#!/usr/bin/python3
from __future__ import annotations  # TODO: Remove if python requirement is >= 3.10
import inspect
import argparse
import sys

import pkg_resources

from flaschengeist.config import config


class PrefixMiddleware(object):

    def __init__(self, app, prefix=''):
        self.app = app
        self.prefix = prefix

    def __call__(self, environ, start_response):

        if environ['PATH_INFO'].startswith(self.prefix):
            environ['PATH_INFO'] = environ['PATH_INFO'][len(self.prefix):]
            environ['SCRIPT_NAME'] = self.prefix
            return self.app(environ, start_response)
        else:
            start_response('404', [('Content-Type', 'text/plain')])
            return ["This url does not belong to the app.".encode()]


class InterfaceGenerator:
    known = []
    classes = {}
    mapper = {"str": "string", "int": "number", "float": "number", "date": "Date", "datetime": "Date",
              "NoneType": "null"}

    def __init__(self, namespace, filename):
        self.basename = ""
        self.namespace = namespace
        self.filename = filename
        self.this_type = None

    def pytype(self, cls):
        a = self._pytype(cls)
        print(f"{cls} -> {a}")
        return a

    def _pytype(self, cls):
        import typing
        origin = typing.get_origin(cls)
        arguments = typing.get_args(cls)

        if origin is typing.ForwardRef:  # isinstance(cls, typing.ForwardRef):
            return "", "this" if cls.__forward_arg__ == self.this_type else cls.__forward_arg__
        if origin is typing.Union:
            print(f"A1:  {arguments[1]}")
            if len(arguments) == 2 and arguments[1] is type(None):
                return "?", self.pytype(arguments[0])[1]
            else:
                return "", "|".join([self.pytype(pt)[1] for pt in arguments])
        if origin is list:
            return "", "Array<{}>".format("|".join([self.pytype(a_type)[1] for a_type in arguments]))

        name = cls.__name__ if hasattr(cls, "__name__") else cls if isinstance(cls, str) else None
        if name is not None:
            if name in self.mapper:
                return "", self.mapper[name]
            else:
                return "", name
        print(
            "WARNING: This python version might not detect all types (try >= 3.9). Could not identify >{}<".format(cls)
        )
        return "?", "any"

    def walker(self, module):
        if sys.version_info < (3, 9):
            raise RuntimeError("Python >= 3.9 is required to export API")
        import typing

        if (
                inspect.ismodule(module[1])
                and module[1].__name__.startswith(self.basename)
                and module[1].__name__ not in self.known
        ):
            self.known.append(module[1].__name__)
            for cls in inspect.getmembers(module[1], lambda x: inspect.isclass(x) or inspect.ismodule(x)):
                self.walker(cls)
        elif (
                inspect.isclass(module[1])
                and module[1].__module__.startswith(self.basename)
                and module[0] not in self.classes
                and not module[0].startswith("_")
                and hasattr(module[1], "__annotations__")
        ):
            self.this_type = module[0]
            print("\n\n" + module[0] + "\n")
            d = {}
            for param, ptype in typing.get_type_hints(module[1], globalns=None, localns=None).items():
                if not param.startswith("_") and not param.endswith("_"):
                    print(f"{param} ::: {ptype}")
                    d[param] = self.pytype(ptype)

            if len(d) == 1:
                key, value = d.popitem()
                self.classes[module[0]] = value[1]
            else:
                self.classes[module[0]] = d

    def run(self, models):
        self.basename = models.__name__
        self.walker(("models", models))

    def write(self):
        with open(self.filename, "w") as file:
            file.write("declare namespace {} {{\n".format(self.namespace))
            for cls, params in self.classes.items():
                if isinstance(params, str):
                    file.write("\ttype {} = {};\n".format(cls, params))
                else:
                    file.write("\tinterface {} {{\n".format(cls))
                    for name in params:
                        file.write("\t\t{}{}: {};\n".format(name, *params[name]))
                    file.write("\t}\n")
            file.write("}\n")


def install(arguments):
    from flaschengeist.app import create_app, install_all

    app = create_app()
    with app.app_context():
        install_all()


def run(arguments):
    from flaschengeist.app import create_app

    app = create_app()
    with app.app_context():
        app.wsgi_app = PrefixMiddleware(app.wsgi_app, prefix=config["FLASCHENGEIST"].get("root", ""))
        if arguments.debug:
            app.run(arguments.host, arguments.port, debug=True)
        else:
            app.run(arguments.host, arguments.port, debug=False)


def export(arguments):
    import flaschengeist.models as models
    from flaschengeist.app import create_app

    app = create_app()
    with app.app_context():
        gen = InterfaceGenerator(arguments.namespace, arguments.file)
        gen.run(models)
        if arguments.plugins:
            for entry_point in pkg_resources.iter_entry_points("flaschengeist.plugin"):
                plg = entry_point.load()
                if hasattr(plg, "models"):
                    gen.run(plg.models)
        gen.write()


if __name__ == "__main__":
    # create the top-level parser
    parser = argparse.ArgumentParser()
    subparsers = parser.add_subparsers(help="sub-command help", dest="sub_command")
    subparsers.required = True
    parser_run = subparsers.add_parser("run", help="run flaschengeist")
    parser_run.set_defaults(func=run)
    parser_run.add_argument("--host", help="set hostname to listen on", default="127.0.0.1")
    parser_run.add_argument("--port", help="set port to listen on", type=int, default=5000)
    parser_run.add_argument("--debug", help="run in debug mode", action="store_true")
    parser_install = subparsers.add_parser(
        "install", help="run database setup for flaschengeist and all installed plugins"
    )
    parser_install.set_defaults(func=install)
    parser_export = subparsers.add_parser("export", help="export models to typescript interfaces")
    parser_export.set_defaults(func=export)
    parser_export.add_argument("--file", help="Filename where to save", default="flaschengeist.d.ts")
    parser_export.add_argument("--namespace", help="Namespace of declarations", default="FG")
    parser_export.add_argument("--plugins", help="Also export plugins", action="store_true")

    args = parser.parse_args()
    args.func(args)