#!/usr/bin/env python -u

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# are met:
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#     notice, this list of conditions and the following disclaimer.
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#     its contributors may be used to endorse or promote products derived
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import argparse
import json


def readJSONFile(path):
    with open(path, 'r') as contents:
        return json.load(contents)


def deepAppend(value1, value2, currentKey=None):
    if type(value1) != type(value2):
        raise TypeError("values have different types for key: {}, {} and {}".format(currentKey, type(value1), type(value2)))
    if isinstance(value1, list):
        return value1 + value2

    result = {};
    for key in (value1.keys() + value2.keys()):
        if key not in result:
            result[key] = deepAppend(value1[key], value2[key], key)
    return result

def mergeJSONs(jsons):
    if len(jsons) == 0:
        raise TypeError("no jsons to merge")

    last = jsons.pop()
    return reduce(deepAppend, jsons, last)

def main():
    parser = argparse.ArgumentParser(description="Merge the resulting json files from multiple invocations of the run_benchmark script.")

    parser.add_argument("-o",
        type=str,
        required=False,
        help="File to put the merged json into prints to standard out if nothing is passed")
    parser.add_argument("jsons",
        type=str,
        nargs='+',
        help="The json files to be merged.")

    # parse_args will error on our list of incomming JSON files...
    args = parser.parse_args()

    result = mergeJSONs(list(map(readJSONFile, args.jsons)))

    if args.o:
        with open(args.o, 'w') as f:
            json.dump(result, f)
    else:
        print(json.dumps(result))


if __name__ == "__main__":
    main()