# 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.

"""Code that creates simple startup projects."""

from pathlib import Path
from enum import Enum
import subprocess
import shutil
import sys
import os
import re
from glob import glob
from mesonbuild import mesonlib
from mesonbuild.environment import detect_ninja
from mesonbuild.templates.samplefactory import sameple_generator

'''
we currently have one meson template at this time.
'''
from mesonbuild.templates.mesontemplates import create_meson_build

FORTRAN_SUFFIXES = {'.f', '.for', '.F', '.f90', '.F90'}
LANG_SUFFIXES = {'.c', '.cc', '.cpp', '.cs', '.cu', '.d', '.m', '.mm', '.rs', '.java'} | FORTRAN_SUFFIXES
LANG_SUPPORTED = {'c', 'cpp', 'cs', 'cuda', 'd', 'fortran', 'java', 'rust', 'objc', 'objcpp'}

DEFAULT_PROJECT = 'executable'
DEFAULT_VERSION = '0.1'
class DEFAULT_TYPES(Enum):
    EXE = 'executable'
    LIB = 'library'

INFO_MESSAGE = '''Sample project created. To build it run the
following commands:

meson builddir
ninja -C builddir
'''


def create_sample(options) -> None:
    '''
    Based on what arguments are passed we check for a match in language
    then check for project type and create new Meson samples project.
    '''
    sample_gen = sameple_generator(options)
    if options.type == DEFAULT_TYPES['EXE'].value:
        sample_gen.create_executable()
    elif options.type == DEFAULT_TYPES['LIB'].value:
        sample_gen.create_library()
    else:
        raise RuntimeError('Unreachable code')
    print(INFO_MESSAGE)

def autodetect_options(options, sample: bool = False) -> None:
    '''
    Here we autodetect options for args not passed in so don't have to
    think about it.
    '''
    if not options.name:
        options.name = Path().resolve().stem
        if not re.match('[a-zA-Z_][a-zA-Z0-9]*', options.name) and sample:
            raise SystemExit('Name of current directory "{}" is not usable as a sample project name.\n'
                             'Specify a project name with --name.'.format(options.name))
        print('Using "{}" (name of current directory) as project name.'
              .format(options.name))
    if not options.executable:
        options.executable = options.name
        print('Using "{}" (project name) as name of executable to build.'
              .format(options.executable))
    if sample:
        # The rest of the autodetection is not applicable to generating sample projects.
        return
    if not options.srcfiles:
        srcfiles = []
        for f in (f for f in Path().iterdir() if f.is_file()):
            if f.suffix in LANG_SUFFIXES:
                srcfiles.append(f)
        if not srcfiles:
            raise SystemExit('No recognizable source files found.\n'
                             'Run meson init in an empty directory to create a sample project.')
        options.srcfiles = srcfiles
        print("Detected source files: " + ' '.join(map(str, srcfiles)))
    options.srcfiles = [Path(f) for f in options.srcfiles]
    if not options.language:
        for f in options.srcfiles:
            if f.suffix == '.c':
                options.language = 'c'
                break
            if f.suffix in ('.cc', '.cpp'):
                options.language = 'cpp'
                break
            if f.suffix in '.cs':
                options.language = 'cs'
                break
            if f.suffix == '.cu':
                options.language = 'cuda'
                break
            if f.suffix == '.d':
                options.language = 'd'
                break
            if f.suffix in FORTRAN_SUFFIXES:
                options.language = 'fortran'
                break
            if f.suffix == '.rs':
                options.language = 'rust'
                break
            if f.suffix == '.m':
                options.language = 'objc'
                break
            if f.suffix == '.mm':
                options.language = 'objcpp'
                break
            if f.suffix == '.java':
                options.language = 'java'
                break
        if not options.language:
            raise SystemExit("Can't autodetect language, please specify it with -l.")
        print("Detected language: " + options.language)

def add_arguments(parser):
    '''
    Here we add args for that the user can passed when making a new
    Meson project.
    '''
    parser.add_argument("srcfiles", metavar="sourcefile", nargs="*", help="source files. default: all recognized files in current directory")
    parser.add_argument('-C', default='.', dest='wd', help='directory to cd into before running')
    parser.add_argument("-n", "--name", help="project name. default: name of current directory")
    parser.add_argument("-e", "--executable", help="executable name. default: project name")
    parser.add_argument("-d", "--deps", help="dependencies, comma-separated")
    parser.add_argument("-l", "--language", choices=sorted(LANG_SUPPORTED), help="project language. default: autodetected based on source files")
    parser.add_argument("-b", "--build", action='store_true', help="build after generation")
    parser.add_argument("--builddir", default='build', help="directory for build")
    parser.add_argument("-f", "--force", action="store_true", help="force overwrite of existing files and directories.")
    parser.add_argument('--type', default=DEFAULT_PROJECT, choices=('executable', 'library'), help="project type. default: {} based project".format(DEFAULT_PROJECT))
    parser.add_argument('--version', default=DEFAULT_VERSION, help="project version. default: {}".format(DEFAULT_VERSION))

def run(options) -> int:
    '''
    Here we generate the new Meson sample project.
    '''
    if not Path(options.wd).exists():
        sys.exit('Project source root directory not found. Run this command in source directory root.')
    os.chdir(options.wd)

    if not glob('*'):
        autodetect_options(options, sample=True)
        if not options.language:
            print('Defaulting to generating a C language project.')
            options.language = 'c'
        create_sample(options)
    else:
        autodetect_options(options)
        if Path('meson.build').is_file() and not options.force:
            raise SystemExit('meson.build already exists. Use --force to overwrite.')
        create_meson_build(options)
    if options.build:
        if Path(options.builddir).is_dir() and options.force:
            print('Build directory already exists, deleting it.')
            shutil.rmtree(options.builddir)
        print('Building...')
        cmd = mesonlib.meson_command + [options.builddir]
        ret = subprocess.run(cmd)
        if ret.returncode:
            raise SystemExit
        cmd = [detect_ninja(), '-C', options.builddir]
        ret = subprocess.run(cmd)
        if ret.returncode:
            raise SystemExit
    return 0