import os
import typing

import tornado
import tornado.web
from tornado_swagger._builders import generate_doc_from_endpoints
from tornado_swagger._handlers import TornadoBaseHandler
from tornado_swagger.const import API_SWAGGER_2
from tornado_swagger.setup import STATIC_PATH

from paste.web.application import ApplicationSwagger


class SwaggerUiHandler(TornadoBaseHandler):
    """
    自定义 Ui，支持从应用程序读取文档页面。
    主要是为了允许不同的应用具有不同的接口描述页面。
    """

    def get(self):
        if hasattr(self.application, 'swagger_home_template'):
            self.write(self.application.swagger_home_template)
        else:
            self.write(
                f'类型错误，无法从应用程序读取 swagger_home_template 属性，'
                f'请使用 ApplicationSwagger 以支持 Swagger。'
            )


class SwaggerSpecHandler(TornadoBaseHandler):
    """
    自定义 Spec，支持从应用程序读取 Schema。
    主要是为了允许不同的应用具有不同的接口描述页面。
    """

    def get(self):
        if hasattr(self.application, 'swagger_schema'):
            self.write(self.application.swagger_schema)
        else:
            self.write(
                f'类型错误，无法从应用程序读取 swagger_schema 属性，'
                f'请使用 ApplicationSwagger 以支持 Swagger。'
            )


def setup_swagger(
    app: ApplicationSwagger,
    routes: typing.List[tornado.web.URLSpec],
    *,
    swagger_url: str = "/api/doc",
    api_base_url: str = "/",
    description: str = "Swagger API definition",
    api_version: str = "1.0.0",
    title: str = "Swagger API",
    contact: str = "",
    schemes: list = None,
    security_definitions: dict = None,
    security: list = None,
    display_models: bool = True,
    api_definition_version: str = API_SWAGGER_2
):
    """
    注入 Swagger ui 到应用程序路由。
    """

    swagger_schema = generate_doc_from_endpoints(
        routes,
        api_base_url=api_base_url,
        description=description,
        api_version=api_version,
        title=title,
        contact=contact,
        schemes=schemes,
        security_definitions=security_definitions,
        security=security,
        api_definition_version=api_definition_version,
    )

    _swagger_ui_url = f"/{swagger_url}" if not swagger_url.startswith("/") else swagger_url
    _base_swagger_ui_url = _swagger_ui_url.rstrip("/")
    _swagger_spec_url = f"{_swagger_ui_url}/swagger.json"

    routes[:0] = [
        tornado.web.url(_swagger_ui_url, SwaggerUiHandler),
        tornado.web.url(f"{_base_swagger_ui_url}/", SwaggerUiHandler),
        tornado.web.url(_swagger_spec_url, SwaggerSpecHandler),
    ]

    app.swagger_schema = swagger_schema

    with open(os.path.join(STATIC_PATH, "ui.html"), "r", encoding="utf-8") as f:
        app.swagger_home_template = (
            f.read().replace(
                "{{ SWAGGER_URL }}", _swagger_spec_url
            ).replace(
                "{{ DISPLAY_MODELS }}", str(-1 if not display_models else 1)
            )
        )