# hgweb/hgwebdir_mod.py - Web interface for a directory of repositories.
#
# Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net>
# Copyright 2005, 2006 Olivia Mackall <olivia@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import annotations

import gc
import os
import time

from ..i18n import _

from .common import (
    ErrorResponse,
    HTTP_SERVER_ERROR,
    cspvalues,
    get_contact,
    get_mtime,
    ismember,
    paritygen,
    staticfile,
    statusmessage,
)

from .. import (
    configitems,
    encoding,
    error,
    extensions,
    pathutil,
    profiling,
    pycompat,
    registrar,
    scmutil,
    templater,
    templateutil,
    ui as uimod,
    util,
)
from ..repo import (
    factory as repo_factory,
)
from . import (
    hgweb_mod_inner as hgweb_mod,
    request as requestmod,
    webutil,
    wsgicgi_inner as wsgicgi,
)
from ..configuration import rcutil
from ..utils import dateutil


def cleannames(items):
    return [(util.pconvert(name).strip(b'/'), path) for name, path in items]


def findrepos(paths):
    repos = []
    for prefix, root in cleannames(paths):
        roothead, roottail = os.path.split(root)
        # "foo = /bar/*" or "foo = /bar/**" lets every repo /bar/N in or below
        # /bar/ be served as as foo/N .
        # '*' will not search inside dirs with .hg (except .hg/patches),
        # '**' will search inside dirs with .hg (and thus also find subrepos).
        try:
            recurse = {b'*': False, b'**': True}[roottail]
        except KeyError:
            # scmutil.walkrepos() will do some validation that the given path
            # exists, and will ignore directories without '.hg' by its nature.
            # Replicate that here so the server doesn't launch with bogus paths.
            # TODO: Follow symlinks for the root path like scmutil.walkrepos()?
            if not os.path.isdir(root) or not os.path.isdir(
                os.path.join(root, b'.hg')
            ):
                msg = _(b"filesystem path is not a repository: '%s'") % root
                hint = _(b"this was mapped to server path '%s'") % prefix
                raise error.InputError(msg, hint=hint)

            repos.append((prefix, root))
            continue
        roothead = os.path.normpath(util.abspath(roothead))
        paths = scmutil.walkrepos(roothead, followsym=True, recurse=recurse)
        repos.extend(urlrepos(prefix, roothead, paths))
    return repos


def urlrepos(prefix, roothead, paths):
    """yield url paths and filesystem paths from a list of repo paths

    >>> conv = lambda seq: [(v, util.pconvert(p)) for v,p in seq]
    >>> conv(urlrepos(b'hg', b'/opt', [b'/opt/r', b'/opt/r/r', b'/opt']))
    [('hg/r', '/opt/r'), ('hg/r/r', '/opt/r/r'), ('hg', '/opt')]
    >>> conv(urlrepos(b'', b'/opt', [b'/opt/r', b'/opt/r/r', b'/opt']))
    [('r', '/opt/r'), ('r/r', '/opt/r/r'), ('', '/opt')]
    """
    for path in paths:
        path = os.path.normpath(path)
        yield (
            prefix + b'/' + util.pconvert(path[len(roothead) :]).lstrip(b'/')
        ).strip(b'/'), path


def readallowed(ui, req):
    """Check allow_read and deny_read config options of a repo's ui object
    to determine user permissions.  By default, with neither option set (or
    both empty), allow all users to read the repo.  There are two ways a
    user can be denied read access:  (1) deny_read is not empty, and the
    user is unauthenticated or deny_read contains user (or *), and (2)
    allow_read is not empty and the user is not in allow_read.  Return True
    if user is allowed to read the repo, else return False."""

    user = req.remoteuser

    deny_read = ui.configlist(b'web', b'deny_read', untrusted=True)
    if deny_read and (not user or ismember(ui, user, deny_read)):
        return False

    allow_read = ui.configlist(b'web', b'allow_read', untrusted=True)
    # by default, allow reading if no allow_read option has been set
    if not allow_read or ismember(ui, user, allow_read):
        return True

    return False


def rawindexentries(ui, repos, req, subdir=b''):
    descend = ui.configbool(b'web', b'descend')
    collapse = ui.configbool(b'web', b'collapse')
    seenrepos = set()
    seendirs = set()
    for name, path in repos:
        if not name.startswith(subdir):
            continue
        name = name[len(subdir) :]
        directory = False

        if b'/' in name:
            if not descend:
                continue

            nameparts = name.split(b'/')
            rootname = nameparts[0]

            if not collapse:
                pass
            elif rootname in seendirs:
                continue
            elif rootname in seenrepos:
                pass
            else:
                directory = True
                name = rootname

                # redefine the path to refer to the directory
                discarded = b'/'.join(nameparts[1:])

                # remove name parts plus accompanying slash
                path = path[: -len(discarded) - 1]

                try:
                    repo_factory.repository(ui, path)
                    directory = False
                except (OSError, error.RepoError):
                    pass

        parts = [
            req.apppath.strip(b'/'),
            subdir.strip(b'/'),
            name.strip(b'/'),
        ]
        url = b'/' + b'/'.join(p for p in parts if p) + b'/'

        # show either a directory entry or a repository
        if directory:
            # get the directory's time information
            try:
                d = (get_mtime(path), dateutil.makedate()[1])
            except OSError:
                continue

            # add '/' to the name to make it obvious that
            # the entry is a directory, not a regular repository
            row = {
                b'contact': b"",
                b'contact_sort': b"",
                b'name': name + b'/',
                b'name_sort': name,
                b'url': url,
                b'description': b"",
                b'description_sort': b"",
                b'lastchange': d,
                b'lastchange_sort': d[1] - d[0],
                b'archives': templateutil.mappinglist([]),
                b'isdirectory': True,
                b'labels': templateutil.hybridlist([], name=b'label'),
            }

            seendirs.add(name)
            yield row
            continue

        u = ui.copy()
        if rcutil.use_repo_hgrc():
            try:
                u.readconfig(os.path.join(path, b'.hg', b'hgrc'))
            except Exception as e:
                u.warn(_(b'error reading %s/.hg/hgrc: %s\n') % (path, e))
                continue

        def get(section, name, default=uimod._unset):
            return u.config(section, name, default, untrusted=True)

        if u.configbool(b"web", b"hidden", untrusted=True):
            continue

        if not readallowed(u, req):
            continue

        # update time with local timezone
        try:
            r = repo_factory.repository(ui, path)
        except OSError:
            u.warn(_(b'error accessing repository at %s\n') % path)
            continue
        except error.RepoError:
            u.warn(_(b'error accessing repository at %s\n') % path)
            continue
        try:
            d = (get_mtime(r.spath), dateutil.makedate()[1])
        except OSError:
            continue

        contact = get_contact(get)
        description = get(b"web", b"description")
        seenrepos.add(name)
        name = get(b"web", b"name", name)
        labels = u.configlist(b'web', b'labels', untrusted=True)
        row = {
            b'contact': contact or b"unknown",
            b'contact_sort': contact.upper() or b"unknown",
            b'name': name,
            b'name_sort': name,
            b'url': url,
            b'description': description or b"unknown",
            b'description_sort': description.upper() or b"unknown",
            b'lastchange': d,
            b'lastchange_sort': d[1] - d[0],
            b'archives': webutil.archivelist(u, b"tip", url),
            b'isdirectory': None,
            b'labels': templateutil.hybridlist(labels, name=b'label'),
        }

        yield row


def _indexentriesgen(
    context, ui, repos, req, stripecount, sortcolumn, descending, subdir
):
    rows = rawindexentries(ui, repos, req, subdir=subdir)

    sortdefault = None, False

    if sortcolumn and sortdefault != (sortcolumn, descending):
        sortkey = b'%s_sort' % sortcolumn
        rows = sorted(rows, key=lambda x: x[sortkey], reverse=descending)

    for row, parity in zip(rows, paritygen(stripecount)):
        row[b'parity'] = parity
        yield row


def indexentries(
    ui, repos, req, stripecount, sortcolumn=b'', descending=False, subdir=b''
):
    args = (ui, repos, req, stripecount, sortcolumn, descending, subdir)
    return templateutil.mappinggenerator(_indexentriesgen, args=args)


class hgwebdir:
    """HTTP server for multiple repositories.

    Given a configuration, different repositories will be served depending
    on the request path.

    Instances are typically used as WSGI applications.
    """

    def __init__(self, conf, baseui=None):
        self.conf = conf
        self.baseui = baseui
        self.ui = None
        self.lastrefresh = 0
        self.motd = None
        self.refresh()
        self.requests_count = 0
        if not baseui:
            # set up environment for new ui
            extensions.loadall(self.ui)
            extensions.populateui(self.ui)

    def refresh(self):
        if self.ui:
            refreshinterval = self.ui.configint(b'web', b'refreshinterval')
        else:
            item = configitems.coreitems[b'web'][b'refreshinterval']
            refreshinterval = item.default

        # refreshinterval <= 0 means to always refresh.
        if (
            refreshinterval > 0
            and self.lastrefresh + refreshinterval > time.time()
        ):
            return

        if self.baseui:
            u = self.baseui.copy()
        else:
            u = uimod.ui.load()
            u.setconfig(b'ui', b'report_untrusted', b'off', b'hgwebdir')
            u.setconfig(b'ui', b'nontty', b'true', b'hgwebdir')
            # displaying bundling progress bar while serving feels wrong and may
            # break some wsgi implementations.
            u.setconfig(b'progress', b'disable', b'true', b'hgweb')

        if isinstance(self.conf, (list, tuple)):
            paths = self.conf
        elif isinstance(self.conf, dict):
            paths = self.conf.items()
        else:
            map = {b'paths': b'hgweb-paths'}
            if not os.path.exists(self.conf):
                raise error.Abort(_(b'config file %s not found!') % self.conf)
            u.readconfig(self.conf, remap=map, trust=True)
            paths = []
            for name, ignored in u.configitems(b'hgweb-paths'):
                for path in u.configlist(b'hgweb-paths', name):
                    paths.append((name, path))

        extensions.populateui(u)

        repos = findrepos(paths)
        for prefix, root in u.configitems(b'collections'):
            prefix = util.pconvert(prefix)
            for path in scmutil.walkrepos(root, followsym=True):
                repo = os.path.normpath(path)
                name = util.pconvert(repo)
                if name.startswith(prefix):
                    name = name[len(prefix) :]
                repos.append((name.lstrip(b'/'), repo))

        self.repos = repos
        self.ui = u
        self.gc_full_collect_rate = self.ui.configint(
            b'experimental', b'web.full-garbage-collection-rate'
        )
        self.gc_full_collections_done = 0
        encoding.encoding = self.ui.config(b'web', b'encoding')
        self.style = self.ui.config(b'web', b'style')
        self.templatepath = self.ui.config(
            b'web', b'templates', untrusted=False
        )
        self.stripecount = self.ui.config(b'web', b'stripes')
        if self.stripecount:
            self.stripecount = int(self.stripecount)
        prefix = self.ui.config(b'web', b'prefix')
        if prefix.startswith(b'/'):
            prefix = prefix[1:]
        if prefix.endswith(b'/'):
            prefix = prefix[:-1]
        self.prefix = prefix
        self.lastrefresh = time.time()

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

    def __call__(self, env, respond):
        baseurl = self.ui.config(b'web', b'baseurl')
        req = requestmod.parserequestfromenv(env, altbaseurl=baseurl)
        res = requestmod.wsgiresponse(req, respond)

        return self.run_wsgi(req, res)

    def run_wsgi(self, req, res):
        profile = self.ui.configbool(b'profiling', b'enabled')
        with profiling.profile(self.ui, enabled=profile):
            try:
                yield from self._runwsgi(req, res)
            finally:
                # There are known cycles in localrepository that prevent
                # those objects (and tons of held references) from being
                # collected through normal refcounting.
                # In some cases, the resulting memory consumption can
                # be tamed by performing explicit garbage collections.
                # In presence of actual leaks or big long-lived caches, the
                # impact on performance of such collections can become a
                # problem, hence the rate shouldn't be set too low.
                # See "Collecting the oldest generation" in
                # https://devguide.python.org/garbage_collector
                # for more about such trade-offs.
                rate = self.gc_full_collect_rate

                # this is not thread safe, but the consequence (skipping
                # a garbage collection) is arguably better than risking
                # to have several threads perform a collection in parallel
                # (long useless wait on all threads).
                self.requests_count += 1
                if rate > 0 and self.requests_count % rate == 0:
                    gc.collect()
                    self.gc_full_collections_done += 1
                else:
                    gc.collect(generation=1)

    def _runwsgi(self, req, res):
        self.refresh()

        csp, nonce = cspvalues(self.ui)
        if csp:
            res.headers[b'Content-Security-Policy'] = csp

        virtual = req.dispatchpath.strip(b'/')
        tmpl = self.templater(req, nonce)
        try:
            ctype = tmpl.render(b'mimetype', {b'encoding': encoding.encoding})

            # Global defaults. These can be overridden by any handler.
            res.status = b'200 Script output follows'
            res.headers[b'Content-Type'] = ctype

            # a static file
            if virtual.startswith(b'static/') or b'static' in req.qsparams:
                if virtual.startswith(b'static/'):
                    fname = virtual[7:]
                else:
                    fname = req.qsparams[b'static']
                static = self.ui.config(b"web", b"static", untrusted=False)
                staticfile(self.templatepath, static, fname, res)
                return res.sendresponse()

            # top-level index

            repos = dict(self.repos)

            if (not virtual or virtual == b'index') and virtual not in repos:
                return self.makeindex(req, res, tmpl)

            # nested indexes and hgwebs

            if virtual.endswith(b'/index') and virtual not in repos:
                subdir = virtual[: -len(b'index')]
                if any(r.startswith(subdir) for r in repos):
                    return self.makeindex(req, res, tmpl, subdir)

            def _virtualdirs():
                # Check the full virtual path, and each parent
                yield virtual
                yield from pathutil.finddirs(virtual)

            for virtualrepo in _virtualdirs():
                real = repos.get(virtualrepo)
                if real:
                    # Re-parse the WSGI environment to take into account our
                    # repository path component.
                    uenv = {
                        k.decode('latin1'): v for k, v in req.rawenv.items()
                    }
                    req = requestmod.parserequestfromenv(
                        uenv,
                        reponame=virtualrepo,
                        altbaseurl=self.ui.config(b'web', b'baseurl'),
                        # Reuse wrapped body file object otherwise state
                        # tracking can get confused.
                        bodyfh=req.bodyfh,
                    )
                    try:
                        # ensure caller gets private copy of ui
                        repo = repo_factory.repository(self.ui.copy(), real)
                        return hgweb_mod.hgweb(repo).run_wsgi(req, res)
                    except OSError as inst:
                        msg = encoding.strtolocal(inst.strerror)
                        raise ErrorResponse(HTTP_SERVER_ERROR, msg)
                    except error.RepoError as inst:
                        raise ErrorResponse(HTTP_SERVER_ERROR, bytes(inst))

            # browse subdirectories
            subdir = virtual + b'/'
            if [r for r in repos if r.startswith(subdir)]:
                return self.makeindex(req, res, tmpl, subdir)

            # prefixes not found
            res.status = b'404 Not Found'
            res.setbodygen(tmpl.generate(b'notfound', {b'repo': virtual}))
            return res.sendresponse()

        except ErrorResponse as e:
            res.status = statusmessage(e.code, pycompat.bytestr(e))
            res.setbodygen(
                tmpl.generate(b'error', {b'error': e.message or b''})
            )
            return res.sendresponse()
        finally:
            del tmpl

    def makeindex(self, req, res, tmpl, subdir=b""):
        self.refresh()
        sortable = [b"name", b"description", b"contact", b"lastchange"]
        sortcolumn, descending = None, False
        if b'sort' in req.qsparams:
            sortcolumn = req.qsparams[b'sort']
            descending = sortcolumn.startswith(b'-')
            if descending:
                sortcolumn = sortcolumn[1:]
            if sortcolumn not in sortable:
                sortcolumn = b""

        sort = [
            (
                b"sort_%s" % column,
                b"%s%s"
                % (
                    b"-" if (not descending and column == sortcolumn) else b"",
                    column,
                ),
            )
            for column in sortable
        ]

        self.refresh()

        entries = indexentries(
            self.ui,
            self.repos,
            req,
            self.stripecount,
            sortcolumn=sortcolumn,
            descending=descending,
            subdir=subdir,
        )

        mapping = {
            b'entries': entries,
            b'subdir': subdir,
            b'pathdef': hgweb_mod.makebreadcrumb(b'/' + subdir, self.prefix),
            b'sortcolumn': sortcolumn,
            b'descending': descending,
        }
        mapping.update(sort)
        res.setbodygen(tmpl.generate(b'index', mapping))
        return res.sendresponse()

    def templater(self, req, nonce):
        def config(*args, **kwargs):
            kwargs.setdefault('untrusted', True)
            return self.ui.config(*args, **kwargs)

        vars = {}
        styles, (style, mapfile, fp) = hgweb_mod.getstyle(
            req, config, self.templatepath
        )
        if style == styles[0]:
            vars[b'style'] = style

        sessionvars = webutil.sessionvars(vars, b'?')
        logourl = config(b'web', b'logourl')
        logoimg = config(b'web', b'logoimg')
        staticurl = (
            config(b'web', b'staticurl')
            or req.apppath.rstrip(b'/') + b'/static/'
        )
        if not staticurl.endswith(b'/'):
            staticurl += b'/'

        defaults = {
            b"encoding": encoding.encoding,
            b"url": req.apppath + b'/',
            b"logourl": logourl,
            b"logoimg": logoimg,
            b"staticurl": staticurl,
            b"sessionvars": sessionvars,
            b"style": style,
            b"nonce": nonce,
        }
        templatekeyword = registrar.templatekeyword(defaults)

        @templatekeyword(b'motd', requires=())
        def motd(context, mapping):
            if self.motd is not None:
                yield self.motd
            else:
                yield config(b'web', b'motd')

        return templater.templater.frommapfile(
            mapfile, fp=fp, defaults=defaults
        )
