# Copyright 2017 The Meson development team

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from mesonbuild import environment, mesonlib

import argparse, sys, os, subprocess, pathlib, stat
import typing as T

def coverage(outputs: T.List[str], source_root: str, subproject_root: str, build_root: str, log_dir: str, use_llvm_cov: bool) -> int:
    outfiles = []
    exitcode = 0

    (gcovr_exe, gcovr_new_rootdir, lcov_exe, genhtml_exe, llvm_cov_exe) = environment.find_coverage_tools()

    # gcovr >= 4.2 requires a different syntax for out of source builds
    if gcovr_new_rootdir:
        gcovr_base_cmd = [gcovr_exe, '-r', source_root, build_root]
    else:
        gcovr_base_cmd = [gcovr_exe, '-r', build_root]

    if use_llvm_cov:
        gcov_exe_args = ['--gcov-executable', llvm_cov_exe + ' gcov']
    else:
        gcov_exe_args = []

    if not outputs or 'xml' in outputs:
        if gcovr_exe:
            subprocess.check_call(gcovr_base_cmd +
                                  ['-x',
                                   '-e', subproject_root,
                                   '-o', os.path.join(log_dir, 'coverage.xml')
                                   ] + gcov_exe_args)
            outfiles.append(('Xml', pathlib.Path(log_dir, 'coverage.xml')))
        elif outputs:
            print('gcovr >= 3.3 needed to generate Xml coverage report')
            exitcode = 1

    if not outputs or 'text' in outputs:
        if gcovr_exe:
            subprocess.check_call(gcovr_base_cmd +
                                  ['-e', subproject_root,
                                   '-o', os.path.join(log_dir, 'coverage.txt')
                                   ] + gcov_exe_args)
            outfiles.append(('Text', pathlib.Path(log_dir, 'coverage.txt')))
        elif outputs:
            print('gcovr >= 3.3 needed to generate text coverage report')
            exitcode = 1

    if not outputs or 'html' in outputs:
        if lcov_exe and genhtml_exe:
            htmloutdir = os.path.join(log_dir, 'coveragereport')
            covinfo = os.path.join(log_dir, 'coverage.info')
            initial_tracefile = covinfo + '.initial'
            run_tracefile = covinfo + '.run'
            raw_tracefile = covinfo + '.raw'
            if use_llvm_cov:
                # Create a shim to allow using llvm-cov as a gcov tool.
                if mesonlib.is_windows():
                    llvm_cov_shim_path = os.path.join(log_dir, 'llvm-cov.bat')
                    with open(llvm_cov_shim_path, 'w') as llvm_cov_bat:
                        llvm_cov_bat.write(f'@"{llvm_cov_exe}" gcov %*')
                else:
                    llvm_cov_shim_path = os.path.join(log_dir, 'llvm-cov.sh')
                    with open(llvm_cov_shim_path, 'w') as llvm_cov_sh:
                        llvm_cov_sh.write(f'#!/usr/bin/env sh\nexec "{llvm_cov_exe}" gcov $@')
                    os.chmod(llvm_cov_shim_path, os.stat(llvm_cov_shim_path).st_mode | stat.S_IEXEC)
                gcov_tool_args = ['--gcov-tool', llvm_cov_shim_path]
            else:
                gcov_tool_args = []
            subprocess.check_call([lcov_exe,
                                   '--directory', build_root,
                                   '--capture',
                                   '--initial',
                                   '--output-file',
                                   initial_tracefile] +
                                  gcov_tool_args)
            subprocess.check_call([lcov_exe,
                                   '--directory', build_root,
                                   '--capture',
                                   '--output-file', run_tracefile,
                                   '--no-checksum',
                                   '--rc', 'lcov_branch_coverage=1'] +
                                  gcov_tool_args)
            # Join initial and test results.
            subprocess.check_call([lcov_exe,
                                   '-a', initial_tracefile,
                                   '-a', run_tracefile,
                                   '--rc', 'lcov_branch_coverage=1',
                                   '-o', raw_tracefile])
            # Remove all directories outside the source_root from the covinfo
            subprocess.check_call([lcov_exe,
                                   '--extract', raw_tracefile,
                                   os.path.join(source_root, '*'),
                                   '--rc', 'lcov_branch_coverage=1',
                                   '--output-file', covinfo])
            # Remove all directories inside subproject dir
            subprocess.check_call([lcov_exe,
                                   '--remove', covinfo,
                                   os.path.join(subproject_root, '*'),
                                   '--rc', 'lcov_branch_coverage=1',
                                   '--output-file', covinfo])
            subprocess.check_call([genhtml_exe,
                                   '--prefix', build_root,
                                   '--prefix', source_root,
                                   '--output-directory', htmloutdir,
                                   '--title', 'Code coverage',
                                   '--legend',
                                   '--show-details',
                                   '--branch-coverage',
                                   covinfo])
            outfiles.append(('Html', pathlib.Path(htmloutdir, 'index.html')))
        elif gcovr_exe:
            htmloutdir = os.path.join(log_dir, 'coveragereport')
            if not os.path.isdir(htmloutdir):
                os.mkdir(htmloutdir)
            subprocess.check_call(gcovr_base_cmd +
                                  ['--html',
                                   '--html-details',
                                   '--print-summary',
                                   '-e', subproject_root,
                                   '-o', os.path.join(htmloutdir, 'index.html'),
                                   ])
            outfiles.append(('Html', pathlib.Path(htmloutdir, 'index.html')))
        elif outputs:
            print('lcov/genhtml or gcovr >= 3.3 needed to generate Html coverage report')
            exitcode = 1

    if not outputs and not outfiles:
        print('Need gcovr or lcov/genhtml to generate any coverage reports')
        exitcode = 1

    if outfiles:
        print('')
        for (filetype, path) in outfiles:
            print(filetype + ' coverage report can be found at', path.as_uri())

    return exitcode

def run(args: T.List[str]) -> int:
    if not os.path.isfile('build.ninja'):
        print('Coverage currently only works with the Ninja backend.')
        return 1
    parser = argparse.ArgumentParser(description='Generate coverage reports')
    parser.add_argument('--text', dest='outputs', action='append_const',
                        const='text', help='generate Text report')
    parser.add_argument('--xml', dest='outputs', action='append_const',
                        const='xml', help='generate Xml report')
    parser.add_argument('--html', dest='outputs', action='append_const',
                        const='html', help='generate Html report')
    parser.add_argument('--use_llvm_cov', action='store_true',
                        help='use llvm-cov')
    parser.add_argument('source_root')
    parser.add_argument('subproject_root')
    parser.add_argument('build_root')
    parser.add_argument('log_dir')
    options = parser.parse_args(args)
    return coverage(options.outputs, options.source_root,
                    options.subproject_root, options.build_root,
                    options.log_dir, options.use_llvm_cov)

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