package api

import (
	"errors"

	"apigo.cc/go/cast"
	"apigo.cc/go/encoding"
)

// Signer 负责为请求附加签名信息
type Signer interface {
	Sign(req *HttpRequest, config map[string]any) error
}

var signers = map[string]Signer{
	"basic":  &basicSigner{},
	"bearer": &bearerSigner{},
}

// RegisterSigner 注册全局签名器
func RegisterSigner(name string, s Signer) {
	signers[name] = s
}

// GetSigner 获取签名器
func GetSigner(name string) Signer {
	return signers[name]
}

// 快速应用签名
func sign(name string, req *HttpRequest, config map[string]any) error {
	if name == "" {
		return nil
	}
	s := GetSigner(name)
	if s == nil {
		return errors.New("signer not found: " + name)
	}
	return s.Sign(req, config)
}

// 内置标准签名器实现

type basicSigner struct{}

func (s *basicSigner) Sign(req *HttpRequest, config map[string]any) error {
	username := cast.String(config["username"])
	password := cast.String(config["password"])
	auth := username + ":" + password
	req.Headers["Authorization"] = "Basic " + encoding.Base64ToString([]byte(auth))
	return nil
}

type bearerSigner struct{}

func (s *bearerSigner) Sign(req *HttpRequest, config map[string]any) error {
	token := cast.String(config["token"])
	if token == "" {
		token = cast.String(config["key"])
	}
	req.Headers["Authorization"] = "Bearer " + token
	return nil
}