dwldutil 1.0.2

use std::{
    fs::{self, File},
    future::Future,
    io::{Read, Write},
    path::Path,
    pin::Pin,
    sync::Arc,
};

use indicatif::{MultiProgress, ProgressBar, ProgressStyle};
use sha1::{Digest, Sha1};
use sha2::{Sha224, Sha256, Sha384, Sha512};
use smol::{Executor, io::AsyncReadExt, lock::Semaphore};
use surf::Client;

#[cfg(feature = "decompress")]
pub mod decompress;
mod redirection_middleware;

/// Struct in which all the files to be downloaded are set up
pub struct DLBuilder {
    files: Vec<DLFile>,
}

/// Struct in which they set the data in a file
pub struct DLFile {
    /// Size of the file in bytes
    pub size: u64,
    /// URL of the file to be downloaded
    pub url: String,
    /// Hashes of the file
    pub hashes: DLHashes,
    /// Path to save the file
    pub path: String,
    /// decompression configuration
    #[cfg(feature = "decompress")]
    pub decompression_config: Option<decompress::DLDecompressionConfig>,
}
#[derive(Debug, Clone)]
pub struct DLHashes {
    pub hashes: Vec<(DLHashType, String)>,
}
impl DLHashes {
    pub fn new() -> Self {
        Self { hashes: Vec::new() }
    }
    pub fn add_hash(mut self, hash_type: DLHashType, hash_value: String) -> Self {
        self.hashes.push((hash_type, hash_value));
        self
    }
    pub fn sha1(mut self, hash: &str) -> Self {
        self.hashes.push((DLHashType::SHA1, hash.to_string()));
        self
    }
    pub fn sha256(mut self, hash: &str) -> Self {
        self.hashes.push((DLHashType::SHA256, hash.to_string()));
        self
    }
    pub fn sha384(mut self, hash: &str) -> Self {
        self.hashes.push((DLHashType::SHA384, hash.to_string()));
        self
    }
    pub fn sha512(mut self, hash: &str) -> Self {
        self.hashes.push((DLHashType::SHA512, hash.to_string()));
        self
    }
    pub fn sha224(mut self, hash: &str) -> Self {
        self.hashes.push((DLHashType::SHA224, hash.to_string()));
        self
    }
    pub fn verify_data(&self, data: &[u8]) -> bool {
        self.hashes
            .iter()
            .find(|hashed| {
                let (typ, hash) = hashed;
                typ.verify_data(data, hash)
            })
            .is_some()
    }
    pub fn verify_str(&self, data: &str) -> bool {
        self.verify_data(data.as_bytes())
    }
    pub fn verify_file(&self, path: &str) -> bool {
        let data = std::fs::read(path).unwrap();
        self.verify_data(&data)
    }
}

#[derive(Debug, Clone)]
pub enum DLHashType {
    SHA1,
    SHA256,
    SHA224,
    SHA384,
    SHA512,
}

impl DLHashType {
    /// Función genérica que crea el hasher, actualiza con los datos y devuelve el hash en hexadecimal.
    fn compute_hash<D: Digest + Default>(data: &[u8]) -> String {
        let mut hasher = D::default();
        hasher.update(data);
        let result = hasher.finalize();
        hex::encode(result)
    }

    /// Calcula el hash usando el algoritmo seleccionado.
    pub fn compute(&self, data: &[u8]) -> String {
        match self {
            DLHashType::SHA1 => Self::compute_hash::<Sha1>(data),
            DLHashType::SHA256 => Self::compute_hash::<Sha256>(data),
            DLHashType::SHA224 => Self::compute_hash::<Sha224>(data),
            DLHashType::SHA384 => Self::compute_hash::<Sha384>(data),
            DLHashType::SHA512 => Self::compute_hash::<Sha512>(data),
        }
    }
    pub fn verify_str(&self, data: &str, hash: &str) -> bool {
        self.compute(data.to_string().as_bytes()) == hash
    }
    pub fn verify_data(&self, data: &[u8], hash: &str) -> bool {
        self.compute(data) == hash
    }
    pub fn verify_file(&self, path: &Path, hash: &str) -> bool {
        let mut buffer = Vec::new();
        File::open(path)
            .expect("Failed to open file")
            .read_to_end(&mut buffer)
            .expect("Failed to read file");
        self.verify_data(buffer.as_slice(), hash)
    }
}

impl DLFile {
    /// Asynchronous download of the file
    pub async fn download(&self, progress: ProgressBar, client: Client) -> Result<(), String> {
        // get the values of the file
        let url = self.url.clone();
        let path = self.path.clone();
        let hashes = self.hashes.clone();
        let size = self.size;
        let path_clone = self.path.clone(); // Para el mensaje de progreso

        // make the request with SURF
        let mut response = client.get(&url).await.expect("Failed to get response");

        // sets progress bar length
        progress.set_length(size);
        // sets progress bar message
        progress.set_message(format!("Downloading {}", path_clone));
        // if the response is successful, write the file
        if response.status().is_success() {
            // create the parent directory if it doesn't exist
            let ppath = Path::new(&path);
            if let Some(parent) = ppath.parent() {
                fs::create_dir_all(parent).unwrap();
            }

            // create the file
            let mut file = File::create(path.clone()).unwrap();

            // bytes downloaded
            let mut downloaded = 0;
            // buffer of bytes in a chunk, DEFAULT = 8KB
            let mut buffer = [0; 8192];

            // read the response body
            let mut body = response.take_body();
            loop {
                match AsyncReadExt::read(&mut body, &mut buffer).await {
                    Ok(0) => break, // EOF
                    Ok(n) => {
                        // write the chunk to the file
                        file.write_all(&buffer[..n]).unwrap();
                        downloaded += n as u64;
                        // update the progress bar
                        progress.set_position(downloaded);
                    }
                    Err(e) => return Err(e.to_string()),
                }
            }
        } else {
            // if the response isn't successful, abandon the download
            progress.abandon_with_message(format!("Error: código de estado {}", response.status()));
        }

        // check the hashes if they exist
        if hashes.hashes.len() > 0 && !hashes.verify_file(&path_clone) {
            // if the hash verification fails, abandon the download
            progress.abandon_with_message(format!("Hash verification failed for {}", path_clone));
            return Err("Hash verification failed".to_string());
        }

        #[cfg(feature = "decompress")]
        {
            if self.decompression_config.is_some() {
                progress.set_message("Decompressing...");
                let config = self.decompression_config.as_ref().unwrap();
                config.decompress(&path_clone)?;

                if config.delete_after {
                    progress.set_message("Cleaning up...");
                    std::fs::remove_file(&path_clone).expect("Failed to delete file");
                }
            }
        }

        // if the hash verification succeeds, finish the download
        progress.finish_with_message(format!("DONE {}", path));
        Ok(())
    }
    /// New instance of DLFile with default values
    pub fn new() -> Self {
        DLFile {
            path: String::new(),
            url: String::new(),
            size: 0,
            hashes: DLHashes::new(),
            #[cfg(feature = "decompress")]
            decompression_config: None,
        }
    }
    /// Adds the path of the file to instance
    pub fn with_path(mut self, path: &str) -> Self {
        self.path = path.to_string();
        self
    }
    /// Adds the URL of the file to instance
    pub fn with_url(mut self, url: &str) -> Self {
        self.url = url.to_string();
        self
    }
    /// Adds the size of the file to instance
    pub fn with_size(mut self, size: u64) -> Self {
        self.size = size;
        self
    }
    /// Adds the hashes of the file to instance
    pub fn with_hashes(mut self, hashes: DLHashes) -> Self {
        self.hashes = hashes;
        self
    }
    /// Adds the decompression configuration of the file to instance
    #[cfg(feature = "decompress")]
    pub fn with_decompression_config(
        mut self,
        config: crate::decompress::DLDecompressionConfig,
    ) -> Self {
        self.decompression_config = Some(config);
        self
    }
}
impl DLBuilder {
    /// Creates a new instance of DLBuilder
    pub fn new() -> Self {
        DLBuilder { files: Vec::new() }
    }
    /// Adds the files to instance
    pub fn with_files(mut self, files: Vec<DLFile>) -> Self {
        self.files.extend(files);
        self
    }
    /// Creates a new instance of DLBuilder with the given files
    pub fn from_files(files: Vec<DLFile>) -> Self {
        DLBuilder { files }
    }
    /// Adds a file to the instance
    pub fn add_file(mut self, file: DLFile) -> Self {
        self.files.push(file);
        self
    }
    /// Starts the download with the given configuration
    pub fn start_with_config(&self, config: DLStartConfig) {
        // create a new MultiProgress instance
        let m = MultiProgress::new();
        // create the semaphore of the maximum concurrent downloads
        let semaphore = Arc::new(Semaphore::new(config.max_concurrent_downloads));
        // create the executor
        let executor = Arc::new(Executor::new());
        let client = Client::new().with(redirection_middleware::RedirectMiddleware::new(
            config.max_redirections,
        ));

        // obtain the futures
        let futures: Vec<Pin<Box<dyn Future<Output = Result<(), String>>>>> = self
            .files
            .iter()
            .map(|dl_file| {
                // create the progress bar
                let progress = m.add(ProgressBar::new(0).with_style(config.style.clone()));
                // obtain the semaphore permit
                let semaphore = Arc::clone(&semaphore);
                let client = client.clone();
                // create the task
                let task: Pin<Box<dyn Future<Output = Result<(), String>>>> =
                    Box::pin(executor.run(async move {
                        // acquire the semaphore permit
                        let permit = semaphore.acquire().await;
                        // download the file
                        dl_file.download(progress, client.clone()).await?;
                        // release the semaphore permit
                        drop(permit);
                        Ok(())
                    }));
                task
            })
            .collect();

        // join all futures
        smol::block_on(async {
            futures::future::join_all(futures).await;
        });
    }
    /// Starts the download with default configuration
    pub fn start(&self) {
        // start the download with default configuration
        self.start_with_config(DLStartConfig::new());
    }
}

/// Configuration for download
pub struct DLStartConfig {
    pub max_concurrent_downloads: usize,
    pub max_redirections: usize,
    pub style: ProgressStyle,
}
impl DLStartConfig {
    /// Creates a new configuration with default values
    pub fn new() -> Self {
        DLStartConfig {
            max_concurrent_downloads: 5,
            max_redirections: 5,
            style: ProgressStyle::with_template(
                "[{elapsed_precise}] {bar:40.green/red} {pos:>7}/{len:7} {msg}",
            )
            .unwrap()
            .progress_chars("##-"),
        }
    }
    /// Sets the style of the progress bar
    pub fn with_style(mut self, style: ProgressStyle) -> Self {
        self.style = style;
        self
    }
    /// Sets the maximum number of concurrent downloads
    pub fn with_max_concurrent_downloads(mut self, max_concurrent_downloads: usize) -> Self {
        self.max_concurrent_downloads = max_concurrent_downloads;
        self
    }
    /// Sets the maximum number of redirections
    pub fn with_max_redirections(mut self, max_redirections: usize) -> Self {
        self.max_redirections = max_redirections;
        self
    }
}