from jinja2 import Environment, FileSystemLoader
import pprint
import os
import json

from yaml import safe_load
try:
    from yaml import CLoader as Loader
except ImportError:
    from yaml import Loader

def main(args: list) -> None:
    template_filepath = args.template
    input_filepath = args.input
    
    with open(input_filepath, 'r') as file:
        input_devices = file.read()
    
    device_info = dict()

    if os.path.splitext(input_filepath)[1] == ".json":
        device_info = json.loads(input_devices)
    # elif os.path.splitext(input_filepath) == ".yaml":
    #     devices = safe_load(input_devices)
    else:
        print(os.path.splitext(input_filepath))
        print('{} is not a valid JSON format!\n'.format(input_filepath))
        return 406
    
    if args.output is not None:
        output_filepath = args.output
    else:
        output_filepath = './output/{}.nso.config'.format(device_info["device"])

    
    template_path = os.path.dirname(os.path.abspath(template_filepath))
    template_filename = os.path.basename(template_filepath)
    
    env = Environment(loader=FileSystemLoader(template_path))
    template = env.get_template(template_filename)
    
    #Path("./output").mkdir(parents=True, exist_ok=True)

    ### Specify output file - current write to script working directory
    #filename = "./output/bdr_output.config"

    ### open output file mode="w" for create/truncate
    #output = open(filename, mode="w", encoding="utf-8")        
    output = open(output_filepath, mode="w", encoding="utf-8")        

    content = template.render(device_info)

    output.write('{}\n'.format(content))
    
    # for host, keys in devices.items():
    #     device = "{"
    #     for key, value in keys.items():
    #         device += "'{}':'{}', ".format(key,value)
    #     device += "'Hostname':'{}' }}".format(host)
    #     #pprint.pprint(device)

    #     device_dict = eval(device)
    #     #pprint.pprint(device_dict)
    #     content = template.render( device_dict )
                
    #     print('{}\n'.format(content))
    #     output.write('{}\n'.format(content))

if __name__ == "__main__":

    import argparse
    
    parser = argparse.ArgumentParser(description='Arguments for '
                                                 'Config_builder.py')
    parser.add_argument('-template',
                        help='Template config with JINJA markup',
                        required=True
                        )

    parser.add_argument('-input',
                        help='Input file with devices and config variables',
                        required=True
                        )

    parser.add_argument('-output',
                        help='Output File',
                        required=False
                        )

    custom_args = parser.parse_known_args()[0]
    
    #template = custom_args.template
    #input = custom_args.input
    #output = custom_args.output
    
    main(custom_args)