stdlib

var (
	ErrNum     = newFuncErr(ErrorNum, "invalid arg type, expected int") // always numeric
	ErrParsing = newFuncErr(ErrorParsing, "unable to parse")            // always non-numeric (eg expression or time)
	ErrConst   = newFuncErr(ErrorConst, "expected const")
	ErrEnum    = newFuncErr(ErrorEnum, "value not in set")
	ErrEmpty   = newFuncErr(ErrorEmpty, "invalid empty value")
	ErrFile    = newFuncErr(ErrorFile, "unable to read file")
	ErrValue   = newFuncErr(ErrorValue, "value out of range")
)

var DisableLoad = false

var (
	ErrArgCount = errors.New("invalid number of arguments")
)

var StandardFunctions = map[string]KeyBuilderFunction{
	"coalesce":    KeyBuilderFunction(kfCoalesce),
	"bucket":      KeyBuilderFunction(kfBucket),
	"bucketrange": kfBucketRange,
	"clamp":       KeyBuilderFunction(kfClamp),
	"expbucket":   KeyBuilderFunction(kfExpBucket),

	"isint": KeyBuilderFunction(kfIsInt),
	"isnum": KeyBuilderFunction(kfIsNum),

	"sumi":  arithmaticHelperi(func(a, b int) int { return a + b }),
	"subi":  arithmaticHelperi(func(a, b int) int { return a - b }),
	"multi": arithmaticHelperi(func(a, b int) int { return a * b }),
	"divi": arithmaticHelperi(func(a, b int) int {
		if b == 0 {
			return math.MaxInt
		}
		return a / b
	}),
	"modi": arithmaticHelperi(func(a, b int) int {
		if b == 0 {
			return 0
		}
		return a % b
	}),
	"maxi": arithmaticHelperi(func(a, b int) int {
		if a > b {
			return a
		}
		return b
	}),
	"mini": arithmaticHelperi(func(a, b int) int {
		if a < b {
			return a
		}
		return b
	}),
	"sumf":  arithmaticHelperf(func(a, b float64) float64 { return a + b }),
	"subf":  arithmaticHelperf(func(a, b float64) float64 { return a - b }),
	"multf": arithmaticHelperf(func(a, b float64) float64 { return a * b }),
	"divf":  arithmaticHelperf(func(a, b float64) float64 { return a / b }),
	"ceil":  unaryArithmaticHelperfi(func(f float64) int64 { return int64(math.Ceil(f)) }),
	"floor": unaryArithmaticHelperfi(func(f float64) int64 { return int64(math.Floor(f)) }),
	"log10": unaryArithmaticHelperf(math.Log10),
	"log2":  unaryArithmaticHelperf(math.Log2),
	"ln":    unaryArithmaticHelperf(math.Log),
	"pow":   arithmaticHelperf(math.Pow),
	"sqrt":  unaryArithmaticHelperf(math.Sqrt),
	"round": kfRound,

	"!": kfMath,

	"if":     KeyBuilderFunction(kfIf),
	"switch": kfSwitch,
	"unless": KeyBuilderFunction(kfUnless),
	"eq": stringComparator(func(a, b string) string {
		if a == b {
			return TruthyVal
		}
		return FalsyVal
	}),
	"neq": stringComparator(func(a, b string) string {
		if a != b {
			return TruthyVal
		}
		return FalsyVal
	}),
	"not": KeyBuilderFunction(kfNot),
	"lt":  arithmaticEqualityHelper(func(a, b float64) bool { return a < b }),
	"gt":  arithmaticEqualityHelper(func(a, b float64) bool { return a > b }),
	"lte": arithmaticEqualityHelper(func(a, b float64) bool { return a <= b }),
	"gte": arithmaticEqualityHelper(func(a, b float64) bool { return a >= b }),
	"and": KeyBuilderFunction(kfAnd),
	"or":  KeyBuilderFunction(kfOr),

	"len":       KeyBuilderFunction(kfLen),
	"like":      KeyBuilderFunction(kfLike),
	"prefix":    KeyBuilderFunction(kfPrefix),
	"suffix":    KeyBuilderFunction(kfSuffix),
	"format":    KeyBuilderFunction(kfFormat),
	"substr":    KeyBuilderFunction(kfSubstr),
	"select":    KeyBuilderFunction(kfSelect),
	"index":     kfIndexOf,
	"lastindex": kfLastIndexOf,
	"pick":      kfPick,
	"upper":     KeyBuilderFunction(kfUpper),
	"lower":     KeyBuilderFunction(kfLower),
	"replace":   KeyBuilderFunction(kfReplace),

	"tab": kfJoin('\t'),
	"$":   kfJoin(ArraySeparator),

	"@":       kfJoin(ArraySeparator),
	"@len":    kfArrayLen,
	"@map":    kfArrayMap,
	"@split":  kfArraySplit,
	"@select": kfArraySelect,
	"@join":   kfArrayJoin,
	"@reduce": kfArrayReduce,
	"@filter": kfArrayFilter,
	"@slice":  kfArraySlice,
	"@in":     kfArrayIn,
	"@range":  kfArrayRange,
	"@for":    kfArrayFor,

	"basename": kfPathBase,
	"dirname":  kfPathDir,
	"extname":  kfPathExt,

	"load":   kfLoadFile,
	"lookup": kfLookupKey,
	"haskey": kfHasKey,

	"hi":         KeyBuilderFunction(kfHumanizeInt),
	"hf":         KeyBuilderFunction(kfHumanizeFloat),
	"bytesize":   kfBytesize,
	"bytesizesi": kfBytesizeSi,
	"downscale":  kfDownscale,
	"percent":    kfPercent,

	"json": KeyBuilderFunction(kfJsonQuery),

	"csv": KeyBuilderFunction(kfCsv),

	"time":           KeyBuilderFunction(kfTimeParse),
	"timeformat":     KeyBuilderFunction(kfTimeFormat),
	"timeattr":       KeyBuilderFunction(kfTimeAttr),
	"buckettime":     KeyBuilderFunction(kfBucketTime),
	"duration":       KeyBuilderFunction(kfDuration),
	"durationformat": KeyBuilderFunction(kfDurationFormat),

	"color":  KeyBuilderFunction(kfColor),
	"repeat": KeyBuilderFunction(kfRepeat),
	"bar":    KeyBuilderFunction(kfBar),
}