/* *********************************************************************************************************************
 * MetaData models for Form Fields
 * -------------------------------
 * Keep in one file for now, but maybe split if this grows too large
 ******************************************************************************************************************** */

import { TemplateRef } from '@angular/core';
import { ValidatorFn, AsyncValidatorFn } from '@angular/forms';
import { ValueTransformer } from './../interfaces';
import { standardModifiers, standardTransformer } from './../utils';

interface ISimpleFieldMetaData {
	name: string; 							// The FormControl name
	type?: string; 							// The component type e.g. Text, Checkbutton, Timepicker, etc
	label?: string;							// The field label - defaults to unCamelCased name if not supplied
	value?: any;							// The field value - defaults to empty string if not supplied
	checkedValue?: boolean|number|string;	// Checkboxes and Checkbuttons only
	default?: any;							// Default value
	placeholder?: string;					// Optional placeholder text
	class?: string | string[];				// CSS classes to apply
	id?: string;							// CSS id to apply
	disabled?: boolean;						// Whether field is initially disabled
	change?: string;						// Name of function in host component to call when value changes
	source?: string;						// Location in API-returned model - defaults to name
	before?: string;						// Ordering instruction - move before <name of another key in group>
	after?: string;							// Ordering instruction - move after <name of another key in group>
	validators?: ValidatorFn[];				// Array of validator functions - following Angular FormControl API
	asyncValidators?: AsyncValidatorFn[];	// Array of async validator functions - following Angular FormControl API
	valFailureMsgs?: StringMap<any>;		// Validation failure messages - display appropriate message if validation fails
}

interface IOption {
	label: string;
	value: string | number | boolean;
}

interface IOptionsFieldMetaData extends ISimpleFieldMetaData {
	options: string[] | IOption[] | (() => IOption[]);	// Array of Options - for select, radio-button-group and other 'multiple-choice' types
	horizontal?: boolean;								// Whether to arrange radio buttons or checkboxes horizontally (default false)
}

// For components that include links to other pages
interface ILink {
	label: string;
	route: any[] | string;
}

interface IDropdownModifiedInputFieldMetaData extends ISimpleFieldMetaData {
	modifiers: string[];
	transform: ValueTransformer;
}

interface ITimePickerFieldMetaData extends ISimpleFieldMetaData {
	value: Date | string;
	format: string;
	steps: StringMap<any>;
}

// Utility to unCamelCase
const unCamelCase = (str: string): string => str.replace(/([A-Z])/g, ' $1')
												.replace(/(\w)(\d)/g, '$1 $2')
												.replace(/^./, s => s.toUpperCase())
												.replace(/([A-Z]) /g, '$1')
												// .replace(/ ([A-Z][a-z])/g, s => s.toLowerCase()) lowercase all but first word and acronyms
												;

// ---------------------------------------------------------------------------------------------------------------------
// Form Field MetaData Models
// ---------------------------------------------------------------------------------------------------------------------
// Base Implementations

abstract class SimpleField {
	type: string;
	name: string;
	source?: string;
	label?: string;
	value;
	checkedValue?: boolean|number|string;
	default = '';
	placeholder = '';
	class?: string | string[];
	id?: string;
	disabled = false;
	change?: string;
	validators: ValidatorFn|ValidatorFn[] = [];
	asyncValidators: AsyncValidatorFn|AsyncValidatorFn[] = [];
	valFailureMsgs: StringMap<any> = {};

	constructor(meta: ISimpleFieldMetaData, context?: any) {
		if (typeof meta !== 'object') {
			return;
		}
		Object.assign(this, meta);
		if (!this.source) {
			// If source is not supplied it's the same as the name
			this.source = this.name;
		}
		if (typeof this.label === 'undefined') {
			// If label is not supplied set it to the unCamelCased'n'Spaced name
			// e.g. supervisorCardNumber --> Supervisor Card Number
			this.label = unCamelCase(this.name);
		}
		if (typeof this.value === 'undefined') {
			this.value = this.default;
		}
		// TODO: Consider binding context to standard validators as well as async validators
		// BUT check this doesn't stop Angular's built-in validators from working (do they use 'this'?)
		if (typeof this.asyncValidators === 'function' || Array.isArray(this.asyncValidators)) {
			if (typeof this.asyncValidators === 'function') {
				const boundFn = this.asyncValidators.bind(context);
				this.asyncValidators = boundFn;
			} else {
				this.asyncValidators.forEach((valFn, i) => {
					const boundFn = valFn.bind(context);
					this.asyncValidators[i] = boundFn;
				});
			}
		}
	}
}

class Option implements IOption {
	// Can take a simple string value, a value-label pair [value, label],
	// or an Option of the form { label: string, value: string }
	label: string;
	value: string | number | boolean;
	constructor(opt: string | string[] | Option) {
		if (typeof opt === 'object') {
			if (Array.isArray(opt)) {
				this.label = opt[1];
				this.value = opt[0];
			} else {
				this.label = opt.label;
				this.value = opt.value;
			}
		} else {
			// Simple string
			this.label = opt;
			this.value = opt;
		}
	}
}

abstract class OptionsField extends SimpleField {
	options: Option[] | (() => Option[]) = [];
	constructor(meta: IOptionsFieldMetaData, context?: any) {
		super(meta);
		let options;
		if (typeof meta.options === 'function') {
			const boundFn = meta.options.bind(context);
			options = boundFn();
		} else {
			options = meta.options;
		}
		if (Array.isArray(options)) {
			this.options = options.reduce((acc, opt) => { acc.push(new Option(opt)); return acc; }, []);
		} else {
			this.options = [
				new Option({ label: 'Yes', value: true }),
				new Option({ label: 'No', value: false })
			];
		}
	}
}

// ---------------------------------------------------------------------------------------------------------------------
// Concrete Implementations - Native Form Components

class TextField extends SimpleField {
	type = 'Text';
	link?: ILink;
}

class TextareaField extends SimpleField {
	type = 'Textarea';
}

class PasswordField extends SimpleField {
	type = 'Password';
}

class SelectField extends OptionsField {
	type = 'Select';
	link?: ILink;
	constructor(meta: IOptionsFieldMetaData, context?: any) {
		super(meta, context);
		// If there's only one possible choice set the value
		if (this.options.length === 1) {
			this.default = this.options[0].value as string;
		}
	}
}

class RadioField extends OptionsField {
	type = 'Radio';
}

class CheckboxField extends SimpleField {
	type = 'Checkbox';
	isChecked: boolean;
	default: any = false;
	checkedValue: boolean|number|string = true;
	rowLabel: null;
	constructor(meta: ISimpleFieldMetaData) {
		super(meta);
		if (meta.default) {
			this.default = meta.default; // Necessary to ovveride defaut of true, since this cannot be done by super(meta)
		}
		if (meta.value) {
			this.checkedValue = meta.value;
		}
		if (meta.checkedValue) {
			this.checkedValue = meta.checkedValue; // Ditto
		}
		if (typeof meta.value === 'undefined') {
			this.value = this.default; // Get default from this class, not superclass
		}
		if (!meta.label) {
			this.label = unCamelCase(this.checkedValue.toString());
		}
	}
}

class HiddenField extends SimpleField {
	type = 'Hidden';
}

// ---------------------------------------------------------------------------------------------------------------------
// Concrete Implementations - Custom Form Components

class CheckbuttonField extends CheckboxField {
	type = 'Checkbutton';
}

class DropdownModifiedInputField extends SimpleField {
	type = 'DropdownModifiedInput';
	modifiers: string[] = standardModifiers;
	transform: ValueTransformer = standardTransformer;
	constructor(meta: IDropdownModifiedInputFieldMetaData) {
		super(meta);
	}
}

class MultilineField extends SimpleField {
	type = 'Multiline';
	lines: number;
	maxLineLength: number;
}

// ---------------------------------------------------------------------------------------------------------------------
// Concrete Implementations - Custom FormGroup Components (which render a group of FormControls)

class CheckboxGroup {
	type = 'CheckboxGroup';
	name: string;
	label?: string;
	groupName: string;
	firstEnablesRest?: boolean;
	showAllOrNone?: boolean;
	meta: CheckboxField[] | { [key: string]: CheckboxField };
	constructor(groupmeta: any) {
		Object.assign(this, groupmeta);
		if (typeof this.label === 'undefined') {
			// If label is not supplied set it to the unCamelCased'n'Spaced name
			// e.g. supervisorCardNumber --> Supervisor Card Number
			this.label = unCamelCase(this.name);
		}
		// Can render as a FormArray or FormGroup depending on input data
		if (Array.isArray(groupmeta.meta)) {
			const arrayMembers = groupmeta.meta;
			this.meta = arrayMembers.map(cb => new CheckboxField(cb));
		} else {
			const groupMembers = groupmeta.meta;
			this.meta = Object.entries(groupMembers)
				.map( ([key, cb]) => [key, new CheckboxField(cb as ISimpleFieldMetaData)] )
				.reduce((res, [key, cbf]) => { res[key as string] = cbf; return res; }, {});
		}
	}
}

class CheckbuttonGroup extends CheckboxGroup {
	type = 'CheckbuttonGroup';
	meta: CheckbuttonField[] | { [key: string]: CheckbuttonField };
}

// ---------------------------------------------------------------------------------------------------------------------
// Concrete Implementations

class DatetimeField extends SimpleField {
	type = 'Datetime';
	value: Date | string;
	constructor(meta) {
		super(meta);
		if (typeof this.value === 'string') {
			this.value = new Date(this.value);
		}
		if (!(this.value instanceof Date)) {
			this.value = new Date();
		}
	}

}

class DatepickerField extends SimpleField {
	type = 'Datepicker';
	value: Date = new Date();
}

// ---------------------------------------------------------------------------------------------------------------------
// Repeating Fields

class RepeatingField<T> {
	type = 'RepeatingField';
	name: string;
	label: string;
	seed: StringMap<any>;
	meta: T[]; // An array of fields of type T
	minRepeat: number = 1;
	maxRepeat: number = 10;
	initialRepeat: number = 1;
	showAddControl:  boolean = true;
	showDeleteControl: boolean = true;
	addControlLabel: string = '';
	deleteControlLabel: string = '';
	constructor(repeatingFieldMeta: StringMap<any>) {
		Object.assign(this, repeatingFieldMeta);
		if (typeof this.label === 'undefined') {
			this.label = unCamelCase(this.name);
		}
	}
}

// ---------------------------------------------------------------------------------------------------------------------
// Containers

class Container {
	type = 'Container';
	name: string;
	label = '';
	seed: StringMap<any>;
	template?: TemplateRef<any>;
	button: string;						// IS THIS ACTUALLY USED?
	focussed: boolean = true;			// IS THIS ACTUALLY USED?
	class?: string | string[];
	id?: string;
	meta: StringMap<any>; // TODO: Tighten up on type with union type
	validators: ValidatorFn[] = [];
	asyncValidators: AsyncValidatorFn[] = [];
	constructor(containerMeta: StringMap<any>) {
		Object.assign(this, containerMeta);
		if (typeof this.label === 'undefined') {
			this.label = unCamelCase(this.name);
		}
	}
}

class RepeatingContainer {
	type = 'RepeatingContainer';
	name: string;
	prefix: string = 'group';
	label = '';
	seed: StringMap<any>;
	template?: TemplateRef<any>;
	meta: Container[]; // An array of Containers
	minRepeat: number = 1;
	maxRepeat: number = 10;
	initialRepeat: number = 1;
	showAddControl:  boolean = true;
	showDeleteControl: boolean = true;
	addControlLabel: string = '';
	deleteControlLabel: string = '';
	primaryField: string = '';
	display: string = 'ALL'; // Display strategy to use  - ALL or SINGLE - All at once, or one at a time (with a switcher)
	constructor(containerMeta: StringMap<any>) {
		Object.assign(this, containerMeta);
		if (typeof this.label === 'undefined') {
			this.label = unCamelCase(this.name);
		}
		if (!containerMeta.initialRepeat) {
			this.initialRepeat = containerMeta.meta.length;
		}
		this.meta = containerMeta.meta.map((m, i) => new Container({
			name: `${this.prefix}${i + 1}`,
			meta: m,
			button: unCamelCase(`${this.prefix}${i + 1}`),
			focussed: this.display === 'SINGLE' ? i === 0 : true
		}));
	}
}

// ---------------------------------------------------------------------------------------------------------------------
// Button Group

interface IButtonInterface {
	label: string;
	fnId: string;
	class?: string;
	icon?: string;
}

class Button implements IButtonInterface {
	label;
	fnId;
	class = 'btn-primary';
	constructor(buttonProps) {
		Object.assign(this, buttonProps);
	}
}

class ButtonGroup {
	type = 'ButtonGroup';
	name: string;
	label = '';
	meta: Button[];
	readonly noFormControls = true; // Indicates this has no FormControls associated with it
	constructor(meta) {
		Object.assign(this, meta);
		this.meta = this.meta.map(b => b instanceof Button ? b : new Button(b));
	}
}

// ---------------------------------------------------------------------------------------------------------------------
// Heading

class Heading {
	type = 'Heading';
	text = 'Missing Heading Text';
	level = 3;
	readonly noFormControls = true; // Indicates this has no FormControls associated with it
	readonly noLabel = true; // Indicates this has no label, so don't create normal form row
	constructor(meta) {
		Object.assign(this, meta);
	}
}

// ---------------------------------------------------------------------------------------------------------------------
// Display - displays non-editable vaklues lie a text field (but no input)

class DisplayField extends SimpleField {
	value: string;
	link?: ILink;
	readonly disabled = true;
	constructor(meta) {
		super(meta);
	}
}

// ---------------------------------------------------------------------------------------------------------------------
// ---------------------------------------------------------------------------------------------------------------------
// ---------------------------------------------------------------------------------------------------------------------
// Exports

// Interfaces
export {
	IOption, ILink
};

// Classes
export {
	SimpleField, Option,
	TextField, TextareaField, PasswordField, SelectField, RadioField, CheckboxField, HiddenField,
	CheckbuttonField, DropdownModifiedInputField, MultilineField,
	CheckboxGroup, CheckbuttonGroup,
	DatetimeField, DatepickerField,
	RepeatingField,
	Container, RepeatingContainer,
	ButtonGroup, Heading, DisplayField
};