routes.go

package main

import (
	"context"
	"errors"
	"fmt"
	"io"
	"log"
	"math"
	"net/http"
	"strconv"
	"strings"
	"sync"
	"time"

	"github.com/redis/go-redis/v9"

	"github.com/google/uuid"

	"pkg.jsn.cam/abacus/utils"

	"github.com/gin-gonic/gin"
)

func StreamValueView(c *gin.Context) {
	namespace, key := utils.GetNamespaceKey(c)
	if namespace == "" || key == "" {
		c.AbortWithStatus(http.StatusBadRequest)
		return
	}

	dbKey := utils.CreateKey(c, namespace, key, false)
	if dbKey == "" {
		c.AbortWithStatus(http.StatusBadRequest)
		return
	}

	// Set SSE headers
	c.Header("Content-Type", "text/event-stream")
	c.Header("Cache-Control", "no-cache")
	c.Header("Connection", "keep-alive")

	// Initialize client channel with a buffer to prevent blocking
	clientChan := make(chan int, 100)

	// Create a context that's canceled when the client disconnects
	ctx := c.Request.Context()

	// Add this client to the event server for this specific key
	utils.ValueEventServer.NewClients <- utils.KeyClientPair{
		Key:    dbKey,
		Client: clientChan,
	}

	// Track if cleanup has been done
	var cleanupDone bool
	var cleanupMutex sync.Mutex

	// Ensure client is always removed when handler exits
	defer func() {
		cleanupMutex.Lock()
		if !cleanupDone {
			cleanupDone = true
			cleanupMutex.Unlock()

			// Signal the event server to remove this client
			select {
			case utils.ValueEventServer.ClosedClients <- utils.KeyClientPair{Key: dbKey, Client: clientChan}:
				// Successfully sent cleanup signal
			case <-time.After(500 * time.Millisecond):
				// Timed out waiting to send cleanup signal
				log.Printf("Warning: Timed out sending cleanup signal for %s", dbKey)
			}
		} else {
			cleanupMutex.Unlock()
		}
	}()

	// Monitor for client disconnection in a separate goroutine
	go func() {
		<-ctx.Done() // Wait for context cancellation (client disconnected)

		cleanupMutex.Lock()
		if !cleanupDone {
			cleanupDone = true
			cleanupMutex.Unlock()

			log.Printf("Client disconnected for key %s, cleaning up", dbKey)

			// Signal the event server to remove this client
			select {
			case utils.ValueEventServer.ClosedClients <- utils.KeyClientPair{Key: dbKey, Client: clientChan}:
				// Successfully sent cleanup signal
			case <-time.After(500 * time.Millisecond):
				// Timed out waiting to send cleanup signal
				log.Printf("Warning: Timed out sending cleanup signal for %s after disconnect", dbKey)
			}
		} else {
			cleanupMutex.Unlock()
		}
	}()

	// Send initial value
	initialVal := Client.Get(context.Background(), dbKey).Val()
	if count, err := strconv.Atoi(initialVal); err == nil {
		// Keep your exact format
		_, err := c.Writer.WriteString(fmt.Sprintf("data: {\"value\":%d}\n\n", count))
		if err != nil {
			log.Printf("Error writing to client: %v", err)
			return
		}
		c.Writer.Flush()
	}

	// Stream updates
	c.Stream(func(w io.Writer) bool {
		select {
		case <-ctx.Done():
			return false
		case count, ok := <-clientChan:
			if !ok {
				return false
			}
			// Keep your exact format
			_, err := c.Writer.WriteString(fmt.Sprintf("data: {\"value\":%d}\n\n", count))
			if err != nil {
				log.Printf("Error writing to client: %v", err)
				return false
			}
			c.Writer.Flush()
			return true
		}
	})
}

func HitView(c *gin.Context) {
	namespace, key := utils.GetNamespaceKey(c)
	if namespace == "" || key == "" {
		return
	}
	dbKey := utils.CreateKey(c, namespace, key, false)
	if dbKey == "" { // error is handled in CreateKey
		return
	}
	// Get data from Redis
	val, err := Client.Incr(context.Background(), dbKey).Result()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to get data. Try again later."})
		return
	}
	// check if val is is greater than the max value of an int
	if val > math.MaxInt {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Value is too large. Max value is " + strconv.Itoa(math.
			MaxInt), "message": "If you are seeing this error and have a legitimate use case, please contact me @ abacus@jasoncameron.dev"})
		return
	}
	go func() {
		utils.SetStream(dbKey, int(val)) // #nosec G115 -- This is safe as we perform a check (
		// see above) to ensure val is within the range of an int.
		Client.Expire(context.Background(), dbKey, utils.BaseTTLPeriod)
	}()
	if c.Query("callback") != "" {
		c.JSONP(http.StatusOK, gin.H{"value": val})

	} else {
		c.JSON(http.StatusOK, gin.H{"value": val})

	}
}

func HitShieldView(c *gin.Context) {
	namespace, key := utils.GetNamespaceKey(c)
	if namespace == "" || key == "" {
		return
	}

	dbKey := utils.CreateKey(c, namespace, key, false)
	if dbKey == "" { // error is handled in CreateKey
		return
	}
	// Get data from Redis
	val, err := Client.Incr(context.Background(), dbKey).Result()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to get data. Try again later."})
		return
	}
	// check if val is is greater than the max value of an int
	if val > math.MaxInt {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Value is too large. Max value is " + strconv.Itoa(math.
			MaxInt), "message": "If you are seeing this error and have a legitimate use case, please contact me @ abacus@jasoncameron.dev"})
		return
	}
	go func() {
		utils.SetStream(dbKey, int(val)) // #nosec G115 -- This is safe as we perform a check (
		// see above) to ensure val is within the range of an int.
		Client.Expire(context.Background(), dbKey, utils.BaseTTLPeriod)
	}()

	badgeSVG, err := utils.GenerateBadge(c, val)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error:": err.Error()})
		return
	}
	c.Header("Content-Type", "image/svg+xml")
	// github camo likes caching this
	c.Header("Cache-Control", "max-age=0, no-cache, no-store, must-revalidate")
	c.Data(http.StatusOK, "image/svg+xml", badgeSVG)
}

func GetView(c *gin.Context) {
	namespace, key := utils.GetNamespaceKey(c)
	if namespace == "" || key == "" {
		return
	}
	dbKey := utils.CreateKey(c, namespace, key, false)
	if dbKey == "" { // error is handled in CreateKey
		return
	}
	// Get data from Redis
	val, err := Client.Get(context.Background(), dbKey).Result()

	if errors.Is(err, redis.Nil) {
		c.JSON(http.StatusNotFound, gin.H{"error": "Key not found"})
		return
	} else if err != nil { // Other Redis errors
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to get data. Try again later."})
		return
	}

	go func() {
		Client.Expire(context.Background(), dbKey, utils.BaseTTLPeriod)
	}()
	intval, _ := strconv.Atoi(val)
	if c.Query("callback") != "" {
		c.JSONP(http.StatusOK, gin.H{"value": intval})

	} else {
		c.JSON(http.StatusOK, gin.H{"value": intval})

	}
}

func GetShieldView(c *gin.Context) {
	namespace, key := utils.GetNamespaceKey(c)
	if namespace == "" || key == "" {
		return
	}
	dbKey := utils.CreateKey(c, namespace, key, false)
	if dbKey == "" { // error is handled in CreateKey
		return
	}
	// Get data from Redis
	val, err := Client.Get(context.Background(), dbKey).Result()

	if errors.Is(err, redis.Nil) {
		c.JSON(http.StatusNotFound, gin.H{"error": "Key not found"})
		return
	} else if err != nil { // Other Redis errors
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to get data. Try again later."})
		return
	}

	go func() {
		Client.Expire(context.Background(), dbKey, utils.BaseTTLPeriod)
	}()

	intval, convErr := strconv.ParseInt(val, 10, 64)
	if convErr != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to get data. Invalid data format."})
		return
	}

	badgeSVG, err := utils.GenerateBadge(c, intval)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to get SVG data."})
		return
	}
	c.Header("Content-Type", "image/svg+xml")
	c.Data(http.StatusOK, "image/svg+xml", badgeSVG)
}

func CreateRandomView(c *gin.Context) {
	key, _ := utils.GenerateRandomString(16)
	namespace, err := utils.GenerateRandomString(16)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to generate random string. Try again later."})
		return
	}

	c.Params = gin.Params{gin.Param{Key: "namespace", Value: namespace}, gin.Param{Key: "key", Value: key}}
	CreateView(c)
}
func CreateView(c *gin.Context) {
	namespace, key := utils.GetNamespaceKey(c)
	if namespace == "" || key == "" {
		return
	}
	dbKey := utils.CreateKey(c, namespace, key, false)
	if dbKey == "" { // error is handled in CreateKey
		return
	}
	initialValue, err := strconv.Atoi(c.DefaultQuery("initializer", "0"))
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "initializer must be a number"})
		return
	}
	// Get data from Redis
	created := Client.SetNX(context.Background(), dbKey, initialValue, utils.BaseTTLPeriod)
	if created.Val() == false {
		c.JSON(http.StatusConflict, gin.H{"error": "Key already exists, please use a different key."})
		return
	}
	AdminKey := uuid.New().String()                                            // Create a new admin key used for deletion and control
	Client.Set(context.Background(), utils.CreateAdminKey(dbKey), AdminKey, 0) // todo: figure out how to handle admin keys (handle alongside admin orrrrrrr separately as in a routine once a month that deletes all admin keys with no corresponding key)
	utils.SetStream(dbKey, initialValue)
	c.JSON(http.StatusCreated, gin.H{"key": key, "namespace": namespace, "admin_key": AdminKey, "value": initialValue})
}

func InfoView(c *gin.Context) { // todo: write docs on what negative values mean (https://redis.io/commands/ttl/)
	namespace, key := utils.GetNamespaceKey(c)
	if namespace == "" || key == "" {
		return
	}
	dbKey := utils.CreateKey(c, namespace, key, true)
	if dbKey == "" { // error is handled in CreateKey
		return
	}
	dbValue := Client.Get(context.Background(), dbKey).Val()
	count, _ := strconv.Atoi(dbValue)

	isGenuine := Client.Exists(context.Background(), utils.CreateAdminKey(dbKey)).Val() == 0
	expiresAt := Client.TTL(context.Background(), dbKey).Val()
	exists := expiresAt != -2
	if !exists {
		count = -1
	}
	c.JSON(http.StatusOK, gin.H{"value": count, "full_key": dbKey, "is_genuine": isGenuine, "expires_in": expiresAt.Seconds(), "expires_str": expiresAt.String(), "exists": exists})
}

func DeleteView(c *gin.Context) {
	namespace, key := utils.GetNamespaceKey(c)
	if namespace == "" || key == "" {
		return
	}
	dbKey := utils.CreateKey(c, namespace, key, true)
	if dbKey == "" { // error is handled in CreateKey
		return
	}
	adminDBKey := utils.CreateAdminKey(dbKey)    // Create the admin key
	Client.Del(context.Background(), dbKey)      // Delete the normal key
	Client.Del(context.Background(), adminDBKey) // delete the admin key as it's now useless
	c.JSON(http.StatusOK, gin.H{"status": "ok", "message": "Deleted key: " + dbKey})
	utils.CloseStream(dbKey)
}

func SetView(c *gin.Context) {
	updatedValueRaw, _ := c.GetQuery("value")
	if updatedValueRaw == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "value is required, please provide a number in the fmt of ?value=NEW_VALUE"})
		return

	}
	updatedValue, err := strconv.Atoi(updatedValueRaw)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "value must be a number"})
		return
	}
	namespace, key := utils.GetNamespaceKey(c)
	if namespace == "" || key == "" {
		return
	}
	dbKey := utils.CreateKey(c, namespace, key, false)
	if dbKey == "" { // error is handled in CreateKey
		return
	}

	// Get data from Redis
	val, err := Client.SetXX(context.Background(), dbKey, updatedValue, utils.BaseTTLPeriod).Result()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to set data. Try again later."})
		return
	}
	if val == false {
		c.JSON(http.StatusConflict, gin.H{"error": "Key does not exist, please use a different key."})
	} else {
		go utils.SetStream(dbKey, updatedValue)
		c.JSON(http.StatusOK, gin.H{"value": updatedValue})
	}
}

func ResetView(c *gin.Context) {
	namespace, key := utils.GetNamespaceKey(c)
	if namespace == "" || key == "" {
		return
	}
	dbKey := utils.CreateKey(c, namespace, key, false)
	if dbKey == "" { // error is handled in CreateKey
		return
	}

	// Get data from Redis
	val, err := Client.SetXX(context.Background(), dbKey, 0, utils.BaseTTLPeriod).Result()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to set data. Try again later."})
		return
	}
	if val == false {
		c.JSON(http.StatusConflict, gin.H{"error": "Key does not exist, please use a different key."})
	} else {
		c.JSON(http.StatusOK, gin.H{"value": 0})
		go utils.SetStream(dbKey, 0)
	}
}

func UpdateByView(c *gin.Context) {
	updatedValueRaw, _ := c.GetQuery("value")
	if updatedValueRaw == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "value is required, please provide a number in the fmt of ?value=NEW_VALUE"})
		return

	}
	incrByValue, err := strconv.Atoi(updatedValueRaw)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "value must be a number, this means no floats."})
		return
	}
	if incrByValue == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "changing value by 0 does nothing, please provide a non-zero value in the fmt of ?value=NEW_VALUE"})
		return
	}
	namespace, key := utils.GetNamespaceKey(c)
	if namespace == "" || key == "" {
		return
	}
	dbKey := utils.CreateKey(c, namespace, key, false)
	if dbKey == "" { // error is handled in CreateKey
		return
	}

	exists := Client.Exists(context.Background(), dbKey).Val() == 0
	if exists {
		c.JSON(http.StatusConflict, gin.H{"error": "Key does not exist, please first create it using /create."})
		return
	}

	// Get data from Redis
	val, err := Client.IncrByFloat(context.Background(), dbKey, float64(incrByValue)).Result()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to set data. Try again later."})
		return
	}

	c.JSON(http.StatusOK, gin.H{"value": int64(val)})
	go utils.SetStream(dbKey, int(val))
}

func StatsView(c *gin.Context) {
	// get average ttl using INFO

	ctx := context.Background()
	infoStr, err := Client.Info(ctx).Result()
	if err != nil {
		panic(err)
	}

	infoDict := make(map[string]map[string]string)
	sections := strings.Split(infoStr, "\r\n\r\n")

	for _, section := range sections {
		lines := strings.Split(section, "\r\n")
		sectionName := lines[0][2:] // Remove "# " prefix

		infoDict[sectionName] = make(map[string]string)
		for _, line := range lines[1:] {
			parts := strings.Split(line, ":")
			if len(parts) == 2 {
				key := strings.TrimSpace(parts[0])
				value := strings.TrimSpace(parts[1])
				infoDict[sectionName][key] = value
			}
		}
	}

	total, _ := strconv.Atoi(Client.Get(ctx, "stats:Total").Val())

	hits, _ := strconv.Atoi(Client.Get(ctx, "stats:hit").Val())
	gets, _ := strconv.Atoi(Client.Get(ctx, "stats:get").Val())

	create, _ := strconv.Atoi(Client.Get(ctx, "stats:create").Val())

	totalKeys := create + (hits / 60) // 60 hits per key (average taken from the first 6m requests) ~ Json

	c.JSON(http.StatusOK, gin.H{
		"version":                     Version,
		"uptime":                      time.Since(StartTime).String(),
		"db_uptime":                   infoDict["Server"]["uptime_in_seconds"],
		"db_version":                  infoDict["Server"]["redis_version"],
		"expired_keys__since_restart": infoDict["Stats"]["expired_keys"],
		"key_misses__since_restart":   infoDict["Stats"]["keyspace_misses"],
		"commands": map[string]int{
			"total":  total,
			"get":    gets,
			"hit":    hits,
			"create": create,
		},
		"total_keys": totalKeys,
		"shard":      Shard,
	})
}