/*
 * Tencent is pleased to support the open source community by making
 * 蓝鲸智云 - 配置平台 (BlueKing - CMDB) available.
 * Copyright (C) 2025 Tencent. All rights reserved.
 * Licensed under the MIT License (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://opensource.org/licenses/MIT
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 * We undertake not to change the open source license (MIT license) applicable
 * to the current version of the project delivered to anyone in the future.
 */

package codec

import (
	"fmt"
	"net/http"
	"reflect"
)

type headerCodec struct {
	values http.Header
}

// NewHeaderCodec ...
func NewHeaderCodec(r *http.Request) *headerCodec {
	c := &headerCodec{values: r.Header}
	return c
}

// Decode ...
func (c *headerCodec) Decode(field reflect.StructField, fv reflect.Value, tag *Tag) error {
	// header统一格式
	key := http.CanonicalHeaderKey(tag.Name)
	v := c.values[key]
	if len(v) == 0 {
		return nil
	}

	rv, err := getFieldValue(field.Type, tag, v)
	if err != nil {
		return err
	}
	if !rv.IsValid() {
		return fmt.Errorf("%s not valid", rv)
	}

	fv.Set(rv)
	return nil
}