ainsleyclark/stock-informer

// Copyright 2023 Ainsley Clark. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package httputil

import (
    "github.com/Danny-Dasilva/CycleTLS/cycletls"
    "github.com/ainsleyclark/errors"
)

type (
    // Client defines the single method interface for creating
    // and performing requests.
    Client interface {
        // Do creates and performs single http Request using the
        // application default client.
        //
        // Returns errors.INTERNAL if the request could not be
        // performed.
        Do(URL, method string) (*Response, error)
    }
    // cycleTLS is an abstraction of the Do method
    // to perform http Requests.
    cycleTLS interface {
        Do(string, cycletls.Options, string) (cycletls.Response, error)
    }
    //Response contains the client response data from
    // the request.
    Response struct {
        RequestID string
        Status    int
        Body      string
        Headers   map[string]string
        Location  string
    }
    // httpClient represents the cycleTLS client used
    // for performing requests.
    httpClient struct {
        cycle cycleTLS
    }
)

const (
    // ClientTimeout specifies a time limit for requests
    // made by the Client in seconds.
    ClientTimeout = 30
    // UserAgent is the user agent header used for making
    // http requests.
    UserAgent = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36"
)

var (
    // options defines the cycleTLS options used for creating
    // http requests.
    options = cycletls.Options{
        Headers: map[string]string{
            "User-Agent":      UserAgent,
            "Accept":          "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9",
            "Accept-Encoding": "gzip, deflate",
            "Accept-Language": "en-GB,en-US;q=0.9,en;q=0.8",
            "Cache-Control":   "no-cache",
        },
        Ja3:             "771,4865-4867-4866-49195-49199-52393-52392-49196-49200-49162-49161-49171-49172-51-57-47-53-10,0-23-65281-10-11-35-16-5-51-43-13-45-28-21,29-23-24-25-256-257,0",
        UserAgent:       UserAgent,
        Cookies:         nil,
        Timeout:         ClientTimeout,
        DisableRedirect: true,
        HeaderOrder: []string{
            "User-Agent",
            "Accept",
            "Accept-Encoding",
            "Accept-Language",
            "Cache-Control",
        },
    }
)

// NewClient returns the common Client used across the
// application
func NewClient() Client {
    return &httpClient{
        cycle: cycletls.Init(),
    }
}

// Do creates and performs single http Request using the
// application default client.
//
// Returns errors.INTERNAL if the request could not be
// performed.
func (h *httpClient) Do(url, method string) (*Response, error) {
    const op = "HTTPClient.Do"
    resp, err := h.cycle.Do(url, options, method)

    // Setup the response data.
    response := &Response{
        RequestID: resp.RequestID,
        Status:    resp.Status,
        Body:      resp.Body,
        Headers:   resp.Headers,
        Location:  resp.Headers["Location"],
    }

    // Handle redirects.
    if Is3xx(resp.Status) && response.Location != "" {
        location, err := GetAbsoluteURL(url, response.Location)
        if err != nil {
            return response, err
        }
        // Bail, the URL and the location header is the same.
        // It could cause an infinite loop
        if location == url {
            return response, nil
        }

        // Recursively call this function with the new
        // location header.
        return h.Do(location, method)
    }

    // Bail if the error is not nil
    if err != nil {
        return nil, errors.NewInternal(err, "Error performing client request", op)
    }

    return response, nil
}