# hgweb/common.py - Utility functions needed by hgweb_mod and hgwebdir_mod

#

# Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net>

# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>

#

import errno, mimetypes, os

HTTP_OK = 200

HTTP_BAD_REQUEST = 400

HTTP_UNAUTHORIZED = 401

HTTP_FORBIDDEN = 403

HTTP_NOT_FOUND = 404

HTTP_METHOD_NOT_ALLOWED = 405

HTTP_SERVER_ERROR = 500

class ErrorResponse(Exception):

    def __init__(self, code, message=None, headers=[]):

        Exception.__init__(self)

        self.code = code

        self.headers = headers

        if message is not None:

            self.message = message

        else:

            self.message = _statusmessage(code)

def _statusmessage(code):

    from BaseHTTPServer import BaseHTTPRequestHandler

    responses = BaseHTTPRequestHandler.responses

    return responses.get(code, ('Error', 'Unknown error'))[0]

def statusmessage(code):

    return '%d %s' % (code, _statusmessage(code))

def get_mtime(repo_path):

    store_path = os.path.join(repo_path, ".hg")

    if not os.path.isdir(os.path.join(store_path, "data")):

        store_path = os.path.join(store_path, "store")

    cl_path = os.path.join(store_path, "00changelog.i")

    if os.path.exists(cl_path):

        return os.stat(cl_path).st_mtime

    else:

        return os.stat(store_path).st_mtime

def staticfile(directory, fname, req):

    """return a file inside directory with guessed Content-Type header

    fname always uses '/' as directory separator and isn't allowed to

    contain unusual path components.

    Content-Type is guessed using the mimetypes module.

    Return an empty string if fname is illegal or file not found.

    """

    parts = fname.split('/')

    for part in parts:

        if (part in ('', os.curdir, os.pardir) or

            os.sep in part or os.altsep is not None and os.altsep in part):

            return ""

    fpath = os.path.join(*parts)

    if isinstance(directory, str):

        directory = [directory]

    for d in directory:

        path = os.path.join(d, fpath)

        if os.path.exists(path):

            break

    try:

        os.stat(path)

        ct = mimetypes.guess_type(path)[0] or "text/plain"

        req.respond(HTTP_OK, ct, length = os.path.getsize(path))

        return file(path, 'rb').read()

    except TypeError:

        raise ErrorResponse(HTTP_SERVER_ERROR, 'illegal file name')

    except OSError, err:

        if err.errno == errno.ENOENT:

            raise ErrorResponse(HTTP_NOT_FOUND)

        else:

            raise ErrorResponse(HTTP_SERVER_ERROR, err.strerror)

def paritygen(stripecount, offset=0):

    """count parity of horizontal stripes for easier reading"""

    if stripecount and offset:

        # account for offset, e.g. due to building the list in reverse

        count = (stripecount + offset) % stripecount

        parity = (stripecount + offset) / stripecount & 1

    else:

        count = 0

        parity = 0

    while True:

        yield parity

        count += 1

        if stripecount and count >= stripecount:

            parity = 1 - parity

            count = 0

def get_contact(config):

    """Return repo contact information or empty string.

    web.contact is the primary source, but if that is not set, try

    ui.username or $EMAIL as a fallback to display something useful.

    """

    return (config("web", "contact") or

            config("ui", "username") or

            os.environ.get("EMAIL") or "")