# -*- coding: iso-8859-1 -*-
#
# Copyright (C) 2011 Edgewall Software
# All rights reserved.
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

"""
Mercurial hook calling `trac-admin $ENV changeset added` for newly added
changesets

The Trac environments to be notified are configured in the `[trac]` section
of `hgrc`. The path to an environment is specified in the `env` key. More
environments can be specified by adding a suffix separated by a dot.

The path to the `trac-admin` executable can be specified in the `trac-admin`
key. A specific path can be set for each environment, by adding the same
suffix to the `trac-admin` key.

The maximum number of changesets to pass per call to `trac-admin` can be
configured with the `revs_per_call` key. The default is relatively low (80
on Windows, 500 on other systems) for maximum compatibility, and can be
increased if you often push thousands of changesets and the system supports
it.

If the Mercurial plugin is installed globally (i.e. not in one of Trac's
plugins directories), the hooks can be configured as follows:
{{{
[hooks]
commit = python:tracext.hg.hooks.add_changesets
changegroup = python:tracext.hg.hooks.add_changesets
}}}

Otherwise, place this file somewhere accessible, and configure the hooks as
follows:
{{{
[hooks]
commit = python:/path/to/hooks.py:add_changesets
changegroup = python:/path/to/hooks.py:add_changesets
}}}

A typical configuration for three environments looks like this:
{{{
[trac]
; For a single Trac environment
env = /path/to/env
trac-admin = /path/to/trac-admin

; Two more environments, with a specific trac-admin for the second
env.other = /path/to/other/env
env.third = /path/to/third/env
trac-admin.third = /path/to/third/trac-admin
}}}
"""

import os
import subprocess

close_fds = os.name == 'posix'


def add_changesets(ui, repo, node, **kwargs):
    """Commit hook calling `trac-admin $ENV changeset added $REPO $NODE ...`
    on all configured Trac environments, for all newly added changesets.
    """
    # Find new nodes
    nodes = [node]
    ctx = repo[node]
    while True:
        # Subtle code ahead :)
        for ctx in ctx.children():
            break
        else:
            break
        nodes.append(ctx.hex())
    
    # Call trac-admin
    error = False
    for name, env in ui.configitems('trac'):
        p = name.split('.', 1)
        if p[0] != 'env' or not env:
            continue
        trac_admin = ui.config('trac', 'trac-admin', 'trac-admin')
        if len(p) > 1:
            trac_admin = ui.config('trac', 'trac-admin.' + p[1], trac_admin)
        try:
            revs_per_call = int(ui.config('trac', 'revs_per_call'))
        except (TypeError, ValueError):
            revs_per_call = 80 if os.name == 'nt' else 500
        
        for i in range(0, len(nodes), revs_per_call):
            command = [trac_admin, env, 'changeset', 'added', repo.root]
            command.extend(nodes[i : i + revs_per_call])
            ui.debug("Calling %r\n" % (command,))
            proc = subprocess.Popen(command, close_fds=close_fds,
                                    stdout=subprocess.PIPE,
                                    stderr=subprocess.STDOUT)
            for line in proc.stdout:
                ui.write(line)
            proc.wait()
            if proc.returncode != 0:
                error = True
                ui.warn("trac-admin failed with return code %d for "
                        "environment:\n  %s\n" % (proc.returncode, env))
    return error