package base

import (
	"database/sql"
	"fmt"
	"log"
	"reflect"
	"sync"
	"unicode"

	"github.com/samber/do/v2"
	"github.com/samber/lo"

	"git.fsdpf.net/go/condition"
	"git.fsdpf.net/go/contracts"
	"git.fsdpf.net/go/db"
	"git.fsdpf.net/go/db/engine"
	"git.fsdpf.net/go/db/exec"
	"git.fsdpf.net/go/db/exp"
	"git.fsdpf.net/go/db/schema"
	"git.fsdpf.net/go/req"
)

// ResChangeEventTopic 资源变更事件
const ResChangeEventTopic = "res-change-event-topic"

// ResChangeRecordTopic 资源变更数据
const ResChangeRecordTopic = "res-change-record-topic"

type ResChangeEventTopicPayload struct {
	Type   string     // insert | delete | update
	Res    Resource   // 变更资源
	Result sql.Result // 执行结果
}

type ResChangeRecordTopicPayload struct {
	Type   string           // insert | delete | update
	User   req.User         // 操作用户
	Res    Resource         // 变更资源
	Result sql.Result       // 执行结果
	Old    []map[string]any // 旧数据
	New    []map[string]any // 新数据
}

// ResVirtualTableSetup 由 framework-v2 在 sqlite_vtable build tag 下注册到容器。
// resource.DB() 通过 do.Invoke 取出后调用，完成 vtab 模块注册和 CREATE VIRTUAL TABLE。
// res 提供 Code / Table / Fields 信息，vt 是 ResVirtualTable 的具体实现。
type ResVirtualTableSetup func(res Resource) error

// Resource 资源
type Resource struct {
	container do.Injector
	initOnce  *sync.Once

	Uuid         string         `db:"uuid"`
	PUuid        string         `db:"pUuid"`
	Code         string         `db:"code"`
	Name         string         `db:"name"`
	Conn         string         `db:"conn"`
	IsResVirtual bool           `db:"isVirtual"`
	Table        string         `db:"table"`
	Primarykey   string         `db:"primaryKey"`
	HistoryRoles []string       `db:"historyRoles"`
	Fields       []ResField     `db:"fields"`
	Roles        map[string]any `db:"roles"`
	UpdatedAt    string         `db:"updated_at"`
	CreatedAt    string         `db:"created_at"`
}

func (this *Resource) InitContainer(container do.Injector) {
	this.container = container
	this.initOnce = &sync.Once{}
}

// GetUuid 资源UUID
func (this Resource) GetUuid() string {
	return this.Uuid
}

// GetCode 资源CODE
func (this Resource) GetCode() string {
	return this.Code
}

// GetName 资源名
func (this Resource) GetName() string {
	return this.Name
}

// GetConn 数据库连接
func (this Resource) GetConn() string {
	return this.Conn
}

// GetPrimarykey 主键
func (this Resource) GetPrimarykey() string {
	return this.Primarykey
}

// IsVirtual 是否虚拟资源
func (this Resource) IsVirtual() bool {
	return this.IsResVirtual
}

// IsSystem 是否系统资源
func (this Resource) IsSystem() bool {
	return this.Conn == "service-support"
}

// GetFields 资源字段
func (this Resource) GetFields() (result []req.ResField) {
	for _, item := range this.Fields {
		result = append(result, item)
	}
	return result
}

// GetField 资源字段
func (this Resource) GetField(code string) (req.ResField, bool) {
	return lo.Find(this.GetFields(), func(v req.ResField) bool {
		return v.GetCode() == code
	})
}

// HasField 判断资源字段
func (this Resource) HasField(code string) bool {
	return lo.SomeBy(this.GetFields(), func(v req.ResField) bool {
		return v.GetCode() == code
	})
}

// BeginTransaction 开启事物
func (this Resource) BeginTransaction() (*db.TxDatabase, error) {
	return this.DB().Begin()
}

// DB 获取资源链接
func (this Resource) DB() *db.Database {
	dbEngine := do.MustInvoke[engine.Engine](this.container)
	conn := dbEngine.Connection(this.Conn)

	if isLocalDB(conn.Dialect()) && !this.IsResVirtual && this.Table != "" && this.initOnce != nil {
		this.initOnce.Do(func() {
			if err := this.autoCreateTable(conn); err != nil {
				panic(err)
			}
		})
	}

	// vtable 资源：查询走 engine 中的 :memory: 连接（"__"+Conn），
	// 原文件连接仅用于 _vtab_cache 持久化，两者互不阻塞。
	if conn.Dialect() == "vtable" && this.Table != "" && this.initOnce != nil {
		memConn := dbEngine.Connection("__" + this.Conn)
		this.initOnce.Do(func() {
			if err := this.autoSetupVtab(memConn); err != nil {
				panic(err)
			}
		})
		return memConn
	}

	return conn
}

// autoSetupVtab 通过容器获取 ResVirtualTableSetup（由 framework-v2 在 sqlite_vtable tag 下注册），
// 再从 App 取出当前资源对应的 ResVirtualTable 实现，完成 vtab 注册和 CREATE VIRTUAL TABLE。
func (this Resource) autoSetupVtab(conn *db.Database) error {
	_, err := conn.Exec(fmt.Sprintf(`CREATE VIRTUAL TABLE IF NOT EXISTS %s USING %s_mod()`, this.Table, this.Table))
	return err
}

// autoCreateTable 自动创建数据表
func (this Resource) autoCreateTable(conn *db.Database) error {
	sb := schema.New(conn)
	return sb.Create(this.Table, func(bp *schema.Blueprint) {
		bp.Comment = this.Name
		for _, field := range this.Fields {
			field.ToBlueprint(bp)
		}
	})
}

// GetTable 获取资源对应的数据表
func (this Resource) GetTable() exp.LiteralExpression {
	if this.IsResVirtual {
		return db.L("(" + this.Table + ")")
	}
	return db.V(db.T(this.Table))
}

// GetDBTable 获取资源对应的数据库连接
func (this Resource) GetDBTable(u req.User, opts ...req.ResOption) (sd *db.SelectDataset) {
	if u == nil {
		panic("GetDBTable: user cannot be nil")
	}

	op := &req.ResOptions{}

	for _, cb := range opts {
		cb(op)
	}

	alias := this.GetCode()

	if op.Alias != "" {
		alias = op.Alias
	}

	sd = this.DB().From(this.GetTable().As(alias))

	if op.Tx != nil {
		sd = op.Tx.From(this.GetTable().As(alias))
	}

	sd.WithHook(&ResourceHooks{res: this, u: u, tx: op.Tx})

	return sd
}

func (this Resource) GetRolesCondition(u req.User) (*db.SelectDataset, db.Expression) {
	isFullRight := false
	isFullNot := false

	if u == nil {
		u = GetAnonymous()
	}

	// 如果是系统用户, 则不做校验
	if u.Uuid() == "ffffffff-ffff-ffff-ffff-ffffffffffff" {
		return nil, nil
	}
	// 这里不能放在 u.Uuid() == "ffffffff-ffff-ffff-ffff-ffffffffffff" 前面
	// 会导致初始化数据时循环依赖
	GetResRoles, err := do.Invoke[GetResRoles](this.container)

	if err != nil {
		return nil, nil
	}

	items := GetResRoles(this.GetUuid(), u.Roles()...)

	if len(items) == 0 {
		return nil, nil
	}

	GetResource := do.MustInvoke[contracts.GetResource](this.container)
	NewOrm := do.MustInvoke[contracts.NewOrm](this.container)
	NewOrmModel := do.MustInvoke[contracts.NewOrmModel](this.container)
	NewOrmJoin := do.MustInvoke[contracts.NewOrmJoin](this.container)

	GetResRelationResource := do.MustInvoke[GetResRelationResource](this.container)
	GetResRelations := do.MustInvoke[GetResRelations](this.container)
	GetOrmConditions := do.MustInvoke[contracts.GetOrmConditions](this.container)

	sub := lo.Reduce(items, func(carry *db.SelectDataset, item ResRole, _ int) *db.SelectDataset {
		sd := this.DB().From(this.GetTable().As(this.GetCode())).Select(db.T(this.GetCode()).All())

		joins := lo.Filter(GetResRelations(item.Uuid), func(item ResRelation, _ int) bool {
			return item.Type == "inner" || item.Type == "left" || item.Type == "right"
		})

		for i := 0; i < len(joins); i++ {
			oResource, ok := GetResource(joins[i].ResourceCode)
			if !ok {
				continue
			}
			rResource, ok := GetResRelationResource(joins[i])
			if !ok {
				continue
			}

			join := NewOrmJoin(contracts.RelationType(joins[i].Type), oResource, joins[i].Code, joins[i].RelationResource, joins[i].RelationField, joins[i].RelationForeignKey)
			// 关联扩展条件
			join.SetCondition(GetOrmConditions(joins[i].Uuid, condition.Describe("关联扩展条件")))

			join.Inject(sd, NewOrmModel(rResource, rResource.GetCode(), rResource.GetName()))
		}

		conditions := GetOrmConditions(item.Uuid, condition.Describe("关联扩展条件"))

		if len(joins) == 0 && conditions.IsEmpty() {
			// 无权限, 直接跳过这个 unoin 语句
			if carry != nil {
				return carry
			}
			// 第一个无权限除外, 避免所有用户所属角色都是无权限
			sd = sd.Where(db.V(false))
			isFullNot = true
		} else if len(joins) == 0 && conditions.IsNotEmpty() && conditions.IsAlwaysRight() /* 1=1 的这种条件*/ {
			// 只要有1个满权限, 直接返回单条语句
			isFullRight = true
			return sd
		} else if conditions.IsNotEmpty() {
			oOrm := NewOrm(this, nil)
			oOrm.SetGlobalParams(req.NewGlobalParams("{}", u))

			sd = sd.Where(conditions.ToSql(oOrm.GetModel()))

			// 如果前面是无权限的sql查看, 这直接返回本次查询
			if isFullNot {
				isFullNot = false
				return sd
			}
		}

		if carry != nil {
			return carry.Union(sd)
		}

		return sd
	}, nil)

	if isFullRight {
		return nil, nil
	}

	if isFullNot {
		return nil, db.V(false)
	}

	return sub, nil
}

func (this Resource) GetStruct(extends ...reflect.StructField) any {
	fields := []reflect.StructField{}

	for _, field := range this.Fields {
		if unicode.IsLetter(rune(field.Code[0])) {
			fields = append(fields, field.ToStructField())
		} else {
			log.Printf("资源字段错误, 必须以字母开头 <- %s", field.Code)
		}
	}

	fields = lo.UniqBy(append(fields, extends...), func(v reflect.StructField) string {
		return v.Name
	})

	t := reflect.StructOf(fields)

	return reflect.New(t).Interface()
}

func (this Resource) GetSliceStruct(extends ...reflect.StructField) any {
	t := reflect.TypeOf(this.GetStruct(extends...))

	st := reflect.SliceOf(t.Elem())

	return reflect.New(st).Interface()
}

// onResEvent 资源事件
func (this Resource) onResEvent(t string, result sql.Result) {
	if num, err := result.RowsAffected(); num == 0 || err != nil {
		return
	}

	// 有些地方可能没有注册 contracts.Queue
	if qu, err := do.Invoke[contracts.Queue](this.container); err == nil {
		// 全局触发器
		// 1. 清除系统缓存
		if err := qu.Publish(ResChangeEventTopic, ResChangeEventTopicPayload{
			Type:   t,
			Res:    this,
			Result: result,
		}); err != nil {
			log.Println("Queue Publish Err:", ResChangeEventTopic, err)
		}
	}
}

// onUserEvent 用户事件
func (this Resource) onUserEvent(builder exec.QueryExecutor, user req.User) {
	// old := []map[string]any{}

	// builder.Before(func(b *db.Builder, t string, data ...map[string]any) {
	// 	if t != db.TYPE_UPDATE && t != db.TYPE_DELETE {
	// 		return
	// 	}
	// 	// 查询保存之前的数据
	// 	if _, err := b.Get(&old); err != nil {
	// 		panic(err)
	// 	}
	// })

	// builder.After(func(b *db.Builder, t string, result sql.Result, err error, data ...map[string]any) {
	// 	if err != nil || t == db.TYPE_SELECT {
	// 		return
	// 	} else if num, err := result.RowsAffected(); num == 0 || err != nil {
	// 		return
	// 	}

	// 	if user == nil {
	// 		user = GetAnonymous()
	// 	}

	// 	// 触发消息队列
	// 	if err := do.MustInvoke[contracts.Queue](this.container).Publish(ResChangeRecordTopic, ResChangeRecordTopicPayload{
	// 		Type:   t,
	// 		User:   user,
	// 		Res:    this,
	// 		Old:    old,
	// 		New:    data,
	// 		Result: result,
	// 	}); err != nil {
	// 		log.Println("Queue Publish Err:", ResChangeRecordTopic, err)
	// 	}
	// })
}

func NewVirtualResource(pRes req.Resource, code, name string, sd *db.SelectDataset, fields []ResField) req.Resource {
	fieldsCopy := make([]ResField, len(fields))

	copy(fieldsCopy, fields)

	for i := 0; i < len(fieldsCopy); i++ {
		fieldsCopy[i].CodeResource = code
	}

	sql, _, err := sd.WithDialect(pRes.DB().Dialect()).ToSQL()

	if err != nil {
		panic(err)
	}

	return &Resource{
		Uuid:         code,
		PUuid:        pRes.GetUuid(),
		Code:         code,
		Name:         name,
		IsResVirtual: true,
		Conn:         pRes.GetConn(),
		Table:        sql,
		Fields:       fieldsCopy,
		Roles:        nil,
	}
}