package server

import (
	"PD2/internal/protocol"
	"PD2/internal/utils/cryptoUtils"
	"crypto/x509"
	"log"
	"net/http"
	"strconv"

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

func HandleGetUserCert(c *gin.Context, dataStore DataStore) {
	user := c.Param("user")
	userCertPacket, err := dataStore.GetUserCertificate(user)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
	} else {
		c.JSON(http.StatusOK, userCertPacket)
	}
}

func HandleStoreUserCert(c *gin.Context, dataStore DataStore) {
	user := c.Param("user")
	var storeUserCert protocol.StoreUserCert
	if err := c.Bind(storeUserCert); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	userCert, err := x509.ParseCertificate(storeUserCert.Certificate)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "User certificate is invalid"})
		return
	}

	err = dataStore.storeUserCertIfNotExists(user, *userCert)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "User already has a certificate stored in the database"})
		return
	}
	c.JSON(http.StatusOK, gin.H{})
}

func HandleGetUnreadMsgsInfo(c *gin.Context, dataStore DataStore) {
	user := c.Param("user")
	pageStr := c.Query("page")
	pagesizeStr := c.Query("pagesize")

    var page int
    var err error
	if pageStr != "" {
		page, err = strconv.Atoi(pageStr)
		if err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "Page is not a number"})
		}
	} else {
        page = 1
	}
	var pagesize int
	if pagesizeStr != "" {
		pagesize, err = strconv.Atoi(pagesizeStr)
		if err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "Pagesize is not a number"})
		}
	} else {
		pagesize = 5
	}

	if page <= 0 || pagesize <= 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Page and Pagesize need to be >= 1"})
		return
	}
	unreadMsgsInfo, err := dataStore.GetUnreadMsgsInfo(user, page, pagesize)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, unreadMsgsInfo)
}

func HandleSendMessage(c *gin.Context, dataStore DataStore) {
	sender := c.Param("user")

	var message protocol.SendMsg
	if err := c.BindJSON(message); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	if message.ToUID == sender {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Message sender and receiver cannot be the same user"})
		return
	}
	if !dataStore.userExists(message.ToUID) {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Message receiver does not exist"})
		return
	}
	err := dataStore.AddMessageToQueue(sender, message)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, nil)
}

func HandleGetMessage(c *gin.Context, dataStore DataStore) {
	user := c.Param("user")
	numStr := c.Param("num")
	num, err := strconv.Atoi(numStr)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
	}

	message, reportError := dataStore.GetMessage(user, num)
	if reportError != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
	}
	dataStore.MarkMessageInQueueAsRead(user, num)
	c.JSON(http.StatusOK, message)
}

func Run() {
	//Open connection to DB
	dataStore, err := OpenDB()
	if err != nil {
		log.Fatalln(err)
	}
	defer dataStore.db.Close()

	//Read server keystore
	keystorePassphrase := readStdin("Insert keystore passphrase")
	serverKeyStore, err := cryptoUtils.LoadKeyStore("certs/server/server.p12", keystorePassphrase)
	if err != nil {
		log.Fatalln(err)
	}

	r := gin.Default()

	r.GET("/message/:user/:num", func(c *gin.Context) {
		HandleGetMessage(c, dataStore)
	})

	r.GET("/queue/:user", func(c *gin.Context) {
		HandleGetUnreadMsgsInfo(c, dataStore)
	})

	r.GET("/cert/:user", func(c *gin.Context) {
		HandleGetUserCert(c, dataStore)
	})

	r.POST("/message/:user", func(c *gin.Context) {
		HandleSendMessage(c, dataStore)
	})

	r.POST("/cert/:user", func(c *gin.Context) {
		HandleStoreUserCert(c, dataStore)
	})

	server := http.Server{
		Addr:    "0.0.0.0:8080",
		Handler: r,
		//TODO: Verify if it's the gateway
		TLSConfig: serverKeyStore.GetServerTLSConfig(),
	}

	err = server.ListenAndServeTLS("", "")
	if err != nil {
		log.Fatal(err.Error())
	}
}