package com.threecloud.dataserviceyy.util;

import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONArray;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
import java.util.Map;

/**
 * VAA录音盒HTTP工具类
 * 用于与录音盒设备进行HTTP通信
 * 参考文档: ebox_developer_guide.html (EBOX-8108 电话录音仪开发手册)
 * 
 * 【说明】
 * 所有方法都不重试，一次失败直接抛出异常，由调用方处理
 */
@Component
public class VaaHttpUtil {

    private static final Logger logger = LoggerFactory.getLogger(VaaHttpUtil.class);

    /** 连接超时：10秒 */
    private static final int CONNECT_TIMEOUT = 10000;
    /** API读取超时：30秒 */
    private static final int READ_TIMEOUT = 30000;
    /** 文件下载读取超时：2分钟 */
    private static final int DOWNLOAD_READ_TIMEOUT = 120000;

    /**
     * HTTP登录认证（无重试）
     * @param loginUrl 登录URL
     * @return 登录成功后返回Authorization Cookie值
     * @throws Exception 登录失败直接抛出异常
     */
    public String httpLogin(String loginUrl) throws Exception {
        logger.debug("正在登录录音盒: {}", loginUrl);

        HttpURLConnection conn = null;
        try {
            URL url = new URL(loginUrl);
            conn = (HttpURLConnection) url.openConnection();
            conn.setInstanceFollowRedirects(false);
            conn.setConnectTimeout(CONNECT_TIMEOUT);
            conn.setReadTimeout(READ_TIMEOUT);
            conn.setRequestMethod("GET");

            int responseCode = conn.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK || responseCode == HttpURLConnection.HTTP_MOVED_TEMP) {
                String authorization = getAuthorizationCookie(conn);
                if (authorization == null || authorization.isEmpty()) {
                    throw new RuntimeException("登录失败，录音盒未返回Authorization Cookie");
                }
                logger.info("录音盒登录成功");
                return authorization;
            }
            throw new RuntimeException("登录失败，HTTP状态码: " + responseCode);
        } finally {
            if (conn != null) {
                conn.disconnect();
            }
        }
    }

    /**
     * HTTP访问API获取数据（无重试）
     * @param apiUrl API地址
     * @param authorization 登录后返回的Authorization Cookie值
     * @return 返回JSON字符串
     * @throws Exception 访问失败直接抛出异常
     */
    public String httpVisit(String apiUrl, String authorization) throws Exception {
        logger.debug("访问API: {}", apiUrl);

        HttpURLConnection conn = null;
        try {
            URL url = new URL(apiUrl);
            conn = (HttpURLConnection) url.openConnection();
            conn.setConnectTimeout(CONNECT_TIMEOUT);
            conn.setReadTimeout(READ_TIMEOUT);
            conn.setRequestMethod("GET");
            addAuthorization(conn, authorization);

            int responseCode = conn.getResponseCode();
            if (responseCode == 200) {
                BufferedReader reader = new BufferedReader(
                    new InputStreamReader(conn.getInputStream(), "UTF-8")
                );
                StringBuilder result = new StringBuilder();
                String line;
                while ((line = reader.readLine()) != null) {
                    result.append(line);
                }
                reader.close();

                String jsonResult = result.toString();
                logger.debug("API响应: {}", jsonResult);
                if (isLoginPage(jsonResult)) {
                    throw new RuntimeException("录音盒认证失效，返回登录页面");
                }
                return jsonResult;
            } else {
                throw new RuntimeException("API访问失败，HTTP状态码: " + responseCode);
            }
        } finally {
            if (conn != null) {
                conn.disconnect();
            }
        }
    }

    /**
     * 下载录音文件（无重试）
     * @param fileUrl 文件URL
     * @param savePath 保存路径
     * @param authorization 登录后返回的Authorization Cookie值
     * @throws Exception 下载失败直接抛出异常
     */
    public void httpDown(String fileUrl, String savePath, String authorization) throws Exception {
        logger.info("开始下载录音文件: {} -> {}", fileUrl, savePath);

        // 确保目录存在
        File saveFile = new File(savePath);
        if (!saveFile.getParentFile().exists()) {
            saveFile.getParentFile().mkdirs();
        }

        HttpURLConnection conn = null;
        InputStream inputStream = null;
        FileOutputStream outputStream = null;

        try {
            URL url = new URL(fileUrl);
            conn = (HttpURLConnection) url.openConnection();
            conn.setConnectTimeout(CONNECT_TIMEOUT);
            conn.setReadTimeout(DOWNLOAD_READ_TIMEOUT);
            conn.setRequestMethod("GET");
            addAuthorization(conn, authorization);

            int responseCode = conn.getResponseCode();
            if (responseCode == 200) {
                // 获取服务器声明的文件大小，用于完整性校验
                long expectedSize = conn.getContentLengthLong();

                inputStream = conn.getInputStream();
                outputStream = new FileOutputStream(savePath);

                byte[] buffer = new byte[8192];
                int bytesRead;
                long totalBytes = 0;

                while ((bytesRead = inputStream.read(buffer)) != -1) {
                    outputStream.write(buffer, 0, bytesRead);
                    totalBytes += bytesRead;
                }

                outputStream.flush();
                logger.info("录音文件下载完成: {}, 大小: {} bytes ({} MB)",
                        savePath, totalBytes, totalBytes / 1024 / 1024);

                // 完整性校验
                if (expectedSize > 0 && totalBytes != expectedSize) {
                    saveFile.delete();
                    throw new RuntimeException(String.format(
                            "文件下载不完整: 期望 %d bytes, 实际 %d bytes", expectedSize, totalBytes));
                }
                // 录音文件至少应有1KB，过小说明下载异常
                if (totalBytes < 1024) {
                    saveFile.delete();
                    throw new RuntimeException(String.format(
                            "文件过小，可能下载异常: 仅 %d bytes", totalBytes));
                }
                // 校验文件头，确保不是HTML错误页面
                byte[] header = new byte[(int) Math.min(totalBytes, 16)];
                try (java.io.RandomAccessFile raf = new java.io.RandomAccessFile(saveFile, "r")) {
                    raf.readFully(header);
                }
                String headerStr = new String(header, "ASCII").trim().toLowerCase();
                if (headerStr.startsWith("<!doctype") || headerStr.startsWith("<html")) {
                    saveFile.delete();
                    throw new RuntimeException("下载内容为HTML页面，非音频文件");
                }
            } else {
                throw new RuntimeException("文件下载失败，HTTP状态码: " + responseCode);
            }
        } finally {
            closeQuietly(inputStream);
            closeQuietly(outputStream);
            if (conn != null) {
                conn.disconnect();
            }
        }
    }

    private void closeQuietly(Closeable c) {
        if (c != null) {
            try { c.close(); } catch (IOException ignored) {}
        }
    }

    private void addAuthorization(HttpURLConnection conn, String authorization) {
        if (authorization != null && !authorization.isEmpty()) {
            conn.setRequestProperty("Cookie", "Authorization=" + authorization);
        }
    }

    private boolean isLoginPage(String responseBody) {
        if (responseBody == null) {
            return false;
        }
        String body = responseBody.trim().toLowerCase();
        return body.startsWith("<!doctype") || body.startsWith("<html")
                || (body.contains("<form") && body.contains("password"));
    }

    private String getAuthorizationCookie(HttpURLConnection conn) {
        for (Map.Entry<String, List<String>> entry : conn.getHeaderFields().entrySet()) {
            if (entry.getKey() == null || !"Set-Cookie".equalsIgnoreCase(entry.getKey())) {
                continue;
            }
            String authorization = getAuthorizationValue(entry.getValue());
            if (authorization != null && !authorization.isEmpty()) {
                return authorization;
            }
        }
        return null;
    }

    private String getAuthorizationValue(List<String> cookies) {
        if (cookies == null || cookies.isEmpty()) {
            return null;
        }
        for (String cookie : cookies) {
            String prefix = "Authorization=";
            int start = cookie.indexOf(prefix);
            if (start < 0) {
                continue;
            }
            start += prefix.length();
            int end = cookie.indexOf(';', start);
            return end >= 0 ? cookie.substring(start, end) : cookie.substring(start);
        }
        return null;
    }

    /**
     * 解析通道状态JSON
     */
    public JSONArray parseChannelData(String jsonData) {
        if (jsonData == null || jsonData.isEmpty() || "[]".equals(jsonData)) {
            return new JSONArray();
        }
        return JSON.parseArray(jsonData);
    }

    /**
     * 解析录音记录JSON
     */
    public JSONArray parseRecordData(String jsonData) {
        if (jsonData == null || jsonData.isEmpty() || "[]".equals(jsonData)) {
            return new JSONArray();
        }
        return JSON.parseArray(jsonData);
    }

    /**
     * 获取分机号码配置
     * EBOX接口: GET /service/ext/number
     * @param extUrl 接口地址
     * @param authorization 登录后返回的Authorization Cookie值
     * @return 通道-分机号映射 Map<channel, phoneNumber>
     */
    public Map<String, String> getExtensionNumbers(String extUrl, String authorization) throws Exception {
        String jsonData = httpVisit(extUrl, authorization);
        if (jsonData == null || jsonData.isEmpty() || "[]".equals(jsonData) || "{}".equals(jsonData)) {
            return new java.util.HashMap<>();
        }
        try {
            com.alibaba.fastjson2.JSONObject jsonObj = JSON.parseObject(jsonData);
            Map<String, String> result = new java.util.HashMap<>();
            for (String key : jsonObj.keySet()) {
                String value = jsonObj.getString(key);
                result.put(key, value != null ? value : "");
            }
            logger.info("获取到分机号码配置: {} 条", result.size());
            return result;
        } catch (Exception e) {
            logger.warn("解析分机号码配置失败: {}", e.getMessage());
            return new java.util.HashMap<>();
        }
    }
}