zed/styles/src/buildLicenses.ts

import * as fs from "fs"
import toml from "toml"
import { schemeMeta } from "./colorSchemes"
import { Meta } from "./themes/common/colorScheme"
import https from "https"
import crypto from "crypto"

const accepted_licenses_file = `${__dirname}/../../script/licenses/zed-licenses.toml`

// Use the cargo-about configuration file as the source of truth for supported licenses.
function parseAcceptedToml(file: string): string[] {
    let buffer = fs.readFileSync(file).toString()

    let obj = toml.parse(buffer)

    if (!Array.isArray(obj.accepted)) {
        throw Error("Accepted license source is malformed")
    }

    return obj.accepted
}

function checkLicenses(schemeMeta: Meta[], licenses: string[]) {
    for (let meta of schemeMeta) {
        // FIXME: Add support for conjuctions and conditions
        if (licenses.indexOf(meta.license.SPDX) < 0) {
            throw Error(
                `License for theme ${meta.name} (${meta.license.SPDX}) is not supported`
            )
        }
    }
}

function getLicenseText(
    schemeMeta: Meta[],
    callback: (meta: Meta, license_text: string) => void
) {
    for (let meta of schemeMeta) {
        // The following copied from the example code on nodejs.org:
        // https://nodejs.org/api/http.html#httpgetoptions-callback
        https
            .get(meta.license.https_url, (res) => {
                const { statusCode } = res

                if (statusCode < 200 || statusCode >= 300) {
                    throw new Error(
                        `Failed to fetch license for: ${meta.name}, Status Code: ${statusCode}`
                    )
                }

                res.setEncoding("utf8")
                let rawData = ""
                res.on("data", (chunk) => {
                    rawData += chunk
                })
                res.on("end", () => {
                    const hash = crypto
                        .createHash("sha256")
                        .update(rawData)
                        .digest("hex")
                    if (meta.license.license_checksum == hash) {
                        callback(meta, rawData)
                    } else {
                        throw Error(
                            `Checksum for ${meta.name} did not match file downloaded from ${meta.license.https_url}`
                        )
                    }
                })
            })
            .on("error", (e) => {
                throw e
            })
    }
}

function writeLicense(schemeMeta: Meta, text: String) {
    process.stdout.write(
        `## [${schemeMeta.name}](${schemeMeta.url})\n\n${text}\n********************************************************************************\n\n`
    )
}

const accepted_licenses = parseAcceptedToml(accepted_licenses_file)
checkLicenses(schemeMeta, accepted_licenses)

getLicenseText(schemeMeta, (meta, text) => {
    writeLicense(meta, text)
})