package tmpl

import (
	"reflect"
	_ "unsafe"
)

type TmplMap struct {
	reflect.Value
}

func (m TmplMap) Keys() ([]reflect.Value) {
	return m.MapKeys()
}

func (m TmplMap) MapWithDefaults(arg0 reflect.Value, args ...reflect.Value) (v reflect.Value) {
	if iarg0 := indirectInterface(arg0); evalTrue(iarg0) {
		if v = m.MapIndex(iarg0); evalTrue(v) {
			return
		}
	}

	for _, v = range args {
		if truth(v) {
			break
		}
	}
	return
}

func (m TmplMap) Map(arg0 reflect.Value, args ...reflect.Value) (v reflect.Value) {
	if iarg0 := indirectInterface(arg0); evalTrue(iarg0) {
		if v = m.MapIndex(iarg0); evalTrue(v) {
			return
		}
	}
	argLen := len(args)
	if argLen == 0 {
		return
	}
	keys, defaultValue := args[:argLen-1], args[argLen-1]
	for _, k := range keys {
		if ik := indirectInterface(k); !evalTrue(ik) {
		} else if v = m.Value.MapIndex(ik); evalTrue(v) {
			return
		}
	}
	v = defaultValue
	return
}

func MakeMapFunc(arg ...reflect.Value) TmplMap {
	if len(arg)%2 != 0 {
		panic("bad makemap")
	}

	m := reflect.MakeMapWithSize(reflect.TypeOf(map[interface{}]interface{}{}), len(arg)/2)
	for i := 0; i < len(arg); i += 2 {
		k, v := indirectInterface(arg[i]), indirectInterface(arg[i+1])
		if !(evalTrue(k) && evalTrue(v)) {
			continue
		}
		m.SetMapIndex(k, v)
	}
	return TmplMap{m}
}