import { AccountInfo, Commitment, Connection, GetAccountInfoConfig, PublicKey } from '@solana/web3.js'
import BN from 'bn.js'

import { SimpleMessageLibProgram, UlnProgram } from '.'
import * as EndpointProgram from './endpoint'
import { COUNT_SEED, LZ_COMPOSE_TYPES_SEED, LZ_RECEIVE_TYPES_SEED, OAppBasePDADeriver } from './pda-deriver'
import { AddressType } from './types'

// TODO - replace default seed to a convention ID Seed

/**
 * Derives the OApp ID PDA.
 *
 * @param {PublicKey} program - The program public key.
 * @param {string} [seed=COUNT_SEED] - The seed.
 * @param {number} [id] - The ID.
 * @returns {[PublicKey, number]} The derived PDA and bump.
 */
export function oappIDPDA(program: PublicKey, seed = COUNT_SEED, id?: number): [PublicKey, number] {
    if (id != undefined) {
        return PublicKey.findProgramAddressSync(
            [Buffer.from(seed, 'utf8'), new BN(id).toArrayLike(Buffer, 'be', 1)],
            program
        )
    } else {
        return PublicKey.findProgramAddressSync([Buffer.from(seed, 'utf8')], program)
    }
}

/**
 * Derives the LZ receive types accounts PDA.
 *
 * @param {PublicKey} program - The program public key.
 * @param {PublicKey} [oappId] - The OApp ID.
 * @returns {[PublicKey, number]} The derived PDA and bump.
 */
export function deriveLzReceiveTypesAccountsPDA(program: PublicKey, oappId?: PublicKey): [PublicKey, number] {
    if (oappId != undefined) {
        return PublicKey.findProgramAddressSync([Buffer.from(LZ_RECEIVE_TYPES_SEED, 'utf8'), oappId.toBytes()], program)
    }
    return PublicKey.findProgramAddressSync([Buffer.from(LZ_RECEIVE_TYPES_SEED, 'utf8')], program)
}

/**
 * Derives the LZ compose types accounts PDA.
 *
 * @param {PublicKey} program - The program public key.
 * @param {PublicKey} [oappId] - The OApp ID.
 * @returns {[PublicKey, number]} The derived PDA and bump.
 */
export function deriveLzComposeTypesAccountsPDA(program: PublicKey, oappId?: PublicKey): [PublicKey, number] {
    if (oappId != undefined) {
        return PublicKey.findProgramAddressSync([Buffer.from(LZ_COMPOSE_TYPES_SEED, 'utf8'), oappId.toBytes()], program)
    }
    return PublicKey.findProgramAddressSync([Buffer.from(LZ_COMPOSE_TYPES_SEED, 'utf8')], program)
}

/**
 * Abstract class representing a base OApp.
 */
export abstract class BaseOApp {
    oappBaseDeriver: OAppBasePDADeriver

    /**
     * Creates an instance of the BaseOApp class.
     *
     * @param {PublicKey} program - The program public key.
     */
    constructor(public program: PublicKey) {
        this.oappBaseDeriver = new OAppBasePDADeriver(program)
    }

    /**
     * Gets the endpoint.
     *
     * @param {Connection} connection - The connection.
     * @returns {Promise<EndpointProgram.Endpoint>} The endpoint.
     */
    abstract getEndpoint(connection: Connection): Promise<EndpointProgram.Endpoint>

    /**
     * Gets the send library program.
     *
     * @param {Connection} connection - The connection.
     * @param {PublicKey} payer - The payer public key.
     * @param {number} dstEid - The destination endpoint ID.
     * @param {EndpointProgram.Endpoint} [endpoint] - The endpoint.
     * @returns {Promise<SimpleMessageLibProgram.SimpleMessageLib | UlnProgram.Uln>} The send library program.
     */
    abstract getSendLibraryProgram(
        connection: Connection,
        payer: PublicKey,
        dstEid: number,
        endpoint?: EndpointProgram.Endpoint
    ): Promise<SimpleMessageLibProgram.SimpleMessageLib | UlnProgram.Uln>

    /**
     * Queries the ID PDA info.
     *
     * @param {Connection} connection - The connection.
     * @param {Commitment | GetAccountInfoConfig} [commitmentOrConfig] - The commitment or config.
     * @returns {Promise<AccountInfo<Buffer> | null>} The account info.
     */
    async queryIDPDAInfo(
        connection: Connection,
        commitmentOrConfig?: Commitment | GetAccountInfoConfig
    ): Promise<AccountInfo<Buffer> | null> {
        return this.queryPDAInfo(connection, this.idPDA()[0], commitmentOrConfig)
    }

    /**
     * Queries the PDA info.
     *
     * @param {Connection} connection - The connection.
     * @param {PublicKey} pda - The PDA public key.
     * @param {Commitment | GetAccountInfoConfig} [commitmentOrConfig] - The commitment or config.
     * @returns {Promise<AccountInfo<Buffer> | null>} The account info.
     */
    async queryPDAInfo(
        connection: Connection,
        pda: PublicKey,
        commitmentOrConfig?: Commitment | GetAccountInfoConfig
    ): Promise<AccountInfo<Buffer> | null> {
        return connection.getAccountInfo(pda, commitmentOrConfig)
    }

    /**
     * Gets the ID PDA.
     *
     * @returns {[PublicKey, number]} The ID PDA and bump.
     */
    idPDA(): [PublicKey, number] {
        return oappIDPDA(this.program)
    }

    /**
     * Gets the remote.
     *
     * @param {Connection} connection - The connection.
     * @param {number} dstEid - The destination endpoint ID.
     * @param {Commitment | GetAccountInfoConfig} [commitmentOrConfig] - The commitment or config.
     * @returns {Promise<Uint8Array | null>} The remote data.
     */
    async getRemote(
        connection: Connection,
        dstEid: number,
        commitmentOrConfig?: Commitment | GetAccountInfoConfig
    ): Promise<Uint8Array | null> {
        const [remotePDA] = this.oappBaseDeriver.remote(dstEid)
        const info = await this.queryPDAInfo(connection, remotePDA, commitmentOrConfig)
        if (info) {
            // the first 8 bytes is account discriminator, so skip it. The next 32 bytes is the address.
            const result = AddressType.read(info.data, 8)
            return Uint8Array.from(result)
        }
        return null
    }
}