import type { UnistylesValues } from '../types'

import { deepMergeObjects } from '../utils'
import { keyInObject } from './utils'

type StylesWithVariants = {
    variants: Record<string, string | boolean | undefined>
    compoundVariants?: Array<
        Record<string, string | boolean | undefined> & {
            styles: Record<string, any>
        }
    >
}
const hasVariants = (value: any): value is StylesWithVariants => {
    return keyInObject(value, 'variants')
}

export const getVariants = (styles: UnistylesValues, selectedVariants: Record<string, any>) => {
    if (!hasVariants(styles)) {
        return {}
    }

    const variantStyles = Object.entries(styles.variants).flatMap(([variant, styles]) => {
        const selectedVariant = selectedVariants[variant]
        const selectedVariantStyles = styles[selectedVariant] ?? styles.default

        if (!selectedVariantStyles) {
            return []
        }

        return selectedVariantStyles
    })

    const compoundVariantStyles =
        styles.compoundVariants?.flatMap((compoundVariant) => {
            const { styles, ...conditions } = compoundVariant

            if (
                Object.entries(conditions).some(
                    ([variant, value]) => String(selectedVariants[variant]) !== String(value),
                )
            ) {
                return []
            }

            return styles
        }) ?? []

    return deepMergeObjects(...variantStyles, ...compoundVariantStyles)
}