namespace system:

@AllowFor(false, false, false, false, true)
@AllowMultiple
attribute ExpectFunc(string name, number paramsCount, bool stat)

@AllowFor(true, false, false, false, false)
@ExpectFunc("it_hasNext", 0, false)
@ExpectFunc("it_next"   , 0, false)
@ExpectFunc("it_reset"  , 0, false)
attribute Iteratable()

enum StaticRequirements
{
    RequireStatic,
    RequireNonStatic,
    DoNotRequire
}

class Array (const csType private)
{
    constructor(len)
    {
        // BUILTIN FUNCTION
    }

    func set(i, operator, val?)
    {
        // BUILTIN FUNCTION
    }

    func get(i)
    {
        // BUILTIN FUNCTION
    }

    func length()
    {
        return lenof this
    }

    func map(mod)
    {
        const n = new Array(lenof this)
        foreach i in this : counter ind
        {
            n[ind] = mod(i)
        }
        return n
    }

    func first(cond)
    {
        if cond is not function
        {
            throw new Exception("This function takes a function as parameter.")
        }
        foreach item in this
        {
            if cond(item) == true
            {
                return item
            }
        }
        return null
    }

    func findAll(cond)
    {
        if cond is not function
        {
            throw new Exception ("This function takes a function as parameter.")
        }
        const all = new List()
        foreach item in this
        {
            if cond(item) == true
            {
                all.add(item)
            }
        }
        return all
    }

    func select(selector)
    {
        const n = new Array(length())
        foreach x in this : counter i
        {
            n[i] = selector(x)
        }
        return n
    }

    func ofType(type)
    {
        const n = new List()
        foreach x in this
        {
            if (x != null & Type.get(x) == type)
            {
                n.add(x)
            }
        }
        return n.toArray()
    }

    /*
    func orderBy(getNum)
    {
        const n = copy()
        const nums = new List()
        foreach item in this : counter i
        {
            var num = getNum(item)
            nums.add(num)
            var ind = i
            while ind > 0 & nums.get(ind - 1) > num
            {
                var x = this[ind - 1]
                this[ind - 1] = item
                this[ind] =
            }
        }
    }
    */

    func copy()
    {
        return map(func(item?) => item)
    }

    func forEach(action)
    {
        foreach item in this : counter i
        {
            action(item, i)
        }
    }
}

class string (const chars private basearray)
{
    @Equalizer func equals(obj?)
    {
        if obj is not string | obj.length() != length()
        {
            return false
        }
        foreach c in chars : counter i
        {
            if c != obj.charAt(i)
            {
                return false
            }
        }

        return true
    }

    constructor (carr)
    {
        if carr is not Array
        {
            throw new Exception ("Argument must be an array.")
        }
        foreach c in carr
        {
            if c is not char
            {
                throw new Exception ("Argument must be an array of chars.")
            }
        }
        chars = carr
    }

    constructor()
    {
        chars = new Array(0)
    }

    func charAt(index)
    {
        return chars[index]
    }

    func length()
    {
        return lenof chars
    }

    func substr(stind, len)
    {
        var str = new string()
        for (var i = stind; i < length(); i++) : counter ind
        {
            str = str + chars[i]
            if ind == len - 1
            {
                return str
            }
        }
    }

    @ReadOnly func remove(start, count)
    {
        var str = ""

        foreach c in chars : counter i
        {
            if i < start | i >= start + count
            {
                str += c
            }
        }

        return str
    }

    func toCharArr() => chars.copy()

    func split(c)
    {
        const ls = new List()
        var str = ""

        foreach x in chars
        {
            if x == c
            {
                ls.add(str)
                str = ""
            }
            else
            {
                str += x
            }
        }

        ls.add(str)
        return ls.toArray()
    }

    func toNum()
    {
        var result = 0.0
        var sign = 1.0
        var fractionMultiplier = 0.1
        var hasDecimalPoint = false
        var i = 0

        // handle sign
        if charAt(0) == '-'
        {
            sign = 0 - 1
            i = 1
        }
        else
        { if charAt(0) == '+'
        {
            i = 1
        } }

        for (; i < length(); i++)
        {
            var c = charAt(i)

            if c == '.'
            {
                if hasDecimalPoint
                {
                    throw new Exception("Multiple decimal points")
                }

                hasDecimalPoint = true
                continue
            }

            if c < '0' | c > '9'
            {
                throw new Exception("Invalid character: '" + c + "'")
            }

            if hasDecimalPoint == false
            {
                // before the decimal point
                result = result * 10 + (c - '0')
            }
            else
            {
                // after the decimal point
                result = result + (c - '0') * fractionMultiplier
                fractionMultiplier = fractionMultiplier * 0.1
            }
        }

        return result * sign
    }
}

@AllowFor(true, false, false, false, false)
@ExpectFunc("getType", 0, false)
@ExpectFunc("getMessage", 0, false)
@ExpectFunc("getData", 0, false)
attribute Throwable()

@Throwable
class Exception (msg, type, const source, const line, const col, data)
{
    static const INDEX_OUT_OF_RANGE = "INDEX_OUT_OF_RANGE"
    static const ARGUMENT_NULL = "ARGUMENT_NULL"
    static const NULL_REFERENCE = "NULL_REFERENCE"
    static const INVALID_ARGUMENT = "INVALID_ARGUMENT"
    static const INVALID_OPERATION = "INVALID_OPERATION"
    static const EXTERN_OPERATION_FAILED = "EXTERN_OPERATION_FAILED"
    static const NOT_FOUND = "NOT_FOUND"
    static const DIVIDE_BY_ZERO = "DIVIDE_BY_ZERO"
    static const STACK_OVERFLOW = "STACK_OVERFLOW"

    constructor (t, m)
    {
        type = t
        msg = m
    }

    constructor(m)
    {
        this.msg = m
        this.type = "UNKNOWN"
    }

    constructor(t, m, d?)
    {
        msg = m
        type = t
        data = d
    }

    func getType() => type
    func getMessage() => msg
    func getData() => data
}

class ExternTypeValue ()
{
    private constructor() {}

    @Translator
    private func str()
    {
        const _this = this
        return _this.toString()
    }
}

class Type (const name, const fullName, const def private)
{
    private constructor() {}
    static func get(obj)
    {
        // BUILTIN FUNCTION
    }
}

class List (array private basearray)
{
    constructor (arr)
    {
        array = arr
    }

    constructor()
    {
        array = []
    }

    func add(val?)
    {
        const n = new Array(array.length() + 1)
        for (var i = 0; i < count(); i++)
        {
            n[i] = array[i]
        }
        n[n.length() - 1] = val
        array = n
    }

    func remove(index)
    {
        const n = new Array (array.length() - 1)
        const len = array.length()
        for (var i = 0; i < index; i++)
        {
            n[i] = array[i]
        }
        for (var i = index + 1 ; i < len ; i++)
        {
            n[i - 1] = array[i]
        }

        array = n
    }

    func setAt(i, val?)
    {
        array[i] = val
    }

    func get(i)
    {
        if i is not number | i > count() - 1 | i < 0
        {
            throw new Exception("Argument out of range.")
        }
        return array[i]
    }

    func first(cond)
    {
        return this.array.first(cond)
    }

    func contains(val?)
    {
        return first(func(v) => v == val) != null
    }

    func findAll(cond)
    {
        return this.array.findAll(cond)
    }

    func clear()
    {
        array = []
    }

    @ReadOnly func toArray()
    {
        return array.copy()
    }

    func count()
    {
        return lenof array
    }

    func indexOf(val?)
    {
        foreach x in this : counter c
        {
            if (x == val)
            {
                return c
            }
        }
        return 0 - 1
    }

    @Translator
    func toString()
    {
        var s = "["
        foreach v in array : counter i
        {
            s = s + v
            if i < count() - 1
            {
                s = s + ", "
            }
        }
        return s + "]"
    }

    func print()
    {
        print toString()
    }
}

class Dictionary (const keys private, const values private basearray)
{
    constructor()
    {
        keys = new List()
        values = new List()
    }

    func set(key, val?)
    {
        const index = keys.indexOf(key)
        if (index >= 0)
        {
            values.setAt(index, val)
        }
        else
        {
            keys.add(key)
            values.add(val)
        }
    }

    func get(key)
    {
        const index = keys.indexOf(key)
        if (index < 0)
        {
            throw new Exception(Exception.NOT_FOUND ?? "NOT_FOUND", "The specified key was not found.") // TODO: remove not_found coalscing after fixing static vars auto init
        }
        return values.get(index)
    }

    func containsKey(key)
    {
        return keys.contains(key)
    }

    @Translator
    func toString()
    {
        var str = "["
        foreach x in keys : counter c
        {
            str = str + x + ": " + values.get(c)
            if (c < keys.count() - 1)
            {
                str = str + ", "
            }
        }
        return str + "]"
    }
}


class Date (year, month, day, hour, minute, sec, millis, nanos)
{
    constructor(year, month, day, hour, minute)
    {
        this.year = year
        this.month = month
        this.day = day
        this.hour = hour
        this.minute = minute
    }

    constructor(year, month, day, hour, minute, sec, millis, nanos)
    {
        this.year = year
        this.month = month
        this.day = day
        this.hour = hour
        this.minute = minute
        this.sec = sec
        this.millis = millis
        this.nanos = nanos
    }

    constructor()
    {

    }

    func setToNow()
    {
        // BUILTIN FUNCTION
    }

    @ReadOnly
    static func now()
    {
        const d = new Date()
        d.setToNow()
        return d
    }

    @Translator
    func toString()
    {
        var h = hour
        if h < 10
        {
            h = "0" + h
        }
        var m = minute
        if m < 10
        {
            m = "0" + m
        }
        return day + "." + month + "." + year + " " + h + ":" + m
    }

    func toFullString()
    {
        var s = sec
        if s < 10
        {
            s = "0" + s
        }
        return toString() + ":" + s + "." + millis + "." + nanos
    }
}

class cs()
{
    private constructor() {}
    static func int(n) {}
    static func byte(n) {}
    static func float(n) {}
    static func long(n) {}
    static func action(f) {}
    static func exp(o) {}
}

func refEquals(a?, b?)
{
    // BUILTIN FUNCTION
}

func round(num)
{
    const up = num % 1 >= 0.5
    num = num - num % 1
    if up
    {
        num = num + 1
    }
    return num
}

func stringOf(obj?)
{
    return obj + ""
}

func floor(num)
{
    return num - num % 1
}

func println(text?)
{
    print text + "\n"
}

func setTimeout(millis, action)
{
    // BUILTIN FUNCTION
}

func runAsync(action, onComplete?)
{
    // BUILTIN FUNCTION
}

func runAsync(action)
{
    runAsync(action, null)
}

func pow(a, b)
{
    if (b == 0)
    {
        return 1
    }

    const power = a
    for (var i = 1; i < b; i++)
    {
        a = a * power
    }

    return a
}

func sign(n)
{
    if n > 0 { return 1 }
    if n < 0 { return -1 }
    return 0
}