// ------------------------------------------------------------------------
//   Project atila
//   Active Thing (activething.com) git.activething.com/go
//
//   File name  value_packer.go
//   Created by DEV
//   Modified   06/02/2024
//
//   Copyright 2024 activething.com 
// ------------------------------------------------------------------------
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ------------------------------------------------------------------------

package pjson

import (
	"activething.com/go/gogo/core/errs"
	"activething.com/go/gogo/core/opts"
	"activething.com/go/gogo/packs"
	"encoding/base32"
	"encoding/base64"
	"encoding/json"
	"math"
	"reflect"
	"strconv"
	"time"
	"unicode/utf8"
)


type (


	Packer 		struct {
		state 	*packs.State
		dirty 	bool
		Options
	}

)


func NewPacker (options ... opts.OptionFnc[Packer]) *Packer {
	return opts.Apply[Packer](&Packer {
		state : packs.NewState(),
	}, options ...)
}



func (p *Packer) Pack (value any, flags packs.Flags) {
	if p.state.Error != nil {
		panic(packs.G.ErrInvalidState.WithCause(p.state.Error))
	}
	if p.dirty {
		panic(packs.G.ErrInvalidState)
	}
	p.dirty = true
	p.PackAny(value,flags)
}

func (p *Packer) Packet () []byte {
	return p.state.Bytes()
}

func (p *Packer) Error () error {
	return p.state.Error
}


func (p *Packer) Reset () {
	p.state.Reset()
	p.Options.reset()
	p.dirty = false
}







func (p *Packer) PackAny (value any, flags packs.Flags) {
	if p.state.Error != nil {
		panic(packs.G.ErrInvalidState.WithCause(p.state.Error))
	}
	if value == nil {
		p.state.W(G.nullValue)
		return
	}

	switch v := value.(type) {
	case packs.Builder:
		p.state.SetError(v.Build(p))

	case json.Marshaler:
		d,e := v.MarshalJSON()
		if e != nil {
			p.state.SetError(e)
		} else {
			p.state.W(d)
		}

	case bool   : packBool  (p.state,v,flags )

	case string : packString(p.state,v,flags )

	case int    : packInt(p.state,int64(v),flags)
	case int8   : packInt(p.state,int64(v),flags)
	case int16  : packInt(p.state,int64(v),flags)
	case int32  : packInt(p.state,int64(v),flags)
	case int64	: packInt(p.state,v,flags )

	case uint   : packUInt(p.state,uint64(v),flags)
	case uint8  : packUInt(p.state,uint64(v),flags)
	case uint16 : packUInt(p.state,uint64(v),flags)
	case uint32 : packUInt(p.state,uint64(v),flags)
	case uint64 : packUInt(p.state,v,flags )

	case float32: packFloatString(p.state,float64(v),flags,32)
	case float64: packFloatString(p.state,v,flags,64)

	case time.Time: packDate (p.state,v,flags)

	case reflect.Value: rTypePacker(v.Type())(p.state,v,flags)

	case []uint8  :
		if flags.Binary() {
			packBinary(p.state,v,flags)
			return
		}
		packListUInt[uint8 ](p.state,v,flags)
	case []uint   : packListUInt [uint  ] (p.state,v,flags)
	case []uint16 : packListUInt [uint16] (p.state,v,flags)
	case []uint32 : packListUInt [uint32] (p.state,v,flags)
	case []uint64 : packListUInt [uint64] (p.state,v,flags)
	case []int    : packListInt  [int  ]  (p.state,v,flags)
	case []int8   : packListInt  [int8 ]  (p.state,v,flags)
	case []int16  : packListInt  [int16]  (p.state,v,flags)
	case []int32  : packListInt  [int32]  (p.state,v,flags)
	case []int64  : packListInt  [int64]  (p.state,v,flags)
	case []float32: packListFloat[float32](p.state,v,flags,32)
	case []float64: packListFloat[float64](p.state,v,flags,64)

	case []bool   : packListBool  (p.state,v,flags)
	case []string : packListString(p.state,v,flags)
	case []time.Time: packListDate(p.state,v,flags)

	default:
		rv := reflect.ValueOf(value)
		rTypePacker(rv.Type())(p.state,rv,flags)
	}
}




func (p *Packer) PackRaw    (value []byte, flags packs.Flags) { packRaw(p.state,value,flags) }

func (p *Packer) PackBinary (value []byte, flags packs.Flags) { packBinary(p.state,value,flags) }
func (p *Packer) PackString (value string, flags packs.Flags) { packString (p.state,value,flags) }

func (p *Packer) PackBool   (value bool, flags packs.Flags) { packBool(p.state,value,flags) }

func (p *Packer) PackInt8   (value int8 , flags packs.Flags) { packInt(p.state,int64(value),flags) }
func (p *Packer) PackInt16  (value int16, flags packs.Flags) { packInt(p.state,int64(value),flags) }
func (p *Packer) PackInt32  (value int32, flags packs.Flags) { packInt(p.state,int64(value),flags) }
func (p *Packer) PackInt64  (value int64, flags packs.Flags) { packInt(p.state,value,flags)}

func (p *Packer) PackUInt8  (value uint8 , flags packs.Flags) { packUInt(p.state,uint64(value),flags) }
func (p *Packer) PackUInt16 (value uint16, flags packs.Flags) { packUInt(p.state,uint64(value),flags) }
func (p *Packer) PackUInt32 (value uint32, flags packs.Flags) { packUInt(p.state,uint64(value),flags) }
func (p *Packer) PackUInt64 (value uint64, flags packs.Flags) { packUInt(p.state, value,flags) }

func (p *Packer) PackFloat32 (value float32, flags packs.Flags) { packFloatString(p.state, float64(value), flags, 32) }
func (p *Packer) PackFloat64 (value float64, flags packs.Flags) { packFloatString(p.state, value, flags, 64) }

func (p *Packer) PackDate (value time.Time, flags packs.Flags) { packDate(p.state,value,flags) }


func (p *Packer) PackList  (builder func(packs.PackListBuilder, packs.Flags), flags packs.Flags)   {
	p.packCompound('[',']',builder==nil,func(pk *Packer, fl packs.Flags){ builder(pk,fl) },flags)
}

func (p *Packer) PackMap   (builder func(packs.PackMapBuilder, packs.Flags), flags packs.Flags)    {
	p.packCompound('{','}',builder==nil,func(pk *Packer, fl packs.Flags){ builder(pk,fl) },flags)
}

func (p *Packer) PackObject(builder func(packs.PackObjectBuilder, packs.Flags), flags packs.Flags) {
	p.packCompound('{','}',builder==nil,func(pk *Packer, fl packs.Flags){ builder(pk,fl) },flags)
}


func (p *Packer) packCompound (opener, closer byte, isnil bool, buildFn func(*Packer,packs.Flags), flags packs.Flags) {
	if p.state.Error != nil {
		panic(packs.G.ErrInvalidState.WithCause(p.state.Error))
	}
	if isnil {
		p.state.W(G.nullValue)
		return
	}

	dn := false
	defer func(d *bool) {
		if !(*d) {
			p.state.SetError(errs.ToError(recover()))
		}
	}(&dn)

	p.state.Open(opener)
	buildFn(p,flags)
	if p.state.Error != nil {
		return
	}
	p.state.Close(closer)
	dn = true
}



func packRaw (state *packs.State, value []byte, flags packs.Flags) {
	if state.Error != nil {
		panic(packs.G.ErrInvalidState.WithCause(state.Error))
	}
	if value == nil {
		state.W(G.nullValue)
		return
	}
	if len(value) == 0 {
		state.Write2Byte('"','"')
		return
	}
	state.WOQ(flags.Quote(),'"',value)
}

func packString (state *packs.State, value string , flags packs.Flags) {
	if state.Error != nil {
		panic(packs.G.ErrInvalidState.WithCause(state.Error))
	}

	if len(value) == 0 {
		state.Write2Byte('"','"')
		return
	}

	state.WriteByte('"')
	start := 0
	for i := 0; i < len(value); {
		if b := value[i]; b < utf8.RuneSelf {
			if !G.jsonChars[b].isHtmlUnsafe() || (!flags.EscapeHTML() && !G.jsonChars[b].isUnsafe()) {
				i++
				continue
			}

			if start < i {
				state.WriteString(value[start:i])
			}
			state.WriteByte('\\')
			switch b {
			case '\\', '"': state.WriteByte(b)
			case '\n': state.WriteByte('n')
			case '\r': state.WriteByte('r')
			case '\t': state.WriteByte('t')
			default:
				state.WriteString(`u00`)
				state.Write2Byte(G.hex[b>>4], G.hex[b&0xF])
			}
			i++
			start = i
			continue
		}
		c, size := utf8.DecodeRuneInString(value[i:])
		if c == utf8.RuneError && size == 1 {
			if start < i {
				state.WriteString(value[start:i])
			}
			state.WriteString(`\ufffd`)
			i += size
			start = i
			continue
		}

		if c == '\u2028' || c == '\u2029' {
			if start < i {
				state.WriteString(value[start:i])
			}
			state.WriteString(`\u202`)
			state.WriteByte(G.hex[c&0xF])
			i += size
			start = i
			continue
		}
		i += size
	}
	if start < len(value) {
		state.WriteString(value[start:])
	}
	state.WriteByte('"')
}




func packBinary (state *packs.State, value []byte , flags packs.Flags) {
	if state.Error != nil {
		panic(packs.G.ErrInvalidState.WithCause(state.Error))
	}

	if value == nil {
		_,_ = state.Write(G.nullValue)
		return
	}
	if len(value) == 0 {
		state.Write2Byte('"','"')
		return
	}
	state.WriteByte('"')

	if flags.Bin64() {
		packBinary64(state, value, 0)
	} else if flags.Bin32() {
		packBinary32(state, value, 0)
	} else {
		state.SetError(packs.G.ErrUnsupportedType)
		return
	}

	if state.Error == nil {
		state.WriteByte('"')
	}
}


func packBinary64 (state *packs.State, value []byte , _ packs.Flags) {
	ln := base64.StdEncoding.EncodedLen(len(value))
	if ln <= len(state.Temp) {
		dst := state.Temp[:ln]
		base64.StdEncoding.Encode(dst, value)
		_,_= state.Write(dst)
	} else if ln <= 1024 {
		dst := make([]byte, ln)
		base64.StdEncoding.Encode(dst, value)
		_,_ = state.Write(dst)
	} else {
		ec := base64.NewEncoder(base64.StdEncoding, state)
		_,_ = ec.Write(value)
		state.SetError(ec.Close())
	}
}

func packBinary32 (state *packs.State, value []byte , _ packs.Flags) {
	ln := base32.StdEncoding.EncodedLen(len(value))
	if ln <= len(state.Temp) {
		dst := state.Temp[:ln]
		base32.StdEncoding.Encode(dst, value)
		_,_= state.Write(dst)
	} else if ln <= 1024 {
		dst := make([]byte, ln)
		base32.StdEncoding.Encode(dst, value)
		_,_ = state.Write(dst)
	} else {
		ec := base32.NewEncoder(base32.StdEncoding, state)
		_,_ = ec.Write(value)
		state.SetError(ec.Close())
	}
}




func packBool   (state *packs.State, value bool   , flags packs.Flags) {
	if state.Error != nil {
		panic(packs.G.ErrInvalidState.WithCause(state.Error))
	}
	if value {
		state.WOQ(flags.Quote(),'"',G.trueValue)
	} else {
		state.WOQ(flags.Quote(),'"',G.falseValue)
	}
}

func packInt 	(state *packs.State, value int64  , flags packs.Flags) {
	if state.Error != nil {
		panic(packs.G.ErrInvalidState.WithCause(state.Error))
	}

	q :=flags.Quote()
	if q {
		state.WriteByte('"')
	}
	if value == 0 {
		state.WriteByte('0')
	} else {
		state.WriteIntStr(value, 10)
	}
	if q {
		state.WriteByte('"')
	}
}


func packUInt 	(state *packs.State, value uint64 , flags packs.Flags) {
	if state.Error != nil {
		panic(packs.G.ErrInvalidState.WithCause(state.Error))
	}
	q :=flags.Quote()
	if q {
		state.WriteByte('"')
	}
	if value == 0 {
		state.WriteByte('0')
	} else {
		state.WriteUIntStr(value, 10)
	}
	if q {
		state.WriteByte('"')
	}
}

func packFloat  (state *packs.State, value float64, flags packs.Flags) {
	packFloatString(state, value, flags, 64)
}

func packFloatString (state *packs.State, f float64, flags packs.Flags, bits int) {
	if state.Error != nil {
		panic(packs.G.ErrInvalidState.WithCause(state.Error))
	}

	if math.IsInf(f, 0) || math.IsNaN(f) {
		state.SetError(packs.G.ErrInvalidValue)
		return
	}

	abs := math.Abs(f)
	fmt := byte('f')

	if abs != 0 {
		if bits == 64 && (abs < 1e-6 || abs >= 1e21) || bits == 32 && (float32(abs) < 1e-6 || float32(abs) >= 1e21) {
			fmt = 'e'
		}
	}
	bf := state.Temp[:0]
	bf = strconv.AppendFloat(bf, f, fmt, -1, int(bits))
	if fmt == 'e' {
		// clean up e-09 to e-9
		n := len(bf)
		if n >= 4 && bf[n-4] == 'e' && bf[n-3] == '-' && bf[n-2] == '0' {
			bf[n-2] = bf[n-1]
			bf = bf[:n-1]
		}
	}

	state.WOQ(flags.Quote(),'"',bf)
}


func packDate(state *packs.State, value time.Time, flags packs.Flags) {
	if state.Error != nil {
		panic(packs.G.ErrInvalidState.WithCause(state.Error))
	}
	state.WOQ(true,'"',value.AppendFormat(state.Temp[:0],flags.DateFormat()))
}






func packListString (state *packs.State, list []string, flags packs.Flags) {
	if !checkList(state,list == nil, len(list) ==0) {
		return
	}
	state.WriteByte('[')
	for i,v := range list {
		if i > 0 {
			state.WriteByte(',')
		}
		packString(state,v,flags)
		if state.Error != nil {
			return
		}
	}
	state.WriteByte(']')
}

func packListBool (state *packs.State, list []bool, flags packs.Flags) {
	if !checkList(state,list == nil, len(list) ==0) {
		return
	}
	state.WriteByte('[')
	for i,v := range list {
		if i > 0 {
			state.WriteByte(',')
		}
		packBool(state,v,flags)
		if state.Error != nil {
			return
		}
	}
	state.WriteByte(']')
}

func packListInt  [T int | int8 | int16 | int32 | int64](state *packs.State, list []T, flags packs.Flags) {
	if !checkList(state,list == nil, len(list) ==0) {
		return
	}
	state.WriteByte('[')
	for i,v := range list {
		if i > 0 {
			state.WriteByte(',')
		}
		packInt(state,int64(v),flags)
		if state.Error != nil {
			return
		}
	}
	state.WriteByte(']')
}

func packListUInt [T uint | uint8 | uint16 | uint32 | uint64](state *packs.State, list []T, flags packs.Flags) {
	if !checkList(state,list == nil, len(list) ==0) {
		return
	}
	state.WriteByte('[')
	for i,v := range list {
		if i > 0 {
			state.WriteByte(',')
		}
		packUInt(state,uint64(v),flags)
		if state.Error != nil {
			return
		}
	}
	state.WriteByte(']')
}

func packListFloat[T float32 | float64](state *packs.State, list []T, flags packs.Flags, bits int) {
	if !checkList(state,list == nil, len(list) ==0) {
		return
	}
	state.WriteByte('[')
	for i,v := range list {
		if i > 0 {
			state.WriteByte(',')
		}
		packFloatString(state,float64(v),flags,bits)
		if state.Error != nil {
			return
		}
	}
	state.WriteByte(']')
}

func packListDate (state *packs.State, list []time.Time, flags packs.Flags) {
	if !checkList(state,list == nil, len(list) ==0) {
		return
	}
	state.WriteByte('[')
	for i,v := range list {
		if i > 0 {
			state.WriteByte(',')
		}
		packDate(state,v,flags)
		if state.Error != nil {
			return
		}
	}
	state.WriteByte(']')
}


func checkList (state *packs.State, isNull, isEmpty bool) bool {
	if isNull {
		state.Write2Byte('"','"')
		return false
	}
	if isEmpty {
		state.Write2Byte('[',']')
		return false
	}
	return true
}