package model

import (
	"context"
	"errors"
	"fmt"
	"strings"
	"time"

	"go.yandata.net/iod/iod/go-trustlog/api/logger"
	"go.yandata.net/iod/iod/go-trustlog/internal/helpers"
)

//
// ===== 操作来源类型 =====
//

// Source 表示操作来源，用于区分不同系统模块（IRP、DOIP）。
type Source string

const (
	OpSourceIRP  Source = "IRP"
	OpSourceDOIP Source = "DOIP"
)

//
// ===== 操作类型枚举 =====
//

// Type 表示操作的具体类型。
type Type string

// DOIP 操作类型枚举。
const (
	OpTypeHello          Type = "Hello"
	OpTypeRetrieve       Type = "Retrieve"
	OpTypeCreate         Type = "Create"
	OpTypeDelete         Type = "Delete"
	OpTypeUpdate         Type = "Update"
	OpTypeSearch         Type = "Search"
	OpTypeListOperations Type = "ListOperations"
)

// IRP 操作类型枚举。
const (
	OpTypeOCReserved                Type = "OC_RESERVED"
	OpTypeOCResolution              Type = "OC_RESOLUTION"
	OpTypeOCGetSiteInfo             Type = "OC_GET_SITEINFO"
	OpTypeOCCreateHandle            Type = "OC_CREATE_HANDLE"
	OpTypeOCDeleteHandle            Type = "OC_DELETE_HANDLE"
	OpTypeOCAddValue                Type = "OC_ADD_VALUE"
	OpTypeOCRemoveValue             Type = "OC_REMOVE_VALUE"
	OpTypeOCModifyValue             Type = "OC_MODIFY_VALUE"
	OpTypeOCListHandle              Type = "OC_LIST_HANDLE"
	OpTypeOCListNA                  Type = "OC_LIST_NA"
	OpTypeOCResolutionDOID          Type = "OC_RESOLUTION_DOID"
	OpTypeOCCreateDOID              Type = "OC_CREATE_DOID"
	OpTypeOCDeleteDOID              Type = "OC_DELETE_DOID"
	OpTypeOCUpdateDOID              Type = "OC_UPDATE_DOID"
	OpTypeOCBatchCreateDOID         Type = "OC_BATCH_CREATE_DOID"
	OpTypeOCResolutionDOIDRecursive Type = "OC_RESOLUTION_DOID_RECURSIVE"
	OpTypeOCGetUsers                Type = "OC_GET_USERS"
	OpTypeOCGetRepos                Type = "OC_GET_REPOS"
	OpTypeOCVerifyIRS               Type = "OC_VERIFY_IRS"
	OpTypeOCResolveGRS              Type = "OC_RESOLVE_GRS"
	OpTypeOCCreateOrgGRS            Type = "OC_CREATE_ORG_GRS"
	OpTypeOCUpdateOrgGRS            Type = "OC_UPDATE_ORG_GRS"
	OpTypeOCDeleteOrgGRS            Type = "OC_DELETE_ORG_GRS"
	OpTypeOCSyncOrgIRSParent        Type = "OC_SYNC_ORG_IRS_PARENT"
	OpTypeOCUpdateOrgIRSParent      Type = "OC_UPDATE_ORG_IRS_PARENT"
	OpTypeOCDeleteOrgIRSParent      Type = "OC_DELETE_ORG_IRS_PARENT"
	OpTypeOCChallengeResponse       Type = "OC_CHALLENGE_RESPONSE"
	OpTypeOCVerifyChallenge         Type = "OC_VERIFY_CHALLENGE"
	OpTypeOCSessionSetup            Type = "OC_SESSION_SETUP"
	OpTypeOCSessionTerminate        Type = "OC_SESSION_TERMINATE"
	OpTypeOCSessionExchangeKey      Type = "OC_SESSION_EXCHANGEKEY"
	OpTypeOCVerifyRouter            Type = "OC_VERIFY_ROUTER"
	OpTypeOCQueryRouter             Type = "OC_QUERY_ROUTER"
)

//
// ===== 操作类型检索工具 =====
//

// allOpTypes 存储不同来源的操作类型列表，用于快速查找和验证。
//
//nolint:gochecknoglobals // 全局常量映射用于操作类型查找
var allOpTypes = map[Source][]Type{
	OpSourceDOIP: {
		OpTypeHello, OpTypeRetrieve, OpTypeCreate,
		OpTypeDelete, OpTypeUpdate, OpTypeSearch,
		OpTypeListOperations,
	},
	OpSourceIRP: {
		OpTypeOCReserved, OpTypeOCResolution, OpTypeOCGetSiteInfo,
		OpTypeOCCreateHandle, OpTypeOCDeleteHandle, OpTypeOCAddValue,
		OpTypeOCRemoveValue, OpTypeOCModifyValue, OpTypeOCListHandle,
		OpTypeOCListNA, OpTypeOCResolutionDOID, OpTypeOCCreateDOID,
		OpTypeOCDeleteDOID, OpTypeOCUpdateDOID, OpTypeOCBatchCreateDOID,
		OpTypeOCResolutionDOIDRecursive, OpTypeOCGetUsers, OpTypeOCGetRepos,
		OpTypeOCVerifyIRS, OpTypeOCResolveGRS, OpTypeOCCreateOrgGRS,
		OpTypeOCUpdateOrgGRS, OpTypeOCDeleteOrgGRS, OpTypeOCSyncOrgIRSParent,
		OpTypeOCUpdateOrgIRSParent, OpTypeOCDeleteOrgIRSParent,
		OpTypeOCChallengeResponse, OpTypeOCVerifyChallenge,
		OpTypeOCSessionSetup, OpTypeOCSessionTerminate,
		OpTypeOCSessionExchangeKey, OpTypeOCVerifyRouter, OpTypeOCQueryRouter,
	},
}

// GetOpTypesBySource 返回指定来源的可用操作类型列表。
func GetOpTypesBySource(source Source) []Type {
	return allOpTypes[source]
}

// IsValidOpType 判断指定操作类型在给定来源下是否合法。
func IsValidOpType(source Source, opType Type) bool {
	for _, t := range GetOpTypesBySource(source) {
		if t == opType {
			return true
		}
	}
	return false
}

//
// ===== 操作记录结构 =====
//

// Operation 表示一次完整的操作记录。
// 用于记录系统中的操作行为，包含操作元数据、数据标识、操作者信息以及请求/响应的哈希值。
type Operation struct {
	OpID             string    `json:"opId"             validate:"max=32"`
	Timestamp        time.Time `json:"timestamp"        validate:"required"`
	OpSource         Source    `json:"opSource"         validate:"required,oneof=IRP DOIP"`
	OpType           Type      `json:"opType"           validate:"required"`
	DoPrefix         string    `json:"doPrefix"         validate:"required,max=512"`
	DoRepository     string    `json:"doRepository"     validate:"required,max=512"`
	Doid             string    `json:"doid"             validate:"required,max=512"`
	ProducerID       string    `json:"producerId"       validate:"required,max=512"`
	OpActor          string    `json:"opActor"          validate:"max=64"`
	RequestBodyHash  *string   `json:"requestBodyHash"  validate:"omitempty,max=128"`
	ResponseBodyHash *string   `json:"responseBodyHash" validate:"omitempty,max=128"`
	// ClientIP 客户端IP地址，仅用于数据库持久化，不参与存证哈希计算
	ClientIP *string `json:"clientIp,omitempty"  validate:"omitempty,max=32"`
	// ServerIP 服务端IP地址，仅用于数据库持久化，不参与存证哈希计算
	ServerIP *string     `json:"serverIp,omitempty"  validate:"omitempty,max=32"`
	Ack      func() bool `json:"-"`
	Nack     func() bool `json:"-"`
	binary   []byte
}

//
// ===== 构造函数 =====
//

// NewFullOperation 创建包含所有字段的完整 Operation。
// 自动完成哈希计算和字段校验，确保创建的 Operation 是完整且有效的。
func NewFullOperation(
	opSource Source,
	opType Type,
	doPrefix, doRepository, doid string,
	producerID string,
	opActor string,
	requestBody, responseBody interface{},
	timestamp time.Time,
) (*Operation, error) {
	log := logger.GetGlobalLogger()
	log.Debug("Creating new full operation",
		"opSource", opSource,
		"opType", opType,
		"doPrefix", doPrefix,
		"doRepository", doRepository,
		"doid", doid,
		"producerID", producerID,
		"opActor", opActor,
	)
	op := &Operation{
		Timestamp:    timestamp,
		OpSource:     opSource,
		OpType:       opType,
		DoPrefix:     doPrefix,
		DoRepository: doRepository,
		Doid:         doid,
		ProducerID:   producerID,
		OpActor:      opActor,
	}

	log.Debug("Setting request body hash")
	if err := op.RequestBodyFlexible(requestBody); err != nil {
		log.Error("Failed to set request body hash",
			"error", err,
		)
		return nil, err
	}
	log.Debug("Setting response body hash")
	if err := op.ResponseBodyFlexible(responseBody); err != nil {
		log.Error("Failed to set response body hash",
			"error", err,
		)
		return nil, err
	}
	log.Debug("Checking and initializing operation")
	if err := op.CheckAndInit(); err != nil {
		log.Error("Failed to check and init operation",
			"error", err,
		)
		return nil, err
	}

	log.Debug("Full operation created successfully",
		"opID", op.OpID,
	)
	return op, nil
}

//
// ===== 接口实现 =====
//

func (o *Operation) Key() string {
	return o.OpID
}

// OperationHashData 实现 HashData 接口，用于存储 Operation 的哈希计算结果。
type OperationHashData struct {
	key  string
	hash string
}

func (o OperationHashData) Key() string {
	return o.key
}

func (o OperationHashData) Hash() string {
	return o.hash
}

func (o OperationHashData) Type() HashType {
	return Sha256Simd
}

// DoHash 计算 Operation 的整体哈希值，用于数据完整性验证。
// 哈希基于序列化后的二进制数据计算，确保操作记录的不可篡改性。
func (o *Operation) DoHash(_ context.Context) (HashData, error) {
	log := logger.GetGlobalLogger()
	log.Debug("Computing hash for operation",
		"opID", o.OpID,
	)
	hashTool := GetHashTool(Sha256Simd)
	binary, err := o.MarshalBinary()
	if err != nil {
		log.Error("Failed to marshal operation for hash",
			"error", err,
			"opID", o.OpID,
		)
		return nil, fmt.Errorf("failed to marshal operation: %w", err)
	}

	log.Debug("Computing hash bytes",
		"opID", o.OpID,
		"binaryLength", len(binary),
	)
	hash, err := hashTool.HashBytes(binary)
	if err != nil {
		log.Error("Failed to compute hash",
			"error", err,
			"opID", o.OpID,
		)
		return nil, fmt.Errorf("failed to compute hash: %w", err)
	}

	log.Debug("Hash computed successfully",
		"opID", o.OpID,
		"hash", hash,
	)
	return OperationHashData{
		key:  o.OpID,
		hash: hash,
	}, nil
}

//
// ===== CBOR 序列化相关 =====
//

// operationData 用于 CBOR 序列化/反序列化的中间结构。
// 排除函数字段和缓存字段，仅包含可序列化的数据字段。
type operationData struct {
	OpID             *string    `cbor:"opId"`
	Timestamp        *time.Time `cbor:"timestamp"`
	OpSource         *Source    `cbor:"opSource"`
	OpType           *Type      `cbor:"opType"`
	DoPrefix         *string    `cbor:"doPrefix"`
	DoRepository     *string    `cbor:"doRepository"`
	Doid             *string    `cbor:"doid"`
	ProducerID       *string    `cbor:"producerId"`
	OpActor          *string    `cbor:"opActor"`
	RequestBodyHash  *string    `cbor:"requestBodyHash"`
	ResponseBodyHash *string    `cbor:"responseBodyHash"`
}

// toOperationData 将 Operation 转换为 operationData，用于序列化。
func (o *Operation) toOperationData() *operationData {
	return &operationData{
		OpID:             &o.OpID,
		Timestamp:        &o.Timestamp,
		OpSource:         &o.OpSource,
		OpType:           &o.OpType,
		DoPrefix:         &o.DoPrefix,
		DoRepository:     &o.DoRepository,
		Doid:             &o.Doid,
		ProducerID:       &o.ProducerID,
		OpActor:          &o.OpActor,
		RequestBodyHash:  o.RequestBodyHash,
		ResponseBodyHash: o.ResponseBodyHash,
	}
}

// fromOperationData 从 operationData 填充 Operation，用于反序列化。
func (o *Operation) fromOperationData(opData *operationData) {
	if opData == nil {
		return
	}

	if opData.OpID != nil {
		o.OpID = *opData.OpID
	}
	if opData.Timestamp != nil {
		o.Timestamp = *opData.Timestamp
	}
	if opData.OpSource != nil {
		o.OpSource = *opData.OpSource
	}
	if opData.OpType != nil {
		o.OpType = *opData.OpType
	}
	if opData.DoPrefix != nil {
		o.DoPrefix = *opData.DoPrefix
	}
	if opData.DoRepository != nil {
		o.DoRepository = *opData.DoRepository
	}
	if opData.Doid != nil {
		o.Doid = *opData.Doid
	}
	if opData.ProducerID != nil {
		o.ProducerID = *opData.ProducerID
	}
	if opData.OpActor != nil {
		o.OpActor = *opData.OpActor
	}
	if opData.RequestBodyHash != nil {
		hash := *opData.RequestBodyHash
		o.RequestBodyHash = &hash
	}
	if opData.ResponseBodyHash != nil {
		hash := *opData.ResponseBodyHash
		o.ResponseBodyHash = &hash
	}
}

// MarshalBinary 将 Operation 序列化为 CBOR 格式的二进制数据。
// 实现 encoding.BinaryMarshaler 接口。
// 使用 Canonical CBOR 编码确保序列化结果的一致性，使用缓存机制避免重复序列化。
func (o *Operation) MarshalBinary() ([]byte, error) {
	log := logger.GetGlobalLogger()
	log.Debug("Marshaling operation to CBOR binary",
		"opID", o.OpID,
	)
	if o.binary != nil {
		log.Debug("Using cached binary data",
			"opID", o.OpID,
		)
		return o.binary, nil
	}

	opData := o.toOperationData()

	log.Debug("Marshaling operation data to canonical CBOR",
		"opID", o.OpID,
	)
	binary, err := helpers.MarshalCanonical(opData)
	if err != nil {
		log.Error("Failed to marshal operation to CBOR",
			"error", err,
			"opID", o.OpID,
		)
		return nil, fmt.Errorf("failed to marshal operation to CBOR: %w", err)
	}

	o.binary = binary

	log.Debug("Operation marshaled successfully",
		"opID", o.OpID,
		"binaryLength", len(binary),
	)
	return binary, nil
}

// GetProducerID 返回 ProducerID，实现 Trustlog 接口。
func (o *Operation) GetProducerID() string {
	return o.ProducerID
}

// UnmarshalBinary 从 CBOR 格式的二进制数据反序列化为 Operation。
// 实现 encoding.BinaryUnmarshaler 接口。
func (o *Operation) UnmarshalBinary(data []byte) error {
	log := logger.GetGlobalLogger()
	log.Debug("Unmarshaling operation from CBOR binary",
		"dataLength", len(data),
	)
	if len(data) == 0 {
		log.Error("Data is empty")
		return errors.New("data is empty")
	}

	opData := &operationData{}

	log.Debug("Unmarshaling operation data from CBOR")
	if err := helpers.Unmarshal(data, opData); err != nil {
		log.Error("Failed to unmarshal operation from CBOR",
			"error", err,
		)
		return fmt.Errorf("failed to unmarshal operation from CBOR: %w", err)
	}

	o.fromOperationData(opData)

	o.binary = data

	log.Debug("Operation unmarshaled successfully",
		"opID", o.OpID,
	)
	return nil
}

//
// ===== 哈希设置方法 =====
//

// setBodyHashFlexible 根据输入数据类型计算哈希，支持 string 和 []byte。
// 使用固定的 Sha256Simd 算法。
// 如果输入为 nil 或空，则目标指针设置为 nil，表示该字段未设置。
func (o *Operation) setBodyHashFlexible(data interface{}, target **string) error {
	log := logger.GetGlobalLogger()
	log.Debug("Setting body hash flexible",
		"opID", o.OpID,
		"dataType", fmt.Sprintf("%T", data),
	)
	if data == nil {
		log.Debug("Data is nil, setting target to nil")
		*target = nil
		return nil
	}

	hashTool := GetHashTool(Sha256Simd)
	var raw []byte

	switch v := data.(type) {
	case string:
		if v == "" {
			log.Debug("String data is empty, setting target to nil")
			*target = nil
			return nil
		}
		raw = []byte(v)
		log.Debug("Converting string to bytes",
			"stringLength", len(v),
		)
	case []byte:
		if len(v) == 0 {
			log.Debug("Byte data is empty, setting target to nil")
			*target = nil
			return nil
		}
		raw = v
		log.Debug("Using byte data directly",
			"byteLength", len(v),
		)
	default:
		log.Error("Unsupported data type",
			"dataType", fmt.Sprintf("%T", v),
		)
		return fmt.Errorf("unsupported data type %T", v)
	}

	log.Debug("Computing hash for body data",
		"dataLength", len(raw),
	)
	hash, err := hashTool.HashBytes(raw)
	if err != nil {
		log.Error("Failed to compute hash",
			"error", err,
		)
		return err
	}

	*target = &hash
	log.Debug("Body hash set successfully",
		"hash", hash,
	)
	return nil
}

// RequestBodyFlexible 设置请求体哈希值。
// 支持 string 和 []byte 类型，nil 或空值会将 RequestBodyHash 设置为 nil。
func (o *Operation) RequestBodyFlexible(data interface{}) error {
	return o.setBodyHashFlexible(data, &o.RequestBodyHash)
}

// ResponseBodyFlexible 设置响应体哈希值。
// 支持 string 和 []byte 类型，nil 或空值会将 ResponseBodyHash 设置为 nil。
func (o *Operation) ResponseBodyFlexible(data interface{}) error {
	return o.setBodyHashFlexible(data, &o.ResponseBodyHash)
}

//
// ===== 链式调用支持 =====
//

// WithRequestBody 设置请求体哈希并返回自身，支持链式调用。
func (o *Operation) WithRequestBody(data []byte) *Operation {
	_ = o.RequestBodyFlexible(data)
	return o
}

// WithResponseBody 设置响应体哈希并返回自身，支持链式调用。
func (o *Operation) WithResponseBody(data []byte) *Operation {
	_ = o.ResponseBodyFlexible(data)
	return o
}

//
// ===== 初始化与验证 =====
//

// CheckAndInit 校验并初始化 Operation。
// 自动填充缺失字段（OpID、OpActor），执行业务逻辑验证（doid 格式），
// 字段非空验证由 validate 标签处理。
func (o *Operation) CheckAndInit() error {
	log := logger.GetGlobalLogger()
	log.Debug("Checking and initializing operation",
		"opSource", o.OpSource,
		"opType", o.OpType,
		"doid", o.Doid,
	)
	if o.OpID == "" {
		o.OpID = helpers.NewUUIDv7()
		log.Debug("Generated new OpID",
			"opID", o.OpID,
		)
	}

	if o.OpActor == "" {
		o.OpActor = "SYSTEM"
		log.Debug("Set default OpActor to SYSTEM")
	}

	expectedPrefix := fmt.Sprintf("%s/%s", o.DoPrefix, o.DoRepository)
	if !strings.HasPrefix(o.Doid, expectedPrefix) {
		log.Error("Doid format validation failed",
			"doid", o.Doid,
			"expectedPrefix", expectedPrefix,
		)
		return fmt.Errorf("doid must start with '%s'", expectedPrefix)
	}

	log.Debug("Validating operation struct")
	if err := helpers.GetValidator().Struct(o); err != nil {
		log.Error("Operation validation failed",
			"error", err,
			"opID", o.OpID,
		)
		return err
	}

	log.Debug("Operation checked and initialized successfully",
		"opID", o.OpID,
	)
	return nil
}