import { Parser } from 'binary-parser-encoder'
import { CertificateChain } from './bcert'
import ECCKey from './ecc_key'
import * as fs from 'fs'

type RawDeviceV2 = {
    signature: string
    version: number
    group_certificate_length: number
    group_certificate: Buffer
    encryption_key: Buffer
    signing_key: Buffer
}

class DeviceStructs {
    static magic = 'PRD'

    static v1 = new Parser()
        .string('signature', { length: 3, assert: DeviceStructs.magic })
        .uint8('version')
        .uint32('group_key_length')
        .buffer('group_key', { length: 'group_key_length' })
        .uint32('group_certificate_length')
        .buffer('group_certificate', { length: 'group_certificate_length' })

    static v2 = new Parser()
        .string('signature', { length: 3, assert: DeviceStructs.magic })
        .uint8('version')
        .uint32('group_certificate_length')
        .buffer('group_certificate', { length: 'group_certificate_length' })
        .buffer('encryption_key', { length: 96 })
        .buffer('signing_key', { length: 96 })
}

export class Device {
    static CURRENT_STRUCT = DeviceStructs.v2

    group_certificate: CertificateChain
    encryption_key: ECCKey
    signing_key: ECCKey
    security_level: number

    constructor(parsedData: RawDeviceV2) {
        this.group_certificate = CertificateChain.loads(
            parsedData.group_certificate
        )
        this.encryption_key = ECCKey.loads(parsedData.encryption_key)
        this.signing_key = ECCKey.loads(parsedData.signing_key)
        this.security_level = this.group_certificate.get_security_level()
    }

    static loads(data: Buffer): Device {
        const parsedData = Device.CURRENT_STRUCT.parse(data)
        return new Device(parsedData)
    }

    static load(filePath: string): Device {
        const data = fs.readFileSync(filePath)
        return Device.loads(data)
    }

    dumps(): Buffer {
        const groupCertBytes = this.group_certificate.dumps()
        const encryptionKeyBytes = this.encryption_key.dumps()
        const signingKeyBytes = this.signing_key.dumps()

        const buildData = {
            signature: DeviceStructs.magic,
            version: 2,
            group_certificate_length: groupCertBytes.length,
            group_certificate: groupCertBytes,
            encryption_key: encryptionKeyBytes,
            signing_key: signingKeyBytes
        }

        return Device.CURRENT_STRUCT.encode(buildData)
    }

    dump(filePath: string): void {
        const data = this.dumps()
        fs.writeFileSync(filePath, data)
    }

    get_name(): string {
        const name = `${this.group_certificate.get_name()}_sl${this.security_level}`
        return name.replace(/[^a-zA-Z0-9]/g, '_').toLowerCase()
    }
}

// Device V2 disabled because unstable provisioning
// export class Device {
//     group_certificate: CertificateChain
//     encryption_key: ECCKey
//     signing_key: ECCKey
//     security_level: number

//     constructor(group_certificate: Buffer, group_key: Buffer) {
// this.group_certificate = CertificateChain.loads(group_certificate)

// this.encryption_key = ECCKey.generate()
// this.signing_key = ECCKey.generate()

// this.security_level = this.group_certificate.get_security_level()

// const new_certificate = Certificate.new_key_cert(
//     randomBytes(16),
//     this.group_certificate.get_security_level(),
//     randomBytes(16),
//     this.signing_key,
//     this.encryption_key,
//     ECCKey.loads(group_key),
//     this.group_certificate
// )

// this.group_certificate.prepend(new_certificate)
//     }
// }