use crate::cfg::config::Config;
use crate::pkgtoolkit::pkgtools::Package;
use futures_util::stream::TryStreamExt;
use indicatif::{ProgressBar, ProgressStyle};
use reqwest;
use serde::Deserialize;
use std::collections::HashMap;
use std::path::Path;
use tokio::fs::File;
use tokio::io::AsyncWriteExt;

pub struct HTTPPackage {
    config: Config,
    index_packages: Option<HashMap<String, Package>>,
}

#[derive(Deserialize, Debug)]
struct IndexData {
    packages: Vec<Package>,
}

impl HTTPPackage {
    /// Creates a new HTTPPackage object with the given configuration.
    ///
    /// # Returns
    ///
    /// A new HTTPPackage object with the given configuration.
    pub fn new(config: Config) -> Self {
        HTTPPackage {
            config,
            index_packages: None,
        }
    }

    /// Downloads the INDEX.tar.gz file from the configured repository
    /// and stores it in the configured cache directory with a progress bar.
    ///
    /// # Errors
    ///
    /// Returns an error if the request fails, if the response status is not successful, or if there's an issue while reading or writing the file.
    pub async fn fetch_index_http(&mut self) -> Result<bool, Box<dyn std::error::Error>> {
        let repo_url_str = &self.config.repo.repo_url;
        let cache_dir = &self.config.paths.cache_dir;

        let index_url = if repo_url_str.ends_with(".tar.gz") {
            repo_url_str.clone()
        } else {
            format!("{}/INDEX.tar.gz", repo_url_str.trim_end_matches('/'))
        };

        let client = reqwest::Client::new();

        // Make a HEAD request to get the content length for the progress bar
        let head_response = client.head(&index_url).send().await?;
        let content_length: u64 = head_response
            .headers()
            .get(reqwest::header::CONTENT_LENGTH)
            .and_then(|ct_len| ct_len.to_str().ok())
            .and_then(|ct_len| ct_len.parse().ok())
            .unwrap_or(0);

        // Create progress bar
        let pb = if content_length > 0 {
            let pb = ProgressBar::new(content_length);
            pb.set_style(
                ProgressStyle::default_bar()
                    .template("{spinner:.green} [{elapsed_precise}] [{bar:40.cyan/blue}] {bytes}/{total_bytes} ({eta})")?
                    .progress_chars("#>-"),
            );
            pb
        } else {
            let pb = ProgressBar::new_spinner();
            pb.set_style(
                ProgressStyle::default_spinner()
                    .template("{spinner:.green} [{elapsed_precise}] Fetching INDEX.tar.gz...")?,
            );
            pb
        };

        // Send GET request and stream the response body
        let response = client.get(&index_url).send().await?;
        if !response.status().is_success() {
            return Err(format!("HTTP Error: {}", response.status()).into());
        }

        let mut stream = response.bytes_stream();
        let file_path = Path::new(cache_dir).join("INDEX.tar.gz");

        let mut file = File::create(&file_path).await?;
        let mut downloaded: u64 = 0;

        while let Some(chunk) = stream.try_next().await? {
            file.write_all(&chunk).await?;
            let chunk_len = chunk.len() as u64;
            downloaded += chunk_len;
            pb.set_position(downloaded);
        }

        pb.finish_with_message("INDEX.tar.gz download finished");

        // --- Извлечение и парсинг INDEX.toml ---
        log::info!("Extracting INDEX.tar.gz to cache directory...");
        Package::extract_archive(&file_path.to_string_lossy())?; // Используем существующую функцию из pkgtoolkit

        let index_toml_path = Path::new(cache_dir).join("INDEX.toml");
        if !index_toml_path.exists() {
            log::warn!("INDEX.toml not found in INDEX.tar.gz. Proceeding without index data.");
            self.index_packages = Some(HashMap::new());
            return Ok(true);
        }

        let index_content = tokio::fs::read_to_string(&index_toml_path).await?;
        let index_data: IndexData = toml::from_str(&index_content)?;

        let mut package_map = HashMap::new();
        for pkg in index_data.packages {
            // PKG_URL = /repo/package.mesk
            // FULL URL = "http://mesk.anthrill.i2p/i2p/repo/pkg.mesk"
            let base_url = url::Url::parse(&self.config.repo.repo_url)?;
            let full_url = base_url.join(&pkg.url)?;
            let mut pkg_clone = pkg.clone();
            pkg_clone.url = full_url.to_string();

            package_map.insert(pkg_clone.name.clone(), pkg_clone);
        }

        self.index_packages = Some(package_map.clone());
        log::info!(
            "Index loaded successfully, {} packages found.",
            package_map.len()
        );

        Ok(true)
    }

    /// An internal auxiliary function for downloading data and writing it to a file with a progress display.
    ///
    /// # Arguments
    /// * `url` - The URL to download from.
    /// * `file_path` - The path to the file to write the data to.
    /// * `description` - Description of the operation for the progress bar.
    ///
    /// # Errors
    ///
    /// Returns an error if the request fails, if the response status is not successful, or if there's an issue while writing the file.
    async fn download_file_with_progress(
        client: &reqwest::Client,
        url: &str,
        file_path: &Path,
        description: &str,
    ) -> Result<(), Box<dyn std::error::Error>> {
        // Make a HEAD request to get the content length for the progress bar
        let head_response = client.head(url).send().await?;
        let content_length: u64 = head_response
            .headers()
            .get(reqwest::header::CONTENT_LENGTH)
            .and_then(|ct_len| ct_len.to_str().ok())
            .and_then(|ct_len| ct_len.parse().ok())
            .unwrap_or(0);
        let pb = if content_length > 0 {
            let pb = ProgressBar::new(content_length);
            pb.set_style(
                ProgressStyle::default_bar()
                    .template(&format!(
                        "{{spinner:.green}} [{{elapsed_precise}}] [{{bar:40.cyan/blue}}] {{bytes}}/{{total_bytes}} ({} {{eta}})",
                        description
                    ))?
                    .progress_chars("#>-"),
            );
            pb
        } else {
            let pb = ProgressBar::new_spinner();
            pb.set_style(ProgressStyle::default_spinner().template(&format!(
                "{{spinner:.green}} [{{elapsed_precise}}] {}...",
                description
            ))?);
            pb
        };

        // Send GET request and stream the response body
        let response = client.get(url).send().await?;
        if !response.status().is_success() {
            return Err(format!("HTTP Error: {}", response.status()).into());
        }

        let mut stream = response.bytes_stream();
        let mut file = File::create(&file_path).await?;
        let mut downloaded: u64 = 0;

        while let Some(chunk) = stream.try_next().await? {
            file.write_all(&chunk).await?;
            let chunk_len = chunk.len() as u64;
            downloaded += chunk_len;
            pb.set_position(downloaded);
        }

        pb.finish_with_message(format!("{} download finished", description));
        Ok(())
    }

    /// Fetches a specific package identified by `package_name`.
    /// Assumes `fetch_index_http` has been called and `self.index_packages` is populated to get the URL.
    /// Downloads the package file (.mesk) to the cache directory with a progress bar.
    ///
    /// # Errors
    ///
    /// Returns an error if the index is not loaded, the package is not found in the index,
    /// the package URL is invalid, the request fails, or if there's an issue writing the file.
    pub async fn fetch_package_http(
        &self,
        package_name: &str,
    ) -> Result<bool, Box<dyn std::error::Error>> {
        let package_info = self.fetch_package_info(package_name)?;
        let url = &package_info.url;

        let client = reqwest::Client::new();

        let file_name = Path::new(url)
            .file_name()
            .ok_or("Could not determine filename from URL")?
            .to_str()
            .ok_or("Filename is not valid UTF-8")?;
        let cache_dir = &self.config.paths.cache_dir;
        let file_path = Path::new(cache_dir).join(file_name);

        Self::download_file_with_progress(&client, url, &file_path, file_name).await?;

        log::info!(
            "Package '{}' downloaded successfully to {:?}",
            package_name,
            file_path
        );
        Ok(true)
    }

    /// Fetches a specific package identified by `index` (likely the package name).
    /// Assumes `fetch_index_http` has been called and `self.index_packages` is populated.
    pub fn fetch_package_info(
        &self,
        package_name: &str,
    ) -> Result<&Package, Box<dyn std::error::Error>> {
        let packages = self
            .index_packages
            .as_ref()
            .ok_or("Index not loaded. Call fetch_index_http first.")?;
        let pkg_info = packages
            .get(package_name)
            .ok_or(format!("Package '{}' not found in index.", package_name))?;
        Ok(pkg_info)
    }
}