package main

import (
	"flag"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

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

func main() {
	gin.SetMode(gin.TestMode)
	// Define a command-line flag for the port
	port := flag.String("port", "8080", "port to listen on")

	// Define a command-line flag for the response message
	responseMessage := flag.String("respond", "hi", "message to respond with")

	silent := flag.Bool("silent", false, "disable all logging")

	flag.Parse() // Parse the command-line flags

	// Create a new Gin router
	r := gin.New()

	// Set up the handler function using the provided response message
	r.POST("/v1/chat/completions", func(c *gin.Context) {
		c.Header("Content-Type", "text/plain")

		// add a wait to simulate a slow query
		if wait, err := time.ParseDuration(c.Query("wait")); err == nil {
			time.Sleep(wait)
		}

		c.String(200, *responseMessage)
	})

	r.POST("/v1/completions", func(c *gin.Context) {
		c.Header("Content-Type", "text/plain")
		c.String(200, *responseMessage)
	})

	r.GET("/slow-respond", func(c *gin.Context) {
		echo := c.Query("echo")
		delay := c.Query("delay")

		if echo == "" {
			echo = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
		}

		// Parse the duration
		if delay == "" {
			delay = "100ms"
		}

		t, err := time.ParseDuration(delay)
		if err != nil {
			c.Header("Content-Type", "text/plain")
			c.String(http.StatusBadRequest, fmt.Sprintf("Invalid duration: %s", err))
			return
		}

		c.Header("Content-Type", "text/plain")
		for _, char := range echo {
			c.Writer.Write([]byte(string(char)))
			c.Writer.Flush()

			// wait
			<-time.After(t)
		}
	})

	r.GET("/test", func(c *gin.Context) {
		c.Header("Content-Type", "text/plain")
		c.String(200, *responseMessage)
	})

	r.GET("/env", func(c *gin.Context) {
		c.Header("Content-Type", "text/plain")
		c.String(200, *responseMessage)

		// Get environment variables
		envVars := os.Environ()

		// Write each environment variable to the response
		for _, envVar := range envVars {
			c.String(200, envVar)
		}
	})

	// Set up the /health endpoint handler function
	r.GET("/health", func(c *gin.Context) {
		c.Header("Content-Type", "application/json")
		c.JSON(200, gin.H{"status": "ok"})
	})

	r.GET("/", func(c *gin.Context) {
		c.Header("Content-Type", "text/plain")
		c.String(200, fmt.Sprintf("%s %s", c.Request.Method, c.Request.URL.Path))
	})

	address := "127.0.0.1:" + *port // Address with the specified port

	srv := &http.Server{
		Addr:    address,
		Handler: r.Handler(),
	}

	// Disable logging if the --silent flag is set
	if *silent {
		gin.SetMode(gin.ReleaseMode)
		gin.DefaultWriter = io.Discard
		log.SetOutput(io.Discard)
	}

	go func() {
		log.Printf("simple-responder listening on %s\n", address)
		// service connections
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("simple-responder err: %s\n", err)
		}
	}()

	// Wait for interrupt signal to gracefully shutdown the server with
	// a timeout of 5 seconds.
	quit := make(chan os.Signal, 1)
	// kill (no param) default send syscall.SIGTERM
	// kill -2 is syscall.SIGINT
	// kill -9 is syscall.SIGKILL but can't be catch, so don't need add it
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit
	log.Println("simple-responder shutting down")
}