"""
Main integration for llvm-lit: This defines a lit test format.
Also contains logic to load benchmark modules.
"""
import lit
import lit.TestRunner
import lit.util
import lit.formats
import litsupport.modules
import litsupport.modules.hash
import litsupport.testfile
import litsupport.testplan
import os


NOCHANGE = lit.Test.ResultCode('NOCHANGE', False)
NOEXE = lit.Test.ResultCode('NOEXE', True)

# add_result_category has been added recently to lit. Lit will crash if it encounters a result code that has not been registered.
# However, some users rely on the lit version provided by pypi that does not require or have add_result_category.
# See for more details: http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20200511/780899.html
try:
    lit.main.add_result_category(NOEXE, "Executable Missing")
    lit.main.add_result_category(NOCHANGE, "Executable Unchanged")
except AttributeError:
    pass


class TestSuiteTest(lit.formats.ShTest):
    def __init__(self):
        super(TestSuiteTest, self).__init__()

    def execute(self, test, litConfig):
        config = test.config
        if config.unsupported:
            return lit.Test.Result(lit.Test.UNSUPPORTED, 'Test is unsupported')
        if litConfig.noExecute:
            return lit.Test.Result(lit.Test.PASS)

        # Parse .test file and initialize context
        tmpDir, tmpBase = lit.TestRunner.getTempPaths(test)
        lit.util.mkdir_p(os.path.dirname(tmpBase))
        context = litsupport.testplan.TestContext(test, litConfig, tmpDir,
                                                  tmpBase)
        litsupport.testfile.parse(context, test.getSourcePath())
        plan = litsupport.testplan.TestPlan()

        # Report missing test executables.
        if not os.path.exists(context.executable):
            return lit.Test.Result(NOEXE, "Executable '%s' is missing" %
                                   context.executable)

        # Skip unchanged tests
        if config.previous_results:
            litsupport.modules.hash.compute(context)
            if litsupport.modules.hash.same_as_previous(context):
                result = lit.Test.Result(
                        NOCHANGE, 'Executable identical to previous run')
                val = lit.Test.toMetricValue(context.executable_hash)
                result.addMetric('hash', val)
                return result

        # Let test modules modify the test plan.
        for modulename in config.test_modules:
            module = litsupport.modules.modules.get(modulename)
            if module is None:
                raise Exception("Unknown testmodule '%s'" % modulename)
            module.mutatePlan(context, plan)

        # Execute Test plan
        result = litsupport.testplan.executePlanTestResult(context, plan)

        return result