import os
from clang.cindex import Config
if 'CLANG_LIBRARY_PATH' in os.environ:
    Config.set_library_path(os.environ['CLANG_LIBRARY_PATH'])

from clang.cindex import CompilationDatabase
from clang.cindex import CompilationDatabaseError
from clang.cindex import CompileCommands
from clang.cindex import CompileCommand
import os
import gc
import unittest
import sys
from .util import skip_if_no_fspath
from .util import str_to_path


kInputsDir = os.path.join(os.path.dirname(__file__), 'INPUTS')


@unittest.skipIf(sys.platform == 'win32', "TODO: Fix these tests on Windows")
class TestCDB(unittest.TestCase):
    def test_create_fail(self):
        """Check we fail loading a database with an assertion"""
        path = os.path.dirname(__file__)

        # clang_CompilationDatabase_fromDirectory calls fprintf(stderr, ...)
        # Suppress its output.
        stderr = os.dup(2)
        with open(os.devnull, 'wb') as null:
            os.dup2(null.fileno(), 2)
        with self.assertRaises(CompilationDatabaseError) as cm:
            cdb = CompilationDatabase.fromDirectory(path)
        os.dup2(stderr, 2)
        os.close(stderr)

        e = cm.exception
        self.assertEqual(e.cdb_error,
            CompilationDatabaseError.ERROR_CANNOTLOADDATABASE)

    def test_create(self):
        """Check we can load a compilation database"""
        cdb = CompilationDatabase.fromDirectory(kInputsDir)

    def test_lookup_succeed(self):
        """Check we get some results if the file exists in the db"""
        cdb = CompilationDatabase.fromDirectory(kInputsDir)
        cmds = cdb.getCompileCommands('/home/john.doe/MyProject/project.cpp')
        self.assertNotEqual(len(cmds), 0)

    @skip_if_no_fspath
    def test_lookup_succeed_pathlike(self):
        """Same as test_lookup_succeed, but with PathLikes"""
        cdb = CompilationDatabase.fromDirectory(str_to_path(kInputsDir))
        cmds = cdb.getCompileCommands(str_to_path('/home/john.doe/MyProject/project.cpp'))
        self.assertNotEqual(len(cmds), 0)

    def test_all_compilecommand(self):
        """Check we get all results from the db"""
        cdb = CompilationDatabase.fromDirectory(kInputsDir)
        cmds = cdb.getAllCompileCommands()
        self.assertEqual(len(cmds), 3)
        expected = [
            { 'wd': '/home/john.doe/MyProject',
              'file': '/home/john.doe/MyProject/project.cpp',
              'line': ['clang++', '-o', 'project.o', '-c',
                       '/home/john.doe/MyProject/project.cpp']},
            { 'wd': '/home/john.doe/MyProjectA',
              'file': '/home/john.doe/MyProject/project2.cpp',
              'line': ['clang++', '-o', 'project2.o', '-c',
                       '/home/john.doe/MyProject/project2.cpp']},
            { 'wd': '/home/john.doe/MyProjectB',
              'file': '/home/john.doe/MyProject/project2.cpp',
              'line': ['clang++', '-DFEATURE=1', '-o', 'project2-feature.o', '-c',
                       '/home/john.doe/MyProject/project2.cpp']},

            ]
        for i in range(len(cmds)):
            self.assertEqual(cmds[i].directory, expected[i]['wd'])
            self.assertEqual(cmds[i].filename, expected[i]['file'])
            for arg, exp in zip(cmds[i].arguments, expected[i]['line']):
                self.assertEqual(arg, exp)

    def test_1_compilecommand(self):
        """Check file with single compile command"""
        cdb = CompilationDatabase.fromDirectory(kInputsDir)
        file = '/home/john.doe/MyProject/project.cpp'
        cmds = cdb.getCompileCommands(file)
        self.assertEqual(len(cmds), 1)
        self.assertEqual(cmds[0].directory, os.path.dirname(file))
        self.assertEqual(cmds[0].filename, file)
        expected = [ 'clang++', '-o', 'project.o', '-c',
                     '/home/john.doe/MyProject/project.cpp']
        for arg, exp in zip(cmds[0].arguments, expected):
            self.assertEqual(arg, exp)

    def test_2_compilecommand(self):
        """Check file with 2 compile commands"""
        cdb = CompilationDatabase.fromDirectory(kInputsDir)
        cmds = cdb.getCompileCommands('/home/john.doe/MyProject/project2.cpp')
        self.assertEqual(len(cmds), 2)
        expected = [
            { 'wd': '/home/john.doe/MyProjectA',
              'line': ['clang++', '-o', 'project2.o', '-c',
                       '/home/john.doe/MyProject/project2.cpp']},
            { 'wd': '/home/john.doe/MyProjectB',
              'line': ['clang++', '-DFEATURE=1', '-o', 'project2-feature.o', '-c',
                       '/home/john.doe/MyProject/project2.cpp']}
            ]
        for i in range(len(cmds)):
            self.assertEqual(cmds[i].directory, expected[i]['wd'])
            for arg, exp in zip(cmds[i].arguments, expected[i]['line']):
                self.assertEqual(arg, exp)

    def test_compilecommand_iterator_stops(self):
        """Check that iterator stops after the correct number of elements"""
        cdb = CompilationDatabase.fromDirectory(kInputsDir)
        count = 0
        for cmd in cdb.getCompileCommands('/home/john.doe/MyProject/project2.cpp'):
            count += 1
            self.assertLessEqual(count, 2)

    def test_compilationDB_references(self):
        """Ensure CompilationsCommands are independent of the database"""
        cdb = CompilationDatabase.fromDirectory(kInputsDir)
        cmds = cdb.getCompileCommands('/home/john.doe/MyProject/project.cpp')
        del cdb
        gc.collect()
        workingdir = cmds[0].directory

    def test_compilationCommands_references(self):
        """Ensure CompilationsCommand keeps a reference to CompilationCommands"""
        cdb = CompilationDatabase.fromDirectory(kInputsDir)
        cmds = cdb.getCompileCommands('/home/john.doe/MyProject/project.cpp')
        del cdb
        cmd0 = cmds[0]
        del cmds
        gc.collect()
        workingdir = cmd0.directory