package starnet

import (
	"context"
	"crypto/tls"
	"fmt"
	"net"
	"net/http"
	"net/url"
	"strings"
	"time"
)

const (
	HEADER_FORM_URLENCODE = `application/x-www-form-urlencoded`
	HEADER_FORM_DATA      = `multipart/form-data`
	HEADER_JSON           = `application/json`
	HEADER_PLAIN          = `text/plain`
)

var (
	DefaultDialTimeout   = 5 * time.Second
	DefaultTimeout       = 10 * time.Second
	DefaultFetchRespBody = false
	DefaultHttpClient    = NewHttpClientNoErr()
)

func UrlEncodeRaw(str string) string {
	strs := strings.Replace(url.QueryEscape(str), "+", "%20", -1)
	return strs
}

func UrlEncode(str string) string {
	return url.QueryEscape(str)
}

func UrlDecode(str string) (string, error) {
	return url.QueryUnescape(str)
}

func BuildQuery(queryData map[string]string) string {
	query := url.Values{}
	for k, v := range queryData {
		query.Add(k, v)
	}
	return query.Encode()
}

// BuildPostForm takes a map of string keys and values, converts it into a URL-encoded query string,
// and then converts that string into a byte slice. This function is useful for preparing data for HTTP POST requests,
// where the server expects the request body to be URL-encoded form data.
//
// Parameters:
// queryMap: A map where the key-value pairs represent the form data to be sent in the HTTP POST request.
//
// Returns:
// A byte slice representing the URL-encoded form data.
func BuildPostForm(queryMap map[string]string) []byte {
	return []byte(BuildQuery(queryMap))
}

func Get(uri string, opts ...RequestOpt) (*Response, error) {
	return NewSimpleRequestWithClient(DefaultHttpClient, uri, "GET", opts...).Do()
}

func Post(uri string, opts ...RequestOpt) (*Response, error) {
	return NewSimpleRequestWithClient(DefaultHttpClient, uri, "POST", opts...).Do()
}

func Options(uri string, opts ...RequestOpt) (*Response, error) {
	return NewSimpleRequestWithClient(DefaultHttpClient, uri, "OPTIONS", opts...).Do()
}

func Put(uri string, opts ...RequestOpt) (*Response, error) {
	return NewSimpleRequestWithClient(DefaultHttpClient, uri, "PUT", opts...).Do()
}

func Delete(uri string, opts ...RequestOpt) (*Response, error) {
	return NewSimpleRequestWithClient(DefaultHttpClient, uri, "DELETE", opts...).Do()
}

func Head(uri string, opts ...RequestOpt) (*Response, error) {
	return NewSimpleRequestWithClient(DefaultHttpClient, uri, "HEAD", opts...).Do()
}

func Patch(uri string, opts ...RequestOpt) (*Response, error) {
	return NewSimpleRequestWithClient(DefaultHttpClient, uri, "PATCH", opts...).Do()
}

func Trace(uri string, opts ...RequestOpt) (*Response, error) {
	return NewSimpleRequestWithClient(DefaultHttpClient, uri, "TRACE", opts...).Do()
}

func Connect(uri string, opts ...RequestOpt) (*Response, error) {
	return NewSimpleRequestWithClient(DefaultHttpClient, uri, "CONNECT", opts...).Do()
}

func DefaultCheckRedirectFunc(req *http.Request, via []*http.Request) error {
	return http.ErrUseLastResponse
}

func DefaultDialFunc(ctx context.Context, netType, addr string) (net.Conn, error) {
	var lastErr error
	var addrs []string
	if dialFn, ok := ctx.Value("dialFunc").(func(context.Context, string, string) (net.Conn, error)); ok {
		if dialFn != nil {
			return dialFn(ctx, netType, addr)
		}
	}
	customIP, ok := ctx.Value("customIP").([]string)
	if !ok {
		customIP = nil
	}
	dialTimeout, ok := ctx.Value("dialTimeout").(time.Duration)
	if !ok {
		dialTimeout = DefaultDialTimeout
	}
	timeout, ok := ctx.Value("timeout").(time.Duration)
	if !ok {
		timeout = DefaultTimeout
	}
	lookUpIPfn, ok := ctx.Value("lookUpIP").(func(context.Context, string) ([]net.IPAddr, error))
	if !ok {
		lookUpIPfn = net.DefaultResolver.LookupIPAddr
	}
	host, port, err := net.SplitHostPort(addr)
	if err != nil {
		return nil, err
	}
	proxy, ok := ctx.Value("proxy").(string)
	if !ok {
		proxy = ""
	}
	if proxy == "" && len(customIP) > 0 {
		for _, v := range customIP {
			ipAddr := net.ParseIP(v)
			if ipAddr == nil {
				return nil, fmt.Errorf("invalid custom ip: %s", customIP)
			}
			tmpAddr := net.JoinHostPort(v, port)
			addrs = append(addrs, tmpAddr)
		}
	} else {
		ipLists, err := lookUpIPfn(ctx, host)
		if err != nil {
			return nil, err
		}
		for _, v := range ipLists {
			tmpAddr := net.JoinHostPort(v.String(), port)
			addrs = append(addrs, tmpAddr)
		}
	}
	for _, addr := range addrs {
		c, err := net.DialTimeout(netType, addr, dialTimeout)
		if err != nil {
			lastErr = err
			continue
		}
		if timeout != 0 {
			err = c.SetDeadline(time.Now().Add(timeout))
		}
		return c, nil
	}
	return nil, lastErr
}

func DefaultDialTlsFunc(ctx context.Context, netType, addr string) (net.Conn, error) {
	conn, err := DefaultDialFunc(ctx, netType, addr)
	if err != nil {
		return nil, err
	}
	tlsConfig, ok := ctx.Value("tlsConfig").(*tls.Config)
	if !ok || tlsConfig == nil {
		return nil, fmt.Errorf("tlsConfig is not set in context")
	}
	tlsConn := tls.Client(conn, tlsConfig)
	if err := tlsConn.Handshake(); err != nil {
		return nil, fmt.Errorf("tls handshake failed: %w", err)
	}
	return tlsConn, nil
}

func DefaultProxyURL() func(*http.Request) (*url.URL, error) {
	return func(req *http.Request) (*url.URL, error) {
		if req == nil {
			return nil, fmt.Errorf("request is nil")
		}
		proxyURL, ok := req.Context().Value("proxy").(string)
		if !ok || proxyURL == "" {
			return nil, nil
		}
		parsedURL, err := url.Parse(proxyURL)
		if err != nil {
			return nil, fmt.Errorf("failed to parse proxy URL: %w", err)
		}
		return parsedURL, nil
	}
}