const { AcademicYear } = require('../models');
const { cacheUtils } = require('../config/redis');


/**
 * Academic Year Controller - Quản lý năm học
 */
class AcademicYearController {
  /**
   * Get all academic years with pagination and caching
   */
  async getAllAcademicYears(req, res, next) {
    try {
      const { page = 1, limit = 20, is_current } = req.query;
      const offset = (page - 1) * limit;
      
      // Generate cache key
      const cacheKey = `academic_years:list:${page}:${limit}:${is_current || 'all'}`;
      
      // Try to get from cache first
      const cached = await cacheUtils.get(cacheKey);
      if (cached) {
        return res.json({
          success: true,
          data: cached,
          cached: true,
        });
      }
      
      // Build query conditions
      const where = {};
      if (is_current !== undefined) where.is_current = is_current === 'true';
      
      // Query from database (through ProxySQL)
      const { count, rows } = await AcademicYear.findAndCountAll({
        where,
        limit: parseInt(limit),
        offset: parseInt(offset),
        order: [['start_date', 'DESC']],
      });
      
      const result = {
        academicYears: rows,
        pagination: {
          total: count,
          page: parseInt(page),
          limit: parseInt(limit),
          totalPages: Math.ceil(count / limit),
        },
      };
      
      // Cache the result
      await cacheUtils.set(cacheKey, result, 3600); // Cache for 1 hour
      
      res.json({
        success: true,
        data: result,
        cached: false,
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Get academic year by ID with caching
   */
  async getAcademicYearById(req, res, next) {
    try {
      const { id } = req.params;
      const cacheKey = `academic_year:${id}`;
      
      // Try cache first
      const cached = await cacheUtils.get(cacheKey);
      if (cached) {
        return res.json({
          success: true,
          data: cached,
          cached: true,
        });
      }
      
      // Query from database
      const academicYear = await AcademicYear.findByPk(id);
      
      if (!academicYear) {
        return res.status(404).json({
          success: false,
          message: 'Academic year not found',
        });
      }
      
      // Cache the result
      await cacheUtils.set(cacheKey, academicYear, 7200); // Cache for 2 hours
      
      res.json({
        success: true,
        data: academicYear,
        cached: false,
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Get current academic year with caching
   */
  async getCurrentAcademicYear(req, res, next) {
    try {
      const cacheKey = 'academic_year:current';
      
      // Try cache first
      const cached = await cacheUtils.get(cacheKey);
      if (cached) {
        return res.json({
          success: true,
          data: cached,
          cached: true,
        });
      }
      
      // Query from database
      const academicYear = await AcademicYear.findOne({
        where: { is_current: true },
      });
      
      if (!academicYear) {
        return res.status(404).json({
          success: false,
          message: 'No current academic year found',
        });
      }
      
      // Cache the result
      await cacheUtils.set(cacheKey, academicYear, 3600); // Cache for 1 hour
      
      res.json({
        success: true,
        data: academicYear,
        cached: false,
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Create new academic year
   */
  async createAcademicYear(req, res, next) {
    try {
      const academicYearData = req.body;
      
      // Create academic year directly
      const academicYear = await AcademicYear.create(academicYearData);
      
      // Invalidate related caches
      await cacheUtils.deletePattern('academic_years:list:*');
      await cacheUtils.delete('academic_year:current');
      
      res.status(201).json({
        success: true,
        message: 'Academic year created successfully',
        data: academicYear,
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Update academic year
   */
  async updateAcademicYear(req, res, next) {
    try {
      const { id } = req.params;
      const updates = req.body;
      
      const academicYear = await AcademicYear.findByPk(id);
      
      if (!academicYear) {
        return res.status(404).json({
          success: false,
          message: 'Academic year not found',
        });
      }
      
      // Update academic year directly
      await academicYear.update(updates);
      
      // Invalidate related caches
      await cacheUtils.delete(`academic_year:${id}`);
      await cacheUtils.deletePattern('academic_years:list:*');
      await cacheUtils.delete('academic_year:current');
      
      res.json({
        success: true,
        message: 'Academic year updated successfully',
        data: academicYear,
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Delete academic year
   */
  async deleteAcademicYear(req, res, next) {
    try {
      const { id } = req.params;
      
      const academicYear = await AcademicYear.findByPk(id);
      
      if (!academicYear) {
        return res.status(404).json({
          success: false,
          message: 'Academic year not found',
        });
      }
      
      // Delete academic year directly
      await academicYear.destroy();
      
      // Invalidate related caches
      await cacheUtils.delete(`academic_year:${id}`);
      await cacheUtils.deletePattern('academic_years:list:*');
      await cacheUtils.delete('academic_year:current');
      
      res.json({
        success: true,
        message: 'Academic year deleted successfully',
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Set academic year as current
   */
  async setCurrentAcademicYear(req, res, next) {
    try {
      const { id } = req.params;
      
      const academicYear = await AcademicYear.findByPk(id);
      
      if (!academicYear) {
        return res.status(404).json({
          success: false,
          message: 'Academic year not found',
        });
      }
      
      // Set all other years to not current
      await AcademicYear.update(
        { is_current: false },
        { where: {} }
      );
      
      // Set this year as current
      await academicYear.update({ is_current: true });
      
      // Invalidate all academic year caches
      await cacheUtils.deletePattern('academic_year*');
      
      res.json({
        success: true,
        message: 'Academic year set as current successfully',
        data: academicYear,
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Get academic year datatypes
   */
  async getAcademicYearDatatypes(req, res, next) {
    try {
      const datatypes = AcademicYear.rawAttributes;
      res.json({
        success: true,
        data: datatypes,
      });
    } catch (error) {
      next(error);
    }
  }
}

module.exports = new AcademicYearController();