'use strict';

import { bigNumberify } from './bignumber';
import { arrayify, concat, hexlify, padZeros} from './bytes';
import { toUtf8Bytes } from './utf8';

import { keccak256 as hashKeccak256 } from './keccak256';
import { sha256 as hashSha256 } from './sha2';

var regexBytes = new RegExp("^bytes([0-9]+)$");
var regexNumber = new RegExp("^(u?int)([0-9]*)$");
var regexArray = new RegExp("^(.*)\\[([0-9]*)\\]$");

var Zeros = '0000000000000000000000000000000000000000000000000000000000000000';

function _pack(type: string, value: any, isArray?: boolean): Uint8Array {
    switch(type) {
        case 'address':
            if (isArray) { return padZeros(value, 32); }
            return arrayify(value);
        case 'string':
            return toUtf8Bytes(value);
        case 'bytes':
            return arrayify(value);
        case 'bool':
            value = (value ? '0x01': '0x00');
            if (isArray) { return padZeros(value, 32); }
            return arrayify(value);
    }

    var match =  type.match(regexNumber);
    if (match) {
        //var signed = (match[1] === 'int')
        let size = parseInt(match[2] || "256")
        if ((size % 8 != 0) || size === 0 || size > 256) {
            throw new Error('invalid number type - ' + type);
        }

        if (isArray) { size = 256; }

        value = bigNumberify(value).toTwos(size);

        return padZeros(value, size / 8);
    }

    match = type.match(regexBytes);
    if (match) {
        let size = parseInt(match[1]);
        if (String(size) != match[1] || size === 0 || size > 32) {
            throw new Error('invalid number type - ' + type);
        }
        if (arrayify(value).byteLength !== size) { throw new Error('invalid value for ' + type); }
        if (isArray) { return arrayify((value + Zeros).substring(0, 66)); }
        return value;
    }

    match = type.match(regexArray);
    if (match) {
        var baseType = match[1];
        var count = parseInt(match[2] || value.length);
        if (count != value.length) { throw new Error('invalid value for ' + type); }
        var result = [];
        value.forEach(function(value) {
            value = _pack(baseType, value, true);
            result.push(value);
        });
        return concat(result);
    }

    throw new Error('unknown type - ' + type);
}

// @TODO: Array Enum

export function pack(types: Array<string>, values: Array<any>) {
    if (types.length != values.length) { throw new Error('type/value count mismatch'); }
    var tight = [];
    types.forEach(function(type, index) {
        tight.push(_pack(type, values[index]));
    });
    return hexlify(concat(tight));
}

export function keccak256(types: Array<string>, values: Array<any>) {
    return hashKeccak256(pack(types, values));
}

export function sha256(types: Array<string>, values: Array<any>) {
    return hashSha256(pack(types, values));
}