package starnet

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

// validMethod 验证 HTTP 方法是否有效
func validMethod(method string) bool {
	return len(method) > 0 && strings.IndexFunc(method, isNotToken) == -1
}

// isNotToken 检查字符是否不是 token 字符
func isNotToken(r rune) bool {
	return !isTokenRune(r)
}

// isTokenRune 检查字符是否是 token 字符
func isTokenRune(r rune) bool {
	i := int(r)
	return i < 127 && isTokenTable[i]
}

// isTokenTable token 字符表
var isTokenTable = [127]bool{
	'!': true, '#': true, '$': true, '%': true, '&': true, '\'': true, '*': true,
	'+': true, '-': true, '.': true, '0': true, '1': true, '2': true, '3': true,
	'4': true, '5': true, '6': true, '7': true, '8': true, '9': true, 'A': true,
	'B': true, 'C': true, 'D': true, 'E': true, 'F': true, 'G': true, 'H': true,
	'I': true, 'J': true, 'K': true, 'L': true, 'M': true, 'N': true, 'O': true,
	'P': true, 'Q': true, 'R': true, 'S': true, 'T': true, 'U': true, 'V': true,
	'W': true, 'X': true, 'Y': true, 'Z': true, '^': true, '_': true, '`': true,
	'a': true, 'b': true, 'c': true, 'd': true, 'e': true, 'f': true, 'g': true,
	'h': true, 'i': true, 'j': true, 'k': true, 'l': true, 'm': true, 'n': true,
	'o': true, 'p': true, 'q': true, 'r': true, 's': true, 't': true, 'u': true,
	'v': true, 'w': true, 'x': true, 'y': true, 'z': true, '|': true, '~': true,
}

// hasPort 检查地址是否包含端口
func hasPort(s string) bool {
	return strings.LastIndex(s, ":") > strings.LastIndex(s, "]")
}

// removeEmptyPort 移除空端口
func removeEmptyPort(host string) string {
	if hasPort(host) {
		return strings.TrimSuffix(host, ":")
	}
	return host
}

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

// UrlEncodeRaw URL 编码（空格编码为 %20）
func UrlEncodeRaw(str string) string {
	return strings.Replace(url.QueryEscape(str), "+", "%20", -1)
}

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

// BuildQuery 构建查询字符串
func BuildQuery(data map[string]string) string {
	query := url.Values{}
	for k, v := range data {
		query.Add(k, v)
	}
	return query.Encode()
}

// BuildPostForm 构建 POST 表单数据
func BuildPostForm(data map[string]string) []byte {
	return []byte(BuildQuery(data))
}

// cloneHeader 克隆 Header
func cloneHeader(h http.Header) http.Header {
	if h == nil {
		return make(http.Header)
	}
	newHeader := make(http.Header, len(h))
	for k, v := range h {
		newHeader[k] = append([]string(nil), v...)
	}
	return newHeader
}

// cloneCookies 克隆 Cookies
func cloneCookies(cookies []*http.Cookie) []*http.Cookie {
	if cookies == nil {
		return nil
	}
	newCookies := make([]*http.Cookie, len(cookies))
	for i, c := range cookies {
		newCookies[i] = &http.Cookie{
			Name:       c.Name,
			Value:      c.Value,
			Path:       c.Path,
			Domain:     c.Domain,
			Expires:    c.Expires,
			RawExpires: c.RawExpires,
			MaxAge:     c.MaxAge,
			Secure:     c.Secure,
			HttpOnly:   c.HttpOnly,
			SameSite:   c.SameSite,
			Raw:        c.Raw,
			Unparsed:   append([]string(nil), c.Unparsed...),
		}
	}
	return newCookies
}

// cloneStringMapSlice 克隆 map[string][]string
func cloneStringMapSlice(m map[string][]string) map[string][]string {
	if m == nil {
		return make(map[string][]string)
	}
	newMap := make(map[string][]string, len(m))
	for k, v := range m {
		newMap[k] = append([]string(nil), v...)
	}
	return newMap
}

// cloneBytes 克隆字节切片
func cloneBytes(b []byte) []byte {
	if b == nil {
		return nil
	}
	newBytes := make([]byte, len(b))
	copy(newBytes, b)
	return newBytes
}

// cloneStringSlice 克隆字符串切片
func cloneStringSlice(s []string) []string {
	if s == nil {
		return nil
	}
	newSlice := make([]string, len(s))
	copy(newSlice, s)
	return newSlice
}

// cloneFiles 克隆文件列表
func cloneFiles(files []RequestFile) []RequestFile {
	if files == nil {
		return nil
	}
	newFiles := make([]RequestFile, len(files))
	copy(newFiles, files)
	return newFiles
}

// cloneTLSConfig 克隆 TLS 配置
func cloneTLSConfig(cfg *tls.Config) *tls.Config {
	if cfg == nil {
		return nil
	}
	return cfg.Clone()
}

// copyWithProgress 带进度的复制
func copyWithProgress(ctx context.Context, dst io.Writer, src io.Reader, filename string, total int64, progress UploadProgressFunc) (int64, error) {
	if progress == nil {
		return io.Copy(dst, src)
	}

	var written int64
	buf := make([]byte, 32*1024) // 32KB buffer

	for {
		select {
		case <-ctx.Done():
			return written, ctx.Err()
		default:
		}

		nr, err := src.Read(buf)
		if nr > 0 {
			nw, ew := dst.Write(buf[:nr])
			if nw > 0 {
				written += int64(nw)
				// 同步调用进度回调（不使用 goroutine）
				progress(filename, written, total)
			}
			if ew != nil {
				return written, ew
			}
			if nr != nw {
				return written, io.ErrShortWrite
			}
		}
		if err != nil {
			if err == io.EOF {
				// 最后一次进度回调
				progress(filename, written, total)
				return written, nil
			}
			return written, err
		}
	}
}