import { getTextDisplayLen } from "./getTextDisplayLen"

/**
 * 截断文本，省略号在中间
 * @param options.enableDisplayLen 是否考虑中文长度
 * @example
 * truncateString("1234567890", 5) // "1...0"
 */
export function truncateString(
    text: string,
    len: number,
    options?: {
        enableDisplayLen?: boolean
    }
) {
    let testLen = options?.enableDisplayLen ? getTextDisplayLen(text) : text.length
    if (testLen <= len) {
        return text
    }

    // 分隔符长度 ...
    let separatorLen = 3
    let lmitLen = len - separatorLen

    let halfLen = lmitLen / 2
    let start = text.substring(0, Math.ceil(halfLen))
    let end = text.substring(testLen - Math.floor(halfLen))
    return `${start}...${end}`
}

/**
 * 截断文本，省略号在开头
 * @param options.enableDisplayLen 是否考虑中文长度
 * @example
 * truncateStringStart("1234567890", 5) // "...90"
 */
export function truncateStringStart(
    text: string,
    len: number,
    options?: {
        enableDisplayLen?: boolean
    }
) {
    let testLen = options?.enableDisplayLen ? getTextDisplayLen(text) : text.length
    if (testLen <= len) {
        return text
    }

    // 分隔符长度 ...
    let separatorLen = 3
    let lmitLen = len - separatorLen

    let end = text.substring(testLen - lmitLen)
    return `...${end}`
}

/**
 * 截断文本，省略号在结尾
 * @param options.enableDisplayLen 是否考虑中文长度
 * @example
 * truncateStringEnd("1234567890", 5) // "12..."
 */
export function truncateStringEnd(
    text: string,
    len: number,
    options?: {
        enableDisplayLen?: boolean
    }
) {
    let testLen = options?.enableDisplayLen ? getTextDisplayLen(text) : text.length
    if (testLen <= len) {
        return text
    }

    // 分隔符长度 ...
    let separatorLen = 3
    let lmitLen = len - separatorLen

    let start = text.substring(0, lmitLen)
    return `${start}...`
}