/**
 * POST /api/quizzes/[taskId]/submit - Submit quiz answers
 */

import { NextRequest, NextResponse } from 'next/server';
import { requireAuth } from '@/app/lib/auth';
import { findTask, findQuizByTaskId, hasUserCompletedTask, createUserTask } from '@/app/lib/db/store';
import { addPoints } from '@/app/lib/points';
import { checkAndAwardBadges } from '@/app/lib/badges';
import { TaskType, ApiResponse } from '@/app/lib/types';

interface SubmitQuizRequest {
  answer: number;
}

interface QuizResult {
  correct: boolean;
  correctAnswer: number;
  pointsEarned: number;
  userTask?: {
    id: string;
    userId: string;
    taskId: string;
    completedAt: Date;
    pointsEarned: number;
  };
}

export async function POST(
  request: NextRequest,
  { params }: { params: Promise<{ taskId: string }> }
) {
  try {
    // Authenticate user
    const user = requireAuth(request);
    const { taskId } = await params;

    // Parse request body
    const body: SubmitQuizRequest = await request.json();
    const { answer } = body;

    if (answer === undefined || answer === null) {
      return NextResponse.json<ApiResponse>(
        {
          success: false,
          error: 'Answer is required'
        },
        { status: 400 }
      );
    }

    // Find the task
    const task = findTask(taskId);
    if (!task) {
      return NextResponse.json<ApiResponse>(
        {
          success: false,
          error: 'Task not found'
        },
        { status: 404 }
      );
    }

    // Verify it's a quiz task
    if (task.type !== TaskType.QUIZ) {
      return NextResponse.json<ApiResponse>(
        {
          success: false,
          error: 'This is not a quiz task'
        },
        { status: 400 }
      );
    }

    // Check if user has already completed this quiz
    if (hasUserCompletedTask(user.id, taskId)) {
      return NextResponse.json<ApiResponse>(
        {
          success: false,
          error: 'You have already completed this quiz'
        },
        { status: 409 }
      );
    }

    // Find the quiz
    const quiz = findQuizByTaskId(taskId);
    if (!quiz) {
      return NextResponse.json<ApiResponse>(
        {
          success: false,
          error: 'Quiz not found for this task'
        },
        { status: 404 }
      );
    }

    // Check the answer
    const isCorrect = answer === quiz.correctAnswer;
    const pointsEarned = isCorrect ? task.pointsReward : 0;

    let userTask = undefined;
    let newBadges = [];

    if (isCorrect) {
      // Complete the task
      userTask = createUserTask(user.id, taskId, pointsEarned);

      // Award points
      addPoints(user.id, pointsEarned, `task:${taskId}`);

      // Check and award badges
      newBadges = checkAndAwardBadges(user.id);
    }

    const result: QuizResult = {
      correct: isCorrect,
      correctAnswer: quiz.correctAnswer,
      pointsEarned,
      userTask
    };

    return NextResponse.json<ApiResponse<QuizResult>>(
      {
        success: true,
        data: result,
        message: isCorrect
          ? `Correct! You earned ${pointsEarned} points${
              newBadges.length > 0 ? ` and ${newBadges.length} new badge(s)!` : ''
            }`
          : `Incorrect. The correct answer was option ${quiz.correctAnswer}.`
      },
      { status: isCorrect ? 201 : 200 }
    );
  } catch (error) {
    if (error instanceof Error && error.message === 'Unauthorized') {
      return NextResponse.json<ApiResponse>(
        {
          success: false,
          error: 'Unauthorized'
        },
        { status: 401 }
      );
    }

    console.error('Submit quiz error:', error);
    return NextResponse.json<ApiResponse>(
      {
        success: false,
        error: 'Internal server error'
      },
      { status: 500 }
    );
  }
}