package testutils

import (
	"crypto/tls"
	"errors"
	"io"
	"net/http"
	"net/http/httptest"
	"net/url"
	"strings"

	"github.com/vulcand/oxy/v2/internal/holsterv4/clock"
	"github.com/vulcand/oxy/v2/utils"
)

// NewHandler creates a new Server.
func NewHandler(handler http.HandlerFunc) *httptest.Server {
	return httptest.NewServer(handler)
}

// NewResponder creates a new Server with response.
func NewResponder(response string) *httptest.Server {
	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = w.Write([]byte(response))
	}))
}

// ParseURI is the version of url.ParseRequestURI that panics if incorrect, helpful to shorten the tests.
func ParseURI(uri string) *url.URL {
	out, err := url.ParseRequestURI(uri)
	if err != nil {
		panic(err)
	}
	return out
}

// ReqOpts request options.
type ReqOpts struct {
	Host    string
	Method  string
	Body    string
	Headers http.Header
	Auth    *utils.BasicAuth
}

// ReqOption request option type.
type ReqOption func(o *ReqOpts) error

// Method sets request method.
func Method(m string) ReqOption {
	return func(o *ReqOpts) error {
		o.Method = m
		return nil
	}
}

// Host sets request host.
func Host(h string) ReqOption {
	return func(o *ReqOpts) error {
		o.Host = h
		return nil
	}
}

// Body sets request body.
func Body(b string) ReqOption {
	return func(o *ReqOpts) error {
		o.Body = b
		return nil
	}
}

// Header sets request header.
func Header(name, val string) ReqOption {
	return func(o *ReqOpts) error {
		if o.Headers == nil {
			o.Headers = make(http.Header)
		}
		o.Headers.Add(name, val)
		return nil
	}
}

// Headers sets request headers.
func Headers(h http.Header) ReqOption {
	return func(o *ReqOpts) error {
		if o.Headers == nil {
			o.Headers = make(http.Header)
		}
		utils.CopyHeaders(o.Headers, h)
		return nil
	}
}

// BasicAuth sets request basic auth.
func BasicAuth(username, password string) ReqOption {
	return func(o *ReqOpts) error {
		o.Auth = &utils.BasicAuth{
			Username: username,
			Password: password,
		}
		return nil
	}
}

// MakeRequest create and do a request.
func MakeRequest(uri string, opts ...ReqOption) (*http.Response, []byte, error) {
	o := &ReqOpts{}
	for _, s := range opts {
		if err := s(o); err != nil {
			return nil, nil, err
		}
	}

	if o.Method == "" {
		o.Method = http.MethodGet
	}

	request, err := http.NewRequest(o.Method, uri, strings.NewReader(o.Body))
	if err != nil {
		return nil, nil, err
	}

	if o.Headers != nil {
		utils.CopyHeaders(request.Header, o.Headers)
	}

	if o.Auth != nil {
		request.Header.Set("Authorization", o.Auth.String())
	}

	if o.Host != "" {
		request.Host = o.Host
	}

	var tr *http.Transport
	if strings.HasPrefix(uri, "https") {
		tr = &http.Transport{
			DisableKeepAlives: true,
			TLSClientConfig: &tls.Config{
				InsecureSkipVerify: true,
				ServerName:         request.Host,
			},
		}
	} else {
		tr = &http.Transport{
			DisableKeepAlives: true,
		}
	}

	client := &http.Client{
		Transport: tr,
		CheckRedirect: func(req *http.Request, via []*http.Request) error {
			return errors.New("no redirects")
		},
	}
	response, err := client.Do(request)
	if err == nil {
		bodyBytes, errRead := io.ReadAll(response.Body)
		return response, bodyBytes, errRead
	}
	return response, nil, err
}

// Get do a GET request.
func Get(uri string, opts ...ReqOption) (*http.Response, []byte, error) {
	opts = append(opts, Method(http.MethodGet))
	return MakeRequest(uri, opts...)
}

// Post do a POST request.
func Post(uri string, opts ...ReqOption) (*http.Response, []byte, error) {
	opts = append(opts, Method(http.MethodPost))
	return MakeRequest(uri, opts...)
}

// FreezeTime to the predetermined time. Returns a function that should be
// deferred to unfreeze time. Meant for testing.
func FreezeTime() func() {
	clock.Freeze(clock.Date(2012, 3, 4, 5, 6, 7, 0, clock.UTC))
	return clock.Unfreeze
}