import "reflect-metadata";
import { MongoSchema } from "../MongoSchema";
import { MongoSchemaRegistry } from "../MongoSchemaRegistry";
import { SchemaFieldValidationError } from "./SchemaValidationResult";
import { MongoSchemaField } from "../MongoSchema";

export class SchemaValidator
{
	static validateField(field: MongoSchemaField, data: any): Error
	{
        // Ignore _id field (It's managed by mongo)
        if(field.name == "_id")
            return null;

		if(data === undefined || data === null)
		{
			if(field.options.required)
			{
				return new Error("Field '" + field.name + "' is required but it's value is: " + data);
			}
		}

		if(data && data.constructor.name !== field.type)
		{
			if(!field.getReferencedCollection())
			{
				return new Error("Field '" + field.name + "' has invalid type. '" + field.type + "' is needed but '" + data.constructor.name + "' was given.");	
			}
		}

        let childSchema = MongoSchemaRegistry.getSchema(field.getType())
        
        if(childSchema)
        {
            return childSchema.validate(data);
        }
		
		return null;
	}
};