package splithttp

import (
	"crypto/rand"
	"math/big"
	"net/http"
	"net/url"
	"strings"

	"github.com/xtls/xray-core/common"
	"github.com/xtls/xray-core/transport/internet"
)

func (c *Config) GetNormalizedPath() string {
	pathAndQuery := strings.SplitN(c.Path, "?", 2)
	path := pathAndQuery[0]

	if path == "" || path[0] != '/' {
		path = "/" + path
	}

	if path[len(path)-1] != '/' {
		path = path + "/"
	}

	return path
}

func (c *Config) GetNormalizedQuery() string {
	pathAndQuery := strings.SplitN(c.Path, "?", 2)
	query := ""

	if len(pathAndQuery) > 1 {
		query = pathAndQuery[1]
	}

	/*
		if query != "" {
			query += "&"
		}
		query += "x_version=" + core.Version()
	*/

	return query
}

func (c *Config) GetRequestHeader(rawURL string) http.Header {
	header := http.Header{}
	for k, v := range c.Headers {
		header.Add(k, v)
	}

	u, _ := url.Parse(rawURL)
	// https://www.rfc-editor.org/rfc/rfc7541.html#appendix-B
	// h2's HPACK Header Compression feature employs a huffman encoding using a static table.
	// 'X' is assigned an 8 bit code, so HPACK compression won't change actual padding length on the wire.
	// https://www.rfc-editor.org/rfc/rfc9204.html#section-4.1.2-2
	// h3's similar QPACK feature uses the same huffman table.
	u.RawQuery = "x_padding=" + strings.Repeat("X", int(c.GetNormalizedXPaddingBytes().rand()))
	header.Set("Referer", u.String())

	return header
}

func (c *Config) WriteResponseHeader(writer http.ResponseWriter) {
	// CORS headers for the browser dialer
	writer.Header().Set("Access-Control-Allow-Origin", "*")
	writer.Header().Set("Access-Control-Allow-Methods", "GET, POST")
	// writer.Header().Set("X-Version", core.Version())
	writer.Header().Set("X-Padding", strings.Repeat("X", int(c.GetNormalizedXPaddingBytes().rand())))
}

func (c *Config) GetNormalizedXPaddingBytes() RangeConfig {
	if c.XPaddingBytes == nil || c.XPaddingBytes.To == 0 {
		return RangeConfig{
			From: 100,
			To:   1000,
		}
	}

	return *c.XPaddingBytes
}

func (c *Config) GetNormalizedScMaxEachPostBytes() RangeConfig {
	if c.ScMaxEachPostBytes == nil || c.ScMaxEachPostBytes.To == 0 {
		return RangeConfig{
			From: 1000000,
			To:   1000000,
		}
	}

	return *c.ScMaxEachPostBytes
}

func (c *Config) GetNormalizedScMinPostsIntervalMs() RangeConfig {
	if c.ScMinPostsIntervalMs == nil || c.ScMinPostsIntervalMs.To == 0 {
		return RangeConfig{
			From: 30,
			To:   30,
		}
	}

	return *c.ScMinPostsIntervalMs
}

func (c *Config) GetNormalizedScMaxBufferedPosts() int {
	if c.ScMaxBufferedPosts == 0 {
		return 30
	}

	return int(c.ScMaxBufferedPosts)
}

func (c *Config) GetNormalizedScStreamUpServerSecs() RangeConfig {
	if c.ScStreamUpServerSecs == nil || c.ScStreamUpServerSecs.To == 0 {
		return RangeConfig{
			From: 20,
			To:   80,
		}
	}

	return *c.ScMinPostsIntervalMs
}

func (m *XmuxConfig) GetNormalizedMaxConcurrency() RangeConfig {
	if m.MaxConcurrency == nil {
		return RangeConfig{
			From: 0,
			To:   0,
		}
	}

	return *m.MaxConcurrency
}

func (m *XmuxConfig) GetNormalizedMaxConnections() RangeConfig {
	if m.MaxConnections == nil {
		return RangeConfig{
			From: 0,
			To:   0,
		}
	}

	return *m.MaxConnections
}

func (m *XmuxConfig) GetNormalizedCMaxReuseTimes() RangeConfig {
	if m.CMaxReuseTimes == nil {
		return RangeConfig{
			From: 0,
			To:   0,
		}
	}

	return *m.CMaxReuseTimes
}

func (m *XmuxConfig) GetNormalizedHMaxRequestTimes() RangeConfig {
	if m.HMaxRequestTimes == nil {
		return RangeConfig{
			From: 0,
			To:   0,
		}
	}

	return *m.HMaxRequestTimes
}

func (m *XmuxConfig) GetNormalizedHMaxReusableSecs() RangeConfig {
	if m.HMaxReusableSecs == nil {
		return RangeConfig{
			From: 0,
			To:   0,
		}
	}

	return *m.HMaxReusableSecs
}

func init() {
	common.Must(internet.RegisterProtocolConfigCreator(protocolName, func() interface{} {
		return new(Config)
	}))
}

func (c RangeConfig) rand() int32 {
	if c.From == c.To {
		return c.From
	}
	bigInt, _ := rand.Int(rand.Reader, big.NewInt(int64(c.To-c.From)))
	return c.From + int32(bigInt.Int64())
}