/**
 * Throttle function
 */
export const throttle = (func: Function, timeout: number) => {
    let ready: boolean = true
    return (...args: any) => {
        if (!ready) return
        ready = false
        func(...args)
        setTimeout(() => ready = true, timeout)
    }
}


/**
 * Debounce function
 */
export const debounce = (func: Function, timeout: number) => {
    let timer: NodeJS.Timeout
    return (...args: any) => {
        clearTimeout(timer)
        timer = setTimeout(() => func(...args), timeout)
    }
}


/**
 * Split text
 * @description Split a string into words or characters
 * @returns string[]
 */
export const splitText = (text: string, mode: string = 'words'): string[] => {
    // Split by words
    if (mode === 'words') {
        const words = text
            .replace(/\\n/g, '\n')
            .replace(/\s+/g, m => m.includes('\n') ? '\n ' : ' ')
            .trim()
            .split(' ')

        return words
    }
    // Split by chars
    else if (mode === 'chars') {
        const chars = Array.from(text).map(char => char === ' ' ? '\xa0' : char)
        return chars
    }
}


/**
 * Capitalize first letter
 */
export const capitalizeFirstLetter = (string: string) => {
    return string[0].toUpperCase() + string.slice(1)
}


/**
 * Create a delay
 */
export const sleep = (milliseconds: number) => {
    return new Promise(resolve => setTimeout(resolve, milliseconds))
}


/**
 * Linear Interpolation
 */
export const lerp = (start: number, end: number, amount: number): number => {
    return (1 - amount) * start + amount * end
}


/**
 * Re-maps a number from one range to another
 * @param value the incoming value to be converted
 * @param start1 lower bound of the value's current range
 * @param stop1 upper bound of the value's current range
 * @param start2 lower bound of the value's target range
 * @param stop2 upper bound of the value's target range
 * @param [withinBounds] constrain the value to the newly mapped range
 * @return remapped number
 */
export const map = (n: number, start1: number, stop1: number, start2: number, stop2: number, withinBounds: boolean): number => {
    const value = (n - start1) / (stop1 - start1) * (stop2 - start2) + start2
    if (!withinBounds) return value
    if (start2 < stop2) {
        return clamp(value, start2, stop2)
    } else {
        return clamp(value, stop2, start2)
    }
}


/**
 * Clamp a number
 */
export const clamp = (num: number, a: number, b: number) => {
    return Math.max(Math.min(num, Math.max(a, b)), Math.min(a, b))
}


/**
 * Return a random element from an array
 */
export const getRandomItem = <T extends unknown> (array: T[]): T => {
    const randomItemIndex = ~~(array.length * Math.random())
    return array[randomItemIndex]
}


/**
 * Return random elements from an array
 */
export const getRandomItems = <T extends unknown> (array: any[], amount: number): T[] => {
    const shuffled = Array.from(array).sort(() => 0.5 - Math.random())
    return shuffled.slice(0, amount)
}


/**
 * Scroll back to top after page transition
 */
export const scrollToTop = (delay?: number) => {
    const scroll = () => window.scrollTo(0,0)

    if (delay && delay > 0) {
        setTimeout(scroll, delay)
    } else {
        scroll()
    }
}


/**
 * Copy mailto links to clipboard and show message
 */
export const mailtoClipboard = (node: HTMLElement) => {
    const links = node.querySelectorAll('a[href^="mailto:"]')

    const clickToCopy = (event) => {
        let emailAddress = event.currentTarget.href.split('mailto:')[1].split('?')[0]

        // Copy email to clipboard
        navigator.clipboard.writeText(emailAddress)

        // Send event
        node.dispatchEvent(new CustomEvent('copied', {
            detail: { email: emailAddress }
        }))

        event.preventDefault()
    }

    links && links.forEach(link => link.addEventListener('click', clickToCopy, true))

    return {
        destroy () {
            links && links.forEach(link => link.removeEventListener('click', clickToCopy, true))
        }
    }
}