package wireproto

import (
	`bytes`
	`fmt`
	`io`
	`strings`

	`github.com/google/uuid`
)

// ConnId returns a copy of the connection ID.
func (r *RequestRecord) ConnId() (conn uuid.UUID) {

	conn = r.connId

	return
}

// GetParent returns the parent RecordGroup.
func (r *RequestRecord) GetParent() (rg RecordGroup) {

	rg = r.parent

	return
}

// MarshalBinary renders a RequestRecord into a byte-packed format.
func (r *RequestRecord) MarshalBinary() (data []byte, err error) {

	var b []byte
	var recSize int
	var buf *bytes.Buffer = new(bytes.Buffer)

	_ = r.Size()

	if _, err = buf.Write(PackInt(len(r.Pairs))); err != nil {
		return
	}
	for _, i := range r.Pairs {
		recSize += i.Size()
	}
	if _, err = buf.Write(PackInt(recSize)); err != nil {
		return
	}

	for _, i := range r.Pairs {
		if b, err = i.MarshalBinary(); err != nil {
			return
		}
		if _, err = buf.Write(b); err != nil {
			return
		}
	}

	data = buf.Bytes()

	return
}

// Model returns an indented string representation of the model.
func (r *RequestRecord) Model() (out string) {

	out = r.ModelCustom(IndentChars, SeparatorChars, indentRec)

	return
}

// ModelCustom is like Model with user-defined formatting.
func (r *RequestRecord) ModelCustom(indent, sep string, level uint) (out string) {

	var size int
	var sb strings.Builder

	for _, p := range r.Pairs {
		size += p.Size()
	}

	// Count
	sb.WriteString(strings.Repeat(indent, int(level)))
	sb.WriteString(fmt.Sprintf("%x", PackUint32(uint32(len(r.Pairs)))))
	sb.WriteString(sep)
	sb.WriteString(fmt.Sprintf("// Field/Value Count (%d)\n", len(r.Pairs)))
	// Size
	sb.WriteString(strings.Repeat(indent, int(level)))
	sb.WriteString(fmt.Sprintf("%x", PackUint32(uint32(size))))
	sb.WriteString(sep)
	sb.WriteString(fmt.Sprintf("// Record Size       (%d)\n", size))

	// VALUES
	for idx, p := range r.Pairs {
		sb.WriteString(strings.Repeat(indent, int(level)))
		sb.WriteString(
			fmt.Sprintf(
				"// Record Group %d, Record %d, Field/Value %d (%d bytes)\n",
				r.rgIdx+1, r.rIdx+1, idx+1, p.Size(),
			),
		)
		sb.WriteString(p.ModelCustom(indent, sep, level+1))
	}

	out = sb.String()

	return
}

// Resolve associates children with parents.
func (r *RequestRecord) Resolve() {
	for idx, i := range r.Pairs {
		i.parent = r
		i.rgIdx = r.rgIdx
		i.rIdx = idx
		i.fvpidx = idx
		// KVP have no Resolve() method.
	}
}

// Size returns the RequestRecord's calculated size (in bytes) and updates the size field if 0.
func (r *RequestRecord) Size() (size int) {

	if r == nil {
		return
	}

	// Count and Size uint32s
	size += PackedNumSize * 2

	for _, i := range r.Pairs {
		size += i.Size()
	}

	if r.common == nil || r.size == 0 {
		r.common = &common{
			size: uint32(size),
		}
	}

	r.size = uint32(size)

	return
}

// ToMap returns a slice of FVP maps for this Record.
func (r *RequestRecord) ToMap() (m []map[string]interface{}) {

	m = make([]map[string]interface{}, len(r.Pairs))
	for idx, p := range r.Pairs {
		m[idx] = p.ToMap()
	}

	return
}

// UnmarshalBinary populates a RequestRecord from packed bytes.
func (r *RequestRecord) UnmarshalBinary(data []byte) (err error) {

	if data == nil || len(data) == 0 {
		return
	}

	var b []byte
	var cnt, size int
	var fvpNmSize, fvpValSize int
	var fvpBuf *bytes.Buffer
	var buf *bytes.Reader = bytes.NewReader(data)

	if r == nil {
		*r = RequestRecord{}
	}
	if r.common == nil {
		r.common = new(common)
	}
	r.size = 0

	// FVP count.
	b = make([]byte, PackedNumSize)
	if _, err = buf.Read(b); err != nil {
		return
	}
	cnt = UnpackInt(b)

	// Size of record.
	b = make([]byte, PackedNumSize)
	if _, err = buf.Read(b); err != nil {
		return
	}
	size = UnpackInt(b)

	// And now we handle the FVPs themselves.
	b = make([]byte, size)
	if _, err = buf.Read(b); err != nil {
		return
	}
	buf = bytes.NewReader(b)

	r.Pairs = make([]*FieldValuePair, cnt)

	for idx := 0; idx < cnt; idx++ {
		fvpBuf = new(bytes.Buffer)

		// Unlike parents, the FVP needs both allocators because they're both size allocators.
		// FVP Name
		b = make([]byte, PackedNumSize)
		if _, err = buf.Read(b); err != nil {
			return
		}
		if _, err = fvpBuf.Write(b); err != nil {
			return
		}
		fvpNmSize = UnpackInt(b)
		// FVP Value
		b = make([]byte, PackedNumSize)
		if _, err = buf.Read(b); err != nil {
			return
		}
		if _, err = fvpBuf.Write(b); err != nil {
			return
		}
		fvpValSize = UnpackInt(b)

		if _, err = io.CopyN(fvpBuf, buf, int64(fvpNmSize+fvpValSize)); err != nil {
			return
		}

		r.Pairs[idx] = new(FieldValuePair)
		if err = r.Pairs[idx].UnmarshalBinary(fvpBuf.Bytes()); err != nil {
			return
		}
	}

	_ = r.Size()
	_ = size

	return
}

// getFvps returns this Record's FVP.
func (r *RequestRecord) getFvps() (fvp []FVP) {

	fvp = make([]FVP, len(r.Pairs))
	for idx, p := range r.Pairs {
		fvp[idx] = p
	}

	return
}

// getIdx returns the Record index in the parent RecordGroup.
func (r *RequestRecord) getIdx() (idx int) {

	idx = r.rIdx

	return
}