# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

'''
Script to generate the browsersearch.json file for Fennec.

This script follows these steps:

1. Read the region.properties file in all the given source directories (see
srcdir option). Merge all properties into a single dict accounting for the
priority of source directories.

2. Read the default search plugin from 'browser.search.defaultenginename'.

3. Read the list of search plugins from the 'browser.search.order.INDEX'
properties with values identifying particular search plugins by name.

4. Read each region-specific default search plugin from each property named like
'browser.search.defaultenginename.REGION'.

5. Read the list of region-specific search plugins from the
'browser.search.order.REGION.INDEX' properties with values identifying
particular search plugins by name. Here, REGION is derived from a REGION for
which we have seen a region-specific default plugin.

6. Generate a JSON representation of the above information, and write the result
to browsersearch.json in the locale-specific raw resource directory
e.g. raw/browsersearch.json, raw-pt-rBR/browsersearch.json.
'''

from __future__ import (
    absolute_import,
    print_function,
    unicode_literals,
)

import argparse
import codecs
import json
import sys
import os

from mozbuild.dotproperties import (
    DotProperties,
)
from mozbuild.util import (
    FileAvoidWrite,
)
import mozpack.path as mozpath


def merge_properties(filename, srcdirs):
    """Merges properties from the given file in the given source directories."""
    properties = DotProperties()
    for srcdir in srcdirs:
        path = mozpath.join(srcdir, filename)
        try:
            properties.update(path)
        except IOError:
            # Ignore non-existing files
            continue
    return properties


def main(args):
    parser = argparse.ArgumentParser()
    parser.add_argument('--verbose', '-v', default=False, action='store_true',
                        help='be verbose')
    parser.add_argument('--silent', '-s', default=False, action='store_true',
                        help='be silent')
    parser.add_argument('--srcdir', metavar='SRCDIR',
                        action='append', required=True,
                        help='directories to read inputs from, in order of priority')
    parser.add_argument('output', metavar='OUTPUT',
                        help='output')
    opts = parser.parse_args(args)

    # Use reversed order so that the first srcdir has higher priority to override keys.
    properties = merge_properties('region.properties', reversed(opts.srcdir))

    # Default, not region-specific.
    default = properties.get('browser.search.defaultenginename')
    engines = properties.get_list('browser.search.order')

    writer = codecs.getwriter('utf-8')(sys.stdout)
    if opts.verbose:
        print('Read {len} engines: {engines}'.format(len=len(engines), engines=engines), file=writer)
        print("Default engine is '{default}'.".format(default=default), file=writer)

    browsersearch = {}
    browsersearch['default'] = default
    browsersearch['engines'] = engines

    # This gets defaults, yes; but it also gets the list of regions known.
    regions = properties.get_dict('browser.search.defaultenginename')

    browsersearch['regions'] = {}
    for region in regions.keys():
        region_default = regions[region]
        region_engines = properties.get_list('browser.search.order.{region}'.format(region=region))

        if opts.verbose:
            print("Region '{region}': Read {len} engines: {region_engines}".format(
                len=len(region_engines), region=region, region_engines=region_engines), file=writer)
            print("Region '{region}': Default engine is '{region_default}'.".format(
                region=region, region_default=region_default), file=writer)

        browsersearch['regions'][region] = {
            'default': region_default,
            'engines': region_engines,
        }

    # FileAvoidWrite creates its parent directories.
    output = os.path.abspath(opts.output)
    fh = FileAvoidWrite(output)
    json.dump(browsersearch, fh)
    existed, updated = fh.close()

    if not opts.silent:
        if updated:
            print('{output} updated'.format(output=output))
        else:
            print('{output} already up-to-date'.format(output=output))

    return 0


if __name__ == '__main__':
    sys.exit(main(sys.argv[1:]))