import argparse, json, os, os.path, sys


def splitall(path):
    allparts = []
    while 1:
        parts = os.path.split(path)
        if parts[0] == path:  # sentinel for absolute paths
            allparts.insert(0, parts[0])
            break
        elif parts[1] == path:  # sentinel for relative paths
            allparts.insert(0, parts[1])
            break
        else:
            path = parts[0]
            allparts.insert(0, parts[1])
    return allparts


def find_subdirectory(subdir, node):
    contents = node["contents"]
    for item in contents:
        if item["type"] == "directory" and item["name"] == subdir:
            return item
    raise RuntimeError("Missing subdir '%s'" % subdir)


def find_directory(subdir, node):
    if subdir == '.' or subdir == None:
        return node
    for part in splitall(subdir):
        node = find_subdirectory(part, node)
    return node


def get_baseline(tname, path, image, root):
    import re
    filename = os.path.join(path, image)
    relpath = os.path.relpath(filename, root)
    return tname + "_" + re.sub('[^0-9a-zA-Z.]+', '_', relpath)


def _get_options():
    parser = argparse.ArgumentParser( \
        description="Validate Extrats generated in tests")

    parser.add_argument("--name", type=str, required=True,
                        help="name of the test being validated")
    parser.add_argument("--subdir", type=str, default=None,
                        help="sub directory to validate")
    parser.add_argument("--root", type=str, required=True,
                        help="root directory with results")
    parser.add_argument("--json", type=str, required=True,
                        help="validation json file")
    parser.add_argument("--baseline-dir", type=str, default=None,
                        help="directory for baselines for regression tests, if any")
    parser.add_argument("--temp-dir", type=str, default="/tmp",
                        help="directory for results for regression test failures, if any")

    return parser


def main():
    parser = _get_options()
    args = parser.parse_args()

    with open(args.json, 'r') as f:
        data = json.load(f)[0]

    node = data
    test_dir = args.root
    if args.subdir is not None:
        node = find_directory(args.subdir, node)
        test_dir = os.path.join(args.root, args.subdir)

    # Check that directory exists since `os.walk()` does not fail
    # for non extant directories.
    if not os.path.isdir(test_dir):
        raise RuntimeError("Missing directory: '%s'" % test_dir)

    # Validate directory structure.
    regressions_failure_count = 0
    for dirpath, dirs, files in os.walk(test_dir):
        # skip hidden files and directories
        # ref: https://stackoverflow.com/questions/13454164/os-walk-without-hidden-folders
        files = [f for f in files if not f[0] == '.']
        dirs[:] = [d for d in dirs if not d[0] == '.']

        relpath = os.path.relpath(dirpath, test_dir)
        currentnode = find_directory(relpath, node)
        if not currentnode:
            raise RuntimeError("Unexpected directory was found: '%s'" % dirpath)

        dirs = set(dirs)
        files = set(files)
        expected_dirs = set()
        expected_files = set()

        regression_test = []
        for item in currentnode["contents"]:
            if item["type"] == "directory":
                expected_dirs.add(item["name"])
            elif item["type"] == "file":
                expected_files.add(item["name"])
                if item.get("compare", False):
                    regression_test.append(item["name"])

        if expected_dirs != dirs:
            missing = expected_dirs - dirs
            unexpected = dirs - expected_dirs
            raise RuntimeError( \
                "Mismatched directories under '%s' found.\n" \
                "Missing : %s\n" \
                "Unexpected: %s" % (dirpath, missing, unexpected))

        if expected_files != files:
            missing = expected_files - files
            unexpected = files - expected_files
            raise RuntimeError( \
                "Mismatched files under '%s' found.\n" \
                "Missing : %s\n" \
                "Unexpected: %s" % (dirpath, missing, unexpected))

        if regression_test:
            from vtkmodules.vtkTestingRendering import vtkTesting

            t = vtkTesting()
            for image in regression_test:
                t.CleanArguments()
                t.AddArgument("-V")
                baseline_name = get_baseline(args.name, dirpath, image, args.root)
                t.AddArgument(os.path.join(args.baseline_dir, baseline_name))
                t.AddArgument("-T")
                t.AddArgument(args.temp_dir)
                if t.RegressionTest(os.path.join(dirpath, image), 15) != t.PASSED:
                    regressions_failure_count += 1
                    print("\n")
    if regressions_failure_count:
        raise RuntimeError("ERROR: %d regression tests failed!" % regressions_failure_count)


if __name__ == '__main__':
    main()
