import fsex from "fs-extra"
import { sleep } from "../../../async"
import nodeFetch from "node-fetch"

// 下载单个文件
// 失败后重试
export async function downloadToFile(url: string, filePath?: string, options?: { retry?: number }) {
    let retry = options?.retry ?? 3
    let response!: Response

    let buffer!: ArrayBuffer
    let isGzipError = false

    while (retry >= 0) {
        try {
            response = await fetch(url)
            if (!response.ok) {
                throw new Error(`Failed to download url: ${url} \n ${response.statusText}`)
            }
            buffer = await response.arrayBuffer()
            break
        } catch (e) {
            if (e.message === "terminated" && e.cause?.code == "Z_DATA_ERROR") {
                console.error(`donwload file gzip error: Z_DATA_ERROR, try download raw data.`)
                isGzipError = true
                buffer = await fetchRawData(url)
                break
            }

            retry--
            if (retry >= 0) {
                console.warn(`Failed to url: ${url}, ${e.message}, retrying... (${retry} times left)`)
                await sleep(2000)
                continue
            } else {
                console.error("Failed to download url: ", url)
                throw e
            }
        }
    }

    try {
        const size = buffer.byteLength

        if (filePath) await fsex.outputFile(filePath, Buffer.from(buffer))

        return {
            size,
            buffer,
            isGzipError,
            headers: {
                "content-type": response.headers.get("content-type"),
                "content-encoding": response.headers.get("content-encoding"),
            },
        }
    } catch (e) {
        console.error(`Failed to download url: ${url} to path:${filePath}`)
        throw e
    }
}

async function fetchRawData(url: string) {
    let res = await nodeFetch(url, { compress: false })
    let buffer = await res.arrayBuffer()
    return buffer
}