package obilua

import (
	"git.metabarcoding.org/obitools/obitools4/obitools4/pkg/obiseq"
	lua "github.com/yuin/gopher-lua"
)

const luaBioSequenceSliceTypeName = "BioSequenceSlice"

func registerBioSequenceSliceType(luaState *lua.LState) {
	bioSequenceSliceType := luaState.NewTypeMetatable(luaBioSequenceSliceTypeName)
	luaState.SetGlobal(luaBioSequenceSliceTypeName, bioSequenceSliceType)
	luaState.SetField(bioSequenceSliceType, "new", luaState.NewFunction(newObiSeqSlice))

	luaState.SetField(bioSequenceSliceType, "__index",
		luaState.SetFuncs(luaState.NewTable(),
			bioSequenceSliceMethods))
}

func obiseqslice2Lua(interpreter *lua.LState,
	seqslice *obiseq.BioSequenceSlice) lua.LValue {
	ud := interpreter.NewUserData()
	ud.Value = seqslice
	interpreter.SetMetatable(ud, interpreter.GetTypeMetatable(luaBioSequenceSliceTypeName))

	return ud
}

func newObiSeqSlice(luaState *lua.LState) int {
	seqslice := obiseq.NewBioSequenceSlice()
	luaState.Push(obiseqslice2Lua(luaState, seqslice))
	return 1
}

var bioSequenceSliceMethods = map[string]lua.LGFunction{
	"push":     bioSequenceSlicePush,
	"pop":      bioSequenceSlicePop,
	"sequence": bioSequenceSliceGetSetSequence,
	"len":      bioSequenceSliceGetLength,
}

func checkBioSequenceSlice(L *lua.LState) *obiseq.BioSequenceSlice {
	ud := L.CheckUserData(1)
	if v, ok := ud.Value.(*obiseq.BioSequenceSlice); ok {
		return v
	}
	L.ArgError(1, "obiseq.BioSequenceSlice expected")
	return nil
}

func bioSequenceSliceGetLength(luaState *lua.LState) int {
	s := checkBioSequenceSlice(luaState)
	luaState.Push(lua.LNumber(s.Len()))
	return 1
}

func bioSequenceSliceGetSetSequence(luaState *lua.LState) int {
	s := checkBioSequenceSlice(luaState)
	index := luaState.CheckInt(2)

	if index > s.Len() || index < 0 {
		luaState.RaiseError("BioSequenceSlice index out of range")
		return 0
	}

	if luaState.GetTop() == 3 {
		ud := luaState.CheckUserData(3)
		if v, ok := ud.Value.(*obiseq.BioSequence); ok {
			(*s)[index] = v
			return 0
		}
		luaState.ArgError(1, "obiseq.BioSequenceSlice expected")
		return 0
	}

	value := obiseq2Lua(luaState, (*s)[index])
	luaState.Push(value)

	return 1
}

func bioSequenceSlicePush(luaState *lua.LState) int {
	s := checkBioSequenceSlice(luaState)

	ud := luaState.CheckUserData(2)
	if v, ok := ud.Value.(*obiseq.BioSequence); ok {
		(*s) = append((*s), v)
		return 0
	}

	luaState.ArgError(1, "obiseq.BioSequenceSlice expected")
	return 0
}

func bioSequenceSlicePop(luaState *lua.LState) int {
	s := checkBioSequenceSlice(luaState)
	if len(*s) == 0 {
		return 0
	}

	seq := (*s)[len(*s)-1]
	(*s) = (*s)[0 : len(*s)-1]
	value := obiseq2Lua(luaState, seq)
	luaState.Push(value)
	return 1

}