package vm_indent

import (
	"encoding/json"
	"unsafe"

	"github.com/goccy/go-json/internal/encoder"
	"github.com/goccy/go-json/internal/runtime"
)

func load(base uintptr, idx uintptr) uintptr {
	addr := base + idx
	return **(**uintptr)(unsafe.Pointer(&addr))
}

func store(base uintptr, idx uintptr, p uintptr) {
	addr := base + idx
	**(**uintptr)(unsafe.Pointer(&addr)) = p
}

func loadNPtr(base uintptr, idx uintptr, ptrNum int) uintptr {
	addr := base + idx
	p := **(**uintptr)(unsafe.Pointer(&addr))
	for i := 0; i < ptrNum; i++ {
		if p == 0 {
			return 0
		}
		p = ptrToPtr(p)
	}
	return p
}

func ptrToUint64(p uintptr) uint64              { return **(**uint64)(unsafe.Pointer(&p)) }
func ptrToFloat32(p uintptr) float32            { return **(**float32)(unsafe.Pointer(&p)) }
func ptrToFloat64(p uintptr) float64            { return **(**float64)(unsafe.Pointer(&p)) }
func ptrToBool(p uintptr) bool                  { return **(**bool)(unsafe.Pointer(&p)) }
func ptrToBytes(p uintptr) []byte               { return **(**[]byte)(unsafe.Pointer(&p)) }
func ptrToNumber(p uintptr) json.Number         { return **(**json.Number)(unsafe.Pointer(&p)) }
func ptrToString(p uintptr) string              { return **(**string)(unsafe.Pointer(&p)) }
func ptrToSlice(p uintptr) *runtime.SliceHeader { return *(**runtime.SliceHeader)(unsafe.Pointer(&p)) }
func ptrToPtr(p uintptr) uintptr {
	return uintptr(**(**unsafe.Pointer)(unsafe.Pointer(&p)))
}
func ptrToNPtr(p uintptr, ptrNum int) uintptr {
	for i := 0; i < ptrNum; i++ {
		if p == 0 {
			return 0
		}
		p = ptrToPtr(p)
	}
	return p
}

func ptrToUnsafePtr(p uintptr) unsafe.Pointer {
	return *(*unsafe.Pointer)(unsafe.Pointer(&p))
}
func ptrToInterface(code *encoder.Opcode, p uintptr) interface{} {
	return *(*interface{})(unsafe.Pointer(&emptyInterface{
		typ: code.Type,
		ptr: *(*unsafe.Pointer)(unsafe.Pointer(&p)),
	}))
}

func appendBool(b []byte, v bool) []byte {
	if v {
		return append(b, "true"...)
	}
	return append(b, "false"...)
}

func appendNull(b []byte) []byte {
	return append(b, "null"...)
}

func appendComma(b []byte) []byte {
	return append(b, ',', '\n')
}

func appendStructHead(b []byte) []byte {
	return append(b, '{', '\n')
}

func appendMarshalJSON(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte, v interface{}) ([]byte, error) {
	return encoder.AppendMarshalJSONIndent(ctx, code, b, v, false)
}

func appendMarshalText(code *encoder.Opcode, b []byte, v interface{}) ([]byte, error) {
	return encoder.AppendMarshalTextIndent(code, b, v, false)
}

func appendStructKey(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
	b = appendIndent(ctx, b, code.Indent)
	b = append(b, code.Key...)
	return append(b, ' ')
}

func appendStructEndSkipLast(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
	last := len(b) - 1
	if b[last-1] == '{' {
		b[last] = '}'
	} else {
		if b[last] == '\n' {
			// to remove ',' and '\n' characters
			b = b[:len(b)-2]
		}
		b = append(b, '\n')
		b = appendIndent(ctx, b, code.Indent-1)
		b = append(b, '}')
	}
	return appendComma(b)
}