package main

import (
	"context"
	"database/sql"
	"fmt"
	"log"
	"net/url"
	"os"
	"strconv"
	"strings"
	"time"

	"github.com/brianvoe/gofakeit/v7"
	"github.com/go-sql-driver/mysql"
	"github.com/gofiber/fiber/v2"
	"github.com/mroth/weightedrand"
	"github.com/segmentio/kafka-go"
)

func ByteCountSI(b int) string {
	const unit = 1000
	if b < unit {
		return fmt.Sprintf("%dB", b)
	}
	div, exp := int(unit), 0
	for n := b / unit; n >= unit; n /= unit {
		div *= unit
		exp++
	}
	return fmt.Sprintf("%.1f%cB",
		float64(b)/float64(div), "kMGTPE"[exp])
}

func main() {
	log.Println("Neptune Project v0.1")

	DATABASE_HOST, ok := os.LookupEnv("DATABASE_HOST")
	if !ok {
		log.Fatalln("DATABASE_HOST_NOT_FOUND")
	}

	DATABASE_PORT, ok := os.LookupEnv("DATABASE_PORT")
	if !ok {
		log.Fatalln("DATABASE_PORT_NOT_FOUND")
	}

	DATABASE_USER, ok := os.LookupEnv("DATABASE_USER")
	if !ok {
		log.Fatalln("DATABASE_USER_NOT_FOUND")
	}

	DATABASE_PASS, ok := os.LookupEnv("DATABASE_PASS")
	if !ok {
		log.Fatalln("DATABASE_PASS_NOT_FOUND")
	}

	DATABASE_SCHEMA, ok := os.LookupEnv("DATABASE_SCHEMA")
	if !ok {
		log.Fatalln("DATABASE_SCHEMA_NOT_FOUND")
	}

	_, DISABLE_LARGE_POOL := os.LookupEnv("DISABLE_LARGE_POOL")

	cfg := mysql.Config{
		User:                 DATABASE_USER,
		Passwd:               DATABASE_PASS,
		Net:                  "tcp",
		Addr:                 DATABASE_HOST + ":" + DATABASE_PORT,
		DBName:               DATABASE_SCHEMA,
		AllowNativePasswords: true,
	}

	db, err := sql.Open("mysql", cfg.FormatDSN())
	if err != nil {
		log.Fatalln("DATABASE_OPEN_FAILED")
	}

	err = db.Ping()
	if err != nil {
		log.Fatalln("DATABASE_CONNECTION_FAILED")
	}

	if !DISABLE_LARGE_POOL {
		stopConn := false
		log.Println("Creating large DB connection pool... Please wait...")
		for i := 0; i < 7000; i++ {
			db, err := sql.Open("mysql", cfg.FormatDSN())
			if err != nil {
				log.Println("DATABASE_OPEN_FAILED")
			}

			_, err = db.Query("SELECT 1")
			if err != nil {
				stopConn = true
			}
		}

		if stopConn {
			log.Println("DATABASE_CONNECTION_FAILED")
			log.Println("Ctrl+C to terminate DB connection pool")
			<-make(chan int)
		}
	}

	app := fiber.New(fiber.Config{
		DisableStartupMessage: true,
	})

	app.Post("/api/streams/persist", func(c *fiber.Ctx) error {
		data := struct {
			GeneratedUserId string `json:"generated_user_id"`
		}{}

		data.GeneratedUserId = gofakeit.UUID()

		stmt, err := db.Prepare("INSERT INTO user (user_id, preferred_category, created_at) VALUES (?, ?, ?)")
		if err != nil {
			log.Println("DATABASE_PREPARE_FAILED")
		}

		stmt.Exec(data.GeneratedUserId, "Test Category", time.Now())
		stmt.Close()

		for j := 0; j < 10; j++ {
			stmt2, err := db.Prepare("INSERT INTO purchase (user_id, purchase_id, item_id, item_category, created_at) VALUES (?, ?, ?, ?, ?)")

			if err != nil {
				log.Println("DATABASE_PREPARE_FAILED")
			}

			stmt2.Exec(data.GeneratedUserId, gofakeit.UUID(), gofakeit.UUID(), "Test Category", time.Now())
			stmt2.Close()
		}

		return c.JSON(data)
	})

	go func() {
		for {
			preferred_categories, _ := weightedrand.NewChooser(
				weightedrand.Choice{Item: "Development", Weight: gofakeit.UintN(10) + 1},
				weightedrand.Choice{Item: "Novel", Weight: gofakeit.UintN(10) + 1},
				weightedrand.Choice{Item: "Cookbook", Weight: gofakeit.UintN(10) + 1},
				weightedrand.Choice{Item: "Journal", Weight: gofakeit.UintN(10) + 1},
				weightedrand.Choice{Item: "Art", Weight: gofakeit.UintN(10) + 1},
				weightedrand.Choice{Item: "History", Weight: gofakeit.UintN(10) + 1},
				weightedrand.Choice{Item: "Science", Weight: gofakeit.UintN(10) + 1},
			)

			for i := 1; i <= 20*60; i++ {
				stmt, err := db.Prepare("INSERT INTO user (user_id, preferred_category, created_at) VALUES (?, ?, ?)")
				if err != nil {
					log.Println("DATABASE_PREPARE_FAILED")
				}

				user_id := gofakeit.UUID()
				preferred_category := preferred_categories.Pick().(string)

				stmt.Exec(user_id, preferred_category, time.Now())
				stmt.Close()

				for j := 0; j < gofakeit.IntN(6); j++ {
					stmt2, err := db.Prepare("INSERT INTO purchase (user_id, purchase_id, item_id, item_category, created_at) VALUES (?, ?, ?, ?, ?)")

					if err != nil {
						log.Println("DATABASE_PREPARE_FAILED")
					}

					preferred_category2 := preferred_categories.Pick().(string)
					stmt2.Exec(user_id, gofakeit.UUID(), gofakeit.UUID(), preferred_category2, time.Now())
					stmt2.Close()
				}

				time.Sleep(50 * time.Millisecond)
			}
		}
	}()

	func() {
		KAFKA_BROKERS, ok := os.LookupEnv("KAFKA_BROKERS")
		if !ok {
			return
		}

		KAFKA_TOPIC, ok := os.LookupEnv("KAFKA_TOPIC")
		if !ok {
			log.Fatalln("KAFKA_TOPIC_NOT_FOUND")
		}

		writer := &kafka.Writer{
			Addr:                   kafka.TCP(strings.Split(KAFKA_BROKERS, ",")...),
			Topic:                  KAFKA_TOPIC,
			AllowAutoTopicCreation: true,
			Balancer:               &kafka.LeastBytes{},
			BatchTimeout:           10 * time.Millisecond,
			Async:                  true,
		}

		app.Post("/api/streams/telemetry", func(c *fiber.Ctx) error {
			data := struct {
				GeneratedUserId    string `json:"generated_user_id"`
				GeneratedCategory  string `json:"generated_category"`
				GeneratedSessionId string `json:"generated_session_id"`
			}{}

			data.GeneratedUserId = gofakeit.UUID()
			data.GeneratedCategory = gofakeit.UUID()

			messages := []kafka.Message{}
			for i := 0; i < 10; i++ {
				messages = append(messages, kafka.Message{
					Value: []byte(fmt.Sprintf("{\"type\":\"login\",\"details\":{\"user_id\":\"%s\",\"user_name\":\"%s\",\"user_age\":%d},\"credentials\":{\"session_id\":\"ubks_%s\",\"session_issuer\":\"mainsvc__vNeptune_1\",\"sys_trace_id\":\"ubks__mainsvc__vNeptune_1_%s\"},\"event_at\":\"%s\"}",
						data.GeneratedUserId, gofakeit.Name(), gofakeit.IntRange(16, 65), "manual_generated", gofakeit.UUID(), time.Now().Format("2006-01-02T15:04:05.999999-07:00"))),
				})
			}

			for i := 0; i < 5; i++ {
				messages = append(messages,
					kafka.Message{
						Value: []byte(fmt.Sprintf("{\"type\":\"select\",\"details\":{\"element\":\"#%s\",\"value\":\"%s\"},\"credentials\":{\"session_id\":\"ubks_%s\",\"session_issuer\":\"mainsvc__vNeptune_1\",\"sys_trace_id\":\"ubks__mainsvc__vNeptune_1_%s\"},\"event_at\":\"%s\"}",
							"searchFilterSelector", data.GeneratedCategory, "HIDE_ME", gofakeit.UUID(), time.Now().Format("2006-01-02T15:04:05.999999-07:00"))),
					})
			}

			for i := 0; i < 5; i++ {
				messages = append(messages,
					kafka.Message{
						Value: []byte(fmt.Sprintf("{\"type\":\"select\",\"details\":{\"element\":\"#%s\",\"value\":\"%s\"},\"credentials\":{\"session_id\":\"ubks_%s\",\"session_issuer\":\"mainsvc__vNeptune_1\",\"sys_trace_id\":\"ubks__mainsvc__vNeptune_1_%s\"},\"event_at\":\"%s\"}",
							"categorySelector", data.GeneratedCategory, "HIDE_ME", gofakeit.UUID(), time.Now().Format("2006-01-02T15:04:05.999999-07:00"))),
					})
			}

			for i := 0; i < 5; i++ {
				messages = append(messages,
					kafka.Message{
						Value: []byte(fmt.Sprintf("{\"type\":\"select\",\"details\":{\"element\":\"#%s\",\"value\":\"%s\"},\"credentials\":{\"session_id\":null,\"session_issuer\":null,\"sys_trace_id\":\"ubks__mainsvc__vNeptune_1_%s\"},\"event_at\":\"%s\"}",
							"categorySelector", data.GeneratedCategory, gofakeit.UUID(), time.Now().Format("2006-01-02T15:04:05.999999-07:00"))),
					})
			}

			data.GeneratedSessionId = gofakeit.UUID()
			click_events1 := []string{}
			click_events2 := []string{}

			for j := 0; j < 5; j++ {
				click_events1 = append(click_events1, fmt.Sprintf("{\"type\":\"click\",\"details\":{\"element\":\".%s\",\"content\":{\"item_name\":\"%s\",\"item_category\":\"%s\",\"item_location\":\"%s\"}},\"credentials\":{\"session_id\":\"ubks_%s\",\"session_issuer\":\"mainsvc__vNeptune_1\",\"sys_trace_id\":\"ubks__mainsvc__vNeptune_1_%s\"},\"event_at\":\"%s\"}",
					"bookItem", gofakeit.Adjective()+" "+gofakeit.Noun(), data.GeneratedCategory, gofakeit.Street(), data.GeneratedSessionId, gofakeit.UUID(), time.Now().Format("2006-01-02T15:04:05.999999-07:00")))
			}

			for j := 0; j < 5; j++ {
				click_events2 = append(click_events2, fmt.Sprintf("{\"type\":\"click\",\"details\":{\"element\":\".%s\",\"content\":{\"item_name\":\"%s\",\"item_category\":\"%s\",\"item_location\":\"%s\"}},\"credentials\":{\"session_id\":\"ubks_%s\",\"session_issuer\":\"mainsvc__vNeptune_1\",\"sys_trace_id\":\"ubks__mainsvc__vNeptune_1_%s\"},\"event_at\":\"%s\"}",
					"bookItem", gofakeit.Adjective()+" "+gofakeit.Noun(), data.GeneratedCategory, gofakeit.Street(), data.GeneratedSessionId, gofakeit.UUID(), time.Now().Format("2006-01-02T15:04:05.999999-07:00")))
			}

			messages = append(messages,
				kafka.Message{
					Value: []byte(fmt.Sprintf("{\"type\":\"login\",\"details\":{\"user_id\":\"%s\",\"user_name\":\"%s\",\"user_age\":%d},\"credentials\":{\"session_id\":\"ubks_%s\",\"session_issuer\":\"mainsvc__vNeptune_1\",\"sys_trace_id\":\"ubks__mainsvc__vNeptune_1_%s\"},\"event_at\":\"%s\"}",
						gofakeit.Username(), gofakeit.Name(), gofakeit.IntRange(16, 65), data.GeneratedSessionId, gofakeit.UUID(), time.Now().Format("2006-01-02T15:04:05.999999-07:00"))),
				},
				kafka.Message{
					Value: []byte("[" + strings.Join(click_events1, ",") + "]"),
				},
				kafka.Message{
					Value: []byte("[" + strings.Join(click_events2, ",") + "]"),
				})

			writer.WriteMessages(context.Background(),
				messages...,
			)

			return c.JSON(data)
		})

		go func() {
			for {
				preferred_categories, _ := weightedrand.NewChooser(
					weightedrand.Choice{Item: "Development", Weight: gofakeit.UintN(10) + 1},
					weightedrand.Choice{Item: "Novel", Weight: gofakeit.UintN(10) + 1},
					weightedrand.Choice{Item: "Cookbook", Weight: gofakeit.UintN(10) + 1},
					weightedrand.Choice{Item: "Journal", Weight: gofakeit.UintN(10) + 1},
					weightedrand.Choice{Item: "Art", Weight: gofakeit.UintN(10) + 1},
					weightedrand.Choice{Item: "History", Weight: gofakeit.UintN(10) + 1},
					weightedrand.Choice{Item: "Science", Weight: gofakeit.UintN(10) + 1},
				)

				for i := 1; i <= 10*60*5; i++ {
					click_events := []string{}
					click_event_count := gofakeit.IntRange(1, 5)
					is_anon := gofakeit.IntN(10) > 3

					if is_anon {
						for j := 0; j < click_event_count; j++ {
							click_events = append(click_events, fmt.Sprintf("{\"type\":\"click\",\"details\":{\"element\":\".%s\",\"content\":{\"item_name\":\"%s\",\"item_category\":\"%s\",\"item_location\":\"%s\"}},\"credentials\":{\"session_id\":null,\"session_issuer\":null,\"sys_trace_id\":\"ubks__mainsvc__vNeptune_1_%s\"},\"event_at\":\"%s\"}",
								gofakeit.RandomString([]string{"bookItem", "audioItem"}), gofakeit.Adjective()+" "+gofakeit.Noun(), preferred_categories.Pick().(string), gofakeit.Street(), gofakeit.UUID(), time.Now().Format("2006-01-02T15:04:05.999999-07:00")))
						}

						writer.WriteMessages(context.Background(),
							kafka.Message{
								Value: []byte("[" + strings.Join(click_events, ",") + "]"),
							},
							kafka.Message{
								Value: []byte(fmt.Sprintf("{\"type\":\"select\",\"details\":{\"element\":\"#%s\",\"value\":\"%s\"},\"credentials\":{\"session_id\":null,\"session_issuer\":null,\"sys_trace_id\":\"ubks__mainsvc__vNeptune_1_%s\"},\"event_at\":\"%s\"}",
									gofakeit.RandomString([]string{"categorySelector", "searchFilterSelector"}), preferred_categories.Pick(), gofakeit.UUID(), time.Now().Format("2006-01-02T15:04:05.999999-07:00"))),
							},
							kafka.Message{
								Value: []byte(fmt.Sprintf("{\"type\":\"move\",\"details\":{\"page\":\"/%s/%s\"},\"event_at\":\"%s\"}",
									gofakeit.Adjective(), gofakeit.Noun(), time.Now().Format("2006-01-02T15:04:05.999999-07:00"))),
							},
							kafka.Message{
								Value: []byte(fmt.Sprintf("{\"type\":\"error\",\"details\":{\"page\":\"/%s/%s\",\"message\":\"%s\"},\"event_at\":\"%s\"}",
									gofakeit.Adjective(), gofakeit.Noun(), gofakeit.LoremIpsumSentence(100), time.Now().Format("2006-01-02T15:04:05.999999-07:00"))),
							},
						)
					} else {
						session_id := gofakeit.UUID()
						for j := 0; j < click_event_count; j++ {
							click_events = append(click_events, fmt.Sprintf("{\"type\":\"click\",\"details\":{\"element\":\".%s\",\"content\":{\"item_name\":\"%s\",\"item_category\":\"%s\",\"item_location\":\"%s\"}},\"credentials\":{\"session_id\":\"ubks_%s\",\"session_issuer\":\"mainsvc__vNeptune_1\",\"sys_trace_id\":\"ubks__mainsvc__vNeptune_1_%s\"},\"event_at\":\"%s\"}",
								gofakeit.RandomString([]string{"bookItem", "audioItem"}), gofakeit.Adjective()+" "+gofakeit.Noun(), preferred_categories.Pick().(string), gofakeit.Street(), session_id, gofakeit.UUID(), time.Now().Format("2006-01-02T15:04:05.999999-07:00")))
						}

						writer.WriteMessages(context.Background(),
							kafka.Message{
								Value: []byte(fmt.Sprintf("{\"type\":\"login\",\"details\":{\"user_id\":\"%s\",\"user_name\":\"%s\",\"user_age\":%d},\"credentials\":{\"session_id\":\"ubks_%s\",\"session_issuer\":\"mainsvc__vNeptune_1\",\"sys_trace_id\":\"ubks__mainsvc__vNeptune_1_%s\"},\"event_at\":\"%s\"}",
									gofakeit.Username(), gofakeit.Name(), gofakeit.IntRange(16, 65), session_id, gofakeit.UUID(), time.Now().Format("2006-01-02T15:04:05.999999-07:00"))),
							},
							kafka.Message{
								Value: []byte("[" + strings.Join(click_events, ",") + "]"),
							},
							kafka.Message{
								Value: []byte(fmt.Sprintf("{\"type\":\"select\",\"details\":{\"element\":\"#%s\",\"value\":\"%s\"},\"credentials\":{\"session_id\":\"ubks_%s\",\"session_issuer\":\"mainsvc__vNeptune_1\",\"sys_trace_id\":\"ubks__mainsvc__vNeptune_1_%s\"},\"event_at\":\"%s\"}",
									gofakeit.RandomString([]string{"categorySelector", "searchFilterSelector"}), preferred_categories.Pick(), session_id, gofakeit.UUID(), time.Now().Format("2006-01-02T15:04:05.999999-07:00"))),
							},
							kafka.Message{
								Value: []byte(fmt.Sprintf("{\"type\":\"move\",\"details\":{\"page\":\"/%s/%s\"},\"event_at\":\"%s\"}",
									gofakeit.Adjective(), gofakeit.Noun(), time.Now().Format("2006-01-02T15:04:05.999999-07:00"))),
							},
							kafka.Message{
								Value: []byte(fmt.Sprintf("{\"type\":\"error\",\"details\":{\"page\":\"/%s/%s\",\"message\":\"%s\"},\"event_at\":\"%s\"}",
									gofakeit.Adjective(), gofakeit.Noun(), gofakeit.LoremIpsumSentence(100), time.Now().Format("2006-01-02T15:04:05.999999-07:00"))),
							},
						)
					}

					time.Sleep(10 * time.Millisecond)
				}
			}
		}()
	}()

	app.Post("/api/streams/log", func(c *fiber.Ctx) error {
		data := struct {
			GeneratedReferrer string `json:"generated_referrer"`
			GeneratedCount    int    `json:"generated_count"`
			SampledLog        string `json:"sampled_log"`
		}{}

		data.GeneratedCount = 100000
		data.GeneratedReferrer = gofakeit.Noun() + ".test.com"

		for i := 0; i < data.GeneratedCount; i++ {
			method := gofakeit.HTTPMethod()
			referrer := gofakeit.RandomString([]string{"http://", "https://"}) + data.GeneratedReferrer + ":" + gofakeit.RandomString([]string{"80", "443", "8080", "8443", "8000", "5000"}) + "/" + url.PathEscape(gofakeit.Adjective()) + "/" + url.PathEscape(gofakeit.Noun())

			if method == "GET" || method == "HEAD" || method == "DELETE" {
				fmt.Printf("%s - [%s] %s %s %d %s %s %s \"%s\"\n",
					gofakeit.IPv4Address(),
					time.Now().Format("2006-01-02T15:04:05.999999 -07:00"),
					method,
					"/api/qry/"+url.PathEscape(gofakeit.Noun())+"?_qtt="+gofakeit.UUID()+"&_st="+url.QueryEscape(gofakeit.StreetName()),
					gofakeit.HTTPStatusCode(),
					"100MB",
					"100s",
					referrer,
					gofakeit.UserAgent())
			} else {
				fmt.Printf("%s - [%s] %s %s %d %s %s %s %s \"%s\"\n",
					gofakeit.IPv4Address(),
					time.Now().Format("2006-01-02T15:04:05.999999 -07:00"),
					method,
					"/api/products?_qcw="+gofakeit.UUID()+"&_rf="+gofakeit.UUID(),
					gofakeit.HTTPStatusCode(),
					"100MB",
					"100MB",
					"100s",
					referrer,
					gofakeit.UserAgent())
			}
		}

		data.SampledLog = fmt.Sprintf("%s - [%s] %s %s %d %s %s %s %s \"%s\"",
			gofakeit.IPv4Address(),
			time.Now().Format("2006-01-02T15:04:05.999999 -07:00"),
			"POST",
			"/test",
			201,
			"1MB",
			"1B",
			"1s",
			"http://referrer",
			"test/"+gofakeit.UUID())

		fmt.Println(data.SampledLog)
		return c.JSON(data)
	})

	go func() {
		for {
			rxSeed := gofakeit.IntN(50) + 1
			txSeed := gofakeit.IntN(100) + 1
			lateSeed := gofakeit.IntN(12) + 1

			referrers, _ := weightedrand.NewChooser(
				weightedrand.Choice{Item: "search.example.com", Weight: gofakeit.UintN(10) + 1},
				weightedrand.Choice{Item: "ad.unicorncorp.net", Weight: gofakeit.UintN(10) + 1},
				weightedrand.Choice{Item: "wiki.spreadinghoax.org", Weight: gofakeit.UintN(10) + 1},
				weightedrand.Choice{Item: "books.unicorn.com", Weight: 15},
			)

			for i := 1; i <= 20*60; i++ {
				method := gofakeit.HTTPMethod()
				duration, _ := time.ParseDuration(strconv.Itoa(gofakeit.IntN(100*lateSeed)) + "ms")
				referrer := gofakeit.RandomString([]string{"http://", "https://"}) + referrers.Pick().(string) + ":" + gofakeit.RandomString([]string{"80", "443", "8080", "8443", "8000", "5000"}) + "/" + url.PathEscape(gofakeit.Adjective()) + "/" + url.PathEscape(gofakeit.Noun())

				if method == "GET" || method == "HEAD" || method == "DELETE" {
					fmt.Printf("%s - [%s] %s %s %d %s %s %s \"%s\"\n",
						gofakeit.IPv4Address(),
						time.Now().Format("2006-01-02T15:04:05.999999 -07:00"),
						method,
						"/api/qry/"+url.PathEscape(gofakeit.Noun())+"?_qtt="+gofakeit.UUID()+"&_st="+url.QueryEscape(gofakeit.StreetName()),
						gofakeit.HTTPStatusCode(),
						ByteCountSI(gofakeit.IntN(1000*10*txSeed)),
						duration,
						referrer,
						gofakeit.UserAgent())
				} else {
					fmt.Printf("%s - [%s] %s %s %d %s %s %s %s \"%s\"\n",
						gofakeit.IPv4Address(),
						time.Now().Format("2006-01-02T15:04:05.999999 -07:00"),
						method,
						"/api/products?_qcw="+gofakeit.UUID()+"&_rf="+gofakeit.UUID(),
						gofakeit.HTTPStatusCode(),
						ByteCountSI(gofakeit.IntN(100*rxSeed)),
						ByteCountSI(gofakeit.IntN(1000*txSeed)),
						duration,
						referrer,
						gofakeit.UserAgent())
				}

				time.Sleep(50 * time.Millisecond)
			}
		}
	}()

	app.Listen(":8080")
}