import fs from "fs"
import path from "path"

export type Version = {
    id: string,
    // This can be the image ID, or a function that takes the version ID and returns the image ID.
    // By default it uses the canonicalImageIDLookup.
    containerImageID?: string | ((id: string) => string),
    // If defined, this will increase the timeout for tests using this version
    timeoutSecs?: number,
    transports: Array<(string | { name: string, onlyDial: boolean })>,
    secureChannels: string[],
    muxers: string[]
}

function canonicalImagePath(id: string): string {
    // Split by implementation and version
    const [impl, version] = id.split("-v")
    // Drop the patch version
    const [major, minor, patch] = version.split(".")
    let versionFolder = `v${major}.${minor}`
    if (major === "0" && minor === "0") {
        // We're still in the 0.0.x phase, so we use the patch version
        versionFolder = `v0.0.${patch}`
    }
    // Read the image ID from the JSON file on the filesystem
    return `./impl/${impl}/${versionFolder}/image.json`
}

// Loads the container image id for the given version id. Expects the form of
// "<impl>-vX.Y.Z" or "<impl>vX.Y" and the image id to be in the file
// "./impl/<impl>/vX.Y/image.json" or "./impl/<impl>/v0.0.Z/image.json"
function canonicalImageIDLookup(id: string): string {
    const imageIDJSON = fs.readFileSync(canonicalImagePath(id), "utf8")
    const imageID = JSON.parse(imageIDJSON).imageID
    return imageID
}

// Loads the container image id for the given browser version id. Expects the
// form of "<browser>-<impl>-vX.Y.Z" or "<impl>vX.Y" and the image id to be in the file
// "./impl/<impl>/vX.Y/<browser>-image.json" or "./impl/<impl>/v0.0.Z/<browser>-image.json"
function browserImageIDLookup(id: string): string {
    const [browser, ...rest] = id.split("-")
    const parentDir = path.dirname(canonicalImagePath(rest.join("-")))

    // Read the image ID from the JSON file on the filesystem
    const imageIDJSON = fs.readFileSync(path.join(parentDir, `${browser}-image.json`), "utf8")
    const imageID = JSON.parse(imageIDJSON).imageID
    return imageID
}

export const versions: Array<Version> = JSON.parse(fs.readFileSync(path.join(__dirname, 'versionsInput.json') , 'utf8')).map((v: Version) => {
    switch(v.containerImageID) {
        case "browser":
            return { ...v, containerImageID: browserImageIDLookup }
        case "canonical":
        default:
            return { ...v, containerImageID: canonicalImageIDLookup }
    }
});