#!/usr/bin/env python
#
# This Python file contains utility scripts to manage Django translations.
# It has to be run inside the django git root directory.
#
# The following commands are available:
#
# * update_catalogs: check for new strings in core and contrib catalogs, and
#                    output how much strings are new/changed.
#
# * lang_stats: output statistics for each catalog/language combination
#
# * fetch: fetch translations from transifex.com
#
# Each command support the --languages and --resources options to limit their
# operation to the specified language or resource. For example, to get stats
# for Spanish in contrib.admin, run:
#
#  $ python scripts/manage_translations.py lang_stats --language=es --resources=admin

import os
from argparse import ArgumentParser
from subprocess import run

import django
from django.conf import settings
from django.core.management import call_command

HAVE_JS = ["admin"]


def _get_locale_dirs(resources, include_core=True):
    """
    Return a tuple (contrib name, absolute path) for all locale directories,
    optionally including the django core catalog.
    If resources list is not None, filter directories matching resources content.
    """
    contrib_dir = os.path.join(os.getcwd(), "django", "contrib")
    dirs = []

    # Collect all locale directories
    for contrib_name in os.listdir(contrib_dir):
        path = os.path.join(contrib_dir, contrib_name, "locale")
        if os.path.isdir(path):
            dirs.append((contrib_name, path))
            if contrib_name in HAVE_JS:
                dirs.append(("%s-js" % contrib_name, path))
    if include_core:
        dirs.insert(0, ("core", os.path.join(os.getcwd(), "django", "conf", "locale")))

    # Filter by resources, if any
    if resources is not None:
        res_names = [d[0] for d in dirs]
        dirs = [ld for ld in dirs if ld[0] in resources]
        if len(resources) > len(dirs):
            print(
                "You have specified some unknown resources. "
                "Available resource names are: %s" % (", ".join(res_names),)
            )
            exit(1)
    return dirs


def _tx_resource_for_name(name):
    """Return the Transifex resource name"""
    if name == "core":
        return "django.core"
    else:
        return "django.contrib-%s" % name


def _check_diff(cat_name, base_path):
    """
    Output the approximate number of changed/added strings in the en catalog.
    """
    po_path = "%(path)s/en/LC_MESSAGES/django%(ext)s.po" % {
        "path": base_path,
        "ext": "js" if cat_name.endswith("-js") else "",
    }
    p = run(
        "git diff -U0 %s | egrep '^[-+]msgid' | wc -l" % po_path,
        capture_output=True,
        shell=True,
    )
    num_changes = int(p.stdout.strip())
    print("%d changed/added messages in '%s' catalog." % (num_changes, cat_name))


def update_catalogs(resources=None, languages=None):
    """
    Update the en/LC_MESSAGES/django.po (main and contrib) files with
    new/updated translatable strings.
    """
    settings.configure()
    django.setup()
    if resources is not None:
        print("`update_catalogs` will always process all resources.")
    contrib_dirs = _get_locale_dirs(None, include_core=False)

    os.chdir(os.path.join(os.getcwd(), "django"))
    print("Updating en catalogs for Django and contrib apps...")
    call_command("makemessages", locale=["en"])
    print("Updating en JS catalogs for Django and contrib apps...")
    call_command("makemessages", locale=["en"], domain="djangojs")

    # Output changed stats
    _check_diff("core", os.path.join(os.getcwd(), "conf", "locale"))
    for name, dir_ in contrib_dirs:
        _check_diff(name, dir_)


def lang_stats(resources=None, languages=None):
    """
    Output language statistics of committed translation files for each
    Django catalog.
    If resources is provided, it should be a list of translation resource to
    limit the output (e.g. ['core', 'gis']).
    """
    locale_dirs = _get_locale_dirs(resources)

    for name, dir_ in locale_dirs:
        print("\nShowing translations stats for '%s':" % name)
        langs = sorted(d for d in os.listdir(dir_) if not d.startswith("_"))
        for lang in langs:
            if languages and lang not in languages:
                continue
            # TODO: merge first with the latest en catalog
            po_path = "{path}/{lang}/LC_MESSAGES/django{ext}.po".format(
                path=dir_, lang=lang, ext="js" if name.endswith("-js") else ""
            )
            p = run(
                ["msgfmt", "-vc", "-o", "/dev/null", po_path],
                capture_output=True,
                env={"LANG": "C"},
                encoding="utf-8",
            )
            if p.returncode == 0:
                # msgfmt output stats on stderr
                print("%s: %s" % (lang, p.stderr.strip()))
            else:
                print(
                    "Errors happened when checking %s translation for %s:\n%s"
                    % (lang, name, p.stderr)
                )


def fetch(resources=None, languages=None):
    """
    Fetch translations from Transifex, wrap long lines, generate mo files.
    """
    locale_dirs = _get_locale_dirs(resources)
    errors = []

    for name, dir_ in locale_dirs:
        # Transifex pull
        if languages is None:
            run(
                [
                    "tx",
                    "pull",
                    "-r",
                    _tx_resource_for_name(name),
                    "-a",
                    "-f",
                    "--minimum-perc=5",
                ]
            )
            target_langs = sorted(
                d for d in os.listdir(dir_) if not d.startswith("_") and d != "en"
            )
        else:
            for lang in languages:
                run(["tx", "pull", "-r", _tx_resource_for_name(name), "-f", "-l", lang])
            target_langs = languages

        # msgcat to wrap lines and msgfmt for compilation of .mo file
        for lang in target_langs:
            po_path = "%(path)s/%(lang)s/LC_MESSAGES/django%(ext)s.po" % {
                "path": dir_,
                "lang": lang,
                "ext": "js" if name.endswith("-js") else "",
            }
            if not os.path.exists(po_path):
                print(
                    "No %(lang)s translation for resource %(name)s"
                    % {"lang": lang, "name": name}
                )
                continue
            run(["msgcat", "--no-location", "-o", po_path, po_path])
            msgfmt = run(["msgfmt", "-c", "-o", "%s.mo" % po_path[:-3], po_path])
            if msgfmt.returncode != 0:
                errors.append((name, lang))
    if errors:
        print("\nWARNING: Errors have occurred in following cases:")
        for resource, lang in errors:
            print("\tResource %s for language %s" % (resource, lang))
        exit(1)


if __name__ == "__main__":
    RUNABLE_SCRIPTS = ("update_catalogs", "lang_stats", "fetch")

    parser = ArgumentParser()
    parser.add_argument("cmd", nargs=1, choices=RUNABLE_SCRIPTS)
    parser.add_argument(
        "-r",
        "--resources",
        action="append",
        help="limit operation to the specified resources",
    )
    parser.add_argument(
        "-l",
        "--languages",
        action="append",
        help="limit operation to the specified languages",
    )
    options = parser.parse_args()

    eval(options.cmd[0])(options.resources, options.languages)