/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Gajus Kuizinas @gajus
*/
"use strict";

const WebpackError = require("./WebpackError");
const webpackOptionsSchema = require("../schemas/WebpackOptions.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 getSchemaPartDescription = schemaPart => {
	while (schemaPart.$ref) {
		schemaPart = getSchemaPart(schemaPart.$ref);
	}
	if (schemaPart.description) {
		return `\n-> ${schemaPart.description}`;
	}
	return "";
};

const SPECIFICITY = {
	type: 1,
	oneOf: 1,
	anyOf: 1,
	allOf: 1,
	additionalProperties: 2,
	enum: 1,
	instanceof: 1,
	required: 2,
	minimum: 2,
	uniqueItems: 2,
	minLength: 2,
	minItems: 2,
	minProperties: 2,
	absolutePath: 2
};

const filterMax = (array, fn) => {
	const max = array.reduce((max, item) => Math.max(max, fn(item)), 0);
	return array.filter(item => fn(item) === max);
};

const filterChildren = children => {
	children = filterMax(children, err =>
		err.dataPath ? err.dataPath.length : 0
	);
	children = filterMax(children, err => SPECIFICITY[err.keyword] || 2);
	return children;
};

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 WebpackError {
	constructor(validationErrors) {
		super(
			"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.name = "WebpackOptionsValidationError";
		this.validationErrors = validationErrors;

		Error.captureStackTrace(this, this.constructor);
	}

	static formatSchema(schema, prevSchemas) {
		prevSchemas = prevSchemas || [];

		const formatInnerSchema = (innerSchema, addSelf) => {
			if (!addSelf) {
				return WebpackOptionsValidationError.formatSchema(
					innerSchema,
					prevSchemas
				);
			}
			if (prevSchemas.includes(innerSchema)) {
				return "(recursive)";
			}
			return WebpackOptionsValidationError.formatSchema(
				innerSchema,
				prevSchemas.concat(schema)
			);
		};

		if (schema.type === "string") {
			if (schema.minLength === 1) {
				return "non-empty string";
			}
			if (schema.minLength > 1) {
				return `string (min length ${schema.minLength})`;
			}
			return "string";
		}
		if (schema.type === "boolean") {
			return "boolean";
		}
		if (schema.type === "number") {
			return "number";
		}
		if (schema.type === "object") {
			if (schema.properties) {
				const required = schema.required || [];
				return `object { ${Object.keys(schema.properties)
					.map(property => {
						if (!required.includes(property)) return property + "?";
						return property;
					})
					.concat(schema.additionalProperties ? ["…"] : [])
					.join(", ")} }`;
			}
			if (schema.additionalProperties) {
				return `object { <key>: ${formatInnerSchema(
					schema.additionalProperties
				)} }`;
			}
			return "object";
		}
		if (schema.type === "array") {
			return `[${formatInnerSchema(schema.items)}]`;
		}

		switch (schema.instanceof) {
			case "Function":
				return "function";
			case "RegExp":
				return "RegExp";
		}

		if (schema.enum) {
			return schema.enum.map(item => JSON.stringify(item)).join(" | ");
		}

		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(" | ");
		}
		return JSON.stringify(schema, null, 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 (
							`${baseMessage}\n` +
							"The 'debug' property was removed in webpack 2.0.0.\n" +
							"Loaders should be updated to allow passing this option via loader options in module.rules.\n" +
							"Until loaders are updated one can use the LoaderOptionsPlugin to switch loaders into debug mode:\n" +
							"plugins: [\n" +
							"  new webpack.LoaderOptionsPlugin({\n" +
							"    debug: true\n" +
							"  })\n" +
							"]"
						);
				}
				return (
					`${baseMessage}\n` +
					"For typos: please correct them.\n" +
					"For loader options: webpack >= v2.0.0 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" +
					`        ${err.params.additionalProperty}: …\n` +
					"      }\n" +
					"    })\n" +
					"  ]"
				);
			}
			return baseMessage;
		} else if (err.keyword === "oneOf" || err.keyword === "anyOf") {
			if (err.children && err.children.length > 0) {
				if (err.schema.length === 1) {
					const lastChild = err.children[err.children.length - 1];
					const remainingChildren = err.children.slice(
						0,
						err.children.length - 1
					);
					return WebpackOptionsValidationError.formatValidationError(
						Object.assign({}, lastChild, {
							children: remainingChildren,
							parentSchema: Object.assign(
								{},
								err.parentSchema,
								lastChild.parentSchema
							)
						})
					);
				}
				const children = filterChildren(err.children);
				if (children.length === 1) {
					return WebpackOptionsValidationError.formatValidationError(
						children[0]
					);
				}
				return (
					`${dataPath} should be one of these:\n${getSchemaPartText(
						err.parentSchema
					)}\n` +
					`Details:\n${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.${getSchemaPartDescription(
						err.parentSchema
					)}`;
				case "string":
					return `${dataPath} should be a string.${getSchemaPartDescription(
						err.parentSchema
					)}`;
				case "boolean":
					return `${dataPath} should be a boolean.${getSchemaPartDescription(
						err.parentSchema
					)}`;
				case "number":
					return `${dataPath} should be a number.${getSchemaPartDescription(
						err.parentSchema
					)}`;
				case "array":
					return `${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 === "minimum") {
			return `${dataPath} ${err.message}.${getSchemaPartDescription(
				err.parentSchema
			)}`;
		} else if (err.keyword === "uniqueItems") {
			return `${dataPath} should not contain the item '${
				err.data[err.params.i]
			}' twice.${getSchemaPartDescription(err.parentSchema)}`;
		} else if (
			err.keyword === "minLength" ||
			err.keyword === "minItems" ||
			err.keyword === "minProperties"
		) {
			if (err.params.limit === 1) {
				switch (err.keyword) {
					case "minLength":
						return `${dataPath} should be an non-empty string.${getSchemaPartDescription(
							err.parentSchema
						)}`;
					case "minItems":
						return `${dataPath} should be an non-empty array.${getSchemaPartDescription(
							err.parentSchema
						)}`;
					case "minProperties":
						return `${dataPath} should be an non-empty object.${getSchemaPartDescription(
							err.parentSchema
						)}`;
				}
				return `${dataPath} should be not empty.${getSchemaPartDescription(
					err.parentSchema
				)}`;
			} else {
				return `${dataPath} ${err.message}${getSchemaPartDescription(
					err.parentSchema
				)}`;
			}
		} else if (err.keyword === "absolutePath") {
			const baseMessage = `${dataPath}: ${
				err.message
			}${getSchemaPartDescription(err.parentSchema)}`;
			if (dataPath === "configuration.output.filename") {
				return (
					`${baseMessage}\n` +
					"Please use output.path to specify absolute path and output.filename for the file name."
				);
			}
			return baseMessage;
		} else {
			return `${dataPath} ${err.message} (${JSON.stringify(
				err,
				null,
				2
			)}).\n${getSchemaPartText(err.parentSchema)}`;
		}
	}
}

module.exports = WebpackOptionsValidationError;
