package imadmin

import (
	"bytes"
	"context"
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"io"
	"net/http"
	"strconv"
	"strings"
	"time"

	"github.com/gogf/gf/v2/errors/gerror"
	"github.com/gogf/gf/v2/frame/g"
)

func (c *Client) InternalGet(ctx context.Context, path string, out any) error {
	return c.internalJSON(ctx, http.MethodGet, path, nil, out)
}

func (c *Client) InternalPost(ctx context.Context, path string, in any, out any) error {
	body, err := json.Marshal(in)
	if err != nil {
		return gerror.Wrap(err, "序列化IM内部请求失败")
	}
	return c.internalJSON(ctx, http.MethodPost, path, body, out)
}

func (c *Client) internalJSON(ctx context.Context, method, path string, body []byte, out any) error {
	req, err := c.newInternalRequest(ctx, method, path, body)
	if err != nil {
		return err
	}
	resp, err := c.http.Do(req)
	if err != nil {
		g.Log().Warningf(ctx, "IM internal query request failed url:%s err:%+v", req.URL.String(), err)
		return gerror.New("IM内部查询服务暂不可用")
	}
	defer resp.Body.Close()
	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		return c.parseError(resp)
	}
	if out == nil {
		return nil
	}
	responseBody, err := io.ReadAll(io.LimitReader(resp.Body, maxResponseBody))
	if err != nil {
		return gerror.Wrap(err, "读取IM内部查询响应失败")
	}
	var envelope struct {
		Code    int             `json:"code"`
		Message string          `json:"message"`
		Reason  string          `json:"reason"`
		Data    json.RawMessage `json:"data"`
	}
	if err = json.Unmarshal(responseBody, &envelope); err == nil && len(envelope.Data) > 0 {
		if envelope.Code != 0 {
			return stableError(envelope.Message, envelope.Reason)
		}
		return json.Unmarshal(envelope.Data, out)
	}
	return json.Unmarshal(responseBody, out)
}

func (c *Client) newInternalRequest(ctx context.Context, method string, path string, bodyBytes []byte) (*http.Request, error) {
	baseUrl := strings.TrimRight(c.conf.InternalBaseUrl, "/")
	if baseUrl == "" {
		baseUrl = strings.TrimRight(c.conf.BaseUrl, "/")
	}
	if baseUrl == "" {
		return nil, gerror.New("IM内部查询API未配置")
	}
	serviceName := strings.TrimSpace(c.conf.InternalServiceName)
	if serviceName == "" {
		serviceName = strings.TrimSpace(c.conf.ServiceId)
	}
	if serviceName == "" {
		return nil, gerror.New("IM内部查询服务名未配置")
	}
	secret := c.conf.InternalServiceSecret
	if secret == "" {
		secret = c.conf.ServiceSecret
	}
	if secret == "" {
		return nil, gerror.New("IM内部查询API密钥未配置")
	}
	req, err := http.NewRequestWithContext(ctx, method, baseUrl+path, bytes.NewReader(bodyBytes))
	if err != nil {
		return nil, gerror.Wrap(err, "创建IM内部查询请求失败")
	}
	timestamp := strconv.FormatInt(time.Now().UTC().Unix(), 10)
	nonce, err := randomNonce()
	if err != nil {
		return nil, err
	}
	bodyHash := sha256.Sum256(bodyBytes)
	signingText := strings.Join([]string{
		method,
		requestTarget(req),
		hex.EncodeToString(bodyHash[:]),
		timestamp,
		nonce,
	}, "\n")
	mac := hmac.New(sha256.New, []byte(secret))
	_, _ = mac.Write([]byte(signingText))
	req.Header.Set("Accept", "application/json")
	req.Header.Set("X-Service-Name", serviceName)
	req.Header.Set("X-Timestamp", timestamp)
	req.Header.Set("X-Nonce", nonce)
	req.Header.Set("X-Signature", hex.EncodeToString(mac.Sum(nil)))
	return req, nil
}