/**
 * WordPress dependencies
 */
import { _x, sprintf } from '@safe-wordpress/i18n';

/**
 * External dependencies
 */
import type {
	CustomPhpScopeRule,
	Experiment,
	Maybe,
	ScopeRule,
	ScopeType,
} from '@nab/types';

export function getScopeExplanation(
	scopeSupport: ScopeType,
	rules: ReadonlyArray< ScopeRule >,
	status: Experiment[ 'status' ]
): string {
	switch ( scopeSupport ) {
		case 'tested-post-with-consistency':
			return getConsistencyExplanation( rules, status );

		case 'tested-product-with-consistency':
			return getProductConsistencyExplanation( rules, status );

		case 'tested-url-with-query-args':
			return getTestedUrlWithQueryArgsExplanation( rules, status );

		case 'urls-with-tested-post':
			return getCustomWithTestedPostExplanation( rules, status );

		case 'urls':
			return getCustomExplanation( rules, status );

		case 'urls-or-php':
			return getPhpExplanation( rules, status );
	}
}

function getConsistencyExplanation(
	rules: ReadonlyArray< ScopeRule >,
	status: Experiment[ 'status' ]
) {
	if ( 'running' === status ) {
		if ( ! rules.length ) {
			return _x(
				'Variants are visible on the tested element’s page. All other pages also show the appropriate variant of this test whenever the tested element appears on them.',
				'text',
				'nelio-ab-testing'
			);
		}

		return _x(
			'Variants are visible only on the tested element’s page.',
			'text',
			'nelio-ab-testing'
		);
	}

	if ( ! rules.length ) {
		return _x(
			'Variants were visible on the tested element’s page. All other pages also showed the appropriate variant of this test whenever the tested element appeared on them.',
			'text',
			'nelio-ab-testing'
		);
	}

	return _x(
		'Variants were visible only on the tested element’s page.',
		'text',
		'nelio-ab-testing'
	);
}

function getProductConsistencyExplanation(
	rules: ReadonlyArray< ScopeRule >,
	status: Experiment[ 'status' ]
) {
	if ( 'running' === status ) {
		if ( ! rules.length ) {
			return _x(
				'Variants are visible everywhere on your store: the product’s page, shopping carts, the checkout page, on a “related products” section, etc.',
				'text',
				'nelio-ab-testing'
			);
		}

		return _x(
			'Variants are visible only on the tested product’s page.',
			'text',
			'nelio-ab-testing'
		);
	}

	if ( ! rules.length ) {
		return _x(
			'Variants were visible everywhere on your store: the product’s page, shopping carts, the checkout page, on a “related products” section, etc.',
			'text',
			'nelio-ab-testing'
		);
	}

	return _x(
		'Variants were visible only on the tested product’s page.',
		'text',
		'nelio-ab-testing'
	);
}

function getTestedUrlWithQueryArgsExplanation(
	rules: ReadonlyArray< ScopeRule >,
	status: Experiment[ 'status' ]
) {
	if ( 'running' === status ) {
		if ( ! rules.length ) {
			return _x(
				'Test is active on all the tested URLs.',
				'text',
				'nelio-ab-testing'
			);
		}

		if ( 1 === rules.length ) {
			return _x(
				'Test is active on a tested URL if the query arguments in said URL satisfy all the following conditions:',
				'text',
				'nelio-ab-testing'
			);
		}

		return _x(
			'Test is active on a tested URL if the query arguments in said URL satisfy all the conditions in any of the following groups:',
			'text',
			'nelio-ab-testing'
		);
	}

	if ( ! rules.length ) {
		return _x(
			'Test was active on all the tested URLs.',
			'text',
			'nelio-ab-testing'
		);
	}

	if ( 1 === rules.length ) {
		return _x(
			'Test was active on a tested URL if the query arguments in said URL satisfied all the following conditions:',
			'text',
			'nelio-ab-testing'
		);
	}

	return _x(
		'Test was active on a tested URL if the query arguments in said URL satisfied all the conditions in any of the following groups:',
		'text',
		'nelio-ab-testing'
	);
}

function getCustomWithTestedPostExplanation(
	rules: ReadonlyArray< ScopeRule >,
	status: Experiment[ 'status' ]
) {
	if ( 'running' === status ) {
		if ( ! rules.length ) {
			return _x(
				'Variants are visible on all the pages of your website, including that of the tested element.',
				'text',
				'nelio-ab-testing'
			);
		}

		return _x(
			'Variants are visible on the tested element’s page, as well as pages matching one of the following criteria.',
			'text',
			'nelio-ab-testing'
		);
	}

	if ( ! rules.length ) {
		return _x(
			'Variants were visible on all the pages of your website, including that of the tested element.',
			'text',
			'nelio-ab-testing'
		);
	}

	return _x(
		'Variants were visible on the tested element’s page, as well as pages matching one of the following criteria.',
		'text',
		'nelio-ab-testing'
	);
}

function getCustomExplanation(
	rules: ReadonlyArray< ScopeRule >,
	status: Experiment[ 'status' ]
) {
	if ( 'running' === status ) {
		if ( ! rules.length ) {
			return _x(
				'Variants are visible on all the pages of your website.',
				'text',
				'nelio-ab-testing'
			);
		}

		return _x(
			'Variants are visible only on pages matching one of the following criteria:',
			'text',
			'nelio-ab-testing'
		);
	}

	if ( ! rules.length ) {
		return _x(
			'Variants were visible on all the pages of your website.',
			'text',
			'nelio-ab-testing'
		);
	}

	return _x(
		'Variants were visible only on pages matching one of the following criteria:',
		'text',
		'nelio-ab-testing'
	);
}

function getPhpExplanation(
	rules: ReadonlyArray< ScopeRule >,
	status: Experiment[ 'status' ]
) {
	const isCustomPhpScopeRule = (
		r: Maybe< ScopeRule >
	): r is CustomPhpScopeRule => 'php-snippet' === r?.attributes.type;

	const [ firstRule ] = rules;
	if ( ! isCustomPhpScopeRule( firstRule ) ) {
		return '';
	}

	const PRIORITY_TO_HOOK = {
		high: 'plugins_loaded',
		mid: 'parse_query',
		low: 'wp',
	};

	return 'running' === status
		? sprintf(
				/* translators: %s: Hook name. */
				_x(
					'This test applies to pages that satisfy the following function, evaluated on “%s”:',
					'command',
					'nelio-ab-testing'
				),
				PRIORITY_TO_HOOK[ firstRule.attributes.value.priority ]
		  )
		: sprintf(
				/* translators: %s: Hook name. */
				_x(
					'This test applied to pages that satisfied the following function, evaluated on “%s”:',
					'command',
					'nelio-ab-testing'
				),
				PRIORITY_TO_HOOK[ firstRule.attributes.value.priority ]
		  );
}