const mongoose = require('mongoose');

const taskSchema = new mongoose.Schema({
  title: {
    type: String,
    required: true,
    trim: true
  },
  description: {
    type: String,
    trim: true
  },
  assignee: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'User',
    required: true
  },
  creator: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'User',
    required: true
  },
  priority: {
    type: String,
    enum: ['low', 'medium', 'high'],
    default: 'medium'
  },
  status: {
    type: String,
    enum: ['pending', 'in-progress', 'completed', 'cancelled'],
    default: 'pending'
  },
  deadline: {
    type: Date,
    required: true
  },
  tags: [{
    type: String,
    trim: true
  }],
  attachments: [{
    filename: String,
    url: String,
    uploadedAt: {
      type: Date,
      default: Date.now
    }
  }],
  comments: [{
    user: {
      type: mongoose.Schema.Types.ObjectId,
      ref: 'User'
    },
    text: String,
    createdAt: {
      type: Date,
      default: Date.now
    }
  }],
  progress: {
    type: Number,
    min: 0,
    max: 100,
    default: 0
  },
  estimatedHours: {
    type: Number,
    default: 0
  },
  actualHours: {
    type: Number,
    default: 0
  }
}, {
  timestamps: true
});

// Index for better query performance
taskSchema.index({ assignee: 1, status: 1 });
taskSchema.index({ creator: 1 });
taskSchema.index({ deadline: 1 });

module.exports = mongoose.model('Task', taskSchema);