package restyclient

import (
	"bytes"
	"fmt"
	"io"
	"log/slog"
	"net/http"
	"time"

	"github.com/dustin/go-humanize"
)

type ctxKey int

const (
	requestIDCtxKey    = ctxKey(1)
	requestIDHeaderKey = "X-Request-Id"
)

var (
	// maskKeys 敏感参数和头部key
	maskKeys = map[string]struct{}{
		"bk_app_secret":         {},
		"bk_token":              {},
		"Authorization":         {},
		"X-Bkapi-Authorization": {},
	}
)

func getRequestID(r *http.Request) string {
	v, ok := r.Context().Value(requestIDCtxKey).(string)
	if ok && v != "" {
		return v
	}

	rid := r.Header.Get(requestIDHeaderKey)
	if rid != "" {
		return rid
	}

	return GenRequestID()
}

// reqToCurl curl 格式的请求日志
func reqToCurl(r *http.Request) (string, error) {
	// 过滤掉敏感信息, header 和 query
	headers := ""
	for key, values := range r.Header {
		for _, value := range values {
			if _, ok := maskKeys[key]; ok {
				value = "***"
			}
			headers += fmt.Sprintf(" -H %q", fmt.Sprintf("%s: %s", key, value))
		}
	}

	rawURL := *r.URL
	queryValue := rawURL.Query()
	for key := range queryValue {
		if _, ok := maskKeys[key]; ok {
			queryValue.Set(key, "<masked>")
		}
	}
	rawURL.RawQuery = queryValue.Encode()

	reqMsg := fmt.Sprintf("curl -X %s '%s'%s", r.Method, rawURL.String(), headers)
	if r.Body != nil {
		bodyBytes, err := io.ReadAll(r.Body)
		if err != nil {
			return "", err
		}
		r.Body.Close() // nolint

		r.Body = io.NopCloser(bytes.NewBuffer(bodyBytes))
		if len(bodyBytes) > 1024 {
			reqMsg += fmt.Sprintf(" -d '%s...(Total %s)'", bodyBytes[:1024], humanize.Bytes(uint64(len(bodyBytes))))
		} else {
			reqMsg += fmt.Sprintf(" -d '%s'", bodyBytes)
		}
	}

	return reqMsg, nil
}

// respToCurl 返回日志
func respToCurl(resp *http.Response, st time.Time) (string, error) {
	var (
		bodyBytes []byte
		err       error
	)
	if resp.Body != nil {
		bodyBytes, err = io.ReadAll(resp.Body)
		if err != nil {
			return "", err
		}
		resp.Body.Close() // nolint

		resp.Body = io.NopCloser(bytes.NewBuffer(bodyBytes))
	}

	if len(bodyBytes) > 1024 {
		respMsg := fmt.Sprintf("[%s] %s %s...(Total %s)",
			resp.Status, time.Since(st), bodyBytes[:1024], humanize.Bytes(uint64(len(bodyBytes))))
		return respMsg, nil
	}

	if len(bodyBytes) > 0 {
		respMsg := fmt.Sprintf("[%s] %s %s", resp.Status, time.Since(st), bodyBytes)
		return respMsg, nil
	}

	respMsg := fmt.Sprintf("[%s] %s", resp.Status, time.Since(st))
	return respMsg, nil
}

// curlLogTransport print curl log transport
type curlLogTransport struct {
	Transport http.RoundTripper
}

// RoundTrip curlLog Transport
func (t *curlLogTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	st := time.Now()

	rid := getRequestID(req)
	req.Header.Set(requestIDHeaderKey, rid)

	// 记录请求
	rbody, err := reqToCurl(req)
	if err != nil {
		return nil, err
	}
	slog.With("req_id", rid).Info("restyclient REQ", "body", rbody)

	resp, err := t.transport(req).RoundTrip(req)
	if err != nil {
		slog.With("req_id", rid).Error("restyclient RESP", "err", err)
		return nil, err
	}

	// 记录返回
	respBody, err := respToCurl(resp, st)
	if err != nil {
		return nil, err
	}
	slog.With("req_id", rid).Info("restyclient REQ", "body", respBody)

	return resp, nil
}

func (t *curlLogTransport) transport(req *http.Request) http.RoundTripper { //nolint:unparam
	if t.Transport != nil {
		return t.Transport
	}
	return http.DefaultTransport
}

// NewCurlLogTransport make a new curl log transport, default transport can be nil
func NewCurlLogTransport(transport http.RoundTripper) http.RoundTripper {
	return &curlLogTransport{Transport: transport}
}