package rt

import (
	"unsafe"
	"encoding/json"
)

// Copied from Golang
var staticuint64s = [...]uint64{
	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
	0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
	0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
	0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
	0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
	0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
	0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
	0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
	0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
	0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
	0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
	0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
	0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
	0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
	0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
	0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
	0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
	0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
	0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
	0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
	0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
	0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
	0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
	0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
	0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
	0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
}

const maxZero = 1024 // must match value in reflect/value.go:maxZero cmd/compile/internal/gc/walk.go:zeroValSize
var zeroVal [maxZero]byte


type TslicePool struct {
	pool   []GoSlice
	index  int
}

func NewTslicePool (hint int) TslicePool {
	return TslicePool{
		pool:  make([]GoSlice, hint, hint),
		index: 0,
	}
}

func (self *TslicePool) Conv(val GoSlice, typ *GoType, ep *interface{}) {
	var vp unsafe.Pointer

	if ((*GoSlice)(unsafe.Pointer(&val))).Ptr == nil {
		vp = unsafe.Pointer(&zeroVal[0])
	} else if self.index < len(self.pool) {
		dst := &(self.pool)[self.index]
		*dst = val
		self.index++
		vp = unsafe.Pointer(dst)
	} else {
		vp = Mallocgc(unsafe.Sizeof(val), BytesType, true)
	}
	*((*GoEface)(unsafe.Pointer(ep))) = GoEface{Type: typ, Value: vp}
}

func (self *TslicePool) Free()  {
	self.pool = nil
}

type TstringPool struct {
	pool  []string
	index int
}

func NewTstringPool (hint int) TstringPool {
	return TstringPool{
		pool: make([]string, hint),
		index: 0,
	}
}

func (self *TstringPool) Conv(val string, ep *interface{}) {
	var vp unsafe.Pointer
	if val == "" {
		vp = unsafe.Pointer(&zeroVal[0])
	} else if self.index < len(self.pool) {
		dst := &(self.pool)[self.index]
		*dst = val
		self.index++
		vp = unsafe.Pointer(dst)
	} else {
		vp = Mallocgc(unsafe.Sizeof(val), StringType, true)
	}

	// convert into interface{}
	*((*GoEface)(unsafe.Pointer(ep))) = GoEface{Type: StringType, Value: vp}
}


func (self *TstringPool) ConvNum(val json.Number, ep *interface{}) {
	var vp unsafe.Pointer
	if val == "" {
		vp = unsafe.Pointer(&zeroVal[0])
	} else if self.index < len(self.pool) {
		dst := &(self.pool)[self.index]
		*dst = string(val)
		self.index++
		vp = unsafe.Pointer(dst)
	} else {
		vp = Mallocgc(unsafe.Sizeof(val), StringType, true)
	}

	// convert into interface{}
	*((*GoEface)(unsafe.Pointer(ep))) = GoEface{Type: JsonNumberType, Value: vp}
}


func (self *TstringPool) Free()  {
	self.pool = nil
}

type T64Pool struct {
	pool  []uint64
	index int
}

func NewT64Pool (hint int) T64Pool {
	return T64Pool{
		pool: make([]uint64, hint, hint),
		index: 0,
	}
}

func (self *T64Pool) Conv(val uint64, typ *GoType, ep *interface{}) {
	var vp unsafe.Pointer
	if val < uint64(len(staticuint64s)) {
		vp = unsafe.Pointer(&staticuint64s[val])
	} else if self.index < len(self.pool) {
		dst := &(self.pool)[self.index]
		*dst = val
		self.index++
		vp = unsafe.Pointer(dst)
	} else {
		vp = Mallocgc(8, Uint64Type, false)
	}

	// convert into interface{}
	*((*GoEface)(unsafe.Pointer(ep))) = GoEface{Type: typ, Value: vp}
}

func (self *T64Pool) Free()  {
	self.pool = nil
}

func ConvTBool(val bool, ep *interface{}) {
	var vp unsafe.Pointer
	if val {
		vp = unsafe.Pointer(&staticuint64s[1])
	} else {
		vp = unsafe.Pointer(&staticuint64s[0])
	}

	*((*GoEface)(unsafe.Pointer(ep))) = GoEface{Type: BoolType, Value: vp}
}

