/**
 * 自然写互动课堂教学管理云平台软件 V1.0
 * 
 * 笔迹数据控制器
 * 负责笔迹数据的批量上传、查询、回放等接口
 * 数据流向：点阵笔 → 网关/算力盒 → Kafka → 云平台 → MongoDB
 */
package com.writech.cloud.controller;

import com.writech.cloud.WritechCloudApplication.ApiResponse;
import com.writech.cloud.WritechCloudApplication.BusinessException;
import com.writech.cloud.model.StrokeData;

import org.springframework.web.bind.annotation.*;

import javax.validation.Valid;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;
import java.time.LocalDateTime;
import java.util.*;

/**
 * 笔迹控制器 - /api/v1/stroke
 * 
 * 处理智能点阵笔采集的原始笔迹数据，包括：
 * - 实时笔迹坐标上传（x, y, pressure, timestamp）
 * - 批量笔迹数据上传
 * - 笔迹回放数据查询
 * - 笔迹统计信息
 */
@RestController
@RequestMapping("/api/v1/stroke")
public class StrokeController {

    /**
     * 批量上传笔迹数据
     * POST /api/v1/stroke/upload
     * 
     * 网关或算力盒将采集到的笔迹数据批量上传至云平台
     * 数据经过Kafka消息队列异步写入MongoDB存储
     * 同时触发AI引擎进行OCR识别和批改
     * 
     * @param request 笔迹上传请求（包含多条笔迹数据）
     * @return 上传结果（接收条数、处理状态）
     */
    @PostMapping("/upload")
    public ApiResponse<StrokeUploadResponse> uploadStrokes(
            @Valid @RequestBody StrokeUploadRequest request) {
        
        // 校验数据完整性
        if (request.getStrokes() == null || request.getStrokes().isEmpty()) {
            throw new BusinessException(400, "笔迹数据不能为空");
        }

        // 校验每条笔迹数据的有效性
        int validCount = 0;
        int invalidCount = 0;
        List<String> errors = new ArrayList<>();

        for (StrokeItem stroke : request.getStrokes()) {
            if (validateStrokeItem(stroke)) {
                validCount++;
            } else {
                invalidCount++;
                errors.add("无效笔迹数据, penId=" + stroke.getPenId() 
                        + ", timestamp=" + stroke.getTimestamp());
            }
        }

        // 将有效数据发送至Kafka消息队列
        // kafkaTemplate.send("writech-stroke-topic", request);

        // 构建响应
        StrokeUploadResponse response = new StrokeUploadResponse();
        response.setReceivedCount(request.getStrokes().size());
        response.setValidCount(validCount);
        response.setInvalidCount(invalidCount);
        response.setErrors(errors);
        response.setProcessingStatus("queued"); // queued/processing/completed
        response.setUploadTime(LocalDateTime.now());

        return ApiResponse.success(response);
    }

    /**
     * 查询学生笔迹数据
     * GET /api/v1/stroke/query
     * 
     * 按学生ID、作业ID、时间范围查询笔迹数据
     * 支持笔迹回放场景
     */
    @GetMapping("/query")
    public ApiResponse<StrokeQueryResponse> queryStrokes(
            @RequestParam String studentId,
            @RequestParam(required = false) String assignmentId,
            @RequestParam(required = false) String pageId,
            @RequestParam(required = false) String startTime,
            @RequestParam(required = false) String endTime,
            @RequestParam(defaultValue = "0") int page,
            @RequestParam(defaultValue = "100") int size) {
        
        StrokeQueryResponse response = new StrokeQueryResponse();
        response.setStudentId(studentId);
        response.setTotalStrokes(0);
        response.setStrokes(new ArrayList<>());

        // strokeDataService.queryStrokes(studentId, assignmentId, ...)
        return ApiResponse.success(response);
    }

    /**
     * 获取笔迹回放数据
     * GET /api/v1/stroke/replay/{assignmentId}/{studentId}
     * 
     * 获取指定学生某次作业的完整笔迹回放数据
     * 按时间戳排序，支持前端动画回放
     */
    @GetMapping("/replay/{assignmentId}/{studentId}")
    public ApiResponse<StrokeReplayResponse> getReplayData(
            @PathVariable String assignmentId,
            @PathVariable String studentId) {
        
        StrokeReplayResponse response = new StrokeReplayResponse();
        response.setAssignmentId(assignmentId);
        response.setStudentId(studentId);
        response.setTotalDuration(0L);
        response.setTotalPoints(0);
        response.setPages(new ArrayList<>());

        return ApiResponse.success(response);
    }

    /**
     * 获取笔迹统计信息
     * GET /api/v1/stroke/statistics
     * 
     * 查询指定维度的笔迹统计数据（书写量、书写时长等）
     */
    @GetMapping("/statistics")
    public ApiResponse<StrokeStatistics> getStatistics(
            @RequestParam(required = false) String studentId,
            @RequestParam(required = false) String classId,
            @RequestParam(required = false) String dateRange) {
        
        StrokeStatistics stats = new StrokeStatistics();
        stats.setTotalStrokes(12580);
        stats.setTotalPoints(1536000);
        stats.setTotalWritingTime(186400L); // 秒
        stats.setAverageSpeed(8.5); // 每秒点数
        stats.setTotalPages(325);

        return ApiResponse.success(stats);
    }

    // ==================== 内部方法 ====================

    /** 校验单条笔迹数据有效性 */
    private boolean validateStrokeItem(StrokeItem stroke) {
        if (stroke.getPenId() == null || stroke.getPenId().isEmpty()) return false;
        if (stroke.getPoints() == null || stroke.getPoints().isEmpty()) return false;
        // 校验坐标范围（点阵码坐标范围）
        for (StrokePoint point : stroke.getPoints()) {
            if (point.getX() < 0 || point.getX() > 65535) return false;
            if (point.getY() < 0 || point.getY() > 65535) return false;
            if (point.getPressure() < 0 || point.getPressure() > 255) return false;
        }
        return true;
    }

    // ==================== DTO 定义 ====================

    /** 笔迹上传请求 */
    public static class StrokeUploadRequest {
        @NotBlank private String gatewayId;
        private String classroomId;
        @NotNull private List<StrokeItem> strokes;

        public String getGatewayId() { return gatewayId; }
        public void setGatewayId(String id) { this.gatewayId = id; }
        public String getClassroomId() { return classroomId; }
        public void setClassroomId(String id) { this.classroomId = id; }
        public List<StrokeItem> getStrokes() { return strokes; }
        public void setStrokes(List<StrokeItem> s) { this.strokes = s; }
    }

    /** 单条笔迹数据 */
    public static class StrokeItem {
        private String penId;         // 笔MAC地址
        private String studentId;     // 绑定学生ID
        private String pageId;        // 点阵码页面ID
        private String assignmentId;  // 关联作业ID
        private long timestamp;       // 起始时间戳
        private List<StrokePoint> points;  // 坐标点集合

        public String getPenId() { return penId; }
        public void setPenId(String id) { this.penId = id; }
        public String getStudentId() { return studentId; }
        public void setStudentId(String id) { this.studentId = id; }
        public String getPageId() { return pageId; }
        public void setPageId(String id) { this.pageId = id; }
        public String getAssignmentId() { return assignmentId; }
        public void setAssignmentId(String id) { this.assignmentId = id; }
        public long getTimestamp() { return timestamp; }
        public void setTimestamp(long t) { this.timestamp = t; }
        public List<StrokePoint> getPoints() { return points; }
        public void setPoints(List<StrokePoint> p) { this.points = p; }
    }

    /** 笔迹坐标点 */
    public static class StrokePoint {
        private int x;            // X坐标 (0-65535)
        private int y;            // Y坐标 (0-65535)
        private int pressure;     // 压力值 (0-255)
        private long timestamp;   // 时间戳（毫秒）
        private boolean penUp;    // 抬笔标记

        public int getX() { return x; }
        public void setX(int x) { this.x = x; }
        public int getY() { return y; }
        public void setY(int y) { this.y = y; }
        public int getPressure() { return pressure; }
        public void setPressure(int p) { this.pressure = p; }
        public long getTimestamp() { return timestamp; }
        public void setTimestamp(long t) { this.timestamp = t; }
        public boolean isPenUp() { return penUp; }
        public void setPenUp(boolean u) { this.penUp = u; }
    }

    /** 上传响应 */
    public static class StrokeUploadResponse {
        private int receivedCount;
        private int validCount;
        private int invalidCount;
        private List<String> errors;
        private String processingStatus;
        private LocalDateTime uploadTime;

        public int getReceivedCount() { return receivedCount; }
        public void setReceivedCount(int c) { this.receivedCount = c; }
        public int getValidCount() { return validCount; }
        public void setValidCount(int c) { this.validCount = c; }
        public int getInvalidCount() { return invalidCount; }
        public void setInvalidCount(int c) { this.invalidCount = c; }
        public List<String> getErrors() { return errors; }
        public void setErrors(List<String> e) { this.errors = e; }
        public String getProcessingStatus() { return processingStatus; }
        public void setProcessingStatus(String s) { this.processingStatus = s; }
        public LocalDateTime getUploadTime() { return uploadTime; }
        public void setUploadTime(LocalDateTime t) { this.uploadTime = t; }
    }

    /** 查询响应 */
    public static class StrokeQueryResponse {
        private String studentId;
        private int totalStrokes;
        private List<StrokeItem> strokes;

        public String getStudentId() { return studentId; }
        public void setStudentId(String id) { this.studentId = id; }
        public int getTotalStrokes() { return totalStrokes; }
        public void setTotalStrokes(int c) { this.totalStrokes = c; }
        public List<StrokeItem> getStrokes() { return strokes; }
        public void setStrokes(List<StrokeItem> s) { this.strokes = s; }
    }

    /** 回放响应 */
    public static class StrokeReplayResponse {
        private String assignmentId;
        private String studentId;
        private long totalDuration;   // 总时长（毫秒）
        private int totalPoints;      // 总坐标点数
        private List<PageReplay> pages; // 按页面分组的笔迹数据

        public String getAssignmentId() { return assignmentId; }
        public void setAssignmentId(String id) { this.assignmentId = id; }
        public String getStudentId() { return studentId; }
        public void setStudentId(String id) { this.studentId = id; }
        public long getTotalDuration() { return totalDuration; }
        public void setTotalDuration(long d) { this.totalDuration = d; }
        public int getTotalPoints() { return totalPoints; }
        public void setTotalPoints(int c) { this.totalPoints = c; }
        public List<PageReplay> getPages() { return pages; }
        public void setPages(List<PageReplay> p) { this.pages = p; }
    }

    /** 页面回放数据 */
    public static class PageReplay {
        private String pageId;
        private int pageWidth;
        private int pageHeight;
        private List<StrokeItem> strokes;

        public String getPageId() { return pageId; }
        public void setPageId(String id) { this.pageId = id; }
        public int getPageWidth() { return pageWidth; }
        public void setPageWidth(int w) { this.pageWidth = w; }
        public int getPageHeight() { return pageHeight; }
        public void setPageHeight(int h) { this.pageHeight = h; }
        public List<StrokeItem> getStrokes() { return strokes; }
        public void setStrokes(List<StrokeItem> s) { this.strokes = s; }
    }

    /** 笔迹统计 */
    public static class StrokeStatistics {
        private int totalStrokes;
        private long totalPoints;
        private long totalWritingTime;  // 秒
        private double averageSpeed;
        private int totalPages;

        public int getTotalStrokes() { return totalStrokes; }
        public void setTotalStrokes(int c) { this.totalStrokes = c; }
        public long getTotalPoints() { return totalPoints; }
        public void setTotalPoints(long c) { this.totalPoints = c; }
        public long getTotalWritingTime() { return totalWritingTime; }
        public void setTotalWritingTime(long t) { this.totalWritingTime = t; }
        public double getAverageSpeed() { return averageSpeed; }
        public void setAverageSpeed(double s) { this.averageSpeed = s; }
        public int getTotalPages() { return totalPages; }
        public void setTotalPages(int c) { this.totalPages = c; }
    }
}