package cache_test

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"time"

	"github.com/go-redis/redis/v8"

	"github.com/mgtv-tech/jetcache-go"
	"github.com/mgtv-tech/jetcache-go/local"
	"github.com/mgtv-tech/jetcache-go/remote"
)

var errRecordNotFound = errors.New("mock gorm.errRecordNotFound")

type object struct {
	Str string
	Num int
}

func mockDBGetObject(id int) (*object, error) {
	if id > 100 {
		return nil, errRecordNotFound
	}
	return &object{Str: "mystring", Num: 42}, nil
}

func mockDBMGetObject(ids []int) (map[int]*object, error) {
	ret := make(map[int]*object)
	for _, id := range ids {
		if id == 3 {
			continue
		}
		ret[id] = &object{Str: "mystring", Num: id}
	}
	return ret, nil
}

func Example_basicUsage() {
	ring := redis.NewRing(&redis.RingOptions{
		Addrs: map[string]string{
			"localhost": ":6379",
		},
	})

	mycache := cache.New(cache.WithName("any"),
		cache.WithRemote(remote.NewGoRedisV8Adaptor(ring)),
		cache.WithLocal(local.NewFreeCache(256*local.MB, time.Minute)),
		cache.WithErrNotFound(errRecordNotFound))

	ctx := context.TODO()
	key := "mykey:1"
	obj, _ := mockDBGetObject(1)
	if err := mycache.Set(ctx, key, cache.Value(obj), cache.TTL(time.Hour)); err != nil {
		panic(err)
	}

	var wanted object
	if err := mycache.Get(ctx, key, &wanted); err == nil {
		fmt.Println(wanted)
	}
	// Output: {mystring 42}

	mycache.Close()
}

func Example_advancedUsage() {
	ring := redis.NewRing(&redis.RingOptions{
		Addrs: map[string]string{
			"localhost": ":6379",
		},
	})

	mycache := cache.New(cache.WithName("any"),
		cache.WithRemote(remote.NewGoRedisV8Adaptor(ring)),
		cache.WithLocal(local.NewFreeCache(256*local.MB, time.Minute)),
		cache.WithErrNotFound(errRecordNotFound),
		cache.WithRefreshDuration(time.Minute))

	ctx := context.TODO()
	key := "mykey:1"
	obj := new(object)
	if err := mycache.Once(ctx, key, cache.Value(obj), cache.TTL(time.Hour), cache.Refresh(true),
		cache.Do(func(ctx context.Context) (any, error) {
			return mockDBGetObject(1)
		})); err != nil {
		panic(err)
	}
	fmt.Println(obj)
	// Output: &{mystring 42}

	mycache.Close()
}

func Example_mGetUsage() {
	ring := redis.NewRing(&redis.RingOptions{
		Addrs: map[string]string{
			"localhost": ":6379",
		},
	})

	mycache := cache.New(cache.WithName("any"),
		cache.WithRemote(remote.NewGoRedisV8Adaptor(ring)),
		cache.WithLocal(local.NewFreeCache(256*local.MB, time.Minute)),
		cache.WithErrNotFound(errRecordNotFound),
		cache.WithRemoteExpiry(time.Minute),
	)
	cacheT := cache.NewT[int, *object](mycache)

	ctx := context.TODO()
	key := "mget"
	ids := []int{1, 2, 3}

	ret := cacheT.MGet(ctx, key, ids, func(ctx context.Context, ids []int) (map[int]*object, error) {
		return mockDBMGetObject(ids)
	})

	var b bytes.Buffer
	for _, id := range ids {
		b.WriteString(fmt.Sprintf("%v", ret[id]))
	}
	fmt.Println(b.String())
	// Output: &{mystring 1}&{mystring 2}<nil>

	cacheT.Close()
}

func Example_syncLocalUsage() {
	ring := redis.NewRing(&redis.RingOptions{
		Addrs: map[string]string{
			"localhost": ":6379",
		},
	})

	sourceID := "12345678" // Unique identifier for this cache instance
	channelName := "syncLocalChannel"
	pubSub := ring.Subscribe(context.Background(), channelName)

	mycache := cache.New(cache.WithName("any"),
		cache.WithRemote(remote.NewGoRedisV8Adaptor(ring)),
		cache.WithLocal(local.NewFreeCache(256*local.MB, time.Minute)),
		cache.WithErrNotFound(errRecordNotFound),
		cache.WithRemoteExpiry(time.Minute),
		cache.WithSourceId(sourceID),
		cache.WithSyncLocal(true),
		cache.WithEventHandler(func(event *cache.Event) {
			// Broadcast local cache invalidation for the received keys
			bs, _ := json.Marshal(event)
			ring.Publish(context.Background(), channelName, string(bs))
		}),
	)
	obj, _ := mockDBGetObject(1)
	if err := mycache.Set(context.TODO(), "mykey", cache.Value(obj), cache.TTL(time.Hour)); err != nil {
		panic(err)
	}

	go func() {
		for {
			msg := <-pubSub.Channel()
			var event *cache.Event
			if err := json.Unmarshal([]byte(msg.Payload), &event); err != nil {
				panic(err)
			}
			fmt.Println(event.Keys)

			// Invalidate local cache for received keys (except own events)
			if event.SourceID != sourceID {
				for _, key := range event.Keys {
					mycache.DeleteFromLocalCache(key)
				}
			}
		}
	}()

	// Output: [mykey]
	mycache.Close()
	time.Sleep(time.Second)
}

// Options are used to store cache options.
Options struct {
    name                       string             // Cache name, used for log identification and metric reporting
    remote                     remote.Remote      // Remote is distributed cache, such as Redis.
    local                      local.Local        // Local is memory cache, such as FreeCache.
    codec                      string             // Value encoding and decoding method. Default is "msgpack.Name". You can also customize it.
    errNotFound                error              // Error to return for cache miss. Used to prevent cache penetration.
    remoteExpiry               time.Duration      // Remote cache ttl, Default is 1 hour.
    notFoundExpiry             time.Duration      // Duration for placeholder cache when there is a cache miss. Default is 1 minute.
    offset                     time.Duration      // Expiration time jitter factor for cache misses.
    refreshDuration            time.Duration      // Interval for asynchronous cache refresh. Default is 0 (refresh is disabled).
    stopRefreshAfterLastAccess time.Duration      // Duration for cache to stop refreshing after no access. Default is refreshDuration + 1 second.
    refreshConcurrency         int                // Maximum number of concurrent cache refreshes. Default is 4.
    statsDisabled              bool               // Flag to disable cache statistics.
    statsHandler               stats.Handler      // Metrics statsHandler collector.
    sourceID                   string             // Unique identifier for cache instance.
    syncLocal                  bool               // Enable events for syncing local cache (only for "Both" cache type).
    eventChBufSize             int                // Buffer size for event channel (default: 100).
    eventHandler               func(event *Event) // Function to handle local cache invalidation events.
}

import "github.com/mgtv-tech/jetcache-go/logger"

// Set your Logger
logger.SetDefaultLogger(l logger.Logger)

import (
    "github.com/mgtv-tech/jetcache-go"
    "github.com/mgtv-tech/jetcache-go/encoding"
)

// Register your codec
encoding.RegisterCodec(codec Codec)

// Set your codec name
mycache := cache.New("any",
    cache.WithRemote(...),
    cache.WithCodec(yourCodecName string))

mycache := cache.New(cache.WithName("any"),
       // ...
       // cache.WithRefreshDuration sets the asynchronous refresh interval
       cache.WithRefreshDuration(time.Minute),
       // cache.WithStopRefreshAfterLastAccess sets the time to cancel the refresh task after the cache key is not accessed
        cache.WithStopRefreshAfterLastAccess(time.Hour))

// `Once` interface starts automatic refresh by `cache.Refresh(true)`
err := mycache.Once(ctx, key, cache.Value(obj), cache.Refresh(true), cache.Do(func(ctx context.Context) (any, error) {
    return mockDBGetObject(1)
}))

mycache := cache.New(cache.WithName("any"),
       // ...
       cache.WithRemoteExpiry(time.Minute),
    )
cacheT := cache.NewT[int, *object](mycache)

ctx := context.TODO()
key := "mykey"
ids := []int{1, 2, 3}

ret := mycache.MGet(ctx, key, ids, func(ctx context.Context, ids []int) (map[int]*object, error) {
    return mockDBMGetObject(ids)
})

 _ "github.com/mgtv-tech/jetcache-go/encoding/sonic"