const mongoose = require('mongoose');

const subtitleSubmissionSchema = new mongoose.Schema({
  userId: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'User',
    required: true
  },
  username: {
    type: String,
    required: true,
    trim: true
  },
  segmentId: {
    type: Number,
    required: true,
    min: 1,
    max: 100,
    // Remove implicit single-field index to avoid duplicate with compound indexes below
    index: false
  },
  chineseTranslation: {
    type: String,
    required: true,
    trim: true,
    maxlength: 500
  },
  submissionDate: {
    type: Date,
    default: Date.now
  },
  isAnonymous: {
    type: Boolean,
    default: false
  },
  weekNumber: {
    type: Number,
    required: true,
    default: 2 // Week 2 for Nike video
  },
  // For future features
  status: {
    type: String,
    enum: ['submitted', 'reviewed', 'approved'],
    default: 'submitted'
  },
  notes: {
    type: String,
    trim: true,
    maxlength: 1000
  }
}, {
  timestamps: true
});

// Indexes for efficient queries
subtitleSubmissionSchema.index({ segmentId: 1, weekNumber: 1 });
subtitleSubmissionSchema.index({ userId: 1, weekNumber: 1 });
subtitleSubmissionSchema.index({ submissionDate: -1 });

// Virtual for display name (anonymous or username)
subtitleSubmissionSchema.virtual('displayName').get(function() {
  return this.isAnonymous ? 'Anonymous' : this.username;
});

// Static method to get submissions for a specific segment
subtitleSubmissionSchema.statics.getSubmissionsForSegment = function(segmentId, weekNumber = 2) {
  return this.find({ segmentId, weekNumber })
    .sort({ submissionDate: -1 })
    .select('username chineseTranslation submissionDate isAnonymous status notes');
};

// Static method to get user's submissions for a week
subtitleSubmissionSchema.statics.getUserSubmissions = function(userId, weekNumber = 2) {
  return this.find({ userId, weekNumber })
    .sort({ segmentId: 1, submissionDate: -1 });
};

// Static method to get submission count for a segment
subtitleSubmissionSchema.statics.getSubmissionCount = function(segmentId, weekNumber = 2) {
  return this.countDocuments({ segmentId, weekNumber });
};

// Method to check if user has already submitted for this segment
subtitleSubmissionSchema.statics.hasUserSubmitted = function(userId, segmentId, weekNumber = 2) {
  return this.exists({ userId, segmentId, weekNumber });
};

// Method to update existing submission
subtitleSubmissionSchema.statics.updateSubmission = function(userId, segmentId, chineseTranslation, weekNumber = 2) {
  return this.findOneAndUpdate(
    { userId, segmentId, weekNumber },
    { 
      chineseTranslation,
      submissionDate: new Date(),
      isAnonymous: false // Reset to false on update
    },
    { new: true, upsert: true }
  );
};

const SubtitleSubmission = mongoose.model('SubtitleSubmission', subtitleSubmissionSchema);

module.exports = SubtitleSubmission;