#!/usr/bin/env python3
# Copyright 2018 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import argparse
from collections import defaultdict
import os
import shutil
import stat
import sys

SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
FUCHSIA_ROOT = os.path.dirname(  # $root
    os.path.dirname(             # scripts
    os.path.dirname(             # sdk
    SCRIPT_DIR)))                # bazel

sys.path += [os.path.join(FUCHSIA_ROOT, 'third_party', 'mako')]
from mako.lookup import TemplateLookup
from mako.template import Template
sys.path += [os.path.join(FUCHSIA_ROOT, 'scripts', 'sdk', 'common')]
from files import copy_tree, make_dir
import template_model as model


class SdkWorkspaceInfo(object):
    '''Gathers information about an SDK workspace that is necessary to generate
    tests for it.
    '''

    def __init__(self):
        # Map of target to list of header files.
        # Used to verify that including said headers works properly.
        self.headers = defaultdict(list)
        # Whether the workspace has C/C++ content.
        self.with_cc = False
        # Whether the workspace has Dart content.
        self.with_dart = False
        # Supported target arches.
        self.target_arches = []
        # List of FIDL libraries in the workspace.
        # Names have already been modified to match Bazel conventions.
        self.fidl_libraries = []

def write_file(path, template_name, data, is_executable=False):
    '''Writes a file based on a Mako template.'''
    base = os.path.join(SCRIPT_DIR, 'templates')
    lookup = TemplateLookup(directories=[base, os.path.join(base, 'tests')])
    template = lookup.get_template(template_name + '.mako')
    with open(path, 'w') as file:
        file.write(template.render(data=data))
    if is_executable:
        st = os.stat(path)
        os.chmod(path, st.st_mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)


def create_test_workspace(sdk, output, workspace_info):
    # Remove any existing output.
    shutil.rmtree(output, True)

    # Copy the base tests.
    copy_tree(os.path.join(SCRIPT_DIR, 'tests', 'common'), output)
    if workspace_info.with_cc:
        copy_tree(os.path.join(SCRIPT_DIR, 'tests', 'cc'), output)
    if workspace_info.with_dart:
        copy_tree(os.path.join(SCRIPT_DIR, 'tests', 'dart'), output)

    # WORKSPACE file.
    workspace = model.TestWorkspace(os.path.relpath(sdk, output),
                                    workspace_info.with_cc,
                                    workspace_info.with_dart)
    write_file(os.path.join(output, 'WORKSPACE'), 'workspace', workspace)

    # .bazelrc file.
    crosstool = model.Crosstool(workspace_info.target_arches)
    write_file(os.path.join(output, '.bazelrc'), 'bazelrc', crosstool)

    # run.py file
    write_file(os.path.join(output, 'run.py'), 'run_py', crosstool,
               is_executable=True)

    if workspace_info.with_cc:
        # Generate tests to verify that headers compile fine.
        for target, files in list(workspace_info.headers.items()):
            if not files:
                continue
            dir = os.path.join(output, 'headers', target[2:])
            write_file(make_dir(os.path.join(dir, 'BUILD')),
                       'headers_build', {
                'dep': target,
                'headers': files,
            })
            write_file(make_dir(os.path.join(dir, 'headers.cc')),
                       'headers', {'headers': files})

    # Tests that generated FIDL bindings are usable.
    for library in workspace_info.fidl_libraries:
        # The zx library is special - we don't generate C++ bindings for it.
        # TODO(https://fxbug.dev/90838): Make zx library less special-cased.
        if library == 'zx': continue
        dir = os.path.join(output, 'fidl', library)
        write_file(make_dir(os.path.join(dir, 'BUILD')), 'fidl_build', {
            'library': library,
        })
        write_file(make_dir(os.path.join(dir, 'header_test.cc')),
                   'fidl_headers', {
            'header': library.replace('_', '/') + '/cpp/fidl.h',
        })

    return True