package mdbc

import (
	"context"
	"errors"
	"fmt"
	"reflect"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

type updateAction string

const (
	updateOne  updateAction = "updateOne"
	updateMany updateAction = "updateMany"
)

type UpdateScope struct {
	scope      *Scope
	cw         *ctxWrap
	err        error
	upsert     *bool
	id         interface{}
	filter     interface{}
	action     updateAction
	updateData interface{}
	opts       *options.UpdateOptions
	result     *mongo.UpdateResult
}

// SetContext 设置上下文
func (us *UpdateScope) SetContext(ctx context.Context) *UpdateScope {
	if us.cw == nil {
		us.cw = &ctxWrap{}
	}
	us.cw.ctx = ctx
	return us
}

func (us *UpdateScope) getContext() context.Context {
	return us.cw.ctx
}

// SetUpsert 设置upsert属性
func (us *UpdateScope) SetUpsert(upsert bool) *UpdateScope {
	us.upsert = &upsert
	return us
}

// SetID 基于ID进行文档更新 这将忽略 filter 只按照ID过滤
func (us *UpdateScope) SetID(id interface{}) *UpdateScope {
	us.id = id
	return us
}

// SetUpdateOption 设置UpdateOption
func (us *UpdateScope) SetUpdateOption(opts options.UpdateOptions) *UpdateScope {
	us.opts = &opts
	return us
}

// SetFilter 设置过滤条件
func (us *UpdateScope) SetFilter(filter interface{}) *UpdateScope {
	if filter == nil {
		us.filter = bson.M{}
		return us
	}

	v := reflect.ValueOf(filter)
	if v.Kind() == reflect.Ptr || v.Kind() == reflect.Map || v.Kind() == reflect.Slice {
		if v.IsNil() {
			us.filter = bson.M{}
		}
	}
	us.filter = filter
	return us
}

func (us *UpdateScope) optionAssembled() {
	// 配置项被直接调用重写过
	if us.opts != nil {
		return
	}

	us.opts = new(options.UpdateOptions)
	if us.upsert != nil {
		us.opts.Upsert = us.upsert
	}
}

func (us *UpdateScope) assertErr() {
	if us.err == nil {
		return
	}
	if errors.Is(us.err, context.DeadlineExceeded) {
		us.err = &ErrRequestBroken
		return
	}
	err, ok := us.err.(mongo.CommandError)
	if !ok {
		return
	}
	if err.HasErrorMessage(context.DeadlineExceeded.Error()) {
		us.err = &ErrRequestBroken
		return
	}
}

func (us *UpdateScope) debug() {
	if !us.scope.debug && !us.scope.debugWhenError {
		return
	}

	debugger := &Debugger{
		collection: us.scope.tableName,
		execT:      us.scope.execT,
		action:     us,
	}

	// 当错误时优先输出
	if us.scope.debugWhenError {
		if us.err != nil {
			debugger.errMsg = us.err.Error()
			debugger.ErrorString()
		}
		return
	}

	// 所有bug输出
	if us.scope.debug {
		debugger.String()
	}
}

func (us *UpdateScope) doReporter() string {
	debugger := &Debugger{
		collection: us.scope.tableName,
		execT:      us.scope.execT,
		action:     us,
	}
	return debugger.Echo()
}

func (us *UpdateScope) reporter() {
	br := &BreakerReporter{
		reportTitle:     "mdbc::update",
		reportMsg:       "熔断错误",
		reportErrorWrap: us.err,
		breakerDo:       us,
	}
	if us.err == &ErrRequestBroken {
		br.Report()
	}
}

func (us *UpdateScope) doString() string {
	builder := RegisterTimestampCodec(nil).Build()
	switch us.action {
	case updateOne:
		filter, _ := bson.MarshalExtJSONWithRegistry(builder, us.filter, true, true)
		updateData, _ := bson.MarshalExtJSONWithRegistry(builder, us.updateData, true, true)
		return fmt.Sprintf("updateOne(%s, %s)", string(filter), string(updateData))
	case updateMany:
		filter, _ := bson.MarshalExtJSONWithRegistry(builder, us.filter, true, true)
		updateData, _ := bson.MarshalExtJSONWithRegistry(builder, us.updateData, true, true)
		return fmt.Sprintf("updateMany(%s, %s)", string(filter), string(updateData))
	default:
		panic("not support update type")
	}
}

// preCheck 预检查
func (us *UpdateScope) preCheck() {
	var breakerTTL time.Duration
	if us.scope.breaker == nil {
		breakerTTL = defaultBreakerTime
	} else if us.scope.breaker.ttl == 0 {
		breakerTTL = defaultBreakerTime
	} else {
		breakerTTL = us.scope.breaker.ttl
	}
	if us.cw == nil {
		us.cw = &ctxWrap{}
	}
	if us.cw.ctx == nil {
		us.cw.ctx, us.cw.cancel = context.WithTimeout(context.Background(), breakerTTL)
	}
}

func (us *UpdateScope) doUpdate(isMany bool) {
	if isMany {
		var starTime time.Time
		if us.scope.debug {
			starTime = time.Now()
		}
		us.result, us.err = db.Collection(us.scope.tableName).UpdateMany(us.getContext(), us.filter, us.updateData, us.opts)
		us.assertErr()
		if us.scope.debug {
			us.scope.execT = time.Since(starTime)
			us.action = updateMany
			us.debug()
		}
		return
	}

	if us.id != nil {
		var starTime time.Time
		if us.scope.debug {
			starTime = time.Now()
		}
		us.result, us.err = db.Collection(us.scope.tableName).UpdateByID(us.getContext(), us.id, us.updateData, us.opts)
		us.assertErr()
		if us.scope.debug {
			us.scope.execT = time.Since(starTime)
			us.filter = bson.M{"_id": us.id}
			us.action = updateOne
			us.debug()
		}
		return
	}

	var starTime time.Time
	if us.scope.debug {
		starTime = time.Now()
	}
	us.result, us.err = db.Collection(us.scope.tableName).UpdateOne(us.getContext(), us.filter, us.updateData, us.opts)
	us.assertErr()
	if us.scope.debug {
		us.scope.execT = time.Since(starTime)
		us.action = updateOne
		us.debug()
	}
}

func (us *UpdateScope) doClear() {
	if us.cw != nil && us.cw.cancel != nil {
		us.cw.cancel()
	}
	us.scope.execT = 0
	us.scope.debug = false
}

// checkObj 检测需要更新的obj是否正常 没有$set将被注入
func (us *UpdateScope) checkObj(obj interface{}) {
	if obj == nil {
		us.err = &ErrObjectEmpty
		return
	}
	us.updateData = obj

	vo := reflect.ValueOf(obj)
	if vo.Kind() == reflect.Ptr {
		vo = vo.Elem()
	}
	if vo.Kind() == reflect.Struct {
		us.updateData = bson.M{
			"$set": obj,
		}
		return
	}
	if vo.Kind() == reflect.Map {
		setKey := vo.MapIndex(reflect.ValueOf("$set"))
		if !setKey.IsValid() {
			us.updateData = bson.M{
				"$set": obj,
			}
		}
		return
	}

	us.err = &ErrUpdateObjectTypeNotSupport
}

// checkMapSetObj 检测需要更新的obj是否正常
func (us *UpdateScope) checkMustMapObj(obj interface{}) {
	if obj == nil {
		us.err = &ErrObjectEmpty
		return
	}
	us.updateData = obj

	vo := reflect.ValueOf(obj)
	if vo.Kind() == reflect.Ptr {
		vo = vo.Elem()
	}

	if vo.Kind() == reflect.Map {
		return
	}

	us.err = &ErrUpdateObjectTypeNotSupport
}

// One 单个更新
// obj: 为*struct时将被自动转换为bson.M并注入$set
// 当指定为map时 若未指定$set 会自动注入$set
// 当指定 非 *struct/ map 类型时 将报错
func (us *UpdateScope) One(obj interface{}) (*mongo.UpdateResult, error) {
	defer us.doClear()
	us.optionAssembled()
	us.preCheck()

	us.checkObj(obj)
	if us.err != nil {
		return nil, us.err
	}
	us.doUpdate(false)
	if us.err != nil {
		return nil, us.err
	}

	return us.result, nil
}

// MustMapOne 单个更新 必须传入map并强制更新这个map
func (us *UpdateScope) MustMapOne(obj interface{}) (*mongo.UpdateResult, error) {
	defer us.doClear()
	us.optionAssembled()
	us.preCheck()

	us.checkMustMapObj(obj)
	if us.err != nil {
		return nil, us.err
	}
	us.doUpdate(false)
	if us.err != nil {
		return nil, us.err
	}

	return us.result, nil
}

// RawOne 单个更新 不对更新内容进行校验
func (us *UpdateScope) RawOne(obj interface{}) (*mongo.UpdateResult, error) {
	defer us.doClear()
	us.optionAssembled()
	us.preCheck()

	us.updateData = obj

	us.doUpdate(false)
	if us.err != nil {
		return nil, us.err
	}

	return us.result, nil
}

// Many 批量更新
// obj: 为*struct时将被自动转换为bson.M并注入$set
// 当指定为map时 若未指定$set 会自动注入$set
// 当指定 非 *struct/ map 类型时 将报错
func (us *UpdateScope) Many(obj interface{}) (*mongo.UpdateResult, error) {
	defer us.doClear()
	us.optionAssembled()
	us.checkObj(obj)
	if us.err != nil {
		return nil, us.err
	}
	us.doUpdate(true)

	if us.err != nil {
		return nil, us.err
	}

	return us.result, nil
}

// MustMapMany 批量更新 必须传入map并强制更新这个map
func (us *UpdateScope) MustMapMany(obj interface{}) (*mongo.UpdateResult, error) {
	defer us.doClear()
	us.optionAssembled()
	us.checkMustMapObj(obj)
	if us.err != nil {
		return nil, us.err
	}
	us.doUpdate(true)

	if us.err != nil {
		return nil, us.err
	}

	return us.result, nil
}

// RawMany 批量更新 不对更新内容进行校验
func (us *UpdateScope) RawMany(obj interface{}) (*mongo.UpdateResult, error) {
	defer us.doClear()
	us.optionAssembled()
	us.preCheck()

	us.updateData = obj

	us.doUpdate(true)
	if us.err != nil {
		return nil, us.err
	}

	return us.result, nil
}