# Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
# for details. All rights reserved. Use of this source code is governed by a
# BSD-style license that can be found in the LICENSE file.

# Runs tests with old ABI versions and check if the results differ from the
# current results.

import argparse
import json
import os
import subprocess
import sys
import time
import utils

scriptDir = os.path.dirname(os.path.realpath(__file__))
outDir = os.path.join(scriptDir, '..', 'out', 'ReleaseX64')
abiDir = os.path.join(outDir, 'dart-sdk', 'lib', '_internal', 'abiversions')


# Parse command line args to flags.
def parseArgs():
    parser = argparse.ArgumentParser(
        'Runs test.py on all supported ABI versions')
    parser.add_argument(
        '--output-directory',
        default=os.path.join(outDir, 'logs'),
        metavar='DIR',
        dest='logDir',
        help='Directory to output results.json and logs.json to.')
    parser.add_argument(
        '-n',
        metavar='NAME',
        dest='configuration_name',
        help='Name of the configuration to use in the results.')
    return parser.parse_args()


# Info about a running test.
class Test:

    def __init__(self, cmd, resultFile, logFile, version):
        self.cmd = cmd  # The test command.
        self.resultFile = resultFile  # The expected location of the result file.
        self.logFile = logFile  # The expected location of the log file.
        self.version = version  # The ABI version, or None.


# Recursively make directories for the path.
def makeDirs(path):
    try:
        os.makedirs(path)
    except OSError:
        pass


# Build a Test object for the given version (or None).
def buildTest(version):
    testDir = os.path.join(outDir,
                           'test%s' % ('' if version is None else str(version)))
    logDir = os.path.join(testDir, 'logs')
    makeDirs(logDir)

    vm_options = ['--enable-interpreter']
    if version is not None:
        vm_options += ['--use-abi-version=%d' % version]
    cmd = [
        'python',
        os.path.join(scriptDir, 'test.py'),
        '--compiler=dartkb',
        '--mode=release',
        '--write-results',
        '--write-logs',
        '--output_directory=%s' % logDir,
        '--vm-options=%s' % ' '.join(vm_options),
        'lib_2',
    ]

    resultFile = os.path.join(logDir, 'results.json')
    logFile = os.path.join(logDir, 'logs.json')
    return Test(cmd, resultFile, logFile, version)


# Returns whether the dill files exist for an ABI version.
def abiVersionExists(version):
    return os.path.isdir(os.path.join(abiDir, str(version)))


# Build tests for every supported version, and return a list of Test objects.
def buildAllTests():
    abi_version = int(utils.GetAbiVersion())
    oldest_abi_version = int(utils.GetOldestSupportedAbiVersion())
    tests = [buildTest(None)]
    for version in xrange(oldest_abi_version, abi_version + 1):
        if abiVersionExists(version):
            tests.append(buildTest(version))
    return tests


# Run all tests, one by one, and wait for them all to complete.
def runAllTests(tests):
    for test in tests:
        print('\n\n\n=== Running tests %s ===' % (
            ('for ABI version %d' % test.version)
            if test.version is not None else ('without an ABI version')))
        print(subprocess.list2cmdline(test.cmd) + '\n\n')
        proc = subprocess.Popen(test.cmd)
        while proc.returncode is None:
            time.sleep(1)
            proc.communicate()
            proc.poll()


# Read a test result file or log file and convert JSON lines to a dictionary of
# JSON records indexed by name. Assumes result and log files both use name key.
def readTestFile(fileName):
    with open(fileName, 'r') as f:
        return {r['name']: r for r in [json.loads(line) for line in f]}


# Read the test result or log files for every version and return a dict like:
# {name: {version: resultJson, ...}, ...}
def readAllTestFiles(tests, nameGetter):
    allRecords = {}
    for test in tests:
        records = readTestFile(nameGetter(test))
        for name, result in records.items():
            if name not in allRecords:
                allRecords[name] = {}
            allRecords[name][test.version] = result
    return allRecords


# Pick any element of the dictionary, favoring the None key if it exists.
def pickOne(d):
    if None in d:
        return d[None]
    for v in d.values():
        return v
    return None


# Diff the results of a test for each version and construct a new test result
# that reports whether the test results match for each version.
def diffResults(results, configuration_name):
    outResult = pickOne(results)
    exp = results[None]['result'] if None in results else None
    outResult['configuration'] = configuration_name
    outResult['expected'] = exp
    outResult['result'] = exp
    outResult['matches'] = True
    diffs = []
    for version, result in results.items():
        if version is not None:
            act = result['result']
            if exp != act:
                diffs.append(version)
                outResult[
                    'result'] = act  # May be overwritten by other versions.
                outResult['matches'] = False
    return outResult, diffs


# Create a log entry for a test that has diffs. Concatenate all the log records
# and include which tests failed.
def makeLog(diffs, results, logRecords, configuration_name):
    result = pickOne(results)
    logs = ["%s: %s" % (str(v), l['log']) for v, l in logRecords.items()]
    log = ('This test fails if there is a difference in the test results\n'
           'between ABI versions. The expected result is the result on the\n'
           'current ABI: %s\n'
           'These ABI versions reported a different result: %s\n\n'
           'These are the logs of the test runs on different ABI versions.\n'
           'There are no logs for versions where the test passed.\n\n%s' %
           (result['result'], repr(diffs), '\n\n\n'.join(logs)))
    return {
        'name': result['name'],
        'configuration': configuration_name,
        'result': result['result'],
        'log': log,
    }


# Diff the results of all the tests and create the merged result and log files.
def diffAllResults(tests, flags):
    allResults = readAllTestFiles(tests, lambda test: test.resultFile)
    allLogs = readAllTestFiles(tests, lambda test: test.logFile)
    makeDirs(flags.logDir)
    resultFileName = os.path.join(flags.logDir, 'results.json')
    logFileName = os.path.join(flags.logDir, 'logs.json')
    with open(resultFileName, 'w') as resultFile:
        with open(logFileName, 'w') as logFile:
            for name, results in allResults.items():
                outResult, diffs = diffResults(results,
                                               flags.configuration_name)
                resultFile.write(json.dumps(outResult) + '\n')
                if diffs:
                    logRecords = allLogs[name] if name in allLogs else []
                    logFile.write(
                        json.dumps(
                            makeLog(diffs, results, logRecords, flags.
                                    configuration_name)) + '\n')
    print('Log files emitted to %s and %s' % (resultFileName, logFileName))


def main():
    flags = parseArgs()
    tests = buildAllTests()
    runAllTests(tests)
    diffAllResults(tests, flags)
    return 0


if __name__ == '__main__':
    sys.exit(main())