const mongoose = require('mongoose');

const degreeSchema = new mongoose.Schema({
  // Required fields
  qualification_number: {
    type: String,
    required: true,
    unique: true,
    trim: true
  },
  student_name: {
    type: String,
    required: true,
    trim: true
  },
  program_name: {
    type: String,
    required: true,
    trim: true
  },
  type: {
    type: String,
    required: true,
    enum: ['qualification', 'certification']
  },
  department: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'Department',
    required: true
  },
  level: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'Level',
    required: true
  },
  issued_date: {
    type: Date,
    required: true
  },
  status: {
    type: String,
    enum: ['active', 'revoked'],
    default: 'active'
  },

  // Optional fields
  certification_number: {
    type: String,
    trim: true,
  },
  passport_number: {
    type: String,
    trim: true
  },
  address: {
    type: String,
    trim: true
  },
  topic_name: {
    type: String,
    trim: true
  },
  topic_short_desc: {
    type: String,
    trim: true
  },
  degree_image: {
    type: String
  },
  certificate_image: {
    type: String
  }
}, {
  timestamps: true
});

// Indexes
degreeSchema.index({ certification_number: 1 }, { unique: true, sparse: true });

// Pre-save hook: certification type requires certification_number
degreeSchema.pre('save', function (next) {
  if (this.type === 'certification' && !this.certification_number) {
    return next(new Error('certification_number is required for certification type'));
  }
  next();
});

module.exports = mongoose.model('Degree', degreeSchema);