/*
Helper functions for user-editable annotations state management.
See also reducers/annotations.js
*/
import { unassignedCategoryLabel } from "../../globals";
import * as SchemaHelpers from "./schemaHelpers";
import { obsAnnoDimensionName } from "../nameCreators";

/*
There are a number of state constraints assumed throughout the
application:
	- all obs annotations are in {world|universe}.obsAnnotations,
		regardless of whether or not they are user editable.
	- the {world|universe}.schema is always up to date and matches
		the data
	- the schema flag `writable` correctly indicates whether
	  the annotation is editable/mutable.

In addition, the current state management only allows for
categorical annotations to be writable.
*/

export function isCategoricalAnnotation(schema, name) {
	/* we treat any string, categorical or boolean as a categorical */
	const { type } = schema.annotations.obsByName[name];
	return type === "string" || type === "boolean" || type === "categorical";
}

export function isContinuousAnnotation(schema, name) {
	return !isCategoricalAnnotation(schema, name);
}

function _isUserAnnotation(schema, name) {
	return schema.annotations.obsByName[name]?.writable;
}

export function isUserAnnotation(worldOrUniverse, name) {
	return _isUserAnnotation(worldOrUniverse.schema, name);
}

export function removeObsAnnoSchema(schema, name) {
	/*
	remove named annotation from obs annotation schema
	*/

	/* only remove if it exists and is a user annotation */
	if (!_isUserAnnotation(schema, name))
		throw new Error("removing non-user-defined schema");
	return SchemaHelpers.removeObsAnnoColumn(schema, name);
}

export function addObsAnnoSchema(schema, name, colSchema) {
	/*
	add a categorical type to the obs annotation schema 
	*/

	/* collision detection */
	if (schema.annotations.obs.columns.some(v => v.name === name))
		throw Error("annotations may not contain duplicate category names");
	if (name !== colSchema.name) throw Error("column schema does not match");
	return SchemaHelpers.addObsAnnoColumn(schema, name, colSchema);
}

export function dupObsAnnoSchema(schema, sourceName, dupName, defaultSchema) {
	/*
	duplicate the obs annotation `sourceName` schema, but with the name `dupName`
	*/
	const colSchema = {
		...schema.annotations.obsByName[sourceName],
		...defaultSchema,
		name: dupName
	};
	/* existance check */
	if (!colSchema) throw Error("source annotation does not exist");
	/* collision detection */
	if (schema.annotations.obs.columns.some(v => v.name === dupName))
		throw Error("annotations may not contain duplicate category names");
	return SchemaHelpers.addObsAnnoColumn(schema, dupName, colSchema);
}

export function removeObsAnnoCategory(schema, name, category) {
	/* don't allow deletion of unassigned category on writable annotations */

	if (!_isUserAnnotation(schema, name))
		throw new Error("unable to modify read-only schema");
	if (category === unassignedCategoryLabel)
		throw new Error("may not remove unassigned category label");

	return SchemaHelpers.removeObsAnnoCategory(schema, name, category);
}

export function addObsAnnoCategory(schema, name, category) {
	if (!_isUserAnnotation(schema, name))
		throw new Error("unable to modify read-only schema");

	return SchemaHelpers.addObsAnnoCategory(schema, name, category);
}

export function setLabelByValue(df, colName, fromLabel, toLabel) {
	/* 
	in the dataframe column `colName`, set any value of `fromLabel` to `toLabel`
	*/
	const keys = df.colIndex.keys();
	const ndf = df.mapColumns((col, colIdx) => {
		if (colName !== keys[colIdx]) return col;

		/* clone data and return it. */
		const newCol = col.slice();
		for (let i = 0, l = newCol.length; i < l; i += 1) {
			if (newCol[i] === fromLabel) newCol[i] = toLabel;
		}
		return newCol;
	});
	return ndf;
}

export function setLabelByMask(df, colName, mask, label) {
	/* 
	in the dataframe column `colName`, set the masked rows to 'label'
	*/
	const keys = df.colIndex.keys();
	const ndf = df.mapColumns((col, colIdx) => {
		if (colName !== keys[colIdx]) return col;

		/* clone data and return it. */
		const newCol = col.slice();
		for (let i = 0, l = newCol.length; i < l; i += 1) {
			if (mask[i]) newCol[i] = label;
		}
		return newCol;
	});
	return ndf;
}

export function allHaveLabelByMask(df, colName, label, mask) {
	// return true if all rows as indicated by mask have the colname set to label.
	// False if not.
	const col = df.col(colName);
	if (!col) return false;
	if (df.length !== mask.length)
		throw new RangeError("mismatch on mask length");

	for (let i = 0; i < df.length; i += 1) {
		if (mask[i]) {
			if (col.iget(i) !== label) return false;
		}
	}
	return true;
}

export function worldToUniverseMask(worldMask, worldObsAnnotations, nObs) {
	/*
	given world seleciton mask, return a selection mask for entire universe 
	that has same selection state.
	*/
	const mask = new Uint8Array(nObs);
	const { rowIndex } = worldObsAnnotations;

	for (let i = 0, l = worldMask.length; i < l; i += 1) {
		if (worldMask[i]) {
			const label = rowIndex.getLabel(i);
			mask[label] = 1;
		}
	}
	return mask;
}

export function createWritableAnnotationDimensions(world, crossfilter) {
	const { obsAnnotations, schema } = world;
	const writableAnnotations = schema.annotations.obs.columns
		.filter(s => s.writable)
		.map(s => s.name);

	crossfilter = writableAnnotations.reduce((xflt, anno) => {
		const dimName = obsAnnoDimensionName(anno);
		if (xflt.hasDimension(dimName)) xflt = xflt.delDimension(dimName);
		return xflt.addDimension(
			dimName,
			"enum",
			obsAnnotations.col(anno).asArray()
		);
	}, crossfilter);
	return crossfilter;
}

const legalCharacters = /^(\w|[ .()-])+$/;
export function annotationNameIsErroneous(name) {
	/*
	Validate the name - return:
	* false - a valid name
	* string - a named error, indicating why it was invalid.

	Tests:
	0. must be string, non-null
	1. no leading or trailing spaces
	2. only accept alpha, numeric, underscore, period, parens, hyphen and space
	3. no runs of multiple spaces
	*/
	if (name === "") {
		return "empty-string";
	}
	if (name[0] === " " || name[name.length - 1] === " ") {
		return "trim-spaces";
	}
	if (!legalCharacters.test(name)) {
		return "illegal-characters";
	}
	for (let i = 1, l = name.length; i < l; i += 1) {
		if (name[i] === " " && name[i - 1] === " ") {
			return "multi-space-run";
		}
	}

	/* all is well!  Indicte not erroneous with a false */
	return false;
}