use std::{
    collections::VecDeque,
    fs,
    io::{self, Read, Write},
    path::Path,
};
use zip::result::ZipError;

use crate::{
    mime_icon::mime_for_path,
    operation::{Controller, OpReader, OperationError, OperationErrorType},
};

pub const SUPPORTED_ARCHIVE_TYPES: &[&str] = &[
    "application/gzip",
    "application/x-compressed-tar",
    "application/x-tar",
    "application/zip",
    #[cfg(feature = "bzip2")]
    "application/x-bzip",
    #[cfg(feature = "bzip2")]
    "application/x-bzip-compressed-tar",
    #[cfg(feature = "bzip2")]
    "application/x-bzip2",
    #[cfg(feature = "bzip2")]
    "application/x-bzip2-compressed-tar",
    #[cfg(feature = "lzma-rust2")]
    "application/x-xz",
    #[cfg(feature = "lzma-rust2")]
    "application/x-xz-compressed-tar",
];

pub const SUPPORTED_EXTENSIONS: &[&str] = &[
    ".tar.bz2",
    ".tar.gz",
    ".tar.lzma",
    ".tar.xz",
    ".tgz",
    ".tar",
    ".zip",
];

pub fn extract(
    path: &Path,
    new_dir: &Path,
    password: &Option<String>,
    controller: &Controller,
) -> Result<(), OperationError> {
    let mime = mime_for_path(path, None, false);
    let password = password.as_deref();
    match mime.essence_str() {
        "application/gzip" | "application/x-compressed-tar" => {
            OpReader::new(path, controller.clone())
                .map(io::BufReader::new)
                .map(flate2::read::GzDecoder::new)
                .map(tar::Archive::new)
                .and_then(|mut archive| archive.unpack(new_dir))
                .map_err(|e| OperationError::from_err(e, controller))?;
        }
        "application/x-tar" => OpReader::new(path, controller.clone())
            .map(io::BufReader::new)
            .map(tar::Archive::new)
            .and_then(|mut archive| archive.unpack(new_dir))
            .map_err(|e| OperationError::from_err(e, controller))?,
        "application/zip" => fs::File::open(path)
            .map(io::BufReader::new)
            .map(zip::ZipArchive::new)
            .map_err(|e| OperationError::from_err(e, controller))?
            .and_then(move |mut archive| {
                zip_extract(&mut archive, new_dir, password, controller.clone())
            })
            .map_err(|e| match e {
                ZipError::UnsupportedArchive(ZipError::PASSWORD_REQUIRED)
                | ZipError::InvalidPassword => {
                    OperationError::from_kind(OperationErrorType::PasswordRequired, controller)
                }
                _ => OperationError::from_err(e, controller),
            })?,
        #[cfg(feature = "bzip2")]
        "application/x-bzip"
        | "application/x-bzip-compressed-tar"
        | "application/x-bzip2"
        | "application/x-bzip2-compressed-tar" => OpReader::new(path, controller.clone())
            .map(io::BufReader::new)
            .map(bzip2::read::BzDecoder::new)
            .map(tar::Archive::new)
            .and_then(|mut archive| archive.unpack(new_dir))
            .map_err(|e| OperationError::from_err(e, controller))?,
        #[cfg(feature = "lzma-rust2")]
        "application/x-xz" | "application/x-xz-compressed-tar" => {
            OpReader::new(path, controller.clone())
                .map(io::BufReader::new)
                .map(|reader| lzma_rust2::XzReader::new(reader, true))
                .map(tar::Archive::new)
                .and_then(|mut archive| archive.unpack(new_dir))
                .map_err(|e| OperationError::from_err(e, controller))?;
        }
        _ => Err(OperationError::from_err(
            format!("unsupported mime type {mime:?}"),
            controller,
        ))?,
    }
    Ok(())
}

// From https://docs.rs/zip/latest/zip/read/struct.ZipArchive.html#method.extract, with cancellation and progress added
fn zip_extract<R: io::Read + io::Seek, P: AsRef<Path>>(
    archive: &mut zip::ZipArchive<R>,
    directory: P,
    password: Option<&str>,
    controller: Controller,
) -> zip::result::ZipResult<()> {
    use std::{ffi::OsString, fs};
    use zip::result::ZipError;

    fn make_writable_dir_all<T: AsRef<Path>>(outpath: T) -> Result<(), ZipError> {
        fs::create_dir_all(outpath.as_ref())?;
        #[cfg(unix)]
        {
            // Dirs must be writable until all normal files are extracted
            use std::os::unix::fs::PermissionsExt;
            std::fs::set_permissions(
                outpath.as_ref(),
                std::fs::Permissions::from_mode(
                    0o700 | std::fs::metadata(outpath.as_ref())?.permissions().mode(),
                ),
            )?;
        }
        Ok(())
    }

    #[cfg(unix)]
    let mut files_by_unix_mode = Vec::new();
    let mut buffer = vec![0; 4 * 1024 * 1024];
    let total_files = archive.len();
    let mut pending_directory_creates = VecDeque::new();

    for i in 0..total_files {
        futures::executor::block_on(async {
            controller
                .check()
                .await
                .map_err(|s| io::Error::other(OperationError::from_state(s, &controller)))
        })?;

        controller.set_progress((i as f32) / total_files as f32);

        let mut file = match password {
            None => archive.by_index(i),
            Some(pwd) => archive.by_index_decrypt(i, pwd.as_bytes()),
        }?;
        let filepath = file
            .enclosed_name()
            .ok_or(ZipError::InvalidArchive("Invalid file path".into()))?;

        let outpath = directory.as_ref().join(filepath);

        if file.is_dir() {
            pending_directory_creates.push_back(outpath.clone());
            continue;
        }
        let symlink_target = if file.is_symlink() && (cfg!(unix) || cfg!(windows)) {
            let mut target = Vec::with_capacity(file.size() as usize);
            file.read_to_end(&mut target)?;
            Some(target)
        } else {
            None
        };
        drop(file);
        if let Some(target) = symlink_target {
            // create all pending dirs
            while let Some(pending_dir) = pending_directory_creates.pop_front() {
                make_writable_dir_all(pending_dir)?;
            }

            if let Some(p) = outpath.parent() {
                make_writable_dir_all(p)?;
            }

            #[cfg(unix)]
            {
                use std::os::unix::ffi::OsStringExt;
                let target = OsString::from_vec(target);
                std::os::unix::fs::symlink(&target, outpath.as_path())?;
            }
            #[cfg(windows)]
            {
                let Ok(target) = String::from_utf8(target) else {
                    return Err(ZipError::InvalidArchive("Invalid UTF-8 as symlink target"));
                };
                let target = target.into_boxed_str();
                let target_is_dir_from_archive =
                    archive.shared.files.contains_key(&target) && is_dir(&target);
                let target_path = directory.as_ref().join(OsString::from(target.to_string()));
                let target_is_dir = if target_is_dir_from_archive {
                    true
                } else if let Ok(meta) = std::fs::metadata(&target_path) {
                    meta.is_dir()
                } else {
                    false
                };
                if target_is_dir {
                    std::os::windows::fs::symlink_dir(target_path, outpath.as_path())?;
                } else {
                    std::os::windows::fs::symlink_file(target_path, outpath.as_path())?;
                }
            }
            continue;
        }
        let mut file = match password {
            None => archive.by_index(i),
            Some(pwd) => archive.by_index_decrypt(i, pwd.as_bytes()),
        }?;

        // create all pending dirs
        while let Some(pending_dir) = pending_directory_creates.pop_front() {
            make_writable_dir_all(pending_dir)?;
        }

        if let Some(p) = outpath.parent() {
            make_writable_dir_all(p)?;
        }

        let total = file.size();
        let mut outfile = fs::File::create(&outpath)?;
        let mut current = 0;
        loop {
            futures::executor::block_on(async {
                controller
                    .check()
                    .await
                    .map_err(|s| io::Error::other(OperationError::from_state(s, &controller)))
            })?;

            let count = file.read(&mut buffer)?;
            if count == 0 {
                break;
            }
            outfile.write_all(&buffer[..count])?;
            current += count as u64;

            if current < total {
                let file_progress = current as f32 / total as f32;
                let total_progress = (i as f32 + file_progress) / total_files as f32;
                controller.set_progress(total_progress);
            }
        }
        #[cfg(unix)]
        {
            // Check for real permissions, which we'll set in a second pass
            if let Some(mode) = file.unix_mode() {
                files_by_unix_mode.push((outpath.clone(), mode));
            }
        }
    }
    #[cfg(unix)]
    {
        use std::cmp::Reverse;
        use std::os::unix::fs::PermissionsExt;

        if files_by_unix_mode.len() > 1 {
            // Ensure we update children's permissions before making a parent unwritable
            files_by_unix_mode.sort_by_key(|(path, _)| Reverse(path.clone()));
        }
        for (path, mode) in files_by_unix_mode {
            fs::set_permissions(&path, fs::Permissions::from_mode(mode))?;
        }
    }
    Ok(())
}