text: /*
  	MIT License http://www.opensource.org/licenses/mit-license.php
  	Author Gajus Kuizinas @gajus
  */
  "use strict";
  
  const webpackOptionsSchema = require("../schemas/webpackOptionsSchema.json");
  
  const getSchemaPart = (path, parents, additionalPath) => {
  	parents = parents || 0;
  	path = path.split("/");
  	path = path.slice(0, path.length - parents);
  	if(additionalPath) {
  		additionalPath = additionalPath.split("/");
  		path = path.concat(additionalPath);
  	}
  	let schemaPart = webpackOptionsSchema;
  	for(let i = 1; i < path.length; i++) {
  		const inner = schemaPart[path[i]];
  		if(inner)
  			schemaPart = inner;
  	}
  	return schemaPart;
  };
  
  const getSchemaPartText = (schemaPart, additionalPath) => {
  	if(additionalPath) {
  		for(let i = 0; i < additionalPath.length; i++) {
  			const inner = schemaPart[additionalPath[i]];
  			if(inner)
  				schemaPart = inner;
  		}
  	}
  	while(schemaPart.$ref) schemaPart = getSchemaPart(schemaPart.$ref);
  	let schemaText = WebpackOptionsValidationError.formatSchema(schemaPart);
  	if(schemaPart.description)
  		schemaText += `\n${schemaPart.description}`;
  	return schemaText;
  };
  
  const indent = (str, prefix, firstLine) => {
  	if(firstLine) {
  		return prefix + str.replace(/\n(?!$)/g, "\n" + prefix);
  	} else {
  		return str.replace(/\n(?!$)/g, `\n${prefix}`);
  	}
  };
  
  class WebpackOptionsValidationError extends Error {
  
  	constructor(validationErrors) {
  		super();
  
  		if(Error.hasOwnProperty("captureStackTrace")) {
  			Error.captureStackTrace(this, this.constructor);
  		}
  		this.name = "WebpackOptionsValidationError";
  
  		this.message = "Invalid configuration object. " +
  			"Webpack has been initialised using a configuration object that does not match the API schema.\n" +
  			validationErrors.map(err => " - " + indent(WebpackOptionsValidationError.formatValidationError(err), "   ", false)).join("\n");
  		this.validationErrors = validationErrors;
  	}
  
  	static formatSchema(schema, prevSchemas) {
  		prevSchemas = prevSchemas || [];
  
  		const formatInnerSchema = (innerSchema, addSelf) => {
  			if(!addSelf) return WebpackOptionsValidationError.formatSchema(innerSchema, prevSchemas);
  			if(prevSchemas.indexOf(innerSchema) >= 0) return "(recursive)";
  			return WebpackOptionsValidationError.formatSchema(innerSchema, prevSchemas.concat(schema));
  		};
  
  		if(schema.type === "string") {
  			if(schema.minLength === 1)
  				return "non-empty string";
  			else if(schema.minLength > 1)
  				return `string (min length ${schema.minLength})`;
  			return "string";
  		} else if(schema.type === "boolean") {
  			return "boolean";
  		} else if(schema.type === "number") {
  			return "number";
  		} else if(schema.type === "object") {
  			if(schema.properties) {
  				const required = schema.required || [];
  				return `object { ${Object.keys(schema.properties).map(property => {
  					if(required.indexOf(property) < 0) return property + "?";
  					return property;
  				}).concat(schema.additionalProperties ? ["..."] : []).join(", ")} }`;
  			}
  			if(schema.additionalProperties) {
  				return `object { <key>: ${formatInnerSchema(schema.additionalProperties)} }`;
  			}
  			return "object";
  		} else if(schema.type === "array") {
  			return `[${formatInnerSchema(schema.items)}]`;
  		}
  
  		switch(schema.instanceof) {
  			case "Function":
  				return "function";
  			case "RegExp":
  				return "RegExp";
  		}
  		if(schema.$ref) return formatInnerSchema(getSchemaPart(schema.$ref), true);
  		if(schema.allOf) return schema.allOf.map(formatInnerSchema).join(" & ");
  		if(schema.oneOf) return schema.oneOf.map(formatInnerSchema).join(" | ");
  		if(schema.anyOf) return schema.anyOf.map(formatInnerSchema).join(" | ");
  		if(schema.enum) return schema.enum.map(item => JSON.stringify(item)).join(" | ");
  		return JSON.stringify(schema, 0, 2);
  	}
  
  	static formatValidationError(err) {
  		const dataPath = `configuration${err.dataPath}`;
  		if(err.keyword === "additionalProperties") {
  			const baseMessage = `${dataPath} has an unknown property '${err.params.additionalProperty}'. These properties are valid:\n${getSchemaPartText(err.parentSchema)}`;
  			if(!err.dataPath) {
  				switch(err.params.additionalProperty) {
  					case "debug":
  						return `${baseMessage}\n` +
  							"The 'debug' property was removed in webpack 2.\n" +
  							"Loaders should be updated to allow passing this option via loader options in module.rules.\n" +
  							"Until loaders are updated one can use the LoaderOptionsPlugin to switch loaders into debug mode:\n" +
  							"plugins: [\n" +
  							"  new webpack.LoaderOptionsPlugin({\n" +
  							"    debug: true\n" +
  							"  })\n" +
  							"]";
  				}
  				return baseMessage + "\n" +
  					"For typos: please correct them.\n" +
  					"For loader options: webpack 2 no longer allows custom properties in configuration.\n" +
  					"  Loaders should be updated to allow passing options via loader options in module.rules.\n" +
  					"  Until loaders are updated one can use the LoaderOptionsPlugin to pass these options to the loader:\n" +
  					"  plugins: [\n" +
  					"    new webpack.LoaderOptionsPlugin({\n" +
  					"      // test: /\\.xxx$/, // may apply this only for some modules\n" +
  					"      options: {\n" +
  					`        ${err.params.additionalProperty}: ...\n` +
  					"      }\n" +
  					"    })\n" +
  					"  ]";
  			}
  			return baseMessage;
  		} else if(err.keyword === "oneOf" || err.keyword === "anyOf") {
  			if(err.children && err.children.length > 0) {
  				return `${dataPath} should be one of these:\n${getSchemaPartText(err.parentSchema)}\n` +
  					`Details:\n${err.children.map(err => " * " + indent(WebpackOptionsValidationError.formatValidationError(err), "   ", false)).join("\n")}`;
  			}
  			return `${dataPath} should be one of these:\n${getSchemaPartText(err.parentSchema)}`;
  
  		} else if(err.keyword === "enum") {
  			if(err.parentSchema && err.parentSchema.enum && err.parentSchema.enum.length === 1) {
  				return `${dataPath} should be ${getSchemaPartText(err.parentSchema)}`;
  			}
  			return `${dataPath} should be one of these:\n${getSchemaPartText(err.parentSchema)}`;
  		} else if(err.keyword === "allOf") {
  			return `${dataPath} should be:\n${getSchemaPartText(err.parentSchema)}`;
  		} else if(err.keyword === "type") {
  			switch(err.params.type) {
  				case "object":
  					return `${dataPath} should be an object.`;
  				case "string":
  					return `${dataPath} should be a string.`;
  				case "boolean":
  					return `${dataPath} should be a boolean.`;
  				case "number":
  					return `${dataPath} should be a number.`;
  				case "array":
  					return `${dataPath} should be an array:\n${getSchemaPartText(err.parentSchema)}`;
  			}
  			return `${dataPath} should be ${err.params.type}:\n${getSchemaPartText(err.parentSchema)}`;
  		} else if(err.keyword === "instanceof") {
  			return `${dataPath} should be an instance of ${getSchemaPartText(err.parentSchema)}.`;
  		} else if(err.keyword === "required") {
  			const missingProperty = err.params.missingProperty.replace(/^\./, "");
  			return `${dataPath} misses the property '${missingProperty}'.\n${getSchemaPartText(err.parentSchema, ["properties", missingProperty])}`;
  		} else if(err.keyword === "minLength" || err.keyword === "minItems") {
  			if(err.params.limit === 1)
  				return `${dataPath} should not be empty.`;
  			else
  				return `${dataPath} ${err.message}`;
  		} else {
  			// eslint-disable-line no-fallthrough
  			return `${dataPath} ${err.message} (${JSON.stringify(err, 0, 2)}).\n${getSchemaPartText(err.parentSchema)}`;
  		}
  	}
  }
  
  module.exports = WebpackOptionsValidationError;
  