package datastructures

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"time"

	"git.cacert.org/cacert-gosigner/shared"
)

type SignerRequest struct {
	Version     uint8
	Action      shared.Action
	System      shared.CryptoSystemId
	Root        shared.CryptoSystemRootId
	Profile     shared.CertificateProfileId
	MdAlgorithm shared.MessageDigestAlgorithmId
	Days        uint16
	Spkac       uint8
	Content1    []byte
	Content2    []byte
	Content3    []byte
}

func SignerRequestFromData(blockData []byte) (*SignerRequest, error) {
	headerLength := Decode24BitLength(blockData[0:3])
	headerBytes := blockData[3 : 3+headerLength]

	contentBytes := blockData[3+headerLength:]
	content1Length := Decode24BitLength(contentBytes[0:3])
	content1 := contentBytes[3 : 3+content1Length]

	content2Offset := 3 + content1Length
	content2Length := Decode24BitLength(contentBytes[content2Offset : content2Offset+3])
	content2 := contentBytes[3+content2Offset : 3+content2Offset+content2Length]

	content3Offset := 3 + content2Offset + content2Length
	content3Length := Decode24BitLength(contentBytes[content3Offset : content3Offset+3])
	content3 := contentBytes[3+content3Offset : 3+content3Offset+content3Length]

	return &SignerRequest{
		Version:     headerBytes[0],
		Action:      shared.Action(headerBytes[1]),
		System:      shared.CryptoSystemId(headerBytes[2]),
		Root:        shared.CryptoSystemRootId(headerBytes[3]),
		Profile:     shared.CertificateProfileId(headerBytes[4]),
		MdAlgorithm: shared.MessageDigestAlgorithmId(headerBytes[5]),
		Days:        binary.BigEndian.Uint16([]byte{headerBytes[6], headerBytes[7]}),
		Spkac:       headerBytes[8],
		Content1:    content1,
		Content2:    content2,
		Content3:    content3,
	}, nil
}

func (r *SignerRequest) Serialize() []byte {
	parameter2Bytes := make([]byte, 2)
	binary.BigEndian.PutUint16(parameter2Bytes, r.Days)
	headerBytes := bytes.Join([][]byte{
		{
			r.Version,
			byte(r.Action),
			byte(r.System),
			byte(r.Root),
			byte(r.Profile),
			byte(r.MdAlgorithm),
		},
		parameter2Bytes, {r.Spkac}}, []byte{})
	content1Bytes := r.Content1
	content2Bytes := r.Content2
	content3Bytes := r.Content3
	blockBytes := bytes.Join([][]byte{
		Encode24BitLength(headerBytes), headerBytes,
		Encode24BitLength(content1Bytes), content1Bytes,
		Encode24BitLength(content2Bytes), content2Bytes,
		Encode24BitLength(content3Bytes), content3Bytes,
	}, []byte{})
	return bytes.Join([][]byte{Encode24BitLength(blockBytes), blockBytes}, []byte{})
}

func (r *SignerRequest) String() string {
	return fmt.Sprintf(
		"v:%d %s s:%d r:%d p:%d md:%d days:%d spkac:%d '%s' '%s' '%s'",
		r.Version,
		r.Action,
		r.System,
		r.Root,
		r.Profile,
		r.MdAlgorithm,
		r.Days,
		r.Spkac,
		r.Content1,
		r.Content2,
		r.Content3,
	)
}

func NewNulRequest() *SignerRequest {
	return &SignerRequest{
		Version:  shared.ProtocolVersion,
		Action:   shared.ActionNul,
		Content1: []byte(time.Now().UTC().Format(signerTimeFormat)),
	}
}