package api

import (
	"context"
	"datart/data"
	"datart/data/mongo"
	"datart/log"
	"errors"
	"fmt"
	"strconv"
	"strings"
	"sync"

	"github.com/gin-gonic/gin"
	"github.com/google/uuid"
	"go.mongodb.org/mongo-driver/v2/bson"
)

const (
	pageSizeLimit = 500
)

func (a *Api) GetEvents(ctx *gin.Context) {
	filter, sort, pageNo, pageSize, err := a.checkAndGenGetEventsRequest(ctx)
	if err != nil {

		log.Error(err)

		ctx.JSON(200, gin.H{
			"code": 1,
			"msg":  err.Error(),
		})
		return
	}

	events, err := mongo.FindEventsWithPageLimit(ctx.Request.Context(), filter, sort, pageNo, pageSize)
	if err != nil {

		log.Error(err, fmt.Sprintf(" params: %v, %d, %d, %d", filter, sort, pageNo, pageSize))

		ctx.JSON(200, gin.H{
			"code": 2,
			"msg":  err.Error(),
		})
		return
	}

	ctx.JSON(200, gin.H{
		"code": 0,
		"msg":  "success",
		"data": events,
	})
}

func (a *Api) PostUpsertEvents(ctx *gin.Context) {
	uuids, update, events, err := a.checkAndGenUpsertEventsRequest(ctx)
	if err != nil {
		log.Error(err)
		ctx.JSON(200, gin.H{
			"code": 1,
			"msg":  err.Error(),
		})
		return
	}

	if len(uuids) > 0 {
		operation := mongo.GenOperation(mongo.EventStatusAction[update.Status], ctx.RemoteIP())
		err := mongo.UpdateEvents(ctx.Request.Context(),
			bson.M{"event_uuid": bson.M{"$in": uuids}},
			bson.M{"$set": bson.M{"status": update.Status}, "$push": bson.M{"operations": operation}})
		if err != nil {
			log.Error(err, fmt.Sprintf(" params:%v %v", update, uuids))
			ctx.JSON(200, gin.H{
				"code": 2,
				"msg":  err.Error(),
			})
			return
		}

		events = make([]map[string]any, len(uuids))
		for i := range events {
			events[i] = map[string]any{"event_uuid": uuids[i], "status": update.Status}
		}
	} else {
		err := mongo.InsertEvents(ctx.Request.Context(), events)
		if err != nil {
			log.Error(err, fmt.Sprintf(" params: %v", events))
			ctx.JSON(200, gin.H{
				"code": 3,
				"msg":  err.Error(),
			})
			return
		}
	}

	go func(evts []map[string]any) {
		workers := 5
		ch := make(chan map[string]any, len(evts))
		var wg sync.WaitGroup
		for range workers {
			wg.Add(1)
			go func() {
				defer wg.Done()
				for e := range ch {
					if err := data.PublishEvent(context.Background(), e); err != nil {
						log.Error(err, fmt.Sprintf("publish event failed: %v", e))
					}
				}
			}()
		}
		for _, e := range evts {
			ch <- e
		}
		close(ch)
		wg.Wait()
	}(events)

	ctx.JSON(200, gin.H{
		"code": 0,
		"msg":  "success",
	})
}

func (a *Api) checkAndGenGetEventsRequest(ctx *gin.Context) (bson.M, int, int64, int64, error) {
	uuidStr := ctx.Query("uuid")
	if len(uuidStr) > 0 {

		if uuid.Validate(uuidStr) != nil {
			return nil, 0, -1, -1, errors.New("invalid uuid")
		}

		return bson.M{"event_uuid": uuidStr}, 0, -1, -1, nil
	}

	filter := bson.M{}

	var err error
	begin, end := int64(-1), int64(-1)
	beginStr := ctx.Query("begin")
	if len(beginStr) > 0 {
		if begin, err = strconv.ParseInt(beginStr, 10, 64); err != nil {
			return nil, 0, -1, -1, err
		}
	}

	endStr := ctx.Query("end")
	if len(endStr) > 0 {
		if end, err = strconv.ParseInt(endStr, 10, 64); err != nil {
			return nil, 0, -1, -1, err
		}
	}

	if begin > 0 && end > 0 && begin > end {
		return nil, 0, -1, -1, errors.New("invalid time")
	}

	switch {
	case begin > 0 && end < 0:
		filter["timestamp"] = bson.M{"$gte": begin}
	case begin < 0 && end > 0:
		filter["timestamp"] = bson.M{"$lte": end}
	case begin > 0 && end > 0:
		filter["timestamp"] = bson.M{"$gte": begin, "$lte": end}
	}

	statusStr := ctx.Query("status")
	if len(statusStr) > 0 {
		statusStrs := strings.Split(statusStr, ",")
		statuss := make([]int, len(statusStrs))
		for i := range statusStrs {
			s, err := strconv.Atoi(statusStrs[i])
			if err != nil {
				return nil, 0, -1, -1, errors.New("invalid status")
			}
			statuss[i] = s
		}
		filter["status"] = bson.M{"$in": statuss}
	}

	var sort int
	sortStr := ctx.Query("sort")
	if len(sortStr) > 0 {
		s, err := strconv.Atoi(sortStr)
		if err != nil {
			return nil, 0, -1, -1, err
		}

		if s != 1 && s != -1 {
			return nil, 0, -1, -1, errors.New("invalid sort")
		}
		sort = s
	}

	pageNo, pageSize := -1, -1
	pageNoStr := ctx.Query("page_no")
	pageSizeStr := ctx.Query("page_size")
	if len(pageNoStr) > 0 && len(pageSizeStr) > 0 {
		pageNo, err = strconv.Atoi(pageNoStr)
		if err != nil {
			return nil, 0, -1, -1, err
		}

		pageSize, err = strconv.Atoi(pageSizeStr)
		if err != nil {
			return nil, 0, -1, -1, err
		}

		if pageNo <= 0 || pageSize <= 0 {
			return nil, 0, -1, -1, errors.New("invalid page param")
		}

		if pageSize > pageSizeLimit {
			return nil, 0, -1, -1, fmt.Errorf("too many events, max %d", pageSizeLimit)
		}
	}

	return filter, sort, int64(pageNo), int64(pageSize), nil
}

func (a *Api) checkAndGenUpsertEventsRequest(ctx *gin.Context) ([]string, *mongo.Event, []map[string]any, error) {
	insert := true
	update := &mongo.Event{}
	statusStr := ctx.Query("status")
	if len(statusStr) > 0 {
		insert = false
		status, err := strconv.Atoi(statusStr)
		if err != nil {
			return nil, nil, nil, err
		}
		update.Status = status
	}

	if !insert {
		uuids := []string{}
		err := ctx.ShouldBindJSON(&uuids)
		if err != nil {
			return nil, nil, nil, err
		}
		if len(uuids) == 0 {
			return nil, nil, nil, errors.New("no uuid")
		}
		if len(uuids) > pageSizeLimit {
			return nil, nil, nil, fmt.Errorf("too many uuids, max %d", pageSizeLimit)
		}

		return uuids, update, nil, nil
	}

	events := []map[string]any{}
	err := ctx.ShouldBindJSON(&events)
	if err != nil {
		return nil, nil, nil, err
	}
	if len(events) == 0 {
		return nil, nil, nil, errors.New("no event")
	}
	if len(events) > pageSizeLimit {
		return nil, nil, nil, fmt.Errorf("too many events, max %d", pageSizeLimit)
	}

	return nil, nil, events, nil
}

func validateEventUpsert(event map[string]any) error {
	noUUID := true
	if eu, ok := event["event_uuid"]; ok {
		if eID, ok := eu.(string); ok {
			if uuid.Validate(eID) == nil {
				noUUID = false
			}
		}
	}

	if noUUID {
		if uid, err := uuid.NewV7(); err != nil {
			return err
		} else {
			event["event_uuid"] = uid.String()
		}
	}

	if len(event) < 2 {
		return errors.New("invalid event")
	}

	return nil
}