rest/model.go

package rest

import (
	"context"
	"encoding/csv"
	"encoding/json"
	"fmt"
	"git.nobla.cn/golang/kos/util/arrays"
	"git.nobla.cn/golang/kos/util/pool"
	"git.nobla.cn/golang/rest/inflector"
	"git.nobla.cn/golang/rest/types"
	"gorm.io/gorm"
	"gorm.io/gorm/clause"
	"gorm.io/gorm/schema"
	"io"
	"mime/multipart"
	"net/http"
	"net/url"
	"os"
	"path"
	"reflect"
	"strconv"
	"strings"
	"time"
)

type Model struct {
	naming        types.Naming           //命名规则
	value         reflect.Value          //模块值
	db            *gorm.DB               //数据库
	primaryKey    string                 //主键
	urlPrefix     string                 //url前缀
	disableDomain bool                   //禁用域
	schemaLookup  types.SchemaLookupFunc //获取schema的函数
	valueLookup   types.ValueLookupFunc  //查看域
	statement     *gorm.Statement        //字段声明
	formatter     *Formatter             //格式化
	response      types.HttpWriter       //HTTP响应
	hookMgr       *hookManager           //钩子管理器
	dirname       string                 //存放文件目录
}

var (
	RuntimeScopeKey = &types.RuntimeScope{}
)

// getDB 获取数据库连接对象
func (m *Model) getDB() *gorm.DB {
	return m.db
}

// getFormatter 获取格式化组件
func (m *Model) getFormatter() *Formatter {
	if m.formatter != nil {
		return m.formatter
	}
	return DefaultFormatter
}

// getHook 获取钩子
func (m *Model) getHook() *hookManager {
	return m.hookMgr
}

// hasScenario 判断是否有该场景
func (m *Model) hasScenario(s string) bool {
	return true
}

// setValue 设置字段的值
func (m *Model) setValue(refValue reflect.Value, column string, value any) {
	SetFieldValue(m.statement, refValue, column, value)
}

func (m *Model) safeSetValue(refValue reflect.Value, column string, value any) {
	SafeSetFileValue(m.statement, refValue, column, value)
}

// getValue 获取字段的值
func (m *Model) getValue(refValue reflect.Value, column string) interface{} {
	return GetFieldValue(m.statement, refValue, column)
}

// hasColumn 判断指定的列是否存在
func (m *Model) hasColumn(column string) bool {
	for _, field := range m.statement.Schema.Fields {
		if field.DBName == column || field.Name == column {
			return true
		}
	}
	return false
}

// getFilename 获取文件存放目录
func (m *Model) getFilename(domain string, spec string, name string) string {
	if m.dirname == "" {
		m.dirname = os.TempDir()
	}
	filename := path.Join(m.dirname, domain, spec, time.Now().Format("20060102"), name)
	if _, err := os.Stat(path.Dir(filename)); err != nil {
		_ = os.MkdirAll(path.Dir(filename), 0755)
	}
	return filename
}

// findPrimaryKey 查找主键的值
func (m *Model) findPrimaryKey(uri string, r *http.Request) string {
	var (
		pos int
	)
	urlPath := r.URL.Path
	pos = strings.IndexByte(uri, ':')
	if pos > 0 {
		return urlPath[pos:]
	}
	return ""
}

// parseReportColumn 解析报表的列
func (m *Model) parseReportColumn(name, props string) *types.SelectColumn {
	var (
		key   string
		value string
	)
	column := &types.SelectColumn{
		Name:   inflector.Camel2id(name),
		Native: false,
	}
	tokens := strings.Split(props, ";")
	for _, token := range tokens {
		pair := strings.SplitN(token, ":", 2)
		if len(pair) == 0 {
			continue
		}
		if len(pair) == 1 {
			key = strings.TrimSpace(pair[0])
			value = ""
		} else {
			key = strings.TrimSpace(pair[0])
			value = strings.TrimSpace(pair[1])
		}
		switch key {
		case "native":
			column.Native = true
		case "name":
			column.Name = value
		case "expr":
			column.Expr = value
		}
	}
	return column
}

func (m *Model) buildReporterCountColumns(ctx context.Context, dest types.Reporter, query *Query) {
	modelType := reflect.ValueOf(dest).Type()
	if modelType.Kind() == reflect.Slice || modelType.Kind() == reflect.Array || modelType.Kind() == reflect.Ptr {
		modelType = modelType.Elem()
	}
	columns := make([]string, 0)
	for i := 0; i < modelType.NumField(); i++ {
		field := modelType.Field(i)
		scenarios := field.Tag.Get("scenarios")
		if !hasToken(types.ScenarioList, scenarios) {
			continue
		}
		isPrimary := field.Tag.Get("is_primary")
		if isPrimary != "true" {
			continue
		}
		column := m.parseReportColumn(field.Name, field.Tag.Get("report"))
		if !column.Native {
			continue
		}
		if column.Expr == "" {
			columns = append(columns, dest.QuoteColumn(ctx, column.Name))
		} else {
			columns = append(columns, fmt.Sprintf("%s AS %s", column.Expr, dest.QuoteColumn(ctx, column.Name)))
		}
	}
	columns = append(columns, "COUNT(*) AS count")
	query.Select(columns...)
}

func (m *Model) buildReporterQueryColumns(ctx context.Context, dest types.Reporter, query *Query) {
	modelType := reflect.ValueOf(dest).Type()
	if modelType.Kind() == reflect.Slice || modelType.Kind() == reflect.Array || modelType.Kind() == reflect.Ptr {
		modelType = modelType.Elem()
	}
	columns := make([]string, 0)
	for i := 0; i < modelType.NumField(); i++ {
		field := modelType.Field(i)
		scenarios := field.Tag.Get("scenarios")
		if !hasToken(types.ScenarioList, scenarios) {
			continue
		}
		column := m.parseReportColumn(field.Name, field.Tag.Get("report"))
		if !column.Native {
			continue
		}
		if column.Expr == "" {
			columns = append(columns, dest.QuoteColumn(ctx, column.Name))
		} else {
			columns = append(columns, fmt.Sprintf("%s AS %s", column.Expr, dest.QuoteColumn(ctx, column.Name)))
		}
	}
	query.Select(columns...)
}

// buildCondition 构建sql条件
func (m *Model) buildCondition(ctx context.Context, r *http.Request, query *Query, schemas []*types.Schema) (err error) {
	return BuildConditions(ctx, r, query, schemas)
}

// ModuleName 模块名称
func (m *Model) ModuleName() string {
	return m.naming.ModuleName
}

// TableName 表的名称
func (m *Model) TableName() string {
	return m.naming.ModuleName
}

// Fields 返回搜索的模型的字段
func (m *Model) Fields() []*schema.Field {
	return m.statement.Schema.Fields
}

// Uri 获取请求的uri
func (m *Model) Uri(scenario string) string {
	ss := make([]string, 4)
	if m.urlPrefix != "" {
		ss = append(ss, m.urlPrefix)
	}
	switch scenario {
	case types.ScenarioList:
		ss = append(ss, m.naming.ModuleName, m.naming.Pluralize)
	case types.ScenarioView:
		ss = append(ss, m.naming.ModuleName, m.naming.Singular, ":id")
	case types.ScenarioCreate:
		ss = append(ss, m.naming.ModuleName, m.naming.Singular)
	case types.ScenarioUpdate:
		ss = append(ss, m.naming.ModuleName, m.naming.Singular, ":id")
	case types.ScenarioDelete:
		ss = append(ss, m.naming.ModuleName, m.naming.Singular, ":id")
	case types.ScenarioExport:
		ss = append(ss, m.naming.ModuleName, m.naming.Singular+"-export")
	case types.ScenarioImport:
		ss = append(ss, m.naming.ModuleName, m.naming.Singular+"-import")
	}
	uri := path.Join(ss...)
	if !strings.HasPrefix(uri, "/") {
		uri = "/" + uri
	}
	return uri
}

// Method 获取HTTP请求的方法
func (m *Model) Method(scenario string) string {
	var (
		method = http.MethodGet
	)
	switch scenario {
	case types.ScenarioCreate:
		method = http.MethodPost
	case types.ScenarioUpdate:
		method = http.MethodPut
	case types.ScenarioDelete:
		method = http.MethodDelete
	}
	return method
}

// Search 实现通过HTTP方法查找数据
func (m *Model) Search(w http.ResponseWriter, r *http.Request) {
	var (
		ok            bool
		err           error
		qs            url.Values
		page          int
		pageSize      int
		pageIndex     int
		query         *Query
		domainName    string
		modelSlices   reflect.Value
		modelValues   reflect.Value
		searchSchemas []*types.Schema
		listSchemas   []*types.Schema
		modelValue    reflect.Value
		scenario      string
		reporter      types.Reporter
		namerTable    tableNamer
	)
	qs = r.URL.Query()
	page, _ = strconv.Atoi(qs.Get("page"))
	pageSize, _ = strconv.Atoi(qs.Get("pagesize"))
	if pageSize <= 0 {
		pageSize = defaultPageSize
	}
	pageIndex = page
	if pageIndex > 0 {
		pageIndex--
	}
	modelValue = reflect.New(m.value.Type())
	//这里创建指针类型，这样的话就能在format里面调用函数
	if m.value.Kind() != reflect.Ptr {
		modelSlices = reflect.MakeSlice(reflect.SliceOf(modelValue.Type()), 0, 0)
	} else {
		modelSlices = reflect.MakeSlice(reflect.SliceOf(m.value.Type()), 0, 0)
	}
	modelValues = reflect.New(modelSlices.Type())
	modelValues.Elem().Set(modelSlices)
	query = NewQuery(m.getDB(), reflect.New(m.value.Type()).Interface())
	domainName = m.valueLookup(types.FieldDomain, w, r)
	childCtx := context.WithValue(r.Context(), RuntimeScopeKey, &types.RuntimeScope{
		Domain:     domainName,
		Request:    r,
		User:       m.valueLookup("user", w, r),
		ModuleName: m.naming.ModuleName,
		TableName:  m.naming.TableName,
		Scenario:   types.ScenarioList,
	})
	if searchSchemas, err = m.schemaLookup(childCtx, m.getDB(), domainName, m.naming.ModuleName, m.naming.TableName, types.ScenarioSearch); err != nil {
		m.response.Failure(w, types.RequestRecordNotFound, "record not found", nil)
		return
	}
	scenario = types.ScenarioList
	if arrays.Exists(r.FormValue("scenario"), allowScenario) {
		scenario = r.FormValue("scenario")
	}
	if listSchemas, err = m.schemaLookup(childCtx, m.getDB(), domainName, m.naming.ModuleName, m.naming.TableName, scenario); err != nil {
		m.response.Failure(w, types.RequestRecordNotFound, "record not found", nil)
		return
	}
	if !m.disableDomain {
		if m.hasColumn(types.FieldDomain) {
			query.AndWhere(newCondition(types.FieldDomain, domainName))
		}
	}
	if err = m.buildCondition(childCtx, r, query, searchSchemas); err != nil {
		m.response.Failure(w, types.RequestPayloadInvalid, "payload invalid", nil)
		return
	}
	// 处理表名逻辑
	if namerTable, ok = query.Model().(tableNamer); ok {
		query.From(namerTable.HttpTableName(r))
	}
	//处理报表逻辑
	if reporter, ok = modelValue.Interface().(types.Reporter); ok {
		query.From(reporter.RealTable())
	}
	res := &types.ListResponse{
		Page:     page,
		PageSize: pageSize,
	}
	if reporter == nil {
		res.TotalCount = query.Limit(0).Offset(0).Count(query.Model())
	} else {
		//如果是报表的情况，需要手动指定COUNT的雨具逻辑才能生效
		m.buildReporterCountColumns(childCtx, reporter, query)
		res.TotalCount = query.Limit(0).Offset(0).Count(query.Model())

		//这里需要重置一下选项，不然会出问题
		query.ResetSelect()
		query.GroupBy(reporter.GroupBy(childCtx)...)
	}
	query.Offset(pageIndex * pageSize).Limit(pageSize)
	if res.TotalCount > 0 {
		if reporter != nil {
			m.buildReporterQueryColumns(childCtx, reporter, query)
		}
		if err = query.All(modelValues.Interface()); err != nil {
			m.response.Failure(w, types.RequestRecordNotFound, "record not found", nil)
			return
		}
		// 不进行格式化输出
		res.Data = m.getFormatter().formatModels(childCtx, modelValues.Interface(), listSchemas, m.statement, qs.Get("__format"))
	} else {
		res.Data = make([]string, 0)
	}
	m.response.Success(w, res)
}

// Create 实现通过HTTP方法创建模型
func (m *Model) Create(w http.ResponseWriter, r *http.Request) {
	var (
		err        error
		model      any
		schemas    []*types.Schema
		diffAttrs  []*types.DiffAttr
		domainName string
		modelValue reflect.Value
	)
	modelValue = reflect.New(m.value.Type())
	model = modelValue.Interface()
	if err = json.NewDecoder(r.Body).Decode(modelValue.Interface()); err != nil {
		m.response.Failure(w, types.RequestPayloadInvalid, err.Error(), nil)
		return
	}
	domainName = m.valueLookup(types.FieldDomain, w, r)
	if schemas, err = m.schemaLookup(r.Context(), m.getDB(), domainName, m.naming.ModuleName, m.naming.TableName, types.ScenarioCreate); err != nil {
		m.response.Failure(w, types.RequestRecordNotFound, "record not found", nil)
		return
	}
	if !m.disableDomain {
		if m.hasColumn(types.FieldDomain) {
			m.setValue(modelValue, types.FieldDomain, domainName)
		}
	}
	diffAttrs = make([]*types.DiffAttr, 0, 10)
	childCtx := context.WithValue(r.Context(), RuntimeScopeKey, &types.RuntimeScope{
		Domain:     domainName,
		User:       m.valueLookup("user", w, r),
		Request:    r,
		ModuleName: m.naming.ModuleName,
		TableName:  m.naming.TableName,
		Scenario:   types.ScenarioCreate,
		Schemas:    schemas,
	})
	dbSess := m.getDB().WithContext(childCtx)
	if err = dbSess.Transaction(func(tx *gorm.DB) (errTx error) {
		if errTx = m.getHook().beforeCreate(childCtx, tx, model); errTx != nil {
			return
		}
		if errTx = m.getHook().beforeSave(childCtx, tx, model); errTx != nil {
			return
		}
		if tabler, ok := model.(types.Tabler); ok {
			errTx = tx.Table(tabler.TableName()).Save(model).Error
		} else {
			errTx = tx.Save(model).Error
		}
		if errTx != nil {
			return
		}
		for _, row := range schemas {
			diffAttrs = append(diffAttrs, &types.DiffAttr{
				Column:   row.Column,
				Label:    row.Label,
				OldValue: nil,
				NewValue: m.getValue(modelValue, row.Column),
			})
		}
		return
	}); err == nil {
		res := &types.CreateResponse{
			ID:     m.getValue(modelValue, m.primaryKey),
			Status: "created",
		}
		if creator, ok := model.(afterCreated); ok {
			creator.AfterCreated(childCtx, dbSess)
		}
		if preserver, ok := model.(afterSaved); ok {
			preserver.AfterSaved(childCtx, dbSess)
		}
		m.getHook().afterCreate(childCtx, dbSess, model, diffAttrs)
		m.getHook().afterSave(childCtx, dbSess, model, diffAttrs)
		m.response.Success(w, res)
	} else {
		m.response.Failure(w, types.RequestCreateFailure, err.Error(), err)
	}
}

// Update 实现通过HTTP方法更新模型
func (m *Model) Update(w http.ResponseWriter, r *http.Request) {
	var (
		err        error
		model      any
		schemas    []*types.Schema
		diffAttrs  []*types.DiffAttr
		domainName string
		modelValue reflect.Value
		oldValues  map[string]any
	)
	idStr := m.findPrimaryKey(m.Uri(types.ScenarioUpdate), r)
	modelValue = reflect.New(m.value.Type())
	model = modelValue.Interface()
	domainName = m.valueLookup(types.FieldDomain, w, r)
	if schemas, err = m.schemaLookup(r.Context(), m.getDB(), domainName, m.naming.ModuleName, m.naming.TableName, types.ScenarioUpdate); err != nil {
		m.response.Failure(w, types.RequestRecordNotFound, "record not found", nil)
		return
	}
	conditions := map[string]any{
		m.primaryKey: idStr,
	}
	if err = m.getDB().Where(conditions).First(model).Error; err != nil {
		m.response.Failure(w, types.RequestRecordNotFound, "record not found", nil)
		return
	}
	oldValues = make(map[string]any)
	for _, row := range schemas {
		oldValues[row.Column] = m.getValue(modelValue, row.Column)
	}
	if err = json.NewDecoder(r.Body).Decode(model); err != nil {
		m.response.Failure(w, types.RequestPayloadInvalid, "payload invalid", nil)
		return
	}
	diffAttrs = make([]*types.DiffAttr, 0, 10)
	updates := make(map[string]any)
	childCtx := context.WithValue(r.Context(), RuntimeScopeKey, &types.RuntimeScope{
		Domain:          domainName,
		Request:         r,
		User:            m.valueLookup("user", w, r),
		ModuleName:      m.naming.ModuleName,
		TableName:       m.naming.TableName,
		Scenario:        types.ScenarioUpdate,
		Schemas:         schemas,
		PrimaryKeyValue: idStr,
	})
	dbSess := m.getDB().WithContext(childCtx)
	if err = dbSess.Transaction(func(tx *gorm.DB) (errTx error) {
		if errTx = m.getHook().beforeUpdate(childCtx, tx, model); errTx != nil {
			return
		}
		if errTx = m.getHook().beforeSave(childCtx, tx, model); errTx != nil {
			return
		}
		for _, row := range schemas {
			v := m.getValue(modelValue, row.Column)
			if oldValues[row.Column] != v {
				updates[row.Column] = v
				diffAttrs = append(diffAttrs, &types.DiffAttr{
					Column:   row.Column,
					Label:    row.Label,
					OldValue: oldValues[row.Column],
					NewValue: v,
				})
			}
		}
		if len(updates) > 0 {
			if tabler, ok := model.(types.Tabler); ok {
				errTx = tx.Model(model).Table(tabler.TableName()).Updates(updates).Error
			} else {
				errTx = tx.Model(model).Updates(updates).Error
			}
			if errTx != nil {
				return
			}
		}
		return
	}); err == nil {
		if updater, ok := model.(afterUpdated); ok {
			updater.AfterUpdated(childCtx, dbSess)
		}
		if preserver, ok := model.(afterSaved); ok {
			preserver.AfterSaved(childCtx, dbSess)
		}
		m.getHook().afterUpdate(childCtx, dbSess, model, diffAttrs)
		m.getHook().afterSave(childCtx, dbSess, model, diffAttrs)
		m.response.Success(w, types.UpdateResponse{
			ID:     idStr,
			Status: "updated",
		})
	} else {
		m.response.Failure(w, types.RequestUpdateFailure, err.Error(), nil)
	}
}

// Delete 实现通过HTTP方法删除模型
func (m *Model) Delete(w http.ResponseWriter, r *http.Request) {
	var (
		err        error
		model      any
		modelValue reflect.Value
	)
	idStr := m.findPrimaryKey(m.Uri(types.ScenarioDelete), r)
	modelValue = reflect.New(m.value.Type())
	model = modelValue.Interface()
	conditions := map[string]any{
		m.primaryKey: idStr,
	}
	if err = m.getDB().Where(conditions).First(model).Error; err != nil {
		m.response.Failure(w, types.RequestRecordNotFound, "record not found", nil)
		return
	}
	childCtx := context.WithValue(r.Context(), RuntimeScopeKey, &types.RuntimeScope{
		Domain:          m.valueLookup(types.FieldDomain, w, r),
		User:            m.valueLookup("user", w, r),
		Request:         r,
		ModuleName:      m.naming.ModuleName,
		TableName:       m.naming.TableName,
		Scenario:        types.ScenarioDelete,
		PrimaryKeyValue: idStr,
	})
	dbSess := m.getDB().WithContext(childCtx)
	if err = dbSess.Transaction(func(tx *gorm.DB) (errTx error) {
		if errTx = m.getHook().beforeDelete(childCtx, tx, model); errTx != nil {
			return
		}
		if tabler, ok := model.(types.Tabler); ok {
			errTx = tx.Table(tabler.TableName()).Delete(model).Error
		} else {
			errTx = tx.Delete(model).Error
		}
		if errTx != nil {
			return
		}
		m.getHook().afterDelete(childCtx, tx, model)
		return
	}); err == nil {
		m.response.Success(w, types.DeleteResponse{
			ID:     idStr,
			Status: "deleted",
		})
	} else {
		m.response.Failure(w, types.RequestDeleteFailure, err.Error(), nil)
	}
}

// View 查看数据详情
func (m *Model) View(w http.ResponseWriter, r *http.Request) {
	var (
		err        error
		model      any
		modelValue reflect.Value
		qs         url.Values
		schemas    []*types.Schema
		scenario   string
		domainName string
	)
	qs = r.URL.Query()
	idStr := m.findPrimaryKey(m.Uri(types.ScenarioUpdate), r)
	modelValue = reflect.New(m.value.Type())
	model = modelValue.Interface()
	conditions := map[string]any{
		m.primaryKey: idStr,
	}
	domainName = m.valueLookup(types.FieldDomain, w, r)
	if err = m.getDB().Where(conditions).First(model).Error; err != nil {
		m.response.Failure(w, types.RequestRecordNotFound, "record not found", nil)
		return
	}
	scenario = qs.Get("scenario")
	if scenario == "" {
		schemas, err = m.schemaLookup(r.Context(), m.getDB(), domainName, m.naming.ModuleName, m.naming.TableName, types.ScenarioView)
	} else {
		schemas, err = m.schemaLookup(r.Context(), m.getDB(), domainName, m.naming.ModuleName, m.naming.TableName, scenario)
	}
	if err == nil {
		m.response.Success(w, m.getFormatter().formatModel(r.Context(), modelValue, schemas, m.statement, qs.Get("__format")))
	} else {
		m.response.Failure(w, types.RequestRecordNotFound, err.Error(), nil)
	}
}

// Export 实现通过HTTP方法导出模型
func (m *Model) Export(w http.ResponseWriter, r *http.Request) {
	var (
		err           error
		query         *Query
		modelSlices   reflect.Value
		modelValues   reflect.Value
		searchSchemas []*types.Schema
		exportSchemas []*types.Schema
		domainName    string
		fp            *os.File
		modelValue    reflect.Value
	)
	if !m.hasScenario(types.ScenarioList) {
		m.response.Failure(w, types.RequestDenied, "request denied", nil)
		return
	}
	domainName = m.valueLookup(types.FieldDomain, w, r)
	filename := m.getFilename(domainName, "export", fmt.Sprintf("%s-%d.csv", m.naming.Singular, time.Now().Unix()))
	if fp, err = os.OpenFile(filename, os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0644); err != nil {
		m.response.Failure(w, types.RequestPayloadInvalid, "directory does not have permission", nil)
		return
	}
	defer func() {
		_ = fp.Close()
	}()
	modelValue = reflect.New(m.value.Type())
	//这里创建指针类型，这样的话就能在format里面调用函数
	if m.value.Kind() != reflect.Ptr {
		modelSlices = reflect.MakeSlice(reflect.SliceOf(modelValue.Type()), 0, 0)
	} else {
		modelSlices = reflect.MakeSlice(reflect.SliceOf(m.value.Type()), 0, 0)
	}
	modelValues = reflect.New(modelSlices.Type())
	modelValues.Elem().Set(modelSlices)
	query = NewQuery(m.getDB(), modelValue.Interface())
	childCtx := context.WithValue(r.Context(), RuntimeScopeKey, &types.RuntimeScope{
		Domain:     domainName,
		Request:    r,
		User:       m.valueLookup("user", w, r),
		ModuleName: m.naming.ModuleName,
		TableName:  m.naming.TableName,
		Scenario:   types.ScenarioExport,
	})
	if searchSchemas, err = m.schemaLookup(childCtx, m.getDB(), domainName, m.naming.ModuleName, m.naming.TableName, types.ScenarioSearch); err != nil {
		m.response.Failure(w, types.RequestRecordNotFound, "record not found", nil)
		return
	}
	if exportSchemas, err = m.schemaLookup(childCtx, m.getDB(), domainName, m.naming.ModuleName, m.naming.TableName, types.ScenarioExport); err != nil {
		m.response.Failure(w, types.RequestRecordNotFound, "record not found", nil)
		return
	}
	if err = m.buildCondition(childCtx, r, query, searchSchemas); err != nil {
		m.response.Failure(w, types.RequestPayloadInvalid, "payload invalid", nil)
		return
	}
	if !m.disableDomain {
		if m.hasColumn(types.FieldDomain) {
			query.AndWhere(newCondition(types.FieldDomain, domainName))
		}
	}
	// 处理表名逻辑
	if namerTable, ok := query.Model().(tableNamer); ok {
		query.From(namerTable.HttpTableName(r))
	}
	//处理报表逻辑
	if reporter, ok := modelValue.Interface().(types.Reporter); ok {
		query.From(reporter.RealTable())
		query.GroupBy(reporter.GroupBy(childCtx)...)
		m.buildReporterQueryColumns(childCtx, reporter, query)
	}
	if err = query.All(modelValues.Interface()); err != nil {
		m.response.Failure(w, types.RequestRecordNotFound, "record not found", nil)
		return
	}
	w.Header().Set("Content-Type", "text/csv")
	w.Header().Set("Access-Control-Expose-Headers", "Content-Disposition")
	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment;filename=%s.csv", m.naming.Singular))
	value := m.getFormatter().formatModels(childCtx, modelValues.Interface(), exportSchemas, m.statement, "")
	writer := csv.NewWriter(fp)
	rows := make([]string, len(exportSchemas))
	for i, field := range exportSchemas {
		rows[i] = field.Label
	}
	_ = writer.Write(rows)
	if values, ok := value.([]any); ok {
		for _, val := range values {
			row, ok2 := val.(map[string]any)
			if !ok2 {
				continue
			}
			for i, field := range exportSchemas {
				if v, ok := row[field.Column]; ok {
					rows[i] = fmt.Sprint(v)
				} else {
					rows[i] = ""
				}
			}
			_ = writer.Write(rows)
		}
	}
	writer.Flush()
	m.getHook().afterExport(childCtx, filename)
	http.ServeContent(w, r, path.Base(filename), time.Now(), fp)
}

// findSchema 查找指定的schema
func (m *Model) findSchema(label string, schemas []*types.Schema) *types.Schema {
	for _, row := range schemas {
		if row.Label == label {
			return row
		}
	}
	return nil
}

// importInternal 文件上传方法
func (m *Model) importInternal(ctx context.Context, domainName string, schemas []*types.Schema, filename string, fast bool, extraFields map[string]string) {
	var (
		err         error
		rows        []string
		fp          *os.File
		tm          time.Time
		fields      []string
		sess        *gorm.DB
		csvReader   *csv.Reader
		csvWriter   *csv.Writer
		modelValue  reflect.Value
		modelEntity any
		diffAttrs   []*types.DiffAttr
		result      *types.ImportResult
		failureFp   *os.File
		failureFile string
	)
	tm = time.Now()
	result = &types.ImportResult{}
	if fp, err = os.Open(filename); err != nil {
		result.Code = types.ErrImportFileNotExists
		goto __end
	}
	defer func() {
		_ = fp.Close()
	}()
	csvReader = csv.NewReader(fp)
	if rows, err = csvReader.Read(); err != nil {
		result.Code = types.ErrImportFileUnavailable
		goto __end
	}
	fields = make([]string, 0, len(rows))
	for _, s := range rows {
		v := m.findSchema(s, schemas)
		if v == nil {
			result.Code = types.ErrImportColumnNotMatch
			goto __end
		}
		fields = append(fields, v.Column)
	}
	sess = m.getDB().WithContext(ctx)
	//失败文件指针
	failureFile = m.getFilename(domainName, "import", fmt.Sprintf("%s-%d-fail.csv", m.naming.Singular, time.Now().Unix()))
	if failureFp, err = os.OpenFile(failureFile, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644); err != nil {
		return
	}
	defer func() {
		_ = failureFp.Close()
	}()
	csvWriter = csv.NewWriter(failureFp)
	rows = append(rows, "Error")
	_ = csvWriter.Write(rows)
	diffAttrs = make([]*types.DiffAttr, len(schemas))
	for {
		if rows, err = csvReader.Read(); err != nil {
			break
		}
		result.TotalCount++
		if len(rows) != len(fields) {
			continue
		}
		modelValue = reflect.New(m.value.Type())
		for idx, field := range fields {
			m.safeSetValue(modelValue, field, rows[idx])
		}
		if len(extraFields) > 0 {
			for k, v := range extraFields {
				m.safeSetValue(modelValue, k, v)
			}
		}
		modelEntity = modelValue.Interface()
		//写入数据
		if fast {
			//如果是快速模式，直接存储数据
			if err = sess.Save(modelEntity).Error; err == nil {
				result.SuccessCount++
			} else {
				rows = append(rows, err.Error())
				_ = csvWriter.Write(rows)
			}
		} else {
			if err = sess.Transaction(func(tx *gorm.DB) (errTx error) {
				if errTx = m.getHook().beforeCreate(ctx, tx, modelEntity); errTx != nil {
					return
				}
				if errTx = m.getHook().beforeSave(ctx, tx, modelEntity); errTx != nil {
					return
				}
				if tabler, ok := modelEntity.(types.Tabler); ok {
					errTx = tx.Table(tabler.TableName()).Save(modelEntity).Error
				} else {
					errTx = tx.Save(modelEntity).Error
				}
				if errTx != nil {
					return
				}
				for idx, row := range schemas {
					diffAttrs[idx] = &types.DiffAttr{
						Column:   row.Column,
						Label:    row.Label,
						NewValue: m.getValue(modelValue, row.Column),
					}
				}
				m.getHook().afterCreate(ctx, tx, modelEntity, diffAttrs)
				m.getHook().afterSave(ctx, tx, modelEntity, diffAttrs)
				return
			}); err == nil {
				result.SuccessCount++
			} else {
				rows = append(rows, err.Error())
				_ = csvWriter.Write(rows)
			}
		}
	}
	csvWriter.Flush()
__end:
	result.UploadFile = filename
	if result.TotalCount > result.SuccessCount {
		result.FailureFile = failureFile
	}
	result.Duration = time.Now().Sub(tm)
	m.getHook().afterImport(ctx, result)
}

// Import 实现通过HTTP方法导入
func (m *Model) Import(w http.ResponseWriter, r *http.Request) {
	var (
		err         error
		fast        bool
		schemas     []*types.Schema
		rows        []string
		domainName  string
		dst         *os.File
		fp          multipart.File
		csvWriter   *csv.Writer
		qs          url.Values
		extraFields map[string]string
	)
	domainName = m.valueLookup(types.FieldDomain, w, r)
	if schemas, err = m.schemaLookup(r.Context(), m.getDB(), domainName, m.naming.ModuleName, m.naming.TableName, types.ScenarioCreate); err != nil {
		m.response.Failure(w, types.RequestRecordNotFound, "record not found", nil)
		return
	}
	//这里用background的context
	childCtx := context.WithValue(context.Background(), RuntimeScopeKey, &types.RuntimeScope{
		Domain:     domainName,
		User:       m.valueLookup("user", w, r),
		ModuleName: m.naming.ModuleName,
		TableName:  m.naming.TableName,
		Scenario:   types.ScenarioImport,
		Schemas:    schemas,
	})
	if r.Method == http.MethodGet {
		//下载导入模板
		csvWriter = csv.NewWriter(w)
		rows = make([]string, 0, len(schemas))
		for _, row := range schemas {
			//主键不需要导入
			if row.IsPrimaryKey == 1 {
				continue
			}
			rows = append(rows, row.Label)
		}
		w.Header().Set("Content-Type", "text/csv")
		w.Header().Set("Access-Control-Expose-Headers", "Content-Disposition")
		w.Header().Set("Content-Disposition", fmt.Sprintf("attachment;filename=%s.csv", m.naming.Singular))
		err = csvWriter.Write(rows)
		csvWriter.Flush()
		return
	}
	filename := m.getFilename(domainName, "import", fmt.Sprintf("%s-%d.csv", m.naming.Singular, time.Now().Unix()))
	if fp, _, err = r.FormFile("file"); err != nil {
		m.response.Failure(w, types.RequestPayloadInvalid, "upload file not exists", nil)
		return
	}
	defer func() {
		_ = fp.Close()
	}()
	if dst, err = os.OpenFile(filename, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644); err == nil {
		buf := pool.GetBytes(32 * 1024)
		_, err = io.CopyBuffer(dst, fp, buf)
		pool.PutBytes(buf)
		_ = dst.Close()
	} else {
		m.response.Failure(w, types.RequestPayloadInvalid, "move upload file failed", nil)
		return
	}
	qs = r.URL.Query()
	if qs != nil {
		extraFields = make(map[string]string)
		for k, _ := range qs {
			if strings.HasPrefix(k, "_attr_") {
				extraFields[strings.TrimPrefix(k, "_attr_")] = qs.Get(k)
			}
		}
	}
	fast, _ = strconv.ParseBool(qs.Get("__fast"))
	go m.importInternal(childCtx, domainName, schemas, filename, fast, extraFields)
	m.response.Success(w, types.ImportResponse{
		UID:    m.valueLookup("user", w, r),
		Status: "committed",
	})
}

// newModel 创建一个模型
func newModel(v any, db *gorm.DB, naming types.Naming) *Model {
	model := &Model{
		db:          db,
		naming:      naming,
		response:    &httpWriter{},
		value:       reflect.Indirect(reflect.ValueOf(v)),
		valueLookup: defaultValueLookup,
	}
	model.statement = &gorm.Statement{
		DB:       model.getDB(),
		ConnPool: model.getDB().ConnPool,
		Clauses:  map[string]clause.Clause{},
	}
	if err := model.statement.Parse(v); err == nil {
		if model.statement.Schema.PrimaryFieldDBNames != nil && len(model.statement.Schema.PrimaryFieldDBNames) > 0 {
			model.primaryKey = model.statement.Schema.PrimaryFieldDBNames[0]
		}
	}
	return model
}