# hgweb/hgweb_mod.py - Web interface for a repository.
#
# Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net>
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2, incorporated herein by reference.

import os
from mercurial import ui, hg, hook, error, encoding, templater
from common import get_mtime, ErrorResponse
from common import HTTP_OK, HTTP_BAD_REQUEST, HTTP_NOT_FOUND, HTTP_SERVER_ERROR
from common import HTTP_UNAUTHORIZED, HTTP_METHOD_NOT_ALLOWED
from request import wsgirequest
import webcommands, protocol, webutil

perms = {
    'changegroup': 'pull',
    'changegroupsubset': 'pull',
    'unbundle': 'push',
    'stream_out': 'pull',
}

class hgweb(object):
    def __init__(self, repo, name=None):
        if isinstance(repo, str):
            u = ui.ui()
            u.setconfig('ui', 'report_untrusted', 'off')
            u.setconfig('ui', 'interactive', 'off')
            self.repo = hg.repository(u, repo)
        else:
            self.repo = repo

        hook.redirect(True)
        self.mtime = -1
        self.reponame = name
        self.archives = 'zip', 'gz', 'bz2'
        self.stripecount = 1
        # a repo owner may set web.templates in .hg/hgrc to get any file
        # readable by the user running the CGI script
        self.templatepath = self.config('web', 'templates')

    # The CGI scripts are often run by a user different from the repo owner.
    # Trust the settings from the .hg/hgrc files by default.
    def config(self, section, name, default=None, untrusted=True):
        return self.repo.ui.config(section, name, default,
                                   untrusted=untrusted)

    def configbool(self, section, name, default=False, untrusted=True):
        return self.repo.ui.configbool(section, name, default,
                                       untrusted=untrusted)

    def configlist(self, section, name, default=None, untrusted=True):
        return self.repo.ui.configlist(section, name, default,
                                       untrusted=untrusted)

    def refresh(self):
        mtime = get_mtime(self.repo.root)
        if mtime != self.mtime:
            self.mtime = mtime
            self.repo = hg.repository(self.repo.ui, self.repo.root)
            self.maxchanges = int(self.config("web", "maxchanges", 10))
            self.stripecount = int(self.config("web", "stripes", 1))
            self.maxshortchanges = int(self.config("web", "maxshortchanges", 60))
            self.maxfiles = int(self.config("web", "maxfiles", 10))
            self.allowpull = self.configbool("web", "allowpull", True)
            encoding.encoding = self.config("web", "encoding",
                                            encoding.encoding)

    def run(self):
        if not os.environ.get('GATEWAY_INTERFACE', '').startswith("CGI/1."):
            raise RuntimeError("This function is only intended to be "
                               "called while running as a CGI script.")
        import mercurial.hgweb.wsgicgi as wsgicgi
        wsgicgi.launch(self)

    def __call__(self, env, respond):
        req = wsgirequest(env, respond)
        return self.run_wsgi(req)

    def run_wsgi(self, req):

        self.refresh()

        # work with CGI variables to create coherent structure
        # use SCRIPT_NAME, PATH_INFO and QUERY_STRING as well as our REPO_NAME

        req.url = req.env['SCRIPT_NAME']
        if not req.url.endswith('/'):
            req.url += '/'
        if 'REPO_NAME' in req.env:
            req.url += req.env['REPO_NAME'] + '/'

        if 'PATH_INFO' in req.env:
            parts = req.env['PATH_INFO'].strip('/').split('/')
            repo_parts = req.env.get('REPO_NAME', '').split('/')
            if parts[:len(repo_parts)] == repo_parts:
                parts = parts[len(repo_parts):]
            query = '/'.join(parts)
        else:
            query = req.env['QUERY_STRING'].split('&', 1)[0]
            query = query.split(';', 1)[0]

        # process this if it's a protocol request
        # protocol bits don't need to create any URLs
        # and the clients always use the old URL structure

        cmd = req.form.get('cmd', [''])[0]
        if cmd and cmd in protocol.__all__:
            if query:
                raise ErrorResponse(HTTP_NOT_FOUND)
            try:
                if cmd in perms:
                    try:
                        self.check_perm(req, perms[cmd])
                    except ErrorResponse, inst:
                        if cmd == 'unbundle':
                            req.drain()
                        raise
                method = getattr(protocol, cmd)
                return method(self.repo, req)
            except ErrorResponse, inst:
                req.respond(inst, protocol.HGTYPE)
                if not inst.message:
                    return []
                return '0\n%s\n' % inst.message,

        # translate user-visible url structure to internal structure

        args = query.split('/', 2)
        if 'cmd' not in req.form and args and args[0]:

            cmd = args.pop(0)
            style = cmd.rfind('-')
            if style != -1:
                req.form['style'] = [cmd[:style]]
                cmd = cmd[style+1:]

            # avoid accepting e.g. style parameter as command
            if hasattr(webcommands, cmd):
                req.form['cmd'] = [cmd]
            else:
                cmd = ''

            if cmd == 'static':
                req.form['file'] = ['/'.join(args)]
            else:
                if args and args[0]:
                    node = args.pop(0)
                    req.form['node'] = [node]
                if args:
                    req.form['file'] = args

            if cmd == 'archive':
                fn = req.form['node'][0]
                for type_, spec in self.archive_specs.iteritems():
                    ext = spec[2]
                    if fn.endswith(ext):
                        req.form['node'] = [fn[:-len(ext)]]
                        req.form['type'] = [type_]

        # process the web interface request

        try:
            tmpl = self.templater(req)
            ctype = tmpl('mimetype', encoding=encoding.encoding)
            ctype = templater.stringify(ctype)

            # check read permissions non-static content
            if cmd != 'static':
                self.check_perm(req, None)

            if cmd == '':
                req.form['cmd'] = [tmpl.cache['default']]
                cmd = req.form['cmd'][0]

            if cmd not in webcommands.__all__:
                msg = 'no such method: %s' % cmd
                raise ErrorResponse(HTTP_BAD_REQUEST, msg)
            elif cmd == 'file' and 'raw' in req.form.get('style', []):
                self.ctype = ctype
                content = webcommands.rawfile(self, req, tmpl)
            else:
                content = getattr(webcommands, cmd)(self, req, tmpl)
                req.respond(HTTP_OK, ctype)

            return content

        except error.LookupError, err:
            req.respond(HTTP_NOT_FOUND, ctype)
            msg = str(err)
            if 'manifest' not in msg:
                msg = 'revision not found: %s' % err.name
            return tmpl('error', error=msg)
        except (error.RepoError, error.RevlogError), inst:
            req.respond(HTTP_SERVER_ERROR, ctype)
            return tmpl('error', error=str(inst))
        except ErrorResponse, inst:
            req.respond(inst, ctype)
            return tmpl('error', error=inst.message)

    def templater(self, req):

        # determine scheme, port and server name
        # this is needed to create absolute urls

        proto = req.env.get('wsgi.url_scheme')
        if proto == 'https':
            proto = 'https'
            default_port = "443"
        else:
            proto = 'http'
            default_port = "80"

        port = req.env["SERVER_PORT"]
        port = port != default_port and (":" + port) or ""
        urlbase = '%s://%s%s' % (proto, req.env['SERVER_NAME'], port)
        staticurl = self.config("web", "staticurl") or req.url + 'static/'
        if not staticurl.endswith('/'):
            staticurl += '/'

        # some functions for the templater

        def header(**map):
            yield tmpl('header', encoding=encoding.encoding, **map)

        def footer(**map):
            yield tmpl("footer", **map)

        def motd(**map):
            yield self.config("web", "motd", "")

        # figure out which style to use

        vars = {}
        style = self.config("web", "style", "paper")
        if 'style' in req.form:
            style = req.form['style'][0]
            vars['style'] = style

        start = req.url[-1] == '?' and '&' or '?'
        sessionvars = webutil.sessionvars(vars, start)
        mapfile = templater.stylemap(style, self.templatepath)

        if not self.reponame:
            self.reponame = (self.config("web", "name")
                             or req.env.get('REPO_NAME')
                             or req.url.strip('/') or self.repo.root)

        # create the templater

        tmpl = templater.templater(mapfile,
                                   defaults={"url": req.url,
                                             "staticurl": staticurl,
                                             "urlbase": urlbase,
                                             "repo": self.reponame,
                                             "header": header,
                                             "footer": footer,
                                             "motd": motd,
                                             "sessionvars": sessionvars
                                            })
        return tmpl

    def archivelist(self, nodeid):
        allowed = self.configlist("web", "allow_archive")
        for i, spec in self.archive_specs.iteritems():
            if i in allowed or self.configbool("web", "allow" + i):
                yield {"type" : i, "extension" : spec[2], "node" : nodeid}

    archive_specs = {
        'bz2': ('application/x-tar', 'tbz2', '.tar.bz2', None),
        'gz': ('application/x-tar', 'tgz', '.tar.gz', None),
        'zip': ('application/zip', 'zip', '.zip', None),
        }

    def check_perm(self, req, op):
        '''Check permission for operation based on request data (including
        authentication info). Return if op allowed, else raise an ErrorResponse
        exception.'''

        user = req.env.get('REMOTE_USER')

        deny_read = self.configlist('web', 'deny_read')
        if deny_read and (not user or deny_read == ['*'] or user in deny_read):
            raise ErrorResponse(HTTP_UNAUTHORIZED, 'read not authorized')

        allow_read = self.configlist('web', 'allow_read')
        result = (not allow_read) or (allow_read == ['*'])
        if not (result or user in allow_read):
            raise ErrorResponse(HTTP_UNAUTHORIZED, 'read not authorized')

        if op == 'pull' and not self.allowpull:
            raise ErrorResponse(HTTP_UNAUTHORIZED, 'pull not authorized')
        elif op == 'pull' or op is None: # op is None for interface requests
            return

        # enforce that you can only push using POST requests
        if req.env['REQUEST_METHOD'] != 'POST':
            msg = 'push requires POST request'
            raise ErrorResponse(HTTP_METHOD_NOT_ALLOWED, msg)

        # require ssl by default for pushing, auth info cannot be sniffed
        # and replayed
        scheme = req.env.get('wsgi.url_scheme')
        if self.configbool('web', 'push_ssl', True) and scheme != 'https':
            raise ErrorResponse(HTTP_OK, 'ssl required')

        deny = self.configlist('web', 'deny_push')
        if deny and (not user or deny == ['*'] or user in deny):
            raise ErrorResponse(HTTP_UNAUTHORIZED, 'push not authorized')

        allow = self.configlist('web', 'allow_push')
        result = allow and (allow == ['*'] or user in allow)
        if not result:
            raise ErrorResponse(HTTP_UNAUTHORIZED, 'push not authorized')