//! Static files support.

// //! TODO: needs to re-implement actual files handling, current impl blocks
use std::io;
use std::io::Read;
use std::fmt::Write;
use std::fs::{File, DirEntry};
use std::path::{Path, PathBuf};
use std::ops::{Deref, DerefMut};

use mime_guess::get_mime_type;
use route::{Handler, FromRequest};
use recognizer::FromParam;
use httprequest::HttpRequest;
use httpresponse::HttpResponse;
use httpcodes::HTTPOk;

/// A file with an associated name; responds with the Content-Type based on the
/// file extension.
#[derive(Debug)]
pub struct NamedFile(PathBuf, File);

impl NamedFile {
    /// Attempts to open a file in read-only mode.
    ///
    /// # Examples
    ///
    /// ```rust
    /// use actix_web::fs::NamedFile;
    ///
    /// # #[allow(unused_variables)]
    /// let file = NamedFile::open("foo.txt");
    /// ```
    pub fn open<P: AsRef<Path>>(path: P) -> io::Result<NamedFile> {
        let file = File::open(path.as_ref())?;
        Ok(NamedFile(path.as_ref().to_path_buf(), file))
    }

    /// Returns reference to the underlying `File` object.
    #[inline]
    pub fn file(&self) -> &File {
        &self.1
    }

    /// Retrieve the path of this file.
    ///
    /// # Examples
    ///
    /// ```rust
    /// # use std::io;
    /// use actix_web::fs::NamedFile;
    ///
    /// # #[allow(dead_code)]
    /// # fn path() -> io::Result<()> {
    /// let file = NamedFile::open("test.txt")?;
    /// assert_eq!(file.path().as_os_str(), "foo.txt");
    /// # Ok(())
    /// # }
    /// ```
    #[inline]
    pub fn path(&self) -> &Path {
        self.0.as_path()
    }
}

impl Deref for NamedFile {
    type Target = File;

    fn deref(&self) -> &File {
        &self.1
    }
}

impl DerefMut for NamedFile {
    fn deref_mut(&mut self) -> &mut File {
        &mut self.1
    }
}

impl FromRequest for NamedFile {
    type Item = HttpResponse;
    type Error = io::Error;

    fn from_request(mut self, _: HttpRequest) -> Result<HttpResponse, io::Error> {
        let mut resp = HTTPOk.build();
        if let Some(ext) = self.path().extension() {
            let mime = get_mime_type(&ext.to_string_lossy());
            resp.content_type(format!("{}", mime).as_str());
        }
        let mut data = Vec::new();
        let _ = self.1.read_to_end(&mut data);
        Ok(resp.body(data).unwrap())
    }
}

/// A directory; responds with the generated directory listing.
#[derive(Debug)]
pub struct Directory{
    base: PathBuf,
    path: PathBuf
}

impl Directory {
    pub fn new(base: PathBuf, path: PathBuf) -> Directory {
        Directory {
            base: base,
            path: path
        }
    }

    fn can_list(&self, entry: &io::Result<DirEntry>) -> bool {
        if let Ok(ref entry) = *entry {
            if let Some(name) = entry.file_name().to_str() {
                if name.starts_with('.') {
                    return false
                }
            }
            if let Ok(ref md) = entry.metadata() {
                let ft = md.file_type();
                return ft.is_dir() || ft.is_file() || ft.is_symlink()
            }
        }
        false
    }
}

impl FromRequest for Directory {
    type Item = HttpResponse;
    type Error = io::Error;

    fn from_request(self, req: HttpRequest) -> Result<HttpResponse, io::Error> {
        let index_of = format!("Index of {}", req.path());
        let mut body = String::new();
        let base = Path::new(req.path());

        for entry in self.path.read_dir()? {
            if self.can_list(&entry) {
                let entry = entry.unwrap();
                let p = match entry.path().strip_prefix(&self.base) {
                    Ok(p) => base.join(p),
                    Err(_) => continue
                };
                // show file url as relative to static path
                let file_url = format!("{}", p.to_string_lossy());

                // if file is a directory, add '/' to the end of the name
                if let Ok(metadata) = entry.metadata() {
                    if metadata.is_dir() {
                        let _ = write!(body, "<li><a href=\"{}\">{}/</a></li>",
                                       file_url, entry.file_name().to_string_lossy());
                    } else {
                        let _ = write!(body, "<li><a href=\"{}\">{}</a></li>",
                                       file_url, entry.file_name().to_string_lossy());
                    }
                } else {
                    continue
                }
            }
        }

        let html = format!("<html>\
                            <head><title>{}</title></head>\
                            <body><h1>{}</h1>\
                            <ul>\
                            {}\
                            </ul></body>\n</html>", index_of, index_of, body);
        Ok(HTTPOk.build()
           .content_type("text/html; charset=utf-8")
           .body(html).unwrap())
    }
}

/// This enum represents all filesystem elements.
pub enum FilesystemElement {
    File(NamedFile),
    Directory(Directory),
}

impl FromRequest for FilesystemElement {
    type Item = HttpResponse;
    type Error = io::Error;

    fn from_request(self, req: HttpRequest) -> Result<HttpResponse, io::Error> {
        match self {
            FilesystemElement::File(file) => file.from_request(req),
            FilesystemElement::Directory(dir) => dir.from_request(req),
        }
    }
}


/// Static files handling
///
/// Can be registered with `Application::route_handler()`.
///
/// ```rust
/// extern crate actix_web;
///
/// fn main() {
///     let app = actix_web::Application::default("/")
///         .route("/static", actix_web::fs::StaticFiles::new(".", true))
///         .finish();
/// }
/// ```
pub struct StaticFiles {
    directory: PathBuf,
    accessible: bool,
    _show_index: bool,
    _chunk_size: usize,
    _follow_symlinks: bool,
}

impl StaticFiles {
    /// Create new `StaticFiles` instance
    ///
    /// `dir` - base directory
    ///
    /// `index` - show index for directory
    pub fn new<D: Into<PathBuf>>(dir: D, index: bool) -> StaticFiles {
        let dir = dir.into();

        let (dir, access) = match dir.canonicalize() {
            Ok(dir) => {
                if dir.is_dir() {
                    (dir, true)
                } else {
                    warn!("Is not directory `{:?}`", dir);
                    (dir, false)
                }
            },
            Err(err) => {
                warn!("Static files directory `{:?}` error: {}", dir, err);
                (dir, false)
            }
        };

        StaticFiles {
            directory: dir,
            accessible: access,
            _show_index: index,
            _chunk_size: 0,
            _follow_symlinks: false,
        }
    }

}

impl<S> Handler<S> for StaticFiles {
    type Result = Result<FilesystemElement, io::Error>;

    fn handle(&self, req: HttpRequest<S>) -> Self::Result {
        if !self.accessible {
            Err(io::Error::new(io::ErrorKind::NotFound, "not found"))
        } else {
            let relpath = PathBuf::from_param(&req.path()[req.prefix_len()..])
                .map_err(|_| io::Error::new(io::ErrorKind::NotFound, "not found"))?;

            // full filepath
            let path = self.directory.join(&relpath).canonicalize()?;

            if path.is_dir() {
                Ok(FilesystemElement::Directory(Directory::new(self.directory.clone(), path)))
            } else {
                Ok(FilesystemElement::File(NamedFile::open(path)?))
            }
        }
    }
}