#!/usr/bin/env python
'''
Simple script to extract metadata (dependencies, labels) from QMTest tests (.qmt
files) and suites (.qms files), and report them as declaration of CTest test
properties.
'''
__author__ = 'Marco Clemencic <marco.clemencic@cern.ch>'

import os
import platform
import xml.etree.ElementTree as ET
import collections
import re
import six


def qmt_filename_to_name(path):
    '''
    convert the relative path to a .qmt/.qms file to the canonical QMTest test
    name.

    For example:

    >>> qmt_filename_to_name('some_suite.qms/sub.qms/mytest.qmt')
    'some_suite.sub.mytest'
    '''
    return '.'.join(
        re.sub(r'\.qm[st]$', '', p) for p in path.split(os.path.sep))


def fix_test_name(name, pkg):
    '''
    Convert the QMTest test name to the name used in CTest.

    >>> fix_test_name('package.bug.123', 'Package')
    'Package.bug.123'

    >>> fix_test_name('simple', 'Package')
    'Package.simple'
    '''
    return re.sub(r'^(%s\.)?' % pkg.lower(), '%s.' % pkg, name)


def find_files(rootdir, ext):
    '''
    Find recursively all the files in a directory with a given extension.
    '''
    for dirpath, _dirnames, filenames in os.walk(rootdir):
        for filename in filenames:
            if os.path.splitext(filename)[1] == ext:
                yield os.path.join(dirpath, filename)


def parse_xml(path):
    '''
    Return the parsed tree, handling exceptions if needed.
    '''
    try:
        return ET.parse(path)
    except ET.ParseError as e:
        sys.stderr.write('ERROR: could not parse {}\n{}\n'.format(path, e))
        sys.stderr.flush()
        exit(1)


def analyze_deps(pkg, rootdir):
    '''
    Collect dependencies from the QMTest tests in a directory and report them
    to stdout as CMake commands.

    @param pkg: name of the package (used to fix the name of the tests to match
                the CMake ones
    @param rootdir: directory containing the QMTest tests (usually tests/qmtest)
    '''
    prereq_xpath = 'argument[@name="prerequisites"]/set/tuple/text'
    for path in find_files(rootdir, '.qmt'):
        name = qmt_filename_to_name(os.path.relpath(path, rootdir))
        name = fix_test_name(name, pkg)

        tree = parse_xml(path)

        prereqs = [
            fix_test_name(el.text, pkg) for el in tree.findall(prereq_xpath)
        ]
        if prereqs:
            print('set_property(TEST {0} APPEND PROPERTY DEPENDS {1})'.format(
                name, ' '.join(prereqs)))


def analyze_suites(pkg, rootdir):
    '''
    Find all the suites (.qms files) defined in a directory and use it as a
    label for the tests in it.
    '''
    labels = collections.defaultdict(list)

    tests_xpath = 'argument[@name="test_ids"]/set/text'
    suites_xpath = 'argument[@name="suite_ids"]/set/text'
    for path in find_files(rootdir, '.qms'):
        name = qmt_filename_to_name(os.path.relpath(path, rootdir))
        name = fix_test_name(name, pkg)

        tree = parse_xml(path)

        labels[name].extend(
            fix_test_name(el.text, pkg) for el in tree.findall(tests_xpath))

        if tree.findall(suites_xpath):
            sys.stderr.write(('WARNING: %s: suites of suites are '
                              'not supported yet\n') % path)
            sys.stderr.flush()

    # transpose the dictionary of lists
    test_labels = collections.defaultdict(set)
    for label, tests in six.iteritems(labels):
        for test in tests:
            test_labels[test].add(label)

    for test, labels in six.iteritems(test_labels):
        print('set_property(TEST {0} APPEND PROPERTY LABELS {1})'.format(
            test, ' '.join(labels)))


def analyze_disabling(pkg, rootdir):
    '''
    Set the label 'disabled' for tests that are not supported on a platform.
    '''
    platform_id = (os.environ.get('BINARY_TAG') or os.environ.get('CMTCONFIG')
                   or platform.platform())

    unsupp_xpath = 'argument[@name="unsupported_platforms"]/set/text'
    for path in find_files(rootdir, '.qmt'):
        name = qmt_filename_to_name(os.path.relpath(path, rootdir))
        name = fix_test_name(name, pkg)

        tree = parse_xml(path)
        # If at least one regex matches the test is disabled.
        skip_test = [
            None for el in tree.findall(unsupp_xpath)
            if re.search(el.text, platform_id)
        ]
        if skip_test:
            print('set_property(TEST {0} APPEND PROPERTY LABELS disabled)'.
                  format(name))


if __name__ == '__main__':
    import sys
    analyze_deps(*sys.argv[1:])
    analyze_suites(*sys.argv[1:])
    analyze_disabling(*sys.argv[1:])