import { getAddress, getCreateAddress } from "../address/index.js";
import { accessListify } from "../transaction/index.js";
import {
    getBigInt, getNumber, hexlify, isHexString, zeroPadValue,
    throwArgumentError, throwError
} from "../utils/index.js";



const BN_0 = BigInt(0);

export type FormatFunc = (value: any) => any;

export function allowNull(format: FormatFunc, nullValue?: any): FormatFunc {
    return (function(value: any) {
        if (value == null) { return nullValue; }
        return format(value);
    });
}

export function arrayOf(format: FormatFunc): FormatFunc {
    return ((array: any) => {
        if (!Array.isArray(array)) { throw new Error("not an array"); }
        return array.map((i) => format(i));
    });
}

// Requires an object which matches a fleet of other formatters
// Any FormatFunc may return `undefined` to have the value omitted
// from the result object. Calls preserve `this`.
export function object(format: Record<string, FormatFunc>, altNames?: Record<string, Array<string>>): FormatFunc {
    return ((value: any) => {
        const result: any = { };
        for (const key in format) {
            let srcKey = key;
            if (altNames && key in altNames && !(srcKey in value)) {
                for (const altKey of altNames[key]) {
                    if (altKey in value) {
                        srcKey = altKey;
                        break;
                    }
                }
            }

            try {
                const nv = format[key](value[srcKey]);
                if (nv !== undefined) { result[key] = nv; }
            } catch (error) {
                const message = (error instanceof Error) ? error.message: "not-an-error";
                throwError(`invalid value for value.${ key } (${ message })`, "BAD_DATA", { value })
            }
        }
        return result;
    });
}

export function formatBoolean(value: any): boolean {
    switch (value) {
        case true: case "true":
            return true;
        case false: case "false":
            return false;
    }
    return throwArgumentError(`invalid boolean; ${ JSON.stringify(value) }`, "value", value);
}

export function formatData(value: string): string {
    if (!isHexString(value, true)) {
        throwArgumentError("", "value", value);
    }
    return value;
}

export function formatHash(value: any): string {
    if (!isHexString(value, 32)) {
        throwArgumentError("", "value", value);
    }
    return value;
}

export function formatUint256(value: any): string {
    if (!isHexString(value)) {
        throw new Error("invalid uint256");
    }
    return zeroPadValue(value, 32);
}

export const formatLog = object({
    address: getAddress,
    blockHash: formatHash,
    blockNumber: getNumber,
    data: formatData,
    index: getNumber,
    removed: formatBoolean,
    topics: arrayOf(formatHash),
    transactionHash: formatHash,
    transactionIndex: getNumber,
}, {
    index: [ "logIndex" ]
});

function _formatBlock(txFunc: FormatFunc): FormatFunc {
    return object({
        hash: allowNull(formatHash),
        parentHash: formatHash,
        number: getNumber,

        timestamp: getNumber,
        nonce: allowNull(formatData),
        difficulty: getBigInt,

        gasLimit: getBigInt,
        gasUsed: getBigInt,

        miner: allowNull(getAddress),
        extraData: formatData,

        transactions: arrayOf(txFunc),

        baseFeePerGas: allowNull(getBigInt)
    });
}

export const formatBlock = _formatBlock(formatHash);

export const formatBlockWithTransactions = _formatBlock(formatTransactionResponse);

export const formatReceiptLog = object({
    transactionIndex: getNumber,
    blockNumber: getNumber,
    transactionHash: formatHash,
    address: getAddress,
    topics: arrayOf(formatHash),
    data: formatData,
    logIndex: getNumber,
    blockHash: formatHash,
});

export const formatTransactionReceipt = object({
    to: allowNull(getAddress, null),
    from: allowNull(getAddress, null),
    contractAddress: allowNull(getAddress, null),
    transactionIndex: getNumber,
    // should be allowNull(hash), but broken-EIP-658 support is handled in receipt
    root: allowNull(hexlify),
    gasUsed: getBigInt,
    logsBloom: allowNull(formatData),
    blockHash: formatHash,
    transactionHash: formatHash,
    logs: arrayOf(formatReceiptLog),
    blockNumber: getNumber,
    confirmations: allowNull(getNumber, null),
    cumulativeGasUsed: getBigInt,
    effectiveGasPrice: allowNull(getBigInt),
    status: allowNull(getNumber),
    type: getNumber
}, {
    effectiveGasPrice: [ "gasPrice" ]
});

export function formatTransactionResponse(value: any) {

    // Some clients (TestRPC) do strange things like return 0x0 for the
    // 0 address; correct this to be a real address
    if (value.to && getBigInt(value.to) === BN_0) {
        value.to = "0x0000000000000000000000000000000000000000";
    }

    const result = object({
        hash: formatHash,

        type: (value: any) => {
            if (value === "0x" || value == null) { return 0; }
            return getNumber(value);
        },
        accessList: allowNull(accessListify, null),

        blockHash: allowNull(formatHash, null),
        blockNumber: allowNull(getNumber, null),
        transactionIndex: allowNull(getNumber, null),

        confirmations: allowNull(getNumber, null),

        from: getAddress,

        // either (gasPrice) or (maxPriorityFeePerGas + maxFeePerGas) must be set
        gasPrice: allowNull(getBigInt),
        maxPriorityFeePerGas: allowNull(getBigInt),
        maxFeePerGas: allowNull(getBigInt),

        gasLimit: getBigInt,
        to: allowNull(getAddress, null),
        value: getBigInt,
        nonce: getNumber,
        data: formatData,

        r: allowNull(formatUint256),
        s: allowNull(formatUint256),
        v: allowNull(getNumber),

        creates: allowNull(getAddress, null),

        chainId: allowNull(getBigInt, null)
    }, {
        data: [ "input" ],
        gasLimit: [ "gas" ]
    })(value);

    // If to and creates are empty, populate the creates from the value
    if (result.to == null && result.creates == null) {
        result.creates = getCreateAddress(result);
    }

    // @TODO: Check fee data

    // Add an access list to supported transaction types
    if ((value.type === 1 || value.type === 2) && value.accessList == null) {
        value.accessList = [ ];
    }

    // @TODO: check chainID
    /*
    if (value.chainId != null) {
        let chainId = value.chainId;

        if (isHexString(chainId)) {
            chainId = BigNumber.from(chainId).toNumber();
        }

        result.chainId = chainId;

    } else {
        let chainId = value.networkId;

        // geth-etc returns chainId
        if (chainId == null && result.v == null) {
            chainId = value.chainId;
        }

        if (isHexString(chainId)) {
            chainId = BigNumber.from(chainId).toNumber();
        }

        if (typeof(chainId) !== "number" && result.v != null) {
            chainId = (result.v - 35) / 2;
            if (chainId < 0) { chainId = 0; }
            chainId = parseInt(chainId);
        }

        if (typeof(chainId) !== "number") { chainId = 0; }

        result.chainId = chainId;
    }
    */

    // 0x0000... should actually be null
    if (result.blockHash && getBigInt(result.blockHash) === BN_0) {
        result.blockHash = null;
    }

    return result;
}