package cc.mrbird.febs.ai.controller.productPoint;

import cc.mrbird.febs.ai.req.memberTalkStream.ApiMemberTalkReloadStreamDto;
import cc.mrbird.febs.ai.req.product.ApiProductInfoDto;
import cc.mrbird.febs.ai.req.product.ApiProductPageDto;
import cc.mrbird.febs.ai.req.productPoint.ApiProductPointInfoDto;
import cc.mrbird.febs.ai.req.productPoint.ApiProductPointPageDto;
import cc.mrbird.febs.ai.req.productPoint.ApiProductPointRecommendDto;
import cc.mrbird.febs.ai.res.product.ApiProductInfoVo;
import cc.mrbird.febs.ai.res.product.ApiProductVo;
import cc.mrbird.febs.ai.res.productPoint.ApiProductPointInfoVo;
import cc.mrbird.febs.ai.res.productPoint.ApiProductPointListVo;
import cc.mrbird.febs.ai.res.productPoint.ApiProductPointRecommendVo;
import cc.mrbird.febs.ai.service.AiProductPointService;
import cc.mrbird.febs.common.entity.FebsResponse;
import cc.mrbird.febs.common.utils.LoginUserUtil;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import io.swagger.annotations.ApiResponse;
import io.swagger.annotations.ApiResponses;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpStatus;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.RandomAccessFile;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

/**
 * @author Administrator
 */
@Slf4j
@Validated
@RestController
@RequiredArgsConstructor
@RequestMapping(value = "/api/ai/productPoint")
@Api(value = "ApiProductPointController", tags = "AI-知识点(学习)")
public class ApiProductPointController {

    private final AiProductPointService aiProductPointService;

    @ApiOperation(value = "知识点列表", notes = "知识点列表")
    @ApiResponses({
            @ApiResponse(code = 200, message = "success", response = ApiProductPointListVo.class)
    })
    @PostMapping(value = "/list")
    public FebsResponse list(@RequestBody @Validated ApiProductPointPageDto dto) {

        return aiProductPointService.productPointList(dto);
    }

    @ApiOperation(value = "知识点详情", notes = "知识点详情")
    @ApiResponses({
            @ApiResponse(code = 200, message = "success", response = ApiProductPointInfoVo.class)
    })
    @PostMapping(value = "/info")
    public FebsResponse info(@RequestBody @Validated ApiProductPointInfoDto dto) {

        return aiProductPointService.productPointInfo(dto);
    }


    @ApiOperation(value = "推荐", notes = "推荐")
    @ApiResponses({
            @ApiResponse(code = 200, message = "success", response = ApiProductPointRecommendVo.class)
    })
    @PostMapping(value = "/recommend")
    public FebsResponse recommend(@RequestBody @Validated ApiProductPointRecommendDto dto) {

        return aiProductPointService.recommend(dto);
    }


    public static final String baseUploadDir = "/home/javaweb/webresource/ai/file";

    @GetMapping("/play/{fileName}")
    public void playVideo(@PathVariable("fileName") String fileName, HttpServletRequest request, HttpServletResponse response) {
        log.info("开始播放视频文件: {}", fileName);

        // 配置参数
        final int BUFFER_SIZE = 1024 * 1024; // 1MB缓冲区，提高I/O性能
        final long MAX_INITIAL_SEGMENT = 1024 * 1024 * 15; // 最大初始片段大小（15MB），约30秒中等码率视频

        try {
            String companyId = LoginUserUtil.getLoginUser().getCompanyId();
            String uploadDir = baseUploadDir + "/" + companyId;
            Path filePath = Paths.get(uploadDir, fileName);

            // 检查文件是否存在
            if (!Files.exists(filePath)) {
                log.warn("视频文件不存在: {}", filePath);
                response.setStatus(HttpStatus.NOT_FOUND.value());
                return;
            }

            // 检查文件是否为常规文件
            if (!Files.isRegularFile(filePath)) {
                log.warn("路径不是常规文件: {}", filePath);
                response.setStatus(HttpStatus.BAD_REQUEST.value());
                return;
            }

            // 获取文件大小
            long fileSize = Files.size(filePath);
            log.debug("视频文件大小: {} bytes", fileSize);

            // 检查是否有Range请求头
            String rangeHeader = request.getHeader("Range");
            if (rangeHeader != null) {
                log.debug("收到Range请求: {}", rangeHeader);
                // 解析Range头，格式为"bytes=start-end"
                String[] ranges = rangeHeader.replace("bytes=", "").split("-");
                long start = 0, end = fileSize - 1;

                try {
                    if (!ranges[0].isEmpty()) {
                        start = Long.parseLong(ranges[0]);
                    }
                    if (ranges.length > 1 && !ranges[1].isEmpty()) {
                        end = Long.parseLong(ranges[1]);
                    } else {
                        // 如果没有指定结束位置，返回从开始位置到文件末尾的内容
                        // 但限制最大长度，避免一次性传输过大的内容
                        end = Math.min(start + BUFFER_SIZE * 10, fileSize - 1);
                    }
                } catch (NumberFormatException e) {
                    log.error("无效的Range头格式: {}", rangeHeader, e);
                    response.setStatus(HttpStatus.BAD_REQUEST.value());
                    return;
                }

                // 确保范围有效
                if (start > end || start >= fileSize) {
                    log.warn("无效的Range范围: {}-{}，文件大小: {}", start, end, fileSize);
                    response.setStatus(HttpStatus.REQUESTED_RANGE_NOT_SATISFIABLE.value());
                    response.setHeader("Content-Range", "bytes */" + fileSize);
                    return;
                }

                // 限制结束位置不超过文件大小
                if (end >= fileSize) {
                    end = fileSize - 1;
                }

                // 计算内容长度
                long contentLength = end - start + 1;
                log.debug("处理Range请求: {}-{}，长度: {}", start, end, contentLength);

                // 设置响应状态和头部信息
                response.setStatus(HttpStatus.PARTIAL_CONTENT.value());
                response.setContentType(getContentTypeByExtension(fileName));
                response.setContentLengthLong(contentLength);
                response.setHeader("Content-Range", "bytes " + start + "-" + end + "/" + fileSize);
                response.setHeader("Accept-Ranges", "bytes");
                response.setHeader("Content-Disposition", "inline; filename=\"" + fileName + "\"");
                response.setHeader("Cache-Control", "public, max-age=3600"); // 添加缓存控制

                // 使用NIO提高读取性能
                try (RandomAccessFile randomAccessFile = new RandomAccessFile(filePath.toFile(), "r");
                     OutputStream outputStream = response.getOutputStream()) {

                    randomAccessFile.seek(start);
                    byte[] buffer = new byte[BUFFER_SIZE];
                    long remaining = contentLength;
                    int bytesRead;

                    while (remaining > 0 && (bytesRead = randomAccessFile.read(buffer, 0, (int) Math.min(buffer.length, remaining))) != -1) {
                        outputStream.write(buffer, 0, bytesRead);
                        remaining -= bytesRead;

                        // 定期刷新输出流，避免缓冲区溢出
                        if (remaining % (BUFFER_SIZE * 4) == 0) {
                            outputStream.flush();
                        }
                    }

                    // 确保所有数据都被写入
                    outputStream.flush();
                    log.debug("Range请求处理完成: {}-{}", start, end);
                }
            } else {
                log.debug("收到完整文件请求，返回初始片段");

                // 没有Range头，返回文件大小的10分之一和15MB中较小的那个
                long oneTenthSize = fileSize / 10;
                // 计算10分之一和15MB的较小值
                long maxInitialSize = Math.min(oneTenthSize, MAX_INITIAL_SEGMENT);
                // 确保至少返回1字节，且不超过文件大小
                long actualEnd = Math.min(Math.max(maxInitialSize, 1), fileSize - 1);
                log.debug("返回初始片段: {} bytes (10分之一大小: {} bytes, 15MB限制: {} bytes, 文件总大小: {} bytes)",
                        actualEnd + 1, oneTenthSize, MAX_INITIAL_SEGMENT, fileSize);

                // 设置响应状态和头部信息
                response.setStatus(HttpStatus.PARTIAL_CONTENT.value()); // 使用206状态码，因为只返回部分内容
                response.setContentType(getContentTypeByExtension(fileName));
                response.setContentLengthLong(actualEnd + 1);
                response.setHeader("Content-Range", "bytes 0-" + actualEnd + "/" + fileSize);
                response.setHeader("Accept-Ranges", "bytes");
                response.setHeader("Content-Disposition", "inline; filename=\"" + fileName + "\"");
                response.setHeader("Cache-Control", "public, max-age=3600"); // 添加缓存控制

                // 流式传输文件的初始片段
                try (InputStream inputStream = Files.newInputStream(filePath);
                     OutputStream outputStream = response.getOutputStream()) {
                    byte[] buffer = new byte[BUFFER_SIZE];
                    long written = 0;
                    int bytesRead;

                    while (written <= actualEnd && (bytesRead = inputStream.read(buffer)) != -1) {
                        long toWrite = Math.min(bytesRead, actualEnd + 1 - written);
                        outputStream.write(buffer, 0, (int)toWrite);
                        written += toWrite;

                        // 定期刷新输出流
                        if (written % (BUFFER_SIZE * 4) == 0) {
                            outputStream.flush();
                        }

                        // 如果已经写完初始片段，则停止
                        if (written > actualEnd) {
                            break;
                        }
                    }

                    // 确保所有数据都被写入
                    outputStream.flush();
                    log.debug("初始片段传输完成，大小: {} bytes", written);
                }
            }
        } catch (Exception e) {
            log.error("播放视频文件时发生错误: {}", fileName, e);
            try {
                // 确保响应状态被设置
                if (!response.isCommitted()) {
                    response.setStatus(HttpStatus.INTERNAL_SERVER_ERROR.value());
                }
            } catch (Exception ex) {
                log.error("设置响应状态时发生错误", ex);
            }
        } finally {
            log.info("视频播放请求处理完成: {}", fileName);
        }
    }

    /**
     * 根据文件扩展名获取MIME类型
     */
    private String getContentTypeByExtension(String fileName) {
        String extension = "";
        int lastDotIndex = fileName.lastIndexOf('.');
        if (lastDotIndex > 0) {
            extension = fileName.substring(lastDotIndex).toLowerCase();
        }

        switch (extension) {
            case ".mp4":
                return "video/mp4";
            case ".avi":
                return "video/x-msvideo";
            case ".mov":
                return "video/quicktime";
            case ".wmv":
                return "video/x-ms-wmv";
            case ".flv":
                return "video/x-flv";
            case ".webm":
                return "video/webm";
            case ".mkv":
                return "video/x-matroska";
            case ".m3u8":
                return "application/vnd.apple.mpegurl";
            case ".ts":
                return "video/MP2T";
            default:
                return "application/octet-stream";
        }
    }

}