from __future__ import print_function

import threading
import posixpath
import os
import http.server
import urllib.parse
import html
import shutil
import io
import hashlib

# The path to the root of the web server.
root = ""

import renpy


class BannedException(Exception):
    pass


class WebHandler(http.server.BaseHTTPRequestHandler):
    """Simple HTTP request handler with GET and HEAD commands.

    This serves files from the current directory and any of its
    subdirectories.  The MIME type for files is determined by
    calling the .guess_type() method.

    The GET and HEAD requests are identical except that the HEAD
    request omits the actual contents of the file.

    """

    server_version = "Ren'Py/" + renpy.version_only  # @UndefinedVariable

    def do_GET(self):
        """Serve a GET request."""
        f = self.send_head()
        if f:
            try:
                self.copyfile(f, self.wfile)
            finally:
                f.close()

    def do_HEAD(self):
        """Serve a HEAD request."""
        f = self.send_head()
        if f:
            f.close()

    def send_head(self):
        """Common code for GET and HEAD commands.

        This sends the response code and MIME headers.

        Return value is either a file object (which has to be copied
        to the outputfile by the caller unless the command was HEAD,
        and must be closed by the caller under all circumstances), or
        None, in which case the caller has nothing further to do.

        """

        try:
            path = self.translate_path(self.path)
        except BannedException:
            self.send_error(403, "File not found")
            return None

        f = None
        if os.path.isdir(path):
            parts = urllib.parse.urlsplit(self.path)
            if not parts.path.endswith("/"):
                # redirect browser - doing basically what apache does
                self.send_response(301)
                new_parts = (parts[0], parts[1], parts[2] + "/", parts[3], parts[4])
                new_url = urllib.parse.urlunsplit(new_parts)
                self.send_header("Location", new_url)
                self.end_headers()
                return None
            for index in "index.html", "index.htm":
                index = os.path.join(path, index)
                if os.path.exists(index):
                    path = index
                    break
            else:
                return self.list_directory(path)
        ctype = self.guess_type(path)
        try:
            # Always read in binary mode. Opening files in text mode may cause
            # newline translations, making the actual size of the content
            # transmitted *less* than the content-length!
            f = open(path, "rb")
            fs = os.fstat(f.fileno())
        except OSError:
            self.send_error(404, "File not found")
            return None
        try:
            last_modified = self.date_time_string(fs.st_mtime)

            ims = self.headers.get("If-Modified-Since", None)
            if (ims is not None) and (ims == last_modified):
                f.close()
                self.send_response(304)
                self.end_headers()
                return None

            hasher = hashlib.md5()

            while True:
                data = f.read(1024 * 1024)
                if not data:
                    break
                hasher.update(data)

            f.seek(0)

            etag = '"{}"'.format(hasher.hexdigest())

            if self.headers.get("If-None-Match", None) == etag:
                f.close()
                self.send_response(304)
                self.end_headers()
                return None

            self.send_response(200)
            self.send_header("Content-type", ctype)

            self.send_header("Cache-Control", "max-age=0, must-revalidate")
            self.send_header("Content-Length", str(fs.st_size))
            self.send_header("Last-Modified", self.date_time_string(fs.st_mtime))
            self.send_header("ETag", etag)
            self.end_headers()
            return f
        except Exception:
            f.close()
            raise

    def list_directory(self, path):
        """Helper to produce a directory listing (absent index.html).

        Return value is either a file object, or None (indicating an
        error).  In either case, the headers are sent, making the
        interface the same as for send_head().

        """
        try:
            entries = os.listdir(path)
        except OSError:
            self.send_error(404, "No permission to list directory")
            return None
        entries.sort(key=lambda entry: entry.lower())
        listing = io.StringIO()
        displaypath = html.escape(urllib.parse.unquote(self.path))
        listing.write('<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">')
        listing.write("<html>\n<title>Directory listing for %s</title>\n" % displaypath)
        listing.write("<body>\n<h2>Directory listing for %s</h2>\n" % displaypath)
        listing.write("<hr>\n<ul>\n")
        for name in entries:
            fullname = os.path.join(path, name)
            displayname = linkname = name
            # Append / for directories or @ for symbolic links
            if os.path.isdir(fullname):
                displayname = name + "/"
                linkname = name + "/"
            if os.path.islink(fullname):
                displayname = name + "@"
                # Note: a link to a directory displays with @ and links with /
            listing.write('<li><a href="%s">%s</a>\n' % (urllib.parse.quote(linkname), html.escape(displayname)))
        listing.write("</ul>\n<hr>\n</body>\n</html>\n")
        content = listing.getvalue().encode("utf-8", "surrogateescape")
        f = io.BytesIO(content)
        self.send_response(200)
        self.send_header("Content-type", "text/html; charset=utf-8")
        self.send_header("Content-Length", str(len(content)))
        self.end_headers()
        return f

    def translate_path(self, path):
        """Translate a /-separated PATH to the local filename syntax.

        Components that mean special things to the local file system
        (e.g. drive or directory names) are ignored.  (XXX They should
        probably be diagnosed.)

        """
        # abandon query parameters
        path = path.split("?", 1)[0]
        path = path.split("#", 1)[0]
        # Don't forget explicit trailing slash when normalizing. Issue17324
        trailing_slash = path.rstrip().endswith("/")
        path = posixpath.normpath(urllib.parse.unquote(path))
        words = path.split("/")
        words = filter(None, words)

        # Ren'Py - use the root we were given.
        path = root

        for word in words:
            if word.startswith("."):
                raise BannedException("Invalid path.")

            if os.path.dirname(word) or word in (os.curdir, os.pardir):
                # Ignore components that are not a simple file/directory name
                continue
            path = os.path.join(path, word)
        if trailing_slash:
            path += "/"
        return path

    def copyfile(self, source, outputfile):
        """Copy all data between two file objects.

        The SOURCE argument is a file object open for reading
        (or anything with a read() method) and the DESTINATION
        argument is a file object open for writing (or
        anything with a write() method).

        The only reason for overriding this would be to change
        the block size or perhaps to replace newlines by CRLF
        -- note however that this the default server uses this
        to copy binary data as well.

        """
        shutil.copyfileobj(source, outputfile)

    def guess_type(self, path):
        """Guess the type of a file.

        Argument is a PATH (a filename).

        Return value is a string of the form type/subtype,
        usable for a MIME Content-type header.

        The default implementation looks the file's extension
        up in the table self.extensions_map, using application/octet-stream
        as a default; however it would be permissible (if
        slow) to look inside the data to make a better guess.

        """

        _base, ext = posixpath.splitext(path)
        if ext in self.extensions_map:
            return self.extensions_map[ext]
        ext = ext.lower()
        if ext in self.extensions_map:
            return self.extensions_map[ext]
        else:
            return self.extensions_map[""]

    extensions_map = {
        "": "application/octet-stream",  # Default
        ".gz": "application/gzip",
        ".htm": "text/html",
        ".html": "text/html",
        ".js": "application/javascript",
        ".wasm": "application/wasm",
        ".avi": "video/x-msvideo",
        ".m1v": "video/mpeg",
        ".m2v": "video/mpeg",
        ".m4v": "video/mp4",
        ".mkv": "video/x-matroska",
        ".mp4": "video/mp4",
        ".mpe": "video/mpeg",
        ".mpeg": "video/mpeg",
        ".mpg": "video/mpeg",
        ".mpg4": "video/mp4",
        ".mpv": "video/x-matroska",
        ".ogv": "video/ogg",
        ".webm": "video/webm",
        ".wmv": "video/x-ms-wmv",
    }


def run():
    bind_address = os.environ.get("RENPY_WEBSERVER_BIND_ADDRESS", "127.0.0.1")

    server = http.server.ThreadingHTTPServer((bind_address, 8042), WebHandler)
    server.serve_forever()


def start(root_):
    """Starts the server if needed and sets the directory it serves."""

    print("----")

    global root

    server_started = root
    root = root_

    if server_started:
        return

    t = threading.Thread(target=run, daemon=True)
    t.start()
