import os
import argparse

# Creates a new metricset with all the necessary file
# In case the module does not exist, also the module is created


def generate_metricset(base_path, metricbeat_path, module, metricset):

    generate_module(base_path, metricbeat_path, module, metricset)
    metricset_path = base_path + "/module/" + module + "/" + metricset
    meta_path = metricset_path + "/_meta"

    if os.path.isdir(metricset_path):
        print("Metricset already exists. Skipping creating metricset {}"
              .format(metricset))
        return

    os.makedirs(meta_path)

    templates = metricbeat_path + "/scripts/module/metricset/"

    content = load_file(templates + "metricset.go.tmpl", module, metricset)
    with open(metricset_path + "/" + metricset + ".go", "w") as f:
        f.write(content)

    content = load_file(templates + "fields.yml", module, metricset)
    with open(meta_path + "/fields.yml", "w") as f:
        f.write(content)

    content = load_file(templates + "docs.asciidoc", module, metricset)
    with open(meta_path + "/docs.asciidoc", "w") as f:
        f.write(content)

    content = load_file(templates + "data.json", module, metricset)
    with open(meta_path + "/data.json", "w") as f:
        f.write(content)

    print("Metricset {} created.".format(metricset))


def generate_module(base_path, metricbeat_path, module, metricset):

    module_path = base_path + "/module/" + module
    meta_path = module_path + "/_meta"

    if os.path.isdir(module_path):
        print("Module already exists. Skipping creating module {}"
              .format(module))
        return

    os.makedirs(meta_path)

    templates = metricbeat_path + "/scripts/module/"

    content = load_file(templates + "fields.yml", module, "")
    with open(meta_path + "/fields.yml", "w") as f:
        f.write(content)

    content = load_file(templates + "docs.asciidoc", module, "")
    with open(meta_path + "/docs.asciidoc", "w") as f:
        f.write(content)

    content = load_file(templates + "config.yml", module, metricset)
    with open(meta_path + "/config.yml", "w") as f:
        f.write(content)

    content = load_file(templates + "doc.go.tmpl", module, "")
    with open(module_path + "/doc.go", "w") as f:
        f.write(content)

    print("Module {} created.".format(module))


def load_file(file, module, metricset):
    content = ""
    with open(file) as f:
        content = f.read()

    return content.replace("{module}", module).replace("{metricset}",
                                                       metricset)


if __name__ == "__main__":

    parser = argparse.ArgumentParser(description="Creates a metricset")
    parser.add_argument("--module", help="Module name")
    parser.add_argument("--metricset", help="Metricset name")

    parser.add_argument("--path", help="Beat path")
    parser.add_argument("--es_beats",
                        help="The path to the general beats folder")

    args = parser.parse_args()

    if args.path is None:
        args.path = './'
        print("Set default path for beat path: " + args.path)

    if args.es_beats is None:
        args.es_beats = '../'
        print("Set default path for es_beats path: " + args.es_beats)

    if args.module is None or args.module == '':
        args.module = raw_input("Module name: ")

    if args.metricset is None or args.metricset == '':
        args.metricset = raw_input("Metricset name: ")

    path = os.path.abspath(args.path)
    metricbeat_path = os.path.abspath(args.es_beats + "/metricbeat")

    generate_metricset(path, metricbeat_path, args.module.lower(),
                       args.metricset.lower())