import json
from collections.abc import Generator
from dataclasses import dataclass
from os import getenv
from typing import Any, Union
from urllib.parse import urlencode

import httpx

from core.file.file_manager import download
from core.helper import ssrf_proxy
from core.tools.__base.tool import Tool
from core.tools.__base.tool_runtime import ToolRuntime
from core.tools.entities.tool_bundle import ApiToolBundle
from core.tools.entities.tool_entities import ToolEntity, ToolInvokeMessage, ToolProviderType
from core.tools.errors import ToolInvokeError, ToolParameterValidationError, ToolProviderCredentialValidationError

API_TOOL_DEFAULT_TIMEOUT = (
    int(getenv("API_TOOL_DEFAULT_CONNECT_TIMEOUT", "10")),
    int(getenv("API_TOOL_DEFAULT_READ_TIMEOUT", "60")),
)


@dataclass
class ParsedResponse:
    """Represents a parsed HTTP response with type information"""

    content: Union[str, dict]
    is_json: bool

    def to_string(self) -> str:
        """Convert response to string format for credential validation"""
        if isinstance(self.content, dict):
            return json.dumps(self.content, ensure_ascii=False)
        return str(self.content)


class ApiTool(Tool):
    """
    Api tool
    """

    def __init__(self, entity: ToolEntity, api_bundle: ApiToolBundle, runtime: ToolRuntime, provider_id: str):
        super().__init__(entity, runtime)
        self.api_bundle = api_bundle
        self.provider_id = provider_id

    def fork_tool_runtime(self, runtime: ToolRuntime):
        """
        fork a new tool with metadata
        :return: the new tool
        """
        if self.api_bundle is None:
            raise ValueError("api_bundle is required")
        return self.__class__(
            entity=self.entity,
            api_bundle=self.api_bundle.model_copy(),
            runtime=runtime,
            provider_id=self.provider_id,
        )

    def validate_credentials(
        self, credentials: dict[str, Any], parameters: dict[str, Any], format_only: bool = False
    ) -> str:
        """
        validate the credentials for Api tool
        """
        # assemble validate request and request parameters
        headers = self.assembling_request(parameters)

        if format_only:
            return ""

        response = self.do_http_request(self.api_bundle.server_url, self.api_bundle.method, headers, parameters)
        # validate response
        parsed_response = self.validate_and_parse_response(response)
        # For credential validation, always return as string
        return parsed_response.to_string()

    def tool_provider_type(self) -> ToolProviderType:
        return ToolProviderType.API

    def assembling_request(self, parameters: dict[str, Any]) -> dict[str, Any]:
        headers = {}
        if self.runtime is None:
            raise ToolProviderCredentialValidationError("runtime not initialized")

        credentials = self.runtime.credentials or {}
        if "auth_type" not in credentials:
            raise ToolProviderCredentialValidationError("Missing auth_type")

        if credentials["auth_type"] in ("api_key_header", "api_key"):  # backward compatibility:
            api_key_header = "Authorization"

            if "api_key_header" in credentials:
                api_key_header = credentials["api_key_header"]

            if "api_key_value" not in credentials:
                raise ToolProviderCredentialValidationError("Missing api_key_value")
            elif not isinstance(credentials["api_key_value"], str):
                raise ToolProviderCredentialValidationError("api_key_value must be a string")

            if "api_key_header_prefix" in credentials:
                api_key_header_prefix = credentials["api_key_header_prefix"]
                if api_key_header_prefix == "basic" and credentials["api_key_value"]:
                    credentials["api_key_value"] = f"Basic {credentials['api_key_value']}"
                elif api_key_header_prefix == "bearer" and credentials["api_key_value"]:
                    credentials["api_key_value"] = f"Bearer {credentials['api_key_value']}"
                elif api_key_header_prefix == "custom":
                    pass

            headers[api_key_header] = credentials["api_key_value"]

        elif credentials["auth_type"] == "api_key_query":
            # For query parameter authentication, we don't add anything to headers
            # The query parameter will be added in do_http_request method
            pass

        needed_parameters = [parameter for parameter in (self.api_bundle.parameters or []) if parameter.required]
        for parameter in needed_parameters:
            if parameter.required and parameter.name not in parameters:
                if parameter.default is not None:
                    parameters[parameter.name] = parameter.default
                else:
                    raise ToolParameterValidationError(f"Missing required parameter {parameter.name}")

        return headers

    def validate_and_parse_response(self, response: httpx.Response) -> ParsedResponse:
        """
        validate the response and return parsed content with type information

        :return: ParsedResponse with content and is_json flag
        """
        if isinstance(response, httpx.Response):
            if response.status_code >= 400:
                raise ToolInvokeError(f"Request failed with status code {response.status_code} and {response.text}")
            if not response.content:
                return ParsedResponse(
                    "Empty response from the tool, please check your parameters and try again.", False
                )

            # Check content type
            content_type = response.headers.get("content-type", "").lower()
            is_json_content_type = "application/json" in content_type

            # Try to parse as JSON
            try:
                json_response = response.json()
                # If content-type indicates JSON, return as JSON object
                if is_json_content_type:
                    return ParsedResponse(json_response, True)
                else:
                    # If content-type doesn't indicate JSON, treat as text regardless of content
                    return ParsedResponse(response.text, False)
            except Exception:
                # Not valid JSON, return as text
                return ParsedResponse(response.text, False)
        else:
            raise ValueError(f"Invalid response type {type(response)}")

    @staticmethod
    def get_parameter_value(parameter, parameters):
        if parameter["name"] in parameters:
            return parameters[parameter["name"]]
        elif parameter.get("required", False):
            raise ToolParameterValidationError(f"Missing required parameter {parameter['name']}")
        else:
            return (parameter.get("schema", {}) or {}).get("default", "")

    def do_http_request(
        self, url: str, method: str, headers: dict[str, Any], parameters: dict[str, Any]
    ) -> httpx.Response:
        """
        do http request depending on api bundle
        """
        method = method.lower()

        params = {}
        path_params = {}
        # FIXME: body should be a dict[str, Any] but it changed a lot in this function
        body: Any = {}
        cookies = {}
        files = []

        # Add API key to query parameters if auth_type is api_key_query
        if self.runtime and self.runtime.credentials:
            credentials = self.runtime.credentials
            if credentials.get("auth_type") == "api_key_query":
                api_key_query_param = credentials.get("api_key_query_param", "key")
                api_key_value = credentials.get("api_key_value")
                if api_key_value:
                    params[api_key_query_param] = api_key_value

        # check parameters
        for parameter in self.api_bundle.openapi.get("parameters", []):
            value = self.get_parameter_value(parameter, parameters)
            if parameter["in"] == "path":
                path_params[parameter["name"]] = value

            elif parameter["in"] == "query":
                if value != "":
                    params[parameter["name"]] = value

            elif parameter["in"] == "cookie":
                cookies[parameter["name"]] = value

            elif parameter["in"] == "header":
                headers[parameter["name"]] = str(value)

        # check if there is a request body and handle it
        if "requestBody" in self.api_bundle.openapi and self.api_bundle.openapi["requestBody"] is not None:
            # handle json request body
            if "content" in self.api_bundle.openapi["requestBody"]:
                for content_type in self.api_bundle.openapi["requestBody"]["content"]:
                    headers["Content-Type"] = content_type
                    body_schema = self.api_bundle.openapi["requestBody"]["content"][content_type]["schema"]

                    # handle ref schema
                    if "$ref" in body_schema:
                        ref_path = body_schema["$ref"].split("/")
                        ref_name = ref_path[-1]
                        if (
                            "components" in self.api_bundle.openapi
                            and "schemas" in self.api_bundle.openapi["components"]
                        ):
                            if ref_name in self.api_bundle.openapi["components"]["schemas"]:
                                body_schema = self.api_bundle.openapi["components"]["schemas"][ref_name]

                    required = body_schema.get("required", [])
                    properties = body_schema.get("properties", {})
                    for name, property in properties.items():
                        if name in parameters:
                            # multiple file upload: if the type is array and the items have format as binary
                            if property.get("type") == "array" and property.get("items", {}).get("format") == "binary":
                                # parameters[name] should be a list of file objects.
                                for f in parameters[name]:
                                    files.append((name, (f.filename, download(f), f.mime_type)))
                            elif property.get("format") == "binary":
                                f = parameters[name]
                                files.append((name, (f.filename, download(f), f.mime_type)))
                            elif "$ref" in property:
                                body[name] = parameters[name]
                            else:
                                # convert type
                                body[name] = self._convert_body_property_type(property, parameters[name])
                        elif name in required:
                            raise ToolParameterValidationError(
                                f"Missing required parameter {name} in operation {self.api_bundle.operation_id}"
                            )
                        elif "default" in property:
                            body[name] = property["default"]
                        else:
                            # omit optional parameters that weren't provided, instead of setting them to None
                            pass
                    break

        # replace path parameters
        for name, value in path_params.items():
            url = url.replace(f"{{{name}}}", f"{value}")

        # parse http body data if needed
        if "Content-Type" in headers:
            if headers["Content-Type"] == "application/json":
                body = json.dumps(body)
            elif headers["Content-Type"] == "application/x-www-form-urlencoded":
                body = urlencode(body)
            else:
                body = body

        # if there is a file upload, remove the Content-Type header
        # so that httpx can automatically generate the boundary header required for multipart/form-data.
        # issue: https://github.com/langgenius/dify/issues/13684
        # reference: https://stackoverflow.com/questions/39280438/fetch-missing-boundary-in-multipart-form-data-post
        if files:
            headers.pop("Content-Type", None)

        _METHOD_MAP = {
            "get": ssrf_proxy.get,
            "head": ssrf_proxy.head,
            "post": ssrf_proxy.post,
            "put": ssrf_proxy.put,
            "delete": ssrf_proxy.delete,
            "patch": ssrf_proxy.patch,
        }
        method_lc = method.lower()
        if method_lc not in _METHOD_MAP:
            raise ValueError(f"Invalid http method {method}")
        response: httpx.Response = _METHOD_MAP[
            method_lc
        ](  # https://discuss.python.org/t/type-inference-for-function-return-types/42926
            url,
            params=params,
            headers=headers,
            cookies=cookies,
            data=body,
            files=files,
            timeout=API_TOOL_DEFAULT_TIMEOUT,
            follow_redirects=True,
        )
        return response

    def _convert_body_property_any_of(
        self, property: dict[str, Any], value: Any, any_of: list[dict[str, Any]], max_recursive=10
    ):
        if max_recursive <= 0:
            raise Exception("Max recursion depth reached")
        for option in any_of or []:
            try:
                if "type" in option:
                    # Attempt to convert the value based on the type.
                    if option["type"] == "integer" or option["type"] == "int":
                        return int(value)
                    elif option["type"] == "number":
                        if "." in str(value):
                            return float(value)
                        else:
                            return int(value)
                    elif option["type"] == "string":
                        return str(value)
                    elif option["type"] == "boolean":
                        if str(value).lower() in {"true", "1"}:
                            return True
                        elif str(value).lower() in {"false", "0"}:
                            return False
                        else:
                            continue  # Not a boolean, try next option
                    elif option["type"] == "null" and not value:
                        return None
                    else:
                        continue  # Unsupported type, try next option
                elif "anyOf" in option and isinstance(option["anyOf"], list):
                    # Recursive call to handle nested anyOf
                    return self._convert_body_property_any_of(property, value, option["anyOf"], max_recursive - 1)
            except ValueError:
                continue  # Conversion failed, try next option
        # If no option succeeded, you might want to return the value as is or raise an error
        return value  # or raise ValueError(f"Cannot convert value '{value}' to any specified type in anyOf")

    def _convert_body_property_type(self, property: dict[str, Any], value: Any):
        try:
            if "type" in property:
                if property["type"] == "integer" or property["type"] == "int":
                    return int(value)
                elif property["type"] == "number":
                    # check if it is a float
                    if "." in str(value):
                        return float(value)
                    else:
                        return int(value)
                elif property["type"] == "string":
                    return str(value)
                elif property["type"] == "boolean":
                    return bool(value)
                elif property["type"] == "null":
                    if value is None:
                        return None
                elif property["type"] == "object" or property["type"] == "array":
                    if isinstance(value, str):
                        try:
                            return json.loads(value)
                        except ValueError:
                            return value
                    elif isinstance(value, dict):
                        return value
                    else:
                        return value
                else:
                    raise ValueError(f"Invalid type {property['type']} for property {property}")
            elif "anyOf" in property and isinstance(property["anyOf"], list):
                return self._convert_body_property_any_of(property, value, property["anyOf"])
        except ValueError:
            return value

    def _invoke(
        self,
        user_id: str,
        tool_parameters: dict[str, Any],
        conversation_id: str | None = None,
        app_id: str | None = None,
        message_id: str | None = None,
    ) -> Generator[ToolInvokeMessage, None, None]:
        """
        invoke http request
        """
        response: httpx.Response | str = ""
        # assemble request
        headers = self.assembling_request(tool_parameters)

        # do http request
        response = self.do_http_request(self.api_bundle.server_url, self.api_bundle.method, headers, tool_parameters)

        # validate response
        parsed_response = self.validate_and_parse_response(response)

        # assemble invoke message based on response type
        if parsed_response.is_json and isinstance(parsed_response.content, dict):
            yield self.create_json_message(parsed_response.content)

            # FIXES: https://github.com/langgenius/dify/pull/23456#issuecomment-3182413088
            # We need never break the original flows
            yield self.create_text_message(response.text)
        else:
            # Convert to string if needed and create text message
            text_response = (
                parsed_response.content if isinstance(parsed_response.content, str) else str(parsed_response.content)
            )
            yield self.create_text_message(text_response)
