// Copyright 2021 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.

package rest

import (
	"net/url"
	"strings"

	"github.com/pingcap/tiflow/pkg/httputil"
)

// HTTPMethod represents HTTP method.
type HTTPMethod int

// Valid HTTP methods.
const (
	HTTPMethodPost = iota + 1
	HTTPMethodPut
	HTTPMethodGet
	HTTPMethodDelete
)

// String implements Stringer.String.
func (h HTTPMethod) String() string {
	switch h {
	case HTTPMethodPost:
		return "POST"
	case HTTPMethodPut:
		return "PUT"
	case HTTPMethodGet:
		return "GET"
	case HTTPMethodDelete:
		return "DELETE"
	default:
		return "unknown"
	}
}

// CDCRESTInterface includes a set of operations to interact with TiCDC RESTful apis.
type CDCRESTInterface interface {
	Method(method HTTPMethod) *Request
	Post() *Request
	Put() *Request
	Get() *Request
	Delete() *Request
}

// BasicAuth holds the basic authentication information.
type BasicAuth struct {
	User     string
	Password string
}

// CDCRESTClient defines a TiCDC RESTful client
type CDCRESTClient struct {
	// base is the root URL for all invocations of the client.
	base      *url.URL
	basicAuth BasicAuth
	params    url.Values

	// versionedAPIPath is a http url prefix with api version. eg. /api/v1.
	versionedAPIPath string

	// Client is a wrapped http client.
	Client *httputil.Client
}

// NewCDCRESTClient creates a new CDCRESTClient.
func NewCDCRESTClient(
	baseURL *url.URL,
	versionedAPIPath string,
	client *httputil.Client,
	basicAuth BasicAuth,
	params url.Values,
) (*CDCRESTClient, error) {
	if !strings.HasSuffix(baseURL.Path, "/") {
		baseURL.Path += "/"
	}
	baseURL.RawQuery = ""
	baseURL.Fragment = ""

	return &CDCRESTClient{
		base:             baseURL,
		basicAuth:        basicAuth,
		versionedAPIPath: versionedAPIPath,
		Client:           client,
		params:           params,
	}, nil
}

// Method begins a request with a http method (GET, POST, PUT, DELETE).
func (c *CDCRESTClient) Method(method HTTPMethod) *Request {
	return NewRequest(c).WithMethod(method)
}

// Post begins a POST request. Short for c.Method(HTTPMethodPost).
func (c *CDCRESTClient) Post() *Request {
	return c.Method(HTTPMethodPost)
}

// Put begins a PUT request. Short for c.Method(HTTPMethodPut).
func (c *CDCRESTClient) Put() *Request {
	return c.Method(HTTPMethodPut)
}

// Delete begins a DELETE request. Short for c.Method(HTTPMethodDelete).
func (c *CDCRESTClient) Delete() *Request {
	return c.Method(HTTPMethodDelete)
}

// Get begins a GET request. Short for c.Method(HTTPMethodGet).
func (c *CDCRESTClient) Get() *Request {
	return c.Method(HTTPMethodGet)
}