package zaptrashlog

import (
	"context"
	"fmt"
	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"
	"google.golang.org/grpc"
	"google.golang.org/grpc/backoff"
	"google.golang.org/grpc/credentials/insecure"
	"penahub.gitlab.yandexcloud.net/external/trashlog.git/dal/bbolt"
	"penahub.gitlab.yandexcloud.net/external/trashlog.git/model"
	pb "penahub.gitlab.yandexcloud.net/external/trashlog.git/proto/generated"
	"penahub.gitlab.yandexcloud.net/external/trashlog.git/sink"
	"strings"
	"sync"
	"time"
)

type levelEnabler struct {
	minLevel zapcore.Level
}

type TrashLogCore struct {
	levelEnabler
	coreFields   map[string]interface{}
	ctx          context.Context
	stream       pb.Trashlog_ValveClient
	svcData      *pb.SvcData
	ctxFields    map[string]*pb.Value
	keyFields    map[string]*pb.Value
	recoverStore *bbolt.DAL
	url          string
	sendMutex    sync.Mutex
	failCh       chan bool
	emitCh       chan entryWithFields
}

type entryWithFields struct {
	entry  zapcore.Entry
	fields []zapcore.Field
}

const dbPath = "recover.bolt"

func NewCore(
	ctx context.Context,
	minLevel zapcore.Level,
	url, version, commit string,
	buildTime int64,

) (*TrashLogCore, error) {
	recoverStore, err := bbolt.New(version + dbPath)
	if err != nil {
		return nil, err
	}

	tlc := TrashLogCore{
		levelEnabler: levelEnabler{
			minLevel: minLevel,
		},
		coreFields:   make(map[string]interface{}),
		ctx:          ctx,
		recoverStore: recoverStore,
		svcData: &pb.SvcData{
			BuildTime: uint64(buildTime),
			Version:   version,
			Commit:    commit,
		},
		url:       url,
		ctxFields: make(map[string]*pb.Value),
		keyFields: make(map[string]*pb.Value),
		sendMutex: sync.Mutex{},
		failCh:    make(chan bool),
		emitCh:    make(chan entryWithFields, 100),
	}

	if err := tlc.connectToTrashlog(url); err != nil {
		fmt.Println("noconnect", err)
		return &tlc, err
	}

	worker := NewWorker(&tlc)
	go worker.EmitWorker()
	go worker.SendWorker()
	go worker.Reconnect()

	return &tlc, nil
}

func (c *TrashLogCore) Close() error {
	fmt.Println("Close")
	var errSender, errRec error
	if c.stream != nil {
		errSender = c.stream.CloseSend()
	}

	errRec = c.recoverStore.Close()

	if errRec != nil {
		return errRec
	}

	if errSender != nil {
		return errSender
	}

	return nil
}

func (c *TrashLogCore) connectToTrashlog(url string) error {
	var opts []grpc.DialOption
	opts = append(opts, grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithConnectParams(grpc.ConnectParams{
		Backoff: backoff.Config{
			BaseDelay:  1.0 * time.Second,
			Multiplier: 1.6,
			Jitter:     0.2,
			MaxDelay:   120 * time.Hour,
		},
	}))
	fmt.Println("connectToTrashlog")
	conn, err := grpc.Dial(url, opts...)
	if err != nil {
		return err
	}
	fmt.Println("Dial")

	client := pb.NewTrashlogClient(conn)

	fmt.Println("NewTrashlogClient")
	var stream pb.Trashlog_ValveClient
	stream, err = client.Valve(c.ctx, grpc.WaitForReady(true))

	fmt.Println("WaitForReady", err)
	if err != nil {
		return err
	}

	c.stream = stream

	return nil
}

func (c *TrashLogCore) WrapLogger(logger *zap.Logger) *zap.Logger {
	return logger.WithOptions(
		zap.WrapCore(func(core zapcore.Core) zapcore.Core {
			return zapcore.NewTee(core, c)
		}),
		zap.AddCallerSkip(1),
	)
}

func (le *levelEnabler) Enabled(l zapcore.Level) bool {
	return l >= le.minLevel
}

func copyFieldsMap(src map[string]*pb.Value) map[string]*pb.Value {
	dst := make(map[string]*pb.Value, len(src))
	for k, v := range src {
		dst[k] = v
	}
	return dst
}

func copyCoreMap(src map[string]any) map[string]any {
	dst := make(map[string]any, len(src))
	for k, v := range src {
		dst[k] = v
	}
	return dst
}

func (c *TrashLogCore) With(fields []zapcore.Field) zapcore.Core {
	fieldMap := fieldsToMap(fields)

	destCoreFields := copyCoreMap(c.coreFields)
	destKeyFields := copyFieldsMap(c.keyFields)
	destCtxFields := copyFieldsMap(c.ctxFields)

	for k, v := range fieldMap {
		destCoreFields[k] = v
		switch {
		case strings.HasPrefix(k, "Ctx"):
			destCtxFields[strings.TrimPrefix(k, "Ctx")] = convertValue(v)
		case strings.HasPrefix(k, "Key"):
			destKeyFields[strings.TrimPrefix(k, "Key")] = convertValue(v)
		default:
			destKeyFields[k] = convertValue(v)
		}
	}

	return &TrashLogCore{
		coreFields:   destCoreFields,
		ctxFields:    destCtxFields,
		keyFields:    destKeyFields,
		svcData:      c.svcData,
		ctx:          c.ctx,
		stream:       c.stream,
		recoverStore: c.recoverStore,
		url:          c.url,
		sendMutex:    c.sendMutex,
	}
}

func convertValue(v interface{}) *pb.Value {
	switch t := v.(type) {
	case string:
		return &pb.Value{Value: &pb.Value_Str{Str: t}}
	case int64:
		return &pb.Value{Value: &pb.Value_Num{Num: t}}
	case float64:
		return &pb.Value{Value: &pb.Value_Double{Double: float32(t)}}
	case bool:
		return &pb.Value{Value: &pb.Value_Flag{Flag: t}}
	}

	return nil
}

func (c *TrashLogCore) Check(
	entry zapcore.Entry,
	checkedEntry *zapcore.CheckedEntry,
) *zapcore.CheckedEntry {
	if c.levelEnabler.Enabled(entry.Level) {
		return checkedEntry.AddCore(entry, c)
	}
	return checkedEntry
}

func (c *TrashLogCore) Write(
	entry zapcore.Entry,
	fields []zapcore.Field,
) error {
	c.emitCh <- entryWithFields{
		entry:  entry,
		fields: fields,
	}

	return nil
}

func (c *TrashLogCore) Sync() error {
	return nil
}

func fieldsToMap(fields []zapcore.Field) map[string]interface{} {
	enc := zapcore.NewMapObjectEncoder()
	for _, f := range fields {
		f.AddTo(enc)
	}

	m := make(map[string]interface{})
	for k, v := range enc.Fields {
		m[k] = v
	}

	return m
}

type Worker struct {
	core     *TrashLogCore
	recordCh chan pb.Record
}

func NewWorker(core *TrashLogCore) *Worker {
	return &Worker{
		core: core,
	}
}

func (w *Worker) EmitWorker() {
	for {
		select {
		case <-w.core.ctx.Done():
			return
		case emit := <-w.core.emitCh:
			w.saveFields(emit.entry, emit.fields)
		}
	}
}

func (w *Worker) SendWorker() {
	ticker := time.NewTicker(5 * time.Second)
	defer ticker.Stop()
	for {
		select {
		case <-ticker.C:
			w.fetchBolt()
		case <-w.core.ctx.Done():
			return
		}
	}
}

func (w *Worker) saveFields(entry zapcore.Entry, fields []zapcore.Field) {
	record := w.prepareRecord(entry, fields)
	err := w.core.recoverStore.PutRecord(sink.Dto2daoRecord(&record))
	if err != nil {
		fmt.Println("ошибка сохранения записи в болт", err)
		return
	}
}

func (w *Worker) fetchBolt() {
	records, err := w.core.recoverStore.GetAllRecords()
	if err != nil {
		fmt.Println("ошибка при получении всех записей из болта", err)
		return
	}

	for key, record := range records {
		if w.core.stream != nil {
			rec := w.convertToProto(record)
			err = w.core.stream.Send(rec)
			if err == nil {
				err = w.core.recoverStore.DeleteRecordByKey([]byte(key))
				if err != nil {
					fmt.Println("ошибка при удалении записи из хранилища по ключу", err)
					continue
				}
			} else {
				fmt.Println("ошибка отправки записи в trashlog", err)
				w.core.failCh <- true
				return
			}
		}
	}
}

func (w *Worker) prepareRecord(entry zapcore.Entry, fields []zapcore.Field) pb.Record {
	fieldMap := fieldsToMap(fields)
	splittedMessage := strings.Split(entry.Message, "!")
	var msg string

	if len(splittedMessage) == 2 {
		msg = splittedMessage[1]
	} else {
		msg = entry.Message
	}

	keyFields, ctxFields := make(map[string]*pb.Value), make(map[string]*pb.Value)

	for k, v := range w.core.keyFields {
		keyFields[k] = v
	}

	for k, v := range w.core.ctxFields {
		ctxFields[k] = v
	}

	for k, v := range fieldMap {
		switch {
		case strings.HasPrefix(k, "Ctx"):
			ctxFields[strings.ToLower(k)] = convertValue(v)
		case strings.HasPrefix(k, "Key"):
			keyFields[strings.ToLower(k)] = convertValue(v)
		default:
			ctxFields[fmt.Sprintf("ctx%s", strings.ToLower(k))] = convertValue(v)
		}
	}

	return pb.Record{
		Level:      entry.Level.String(),
		TS:         uint64(entry.Time.Unix()),
		Message:    msg,
		Module:     strings.Split(entry.LoggerName, "."),
		Stacktrace: entry.Stack,
		KeyFields:  keyFields,
		CtxFields:  ctxFields,
		SvcFields: &pb.SvcData{
			BuildTime: w.core.svcData.BuildTime,
			Version:   w.core.svcData.Version,
			Commit:    w.core.svcData.Commit,
			File:      entry.Caller.File,
			Line:      uint64(entry.Caller.Line),
		},
	}
}

func (w *Worker) convertToProto(record model.Record) *pb.Record {
	keyFields, ctxFields := make(map[string]*pb.Value), make(map[string]*pb.Value)
	for k, v := range record.KeyFields {
		keyFields[k] = convertValue(v)
	}

	for k, v := range record.CtxFields {
		ctxFields[k] = convertValue(v)
	}

	return &pb.Record{
		Level:      record.Level,
		TS:         record.TS,
		Message:    record.Message,
		Module:     record.Module,
		Stacktrace: record.Stacktrace,
		KeyFields:  keyFields,
		CtxFields:  ctxFields,
		SvcFields: &pb.SvcData{
			BuildTime: record.SvcBuildTime,
			Version:   record.SvcVersion,
			Commit:    record.SvcCommit,
			File:      record.SvcFile,
			Line:      record.SvcLine,
		},
	}
}

func (w *Worker) Reconnect() {
	select {
	case <-w.core.ctx.Done():
		return
	case <-w.core.failCh:
		if err := w.core.connectToTrashlog(w.core.url); err == nil {
			fmt.Println("Reconnect successful")
		}
	}
}