/**
 * 自然写互动课堂教学管理云平台软件 V1.0
 * 
 * 作业管理控制器
 * 负责作业/试卷的发布、回收、批改结果查询等接口
 */
package com.writech.cloud.controller;

import com.writech.cloud.WritechCloudApplication.ApiResponse;
import com.writech.cloud.WritechCloudApplication.BusinessException;
import com.writech.cloud.model.Assignment;
import com.writech.cloud.service.UserService;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.web.bind.annotation.*;

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

/**
 * 作业控制器 - /api/v1/assignment
 * 
 * 教师发布作业/试卷 → 学生纸上作答（笔迹通过点阵笔采集）
 * → 系统自动收集 → AI引擎识别批改 → 结果推送教师和家长
 */
@RestController
@RequestMapping("/api/v1/assignment")
public class AssignmentController {

    @Autowired
    private UserService userService;

    /**
     * 发布作业
     * POST /api/v1/assignment/publish
     * 
     * 教师创建并发布作业/试卷，指定班级、截止时间、题目内容
     * 发布后自动推送通知至学生端和家长端
     */
    @PostMapping("/publish")
    public ApiResponse<AssignmentPublishResponse> publishAssignment(
            @Valid @RequestBody AssignmentPublishRequest request,
            @RequestHeader("Authorization") String auth) {
        
        // 验证教师身份
        String teacherId = extractUserIdFromToken(auth);
        
        // 校验截止时间
        if (request.getDeadline() != null && request.getDeadline().isBefore(LocalDateTime.now())) {
            throw new BusinessException(400, "截止时间不能早于当前时间");
        }

        // 校验题目列表
        if (request.getQuestions() == null || request.getQuestions().isEmpty()) {
            throw new BusinessException(400, "作业题目不能为空");
        }

        // 创建作业记录
        Assignment assignment = new Assignment();
        assignment.setId(UUID.randomUUID().toString().replace("-", ""));
        assignment.setTeacherId(teacherId);
        assignment.setClassId(request.getClassId());
        assignment.setTitle(request.getTitle());
        assignment.setType(request.getType()); // homework/exam/practice
        assignment.setSubject(request.getSubject());
        assignment.setDeadline(request.getDeadline());
        assignment.setStatus("published");
        assignment.setPublishTime(LocalDateTime.now());
        assignment.setTotalScore(calculateTotalScore(request.getQuestions()));
        assignment.setQuestionCount(request.getQuestions().size());

        // 关联点阵码页面（每道题对应特定点阵码区域）
        if (request.getDotCodePages() != null) {
            assignment.setDotCodePages(request.getDotCodePages());
        }

        // 保存作业及题目
        // assignmentService.saveWithQuestions(assignment, request.getQuestions());

        // 异步推送通知至学生端和家长端
        // messageService.pushAssignmentNotification(assignment);

        AssignmentPublishResponse response = new AssignmentPublishResponse();
        response.setAssignmentId(assignment.getId());
        response.setTitle(assignment.getTitle());
        response.setPublishTime(assignment.getPublishTime());
        response.setStudentCount(getClassStudentCount(request.getClassId()));

        return ApiResponse.success(response);
    }

    /**
     * 获取作业列表
     * GET /api/v1/assignment/list
     * 
     * 教师查看已发布的作业列表，支持按班级、状态、时间筛选
     */
    @GetMapping("/list")
    public ApiResponse<Page<AssignmentSummary>> listAssignments(
            @RequestParam(required = false) String classId,
            @RequestParam(required = false) String status,
            @RequestParam(required = false) String subject,
            @RequestParam(defaultValue = "0") int page,
            @RequestParam(defaultValue = "20") int size,
            @RequestHeader("Authorization") String auth) {
        
        String userId = extractUserIdFromToken(auth);
        // Page<AssignmentSummary> result = assignmentService.queryList(...)
        return ApiResponse.success(null);
    }

    /**
     * 获取作业详情
     * GET /api/v1/assignment/{id}
     */
    @GetMapping("/{id}")
    public ApiResponse<AssignmentDetailResponse> getAssignment(@PathVariable String id) {
        // Assignment assignment = assignmentService.findById(id);
        return ApiResponse.success(null);
    }

    /**
     * 获取批改结果
     * GET /api/v1/result/{assignmentId}
     * 
     * 查询指定作业的AI批改结果，包含每个学生的识别文本、
     * 得分、错误详情及AI反馈建议
     */
    @GetMapping("/result/{assignmentId}")
    public ApiResponse<AssignmentResultResponse> getResult(
            @PathVariable String assignmentId,
            @RequestParam(required = false) String studentId) {
        
        AssignmentResultResponse response = new AssignmentResultResponse();
        response.setAssignmentId(assignmentId);
        response.setTotalStudents(40);
        response.setSubmittedCount(38);
        response.setGradedCount(38);
        response.setAverageScore(85.5);
        response.setHighestScore(100.0);
        response.setLowestScore(45.0);

        // 每个学生的批改结果
        List<StudentResult> studentResults = new ArrayList<>();
        // studentResults = resultService.getStudentResults(assignmentId, studentId);
        response.setStudentResults(studentResults);

        return ApiResponse.success(response);
    }

    /**
     * 教师人工复核批改
     * PUT /api/v1/assignment/review/{assignmentId}
     * 
     * AI批改后教师可进行人工复核，修正AI评分或添加评语
     */
    @PutMapping("/review/{assignmentId}")
    public ApiResponse<Void> reviewAssignment(
            @PathVariable String assignmentId,
            @Valid @RequestBody ReviewRequest request,
            @RequestHeader("Authorization") String auth) {
        
        String teacherId = extractUserIdFromToken(auth);

        // 遍历教师的复核修改
        for (ReviewItem item : request.getReviewItems()) {
            // resultService.updateReview(assignmentId, item.getStudentId(),
            //         item.getQuestionId(), item.getManualScore(),
            //         item.getTeacherComment(), teacherId);
        }

        return ApiResponse.success();
    }

    /**
     * 学情报告接口
     * GET /api/v1/report/student/{id}
     * 
     * 获取指定学生的学情报告，包含知识点掌握度、
     * 书写能力评估、成绩趋势等多维度分析数据
     */
    @GetMapping("/report/student/{studentId}")
    public ApiResponse<StudentReportResponse> getStudentReport(
            @PathVariable String studentId,
            @RequestParam(required = false) String subject,
            @RequestParam(required = false) String dateRange) {
        
        StudentReportResponse report = new StudentReportResponse();
        report.setStudentId(studentId);
        report.setReportDate(LocalDateTime.now());

        // 知识点掌握度
        List<KnowledgePoint> knowledgePoints = new ArrayList<>();
        // knowledgePoints = analyticsService.getKnowledgeMastery(studentId, subject);
        report.setKnowledgePoints(knowledgePoints);

        // 书写能力评估
        WritingAbility writingAbility = new WritingAbility();
        writingAbility.setStrokeOrderScore(88.5);
        writingAbility.setStructureScore(82.3);
        writingAbility.setNeatnessScore(90.1);
        writingAbility.setOverallScore(86.9);
        report.setWritingAbility(writingAbility);

        return ApiResponse.success(report);
    }

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

    private String extractUserIdFromToken(String auth) {
        // 从JWT Token解析用户ID
        return "teacher_001";
    }

    private double calculateTotalScore(List<QuestionItem> questions) {
        return questions.stream()
                .mapToDouble(QuestionItem::getScore)
                .sum();
    }

    private int getClassStudentCount(String classId) {
        return 40; // 查询班级学生数
    }

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

    public static class AssignmentPublishRequest {
        @NotBlank private String classId;
        @NotBlank private String title;
        private String type;       // homework/exam/practice
        private String subject;
        private LocalDateTime deadline;
        private List<QuestionItem> questions;
        private List<String> dotCodePages;  // 关联的点阵码页面ID

        public String getClassId() { return classId; }
        public void setClassId(String id) { this.classId = id; }
        public String getTitle() { return title; }
        public void setTitle(String t) { this.title = t; }
        public String getType() { return type; }
        public void setType(String t) { this.type = t; }
        public String getSubject() { return subject; }
        public void setSubject(String s) { this.subject = s; }
        public LocalDateTime getDeadline() { return deadline; }
        public void setDeadline(LocalDateTime d) { this.deadline = d; }
        public List<QuestionItem> getQuestions() { return questions; }
        public void setQuestions(List<QuestionItem> q) { this.questions = q; }
        public List<String> getDotCodePages() { return dotCodePages; }
        public void setDotCodePages(List<String> p) { this.dotCodePages = p; }
    }

    public static class QuestionItem {
        private int questionNo;
        private String type;      // choice/fill/short_answer/essay/math
        private String content;
        private String answer;
        private double score;
        private String knowledgePointId;

        public int getQuestionNo() { return questionNo; }
        public void setQuestionNo(int n) { this.questionNo = n; }
        public String getType() { return type; }
        public void setType(String t) { this.type = t; }
        public String getContent() { return content; }
        public void setContent(String c) { this.content = c; }
        public String getAnswer() { return answer; }
        public void setAnswer(String a) { this.answer = a; }
        public double getScore() { return score; }
        public void setScore(double s) { this.score = s; }
        public String getKnowledgePointId() { return knowledgePointId; }
        public void setKnowledgePointId(String id) { this.knowledgePointId = id; }
    }

    public static class AssignmentPublishResponse {
        private String assignmentId;
        private String title;
        private LocalDateTime publishTime;
        private int studentCount;

        public String getAssignmentId() { return assignmentId; }
        public void setAssignmentId(String id) { this.assignmentId = id; }
        public String getTitle() { return title; }
        public void setTitle(String t) { this.title = t; }
        public LocalDateTime getPublishTime() { return publishTime; }
        public void setPublishTime(LocalDateTime t) { this.publishTime = t; }
        public int getStudentCount() { return studentCount; }
        public void setStudentCount(int c) { this.studentCount = c; }
    }

    public static class AssignmentSummary {
        private String id;
        private String title;
        private String type;
        private String status;
        private int submittedCount;
        private int totalCount;
        private LocalDateTime publishTime;

        public String getId() { return id; }
        public void setId(String id) { this.id = id; }
        public String getTitle() { return title; }
        public void setTitle(String t) { this.title = t; }
        public String getType() { return type; }
        public void setType(String t) { this.type = t; }
        public String getStatus() { return status; }
        public void setStatus(String s) { this.status = s; }
        public int getSubmittedCount() { return submittedCount; }
        public void setSubmittedCount(int c) { this.submittedCount = c; }
        public int getTotalCount() { return totalCount; }
        public void setTotalCount(int c) { this.totalCount = c; }
        public LocalDateTime getPublishTime() { return publishTime; }
        public void setPublishTime(LocalDateTime t) { this.publishTime = t; }
    }

    public static class AssignmentDetailResponse {
        private Assignment assignment;
        private List<QuestionItem> questions;
        public Assignment getAssignment() { return assignment; }
        public void setAssignment(Assignment a) { this.assignment = a; }
        public List<QuestionItem> getQuestions() { return questions; }
        public void setQuestions(List<QuestionItem> q) { this.questions = q; }
    }

    public static class AssignmentResultResponse {
        private String assignmentId;
        private int totalStudents;
        private int submittedCount;
        private int gradedCount;
        private double averageScore;
        private double highestScore;
        private double lowestScore;
        private List<StudentResult> studentResults;

        public String getAssignmentId() { return assignmentId; }
        public void setAssignmentId(String id) { this.assignmentId = id; }
        public int getTotalStudents() { return totalStudents; }
        public void setTotalStudents(int c) { this.totalStudents = c; }
        public int getSubmittedCount() { return submittedCount; }
        public void setSubmittedCount(int c) { this.submittedCount = c; }
        public int getGradedCount() { return gradedCount; }
        public void setGradedCount(int c) { this.gradedCount = c; }
        public double getAverageScore() { return averageScore; }
        public void setAverageScore(double s) { this.averageScore = s; }
        public double getHighestScore() { return highestScore; }
        public void setHighestScore(double s) { this.highestScore = s; }
        public double getLowestScore() { return lowestScore; }
        public void setLowestScore(double s) { this.lowestScore = s; }
        public List<StudentResult> getStudentResults() { return studentResults; }
        public void setStudentResults(List<StudentResult> r) { this.studentResults = r; }
    }

    public static class StudentResult {
        private String studentId;
        private String studentName;
        private double totalScore;
        private List<QuestionResult> questionResults;

        public String getStudentId() { return studentId; }
        public void setStudentId(String id) { this.studentId = id; }
        public String getStudentName() { return studentName; }
        public void setStudentName(String n) { this.studentName = n; }
        public double getTotalScore() { return totalScore; }
        public void setTotalScore(double s) { this.totalScore = s; }
        public List<QuestionResult> getQuestionResults() { return questionResults; }
        public void setQuestionResults(List<QuestionResult> r) { this.questionResults = r; }
    }

    public static class QuestionResult {
        private int questionNo;
        private String ocrText;
        private double score;
        private boolean isCorrect;
        private String aiFeedback;

        public int getQuestionNo() { return questionNo; }
        public void setQuestionNo(int n) { this.questionNo = n; }
        public String getOcrText() { return ocrText; }
        public void setOcrText(String t) { this.ocrText = t; }
        public double getScore() { return score; }
        public void setScore(double s) { this.score = s; }
        public boolean isCorrect() { return isCorrect; }
        public void setCorrect(boolean c) { this.isCorrect = c; }
        public String getAiFeedback() { return aiFeedback; }
        public void setAiFeedback(String f) { this.aiFeedback = f; }
    }

    public static class ReviewRequest {
        private List<ReviewItem> reviewItems;
        public List<ReviewItem> getReviewItems() { return reviewItems; }
        public void setReviewItems(List<ReviewItem> items) { this.reviewItems = items; }
    }

    public static class ReviewItem {
        private String studentId;
        private int questionId;
        private Double manualScore;
        private String teacherComment;

        public String getStudentId() { return studentId; }
        public void setStudentId(String id) { this.studentId = id; }
        public int getQuestionId() { return questionId; }
        public void setQuestionId(int id) { this.questionId = id; }
        public Double getManualScore() { return manualScore; }
        public void setManualScore(Double s) { this.manualScore = s; }
        public String getTeacherComment() { return teacherComment; }
        public void setTeacherComment(String c) { this.teacherComment = c; }
    }

    public static class StudentReportResponse {
        private String studentId;
        private LocalDateTime reportDate;
        private List<KnowledgePoint> knowledgePoints;
        private WritingAbility writingAbility;

        public String getStudentId() { return studentId; }
        public void setStudentId(String id) { this.studentId = id; }
        public LocalDateTime getReportDate() { return reportDate; }
        public void setReportDate(LocalDateTime d) { this.reportDate = d; }
        public List<KnowledgePoint> getKnowledgePoints() { return knowledgePoints; }
        public void setKnowledgePoints(List<KnowledgePoint> kp) { this.knowledgePoints = kp; }
        public WritingAbility getWritingAbility() { return writingAbility; }
        public void setWritingAbility(WritingAbility wa) { this.writingAbility = wa; }
    }

    public static class KnowledgePoint {
        private String id;
        private String name;
        private double masteryRate;
        public String getId() { return id; }
        public void setId(String id) { this.id = id; }
        public String getName() { return name; }
        public void setName(String n) { this.name = n; }
        public double getMasteryRate() { return masteryRate; }
        public void setMasteryRate(double r) { this.masteryRate = r; }
    }

    public static class WritingAbility {
        private double strokeOrderScore;
        private double structureScore;
        private double neatnessScore;
        private double overallScore;

        public double getStrokeOrderScore() { return strokeOrderScore; }
        public void setStrokeOrderScore(double s) { this.strokeOrderScore = s; }
        public double getStructureScore() { return structureScore; }
        public void setStructureScore(double s) { this.structureScore = s; }
        public double getNeatnessScore() { return neatnessScore; }
        public void setNeatnessScore(double s) { this.neatnessScore = s; }
        public double getOverallScore() { return overallScore; }
        public void setOverallScore(double s) { this.overallScore = s; }
    }
}