import mongoose, { Document, Model, Schema } from 'mongoose';
import bcrypt from 'bcryptjs';

export interface IStudent extends Document {
  name: string;
  email: string;
  password?: string;
  phoneNumber?: string;
  status: 'active' | 'deactivated';
  lastLogin?: Date;
  createdAt: Date;
  updatedAt: Date;
  comparePassword(candidatePassword: string): Promise<boolean>;
}

const StudentSchema: Schema<IStudent> = new Schema(
  {
    name: {
      type: String,
      required: [true, 'Student name is required'],
      trim: true,
      maxlength: [100, 'Name cannot exceed 100 characters'],
    },
    email: {
      type: String,
      required: [true, 'Student email is required'],
      unique: true,
      lowercase: true,
      trim: true,
      match: [/^\S+@\S+\.\S+$/, 'Please provide a valid email address'],
      index: true,
    },
    password: {
      type: String,
      required: [true, 'Password is required'],
      minlength: [6, 'Password must be at least 6 characters'],
      select: false, // Never return password hash by default
    },
    phoneNumber: {
      type: String,
      trim: true,
      default: '',
    },
    status: {
      type: String,
      enum: {
        values: ['active', 'deactivated'],
        message: '{VALUE} is not a valid student status',
      },
      default: 'active',
      index: true,
    },
    lastLogin: {
      type: Date,
    },
  },
  {
    timestamps: true,
  }
);

// Hash password before saving if modified
StudentSchema.pre<IStudent>('save', async function (next) {
  if (!this.isModified('password') || !this.password) {
    return next();
  }
  try {
    const salt = await bcrypt.genSalt(10);
    this.password = await bcrypt.hash(this.password, salt);
    next();
  } catch (error: any) {
    next(error);
  }
});

// Compare password method
StudentSchema.methods.comparePassword = async function (candidatePassword: string): Promise<boolean> {
  if (!this.password) return false;
  return bcrypt.compare(candidatePassword, this.password);
};

export const Student: Model<IStudent> =
  mongoose.models.Student || mongoose.model<IStudent>('Student', StudentSchema);

export default Student;