#!/usr/bin/env python3

# Copyright 2012-2015 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.

import sys, stat, traceback, pickle, argparse
import datetime
import os.path
import environment, interpreter, mesonlib
import build
import platform
import mlog, coredata

from coredata import MesonException

parser = argparse.ArgumentParser()

backendlist = ['ninja', 'vs2010', 'xcode']
build_types = ['plain', 'debug', 'debugoptimized', 'release']
layouts = ['mirror', 'flat']
warning_levels = ['1', '2', '3']

default_warning = '1'
try:
    warn_candidate = os.environ['MESON_WARN_LEVEL']
    if warn_candidate in warning_levels:
        default_warning = warn_candidate
except KeyError:
    pass

if mesonlib.is_windows():
    def_prefix = 'c:/'
else:
    def_prefix = '/usr/local'

parser.add_argument('--prefix', default=def_prefix, dest='prefix',
                    help='the installation prefix (default: %(default)s)')
parser.add_argument('--libdir', default=mesonlib.default_libdir(), dest='libdir',
                    help='the installation subdir of libraries (default: %(default)s)')
parser.add_argument('--bindir', default='bin', dest='bindir',
                    help='the installation subdir of executables (default: %(default)s)')
parser.add_argument('--includedir', default='include', dest='includedir',
                    help='relative path of installed headers (default: %(default)s)')
parser.add_argument('--datadir', default='share', dest='datadir',
                    help='relative path to the top of data file subdirectory (default: %(default)s)')
parser.add_argument('--mandir', default='share/man', dest='mandir',
                    help='relative path of man files (default: %(default)s)')
parser.add_argument('--localedir', default='share/locale', dest='localedir',
                    help='relative path of locale data (default: %(default)s)')
parser.add_argument('--backend', default='ninja', dest='backend', choices=backendlist,
                    help='backend to use (default: %(default)s)')
parser.add_argument('--buildtype', default='debug', choices=build_types, dest='buildtype',
                    help='build type go use (default: %(default)s)')
parser.add_argument('--strip', action='store_true', dest='strip', default=False,\
                    help='strip targets on install (default: %(default)s)')
parser.add_argument('--enable-gcov', action='store_true', dest='coverage', default=False,\
                    help='measure test coverage')
parser.add_argument('--disable-pch', action='store_false', dest='use_pch', default=True,\
                    help='do not use precompiled headers')
parser.add_argument('--unity', action='store_true', dest='unity', default=False,\
                    help='unity build')
parser.add_argument('--werror', action='store_true', dest='werror', default=False,\
                    help='Treat warnings as errors')
parser.add_argument('--layout', choices=layouts, dest='layout', default='mirror',\
                    help='Build directory layout.')
parser.add_argument('--warnlevel', default=default_warning, dest='warning_level', choices=warning_levels,\
                    help='Level of compiler warnings to use (larger is more, default is %(default)s)')
parser.add_argument('--cross-file', default=None, dest='cross_file',
                    help='file describing cross compilation environment')
parser.add_argument('-D', action='append', dest='projectoptions', default=[],
                    help='Set project options.')
parser.add_argument('-v', action='store_true', dest='print_version', default=False,
                    help='Print version.')
parser.add_argument('directories', nargs='*')

class MesonApp():

    def __init__(self, dir1, dir2, script_file, handshake, options):
        (self.source_dir, self.build_dir) = self.validate_dirs(dir1, dir2, handshake)
        if not os.path.isabs(options.prefix):
            raise RuntimeError('--prefix must be an absolute path.')
        self.meson_script_file = script_file
        self.options = options

    def has_build_file(self, dirname):
        fname = os.path.join(dirname, environment.build_filename)
        return os.path.exists(fname)

    def validate_core_dirs(self, dir1, dir2):
        ndir1 = os.path.abspath(dir1)
        ndir2 = os.path.abspath(dir2)
        if not stat.S_ISDIR(os.stat(ndir1).st_mode):
            raise RuntimeError('%s is not a directory' % dir1)
        if not stat.S_ISDIR(os.stat(ndir2).st_mode):
            raise RuntimeError('%s is not a directory' % dir2)
        if os.path.samefile(dir1, dir2):
            raise RuntimeError('Source and build directories must not be the same. Create a pristine build directory.')
        if self.has_build_file(ndir1):
            if self.has_build_file(ndir2):
                raise RuntimeError('Both directories contain a build file %s.' % environment.build_filename)
            return (ndir1, ndir2)
        if self.has_build_file(ndir2):
            return (ndir2, ndir1)
        raise RuntimeError('Neither directory contains a build file %s.' % environment.build_filename)

    def validate_dirs(self, dir1, dir2, handshake):
        (src_dir, build_dir) = self.validate_core_dirs(dir1, dir2)
        priv_dir = os.path.join(build_dir, 'meson-private/coredata.dat')
        if os.path.exists(priv_dir):
            if not handshake:
                msg = '''Trying to run Meson on a build directory that has already been configured.
If you want to build it, just run your build command (e.g. ninja) inside the
build directory. Meson will autodetect any changes in your setup and regenerate
itself as required.'''
                raise RuntimeError(msg)
        else:
            if handshake:
                raise RuntimeError('Something went terribly wrong. Please file a bug.')
        return (src_dir, build_dir)

    def generate(self):
        env = environment.Environment(self.source_dir, self.build_dir, self.meson_script_file, self.options)
        mlog.initialize(env.get_log_dir())
        mlog.debug('Build started at', datetime.datetime.now().isoformat())
        mlog.debug('Python binary:', sys.executable)
        mlog.debug('Python system:', platform.system())
        mlog.log(mlog.bold('The Meson build system'))
        mlog.log('Version:', coredata.version)
        mlog.log('Source dir:', mlog.bold(self.source_dir))
        mlog.log('Build dir:', mlog.bold(self.build_dir))
        if env.is_cross_build():
            mlog.log('Build type:', mlog.bold('cross build'))
        else:
            mlog.log('Build type:', mlog.bold('native build'))
        b = build.Build(env)
        if self.options.backend == 'ninja':
            import ninjabackend
            g = ninjabackend.NinjaBackend(b)
        elif self.options.backend == 'vs2010':
            import vs2010backend
            g = vs2010backend.Vs2010Backend(b)
        elif self.options.backend == 'xcode':
            import xcodebackend
            g = xcodebackend.XCodeBackend(b)
        else:
            raise RuntimeError('Unknown backend "%s".' % self.options.backend)

        intr = interpreter.Interpreter(b, g)
        if env.is_cross_build():
            mlog.log('Host machine cpu:', mlog.bold(intr.builtin['host_machine'].cpu_method([], {})))
            mlog.log('Target machine cpu:', mlog.bold(intr.builtin['target_machine'].cpu_method([], {})))
        mlog.log('Build machine cpu:', mlog.bold(intr.builtin['build_machine'].cpu_method([], {})))
        intr.run()
        g.generate(intr)
        env.generating_finished()
        dumpfile = os.path.join(env.get_scratch_dir(), 'build.dat')
        pickle.dump(b, open(dumpfile, 'wb'))

def run(args):
    if sys.version_info < (3, 4):
        print('Meson works correctly only with python 3.4+.')
        print('You have python %s.' % sys.version)
        print('Please update your environment')
        return 1
    if args[-1] == 'secret-handshake':
        args = args[:-1]
        handshake = True
    else:
        handshake = False
    options = parser.parse_args(args[1:])
    if options.print_version:
        print(coredata.version)
        return 0
    args = options.directories
    if len(args) == 0 or len(args) > 2:
        print('%s <source directory> <build directory>' % sys.argv[0])
        print('If you omit either directory, the current directory is substituted.')
        return 1
    dir1 = args[0]
    if len(args) > 1:
        dir2 = args[1]
    else:
        dir2 = '.'
    this_file = os.path.abspath(__file__)
    while os.path.islink(this_file):
        resolved = os.readlink(this_file)
        if resolved[0] != '/':
            this_file = os.path.join(os.path.dirname(this_file), resolved)
        else:
            this_file = resolved

    try:
        app = MesonApp(dir1, dir2, this_file, handshake, options)
    except Exception as e:
        # Log directory does not exist, so just print
        # to stdout.
        print('Error during basic setup:\n')
        print(e)
        return 1
    try:
        app.generate()
    except Exception as e:
        if isinstance(e, MesonException):
            if hasattr(e, 'file') and hasattr(e, 'lineno') and hasattr(e, 'colno'):
                mlog.log(mlog.red('\nMeson encountered an error in file %s, line %d, column %d:' % (e.file, e.lineno, e.colno)))
            else:
                mlog.log(mlog.red('\nMeson encountered an error:'))
            mlog.log(e)
        else:
            traceback.print_exc()
        return 1
    return 0

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