package utils;

import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.web.client.RestTemplate;

import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author JP
 * @createTime 2021/9/23
 */
public class ThirdApiCaller {
    private static final String FORM_CONTENT_TYPE = "application/x-www-form-urlencoded";

    private static final String JSON_CONTENT_TYPE = "application/json;charset=utf8";

    private static final String XML_CONTENT_TYPE = "application/xml;charset=utf8";

    private static RestTemplate REST_TEMPLATE;

    static {
        RestTemplate restTemplate = new RestTemplate();
        List<HttpMessageConverter<?>> list = restTemplate.getMessageConverters();
        for (HttpMessageConverter<?> httpMessageConverter:list){
            if (httpMessageConverter instanceof StringHttpMessageConverter){
                ((StringHttpMessageConverter) httpMessageConverter).setDefaultCharset(StandardCharsets.UTF_8);
            }
        }
        REST_TEMPLATE = restTemplate;
    }

    /**
     * FORM形式
     *
     * @param url
     * @param body
     * @param header
     * @param clazz
     * @param <T>
     * @return
     */
    public static <T> T postForm(String url, LinkedMultiValueMap<String, ? extends Object> body,
                                 Map<String, String> header, Class<T> clazz) {
        try {
            HttpHeaders httpHeaders = createFormHttpHeaders(header);
            body = body == null ? new LinkedMultiValueMap<String, Object>() : body;
            return REST_TEMPLATE.postForObject(url, new HttpEntity(body, httpHeaders), clazz);
        } catch (Exception e) {
            throw e;
        }
    }

    /**
     * JSON形式
     *
     * @param url
     * @param body
     * @param header
     * @param clazz
     * @param <T>
     * @return
     */
    public static <T> T postJson(String url, Object body, Map<String, String> header, Class<T> clazz) {
        try {
            HttpHeaders httpHeaders = createJsonHttpHeaders(header);
            body = body == null ? new HashMap<String, String>() : body;
            return REST_TEMPLATE.postForObject(url, new HttpEntity(body, httpHeaders), clazz);
        } catch (Exception e) {
            throw e;
        }
    }

    public static <T> T postXml(String url, Object body, Map<String, String> header, Class<T> clazz) {
        try {
            HttpHeaders httpHeaders = createXmlHttpHeaders(header);
            body = body == null ? new HashMap<String, String>() : body;
            return REST_TEMPLATE.postForObject(url, new HttpEntity(body, httpHeaders), clazz);
        } catch (Exception e) {
            throw e;
        }
    }

    private static HttpHeaders createFormHttpHeaders(Map<String, String> header) {
        HttpHeaders headers = new HttpHeaders();
        if (header != null) {
            for (Map.Entry<String, String> entry : header.entrySet()) {
                headers.add(entry.getKey(), entry.getValue());
            }
        }
        headers.add("Content-Type", FORM_CONTENT_TYPE);
        return headers;
    }

    private static HttpHeaders createJsonHttpHeaders(Map<String, String> header) {
        HttpHeaders headers = new HttpHeaders();
        if (header != null) {
            for (Map.Entry<String, String> entry : header.entrySet()) {
                headers.add(entry.getKey(), entry.getValue());
            }
        }
        headers.add("Content-Type", JSON_CONTENT_TYPE);
        return headers;
    }

    private static HttpHeaders createXmlHttpHeaders(Map<String, String> header) {
        HttpHeaders headers = new HttpHeaders();
        if (header != null) {
            for (Map.Entry<String, String> entry : header.entrySet()) {
                headers.add(entry.getKey(), entry.getValue());
            }
        }
        headers.add("Content-Type", XML_CONTENT_TYPE);
        return headers;
    }

}