from __future__ import print_function

import copy
import os, sys, json
import spec_validator
import argparse
import util


def expand_pattern(expansion_pattern, test_expansion_schema):
    expansion = {}
    for artifact_key in expansion_pattern:
        artifact_value = expansion_pattern[artifact_key]
        if artifact_value == '*':
            expansion[artifact_key] = test_expansion_schema[artifact_key]
        elif isinstance(artifact_value, list):
            expansion[artifact_key] = artifact_value
        elif isinstance(artifact_value, dict):
            # Flattened expansion.
            expansion[artifact_key] = []
            values_dict = expand_pattern(artifact_value,
                                         test_expansion_schema[artifact_key])
            for sub_key in values_dict.keys():
                expansion[artifact_key] += values_dict[sub_key]
        else:
            expansion[artifact_key] = [artifact_value]

    return expansion


def permute_expansion(expansion, artifact_order, selection = {}, artifact_index = 0):
    assert isinstance(artifact_order, list), "artifact_order should be a list"

    if artifact_index >= len(artifact_order):
        yield selection
        return

    artifact_key = artifact_order[artifact_index]

    for artifact_value in expansion[artifact_key]:
        selection[artifact_key] = artifact_value
        for next_selection in permute_expansion(expansion,
                                                artifact_order,
                                                selection,
                                                artifact_index + 1):
            yield next_selection


def generate_selection(config, selection, spec, test_html_template_basename):
    # TODO: Refactor out this referrer-policy-specific part.
    if 'referrer_policy' in spec:
      # Oddball: it can be None, so in JS it's null.
      selection['referrer_policy'] = spec['referrer_policy']

    test_parameters = json.dumps(selection, indent=2, separators=(',', ':'))
    # Adjust the template for the test invoking JS. Indent it to look nice.
    indent = "\n" + " " * 8
    test_parameters = test_parameters.replace("\n", indent)

    selection['test_js'] = '''
      %s(
        %s,
        document.querySelector("meta[name=assert]").content,
        new SanityChecker()
      ).start();
      ''' % (config.test_case_name, test_parameters)

    selection['spec_name'] = spec['name']
    selection['test_page_title'] = config.test_page_title_template % spec['title']
    selection['spec_description'] = spec['description']
    selection['spec_specification_url'] = spec['specification_url']
    selection['helper_js'] = config.helper_js
    selection['sanity_checker_js'] = config.sanity_checker_js
    selection['spec_json_js'] = config.spec_json_js

    test_filename = os.path.join(config.spec_directory, config.test_file_path_pattern % selection)
    test_headers_filename = test_filename + ".headers"
    test_directory = os.path.dirname(test_filename)

    test_html_template = util.get_template(test_html_template_basename)
    disclaimer_template = util.get_template('disclaimer.template')

    html_template_filename = os.path.join(util.template_directory,
                                          test_html_template_basename)
    generated_disclaimer = disclaimer_template \
        % {'generating_script_filename': os.path.relpath(__file__,
                                                         util.test_root_directory),
           'html_template_filename': os.path.relpath(html_template_filename,
                                                     util.test_root_directory)}

    # Adjust the template for the test invoking JS. Indent it to look nice.
    selection['generated_disclaimer'] = generated_disclaimer.rstrip()
    selection['test_description'] = config.test_description_template % selection
    selection['test_description'] = \
        selection['test_description'].rstrip().replace("\n", "\n" + " " * 33)

    # Directory for the test files.
    try:
        os.makedirs(test_directory)
    except:
        pass

    delivery = config.handleDelivery(selection, spec)

    if len(delivery['headers']) > 0:
        with open(test_headers_filename, "w") as f:
            for header in delivery['headers']:
                f.write(header)
                f.write('\n')

    selection['meta_delivery_method'] = delivery['meta']
    # Obey the lint and pretty format.
    if len(selection['meta_delivery_method']) > 0:
        selection['meta_delivery_method'] = "\n    " + \
                                            selection['meta_delivery_method']

    # Write out the generated HTML file.
    util.write_file(test_filename, test_html_template % selection)


def generate_test_source_files(config, spec_json, target):
    test_expansion_schema = spec_json['test_expansion_schema']
    specification = spec_json['specification']

    spec_json_js_template = util.get_template('spec_json.js.template')
    generated_spec_json_filename = os.path.join(config.spec_directory, "spec_json.js")
    util.write_file(generated_spec_json_filename,
               spec_json_js_template % {'spec_json': json.dumps(spec_json)})

    # Choose a debug/release template depending on the target.
    html_template = "test.%s.html.template" % target

    artifact_order = test_expansion_schema.keys() + ['name']
    artifact_order.remove('expansion')

    # Create list of excluded tests.
    exclusion_dict = {}
    for excluded_pattern in spec_json['excluded_tests']:
        excluded_expansion = \
            expand_pattern(excluded_pattern, test_expansion_schema)
        for excluded_selection in permute_expansion(excluded_expansion,
                                                    artifact_order):
            excluded_selection_path = config.selection_pattern % excluded_selection
            exclusion_dict[excluded_selection_path] = True

    for spec in specification:
        # Used to make entries with expansion="override" override preceding
        # entries with the same |selection_path|.
        output_dict = {}

        for expansion_pattern in spec['test_expansion']:
            expansion = expand_pattern(expansion_pattern, test_expansion_schema)
            for selection in permute_expansion(expansion, artifact_order):
                selection_path = config.selection_pattern % selection
                if not selection_path in exclusion_dict:
                    if selection_path in output_dict:
                        if expansion_pattern['expansion'] != 'override':
                            print("Error: %s's expansion is default but overrides %s" % (selection['name'], output_dict[selection_path]['name']))
                            sys.exit(1)
                    output_dict[selection_path] = copy.deepcopy(selection)
                else:
                    print('Excluding selection:', selection_path)

        for selection_path in output_dict:
            selection = output_dict[selection_path]
            generate_selection(config,
                               selection,
                               spec,
                               html_template)


def main(config):
    parser = argparse.ArgumentParser(description='Test suite generator utility')
    parser.add_argument('-t', '--target', type = str,
        choices = ("release", "debug"), default = "release",
        help = 'Sets the appropriate template for generating tests')
    parser.add_argument('-s', '--spec', type = str, default = None,
        help = 'Specify a file used for describing and generating the tests')
    # TODO(kristijanburnik): Add option for the spec_json file.
    args = parser.parse_args()

    if args.spec:
      config.spec_directory = args.spec

    spec_filename = os.path.join(config.spec_directory, "spec.src.json")
    spec_json = util.load_spec_json(spec_filename)
    spec_validator.assert_valid_spec_json(spec_json)

    generate_test_source_files(config, spec_json, args.target)