// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.

package ghttp

import (
	"mime"
	"net/http"

	"github.com/gogf/gf/v2/errors/gcode"
	"github.com/gogf/gf/v2/errors/gerror"
)

// DefaultHandlerResponse is the default implementation of HandlerResponse.
type DefaultHandlerResponse struct {
	Code    int         `json:"code"    dc:"Error code"`
	Message string      `json:"message" dc:"Error message"`
	Data    interface{} `json:"data"    dc:"Result data for certain request according API definition"`
}

const (
	contentTypeEventStream  = "text/event-stream"
	contentTypeOctetStream  = "application/octet-stream"
	contentTypeMixedReplace = "multipart/x-mixed-replace"
)

var (
	// streamContentType is the content types for stream response.
	streamContentType = []string{contentTypeEventStream, contentTypeOctetStream, contentTypeMixedReplace}
)

// MiddlewareHandlerResponse is the default middleware handling handler response object and its error.
func MiddlewareHandlerResponse(r *Request) {
	r.Middleware.Next()

	// There's custom buffer content, it then exits current handler.
	if r.Response.BufferLength() > 0 {
		return
	}

	// It does not output common response content if it is stream response.
	mediaType, _, _ := mime.ParseMediaType(r.Response.Header().Get("Content-Type"))
	for _, ct := range streamContentType {
		if mediaType == ct {
			return
		}
	}

	var (
		msg  string
		err  = r.GetError()
		res  = r.GetHandlerResponse()
		code = gerror.Code(err)
	)
	if err != nil {
		if code == gcode.CodeNil {
			code = gcode.CodeInternalError
		}
		msg = err.Error()
	} else {
		if r.Response.Status > 0 && r.Response.Status != http.StatusOK {
			msg = http.StatusText(r.Response.Status)
			switch r.Response.Status {
			case http.StatusNotFound:
				code = gcode.CodeNotFound
			case http.StatusForbidden:
				code = gcode.CodeNotAuthorized
			default:
				code = gcode.CodeUnknown
			}
			// It creates error as it can be retrieved by other middlewares.
			err = gerror.NewCode(code, msg)
			r.SetError(err)
		} else {
			code = gcode.CodeOK
		}
	}

	r.Response.WriteJson(DefaultHandlerResponse{
		Code:    code.Code(),
		Message: msg,
		Data:    res,
	})
}