// taken from https://www.prompt-kit.com/docs/jsx-preview

function matchJsxTag(code: string) {
    if (code.trim() === '') {
        return null
    }

    const tagRegex = /<\/?([a-zA-Z][a-zA-Z0-9]*)\s*([^>]*?)(\/)?>/
    const match = code.match(tagRegex)

    if (!match || typeof match.index === 'undefined') {
        return null
    }

    const [fullMatch, tagName, attributes, selfClosing] = match

    const type = selfClosing
        ? 'self-closing'
        : fullMatch.startsWith('</')
        ? 'closing'
        : 'opening'

    return {
        tag: fullMatch,
        tagName,
        type,
        attributes: attributes.trim(),
        startIndex: match.index,
        endIndex: match.index + fullMatch.length,
    }
}

export function completeJsxTags(code: string) {
    const stack: string[] = []
    let result = ''
    let currentPosition = 0

    while (currentPosition < code.length) {
        const match = matchJsxTag(code.slice(currentPosition))
        if (!match) break
        const { tagName, type, endIndex } = match

        if (type === 'opening') {
            stack.push(tagName)
        } else if (type === 'closing') {
            stack.pop()
        }

        result += code.slice(currentPosition, currentPosition + endIndex)
        currentPosition += endIndex
    }

    return (
        result +
        stack
            .reverse()
            .map((tag) => `</${tag}>`)
            .join('')
    )
}