package validate

import (
	"reflect"
	"regexp"
	"strings"
)

// ValidationFunc is a function to validate a field
type ValidationFunc func(reflect.Value, interface{}) bool

// Kinds is a map with validation funcs for each reflect.Kind
type Kinds map[reflect.Kind]ValidationFunc

type listFuncInfo struct {
	inputFunc InputFunc
	kinds     Kinds
}

// AddRule adds a rule to the list of validation functions
func AddRule(name string, inputFunc InputFunc, kinds Kinds) {
	funcs[name] = listFuncInfo{inputFunc, kinds}
}

// nolint: dupl
var funcs = map[string]listFuncInfo{
	`required`: {nil, Kinds{
		reflect.Ptr: func(rv reflect.Value, _ interface{}) bool {
			return !rv.IsNil()
		},
		reflect.Interface: func(rv reflect.Value, _ interface{}) bool {
			return !rv.IsNil()
		},
		reflect.Slice: func(rv reflect.Value, _ interface{}) bool {
			return !rv.IsNil() && rv.Len() > 0
		},
		reflect.Map: func(rv reflect.Value, _ interface{}) bool {
			return !rv.IsNil() && rv.Len() > 0
		},
		reflect.String: func(rv reflect.Value, _ interface{}) bool {
			return rv.String() != ``
		},
		reflect.Int: func(rv reflect.Value, _ interface{}) bool {
			return rv.Int() != 0
		},
		reflect.Uint: func(rv reflect.Value, _ interface{}) bool {
			return rv.Uint() != 0
		},
		reflect.Float64: func(rv reflect.Value, _ interface{}) bool {
			return rv.Float() != 0
		},
	}},

	// Strings
	`prefix`: {InputSame, Kinds{
		reflect.String: func(rv reflect.Value, val interface{}) bool {
			return strings.HasPrefix(rv.String(), val.(string))
		},
	}},
	`suffix`: {InputSame, Kinds{
		reflect.String: func(rv reflect.Value, val interface{}) bool {
			return strings.HasSuffix(rv.String(), val.(string))
		},
	}},
	`contains`: {InputSame, Kinds{
		reflect.String: func(rv reflect.Value, val interface{}) bool {
			return strings.Contains(rv.String(), val.(string))
		},
	}},
	`regexp`: {InputRegexp, Kinds{
		reflect.String: func(rv reflect.Value, val interface{}) bool {
			return val.(*regexp.Regexp).MatchString(rv.String())
		},
	}},

	// Comparisons
	`eq`: {InputSame, Kinds{
		reflect.String: func(rv reflect.Value, val interface{}) bool {
			return rv.String() == val.(string)
		},
		reflect.Int: func(rv reflect.Value, val interface{}) bool {
			return rv.Int() == val.(int64)
		},
		reflect.Uint: func(rv reflect.Value, val interface{}) bool {
			return rv.Uint() == val.(uint64)
		},
		reflect.Float64: func(rv reflect.Value, val interface{}) bool {
			return rv.Float() == val.(float64)
		},
	}},

	// Integers
	`gte`: {InputSame, Kinds{
		reflect.Int: func(rv reflect.Value, val interface{}) bool {
			return rv.Int() >= val.(int64)
		},
		reflect.Uint: func(rv reflect.Value, val interface{}) bool {
			return rv.Uint() >= val.(uint64)
		},
		reflect.Float64: func(rv reflect.Value, val interface{}) bool {
			return rv.Float() >= val.(float64)
		},
	}},
	`lte`: {InputSame, Kinds{
		reflect.Int: func(rv reflect.Value, val interface{}) bool {
			return rv.Int() <= val.(int64)
		},
		reflect.Uint: func(rv reflect.Value, val interface{}) bool {
			return rv.Uint() <= val.(uint64)
		},
		reflect.Float64: func(rv reflect.Value, val interface{}) bool {
			return rv.Float() <= val.(float64)
		},
	}},
	`gt`: {InputSame, Kinds{
		reflect.Int: func(rv reflect.Value, val interface{}) bool {
			return rv.Int() > val.(int64)
		},
		reflect.Uint: func(rv reflect.Value, val interface{}) bool {
			return rv.Uint() > val.(uint64)
		},
		reflect.Float64: func(rv reflect.Value, val interface{}) bool {
			return rv.Float() > val.(float64)
		},
	}},
	`lt`: {InputSame, Kinds{
		reflect.Int: func(rv reflect.Value, val interface{}) bool {
			return rv.Int() < val.(int64)
		},
		reflect.Uint: func(rv reflect.Value, val interface{}) bool {
			return rv.Uint() < val.(uint64)
		},
		reflect.Float64: func(rv reflect.Value, val interface{}) bool {
			return rv.Float() < val.(float64)
		},
	}},

	// Slices, maps & strings
	`len`: {InputInt, Kinds{
		reflect.Slice: func(rv reflect.Value, val interface{}) bool {
			return rv.Len() == val.(int)
		},
		reflect.Map: func(rv reflect.Value, val interface{}) bool {
			return rv.Len() == val.(int)
		},
		reflect.String: func(rv reflect.Value, val interface{}) bool {
			return rv.Len() == val.(int)
		},
	}},
	`min`: {InputInt, Kinds{
		reflect.Slice: func(rv reflect.Value, val interface{}) bool {
			return rv.Len() >= val.(int)
		},
		reflect.Map: func(rv reflect.Value, val interface{}) bool {
			return rv.Len() >= val.(int)
		},
		reflect.String: func(rv reflect.Value, val interface{}) bool {
			return rv.Len() >= val.(int)
		},
	}},
	`max`: {InputInt, Kinds{
		reflect.Slice: func(rv reflect.Value, val interface{}) bool {
			return rv.Len() <= val.(int)
		},
		reflect.Map: func(rv reflect.Value, val interface{}) bool {
			return rv.Len() <= val.(int)
		},
		reflect.String: func(rv reflect.Value, val interface{}) bool {
			return rv.Len() <= val.(int)
		},
	}},
}