chars(PROGRESS_CHARS),
    );
    all.set_message(format!("✓Downloading {}", list.id));

    for ver in versions {
        let p = progress.insert_before(&all, ProgressBar::new(1));
        p.set_style(style_spinner.clone());
        js.spawn(download_version(
            config.clone(),
            list.clone(),
            ver,
            cached.clone(),
            p,
        ));
    }

    while js.join_next().await.is_some() {
        all.inc(1)
    }

    all.finish_with_message(format!("✓Downloading {}", list.id));

    Ok(())
}

async fn download_version(
    config: Cfg,
    list: List,
    version: Version,
    mut cached: HashMap<String, String>,
    progress: ProgressBar,
) -> MLE<()> {
    let project_info = mods_get_info(&config, &version.project_id)?;

    let dl_path = String::from(&list.download_folder);

    progress.set_message(format!("{} - {}", project_info.title, version.id));

    let mut cache_msg = "";
    //Check cache if already downloaded
    let c = cached.remove(&version.id);
    if c.is_some() {
        progress.set_message(format!("Get {} from cache", version.id));
        cache_msg = " (cached)";
        copy_cached_version(&c.unwrap(), &dl_path);
    } else {
        let files = version.files;
        let file = match files.clone().into_iter().find(|f| f.primary) {
            Some(f) => f,
            None => files[0].clone(),
        };
        let mut splitname: Vec<&str> = file.filename.split('.').collect();
        let extension = match splitname.pop().ok_or("") {
            Ok(e) => e,
            Err(..) => return Err(MLError::new(ErrorType::Other, "NO_FILE_EXTENSION")),
        };
        let filename = format!(
            "{}.mr.{}.{}.{}",
            splitname.join("."),
            version.project_id,
            version.id,
            extension
        );

        download_file(&file.url, &list.download_folder, &filename, &progress).await?;

        progress.set_message(format!("Copy {} to cache", version.id));
        let dl_path_file = format!("{}/{}", list.download_folder, filename);
        let cache_path = format!("{}/{}", &config.cache, filename);

        copy(dl_path_file, cache_path)?;
    }

    progress.finish_with_message(format!(
        "✓{} - {}{}",
        project_info.title, version.id, cache_msg
    ));

    Ok(())
}

async fn download_file(url: &str, path: &str, name: &str, progress: &ProgressBar) -> MLE<()> {
    let dl_path_file = format!("{}/{}", path, name);
    let res = Client::new().get(url).send().await?;

    let size = res.content_length().expect("Couldn't get content length");

    let style_bar_byte = ProgressStyle::with_template(STYLE_BAR_BYTE)
        .unwrap()
        .progress_chars(PROGRESS_CHARS);

    progress.set_length(size);
    progress.set_style(style_bar_byte);

    // download chunks
    let mut file = File::create(&dl_path_file)?;
    let mut stream = res.bytes_stream();

    let mut downloaded: u64 = 0;

    while let Some(item) = stream.next().await {
        // progress.inc(1);
        let chunk = item?;
        file.write_all(&chunk)?;

        // Progress bar
        let new = min(downloaded + (chunk.len() as u64), size);
        downloaded = new;
        progress.set_position(new);

        // std::thread::sleep(std::time::Duration::from_millis(100));
    }

    Ok(())
}

pub fn disable_version(
    config: &Cfg,
    current_list: List,
    versionid: String,
    mod_id: String,
) -> MLE<()> {
    let file = get_file_path(&current_list, String::from(&versionid))?;
    let disabled = format!("{}.disabled", file);

    rename(file, disabled)?;

    userlist_add_disabled_versions(config, current_list.id, versionid, mod_id)?;

    Ok(())
}

pub fn delete_version(list: &List, version: String) -> MLE<()> {
    let file = get_file_path(list, version)?;

    remove_file(file)?;

    Ok(())
}

pub fn get_file_path(list: &List, versionid: String) -> MLE<String> {
    let mut names: HashMap<String, String> = HashMap::new();
    for file in read_dir(&list.download_folder)? {
        let path = file?.path();
        if path.is_file() {
            let pathstr = match path.to_str().ok_or("") {
                Ok(s) => s,
                Err(..) => return Err(MLError::new(ErrorType::Other, "INVALID_PATH")),
            };
            let namesplit: Vec<&str> = pathstr.split('.').collect();
            let ver_id = namesplit[namesplit.len() - 2];
            names.insert(String::from(ver_id), String::from(pathstr));
        }
    }

    let filename = match names.get(&versionid).ok_or("") {
        Ok(n) => n,
        Err(..) => {
            return Err(MLError::new(
                ErrorType::ArgumentError,
                "VERSION_NOT_FOUND_IN_FILES",
            ))
        }
    };

    Ok(filename.to_owned())
}

pub fn get_downloaded_versions(list: List) -> MLE<HashMap<String, String>> {
    let mut versions: HashMap<String, String> = HashMap::new();
    for file in read_dir(&list.download_folder)? {
        let path = file?.path();
        if path.is_file() && path.extension().ok_or("BAH").unwrap() == "jar" {
            let pathstr = path.to_str().ok_or("BAH").unwrap();
            let namesplit: Vec<&str> = pathstr.split('.').collect();
            versions.insert(
                String::from(namesplit[namesplit.len() - 3]),
                String::from(namesplit[namesplit.len() - 2]),
            );
        }
    }
    Ok(versions)
}

pub fn clean_list_dir(list: &List) -> MLE<()> {
    let dl_path = &list.download_folder;
    for entry in std::fs::read_dir(dl_path)? {
        let entry = entry?;
        std::fs::remove_file(entry.path())?;
    }
    Ok(())
}