// Package main defines the entry point of the Go application.
package main

// Importing necessary packages for database interaction, web server functionality, logging, and more.
import (
	"database/sql"
	"fmt"
	"html/template"
	"io"
	"log"
	"net/http"
	"os"
	"strings"
	"time"

	_ "modernc.org/sqlite" // Importing SQLite driver for database interaction.
)

// readHtml function reads an HTML file and applies a CSS template to it before sending it to the client.
func readHtml(res http.ResponseWriter, req *http.Request) {
	g := template.CSS("./html/public/mod.css") // Define the CSS path.
	f, err := template.ParseFiles("./html/wsb.html") // Parse the HTML file.
	if err != nil {
		log.Println(err) // Log any errors encountered.
	}
	err = f.Execute(res, g) // Execute the template with the CSS and send it to the client.
	if err != nil {
		log.Println(err) // Log any errors encountered.
	}

}
// simpRequestResp sends a simple response to the client.
func simpRequestResp(res http.ResponseWriter, req *http.Request) {
	fmt.Fprint(res, "Hello, M'Lord", 153*4, " I'm here to serveè") // Print a formatted string to the client.
}

// getMsgFromDB retrieves a message from the database based on the provided ID and language.
func getMsgFromDB(sqldb *sql.DB, id string, lang string) string {
	var lngs []string
	lngs = append(lngs, lang) // Append the language to the slice.
	query := generateSQL("msgs", lngs, [2]string{"content", id}) // Generate the SQL query.
	res := sqldb.QueryRow(query) // Execute the query.
	lng := ""
	dt := res.Scan(&lng) // Scan the result into the lng variable.
	if dt != nil {
		return "" // Return an empty string if there's an error.
	}
	return lng // Return the retrieved message.
}

// queryPacks retrieves a list of packages from the database.
func queryPacks(sqldb *sql.DB, element *elements) []packages {
	pkg_list := getPkgIdFromDB(sqldb) // Get the list of package IDs from the database.
	pkgs := make([]packages, 0) // Initialize a slice to hold the packages.
	for _, p := range pkg_list {
		query := generateSQL("packs_all", []string{"*"}, [2]string{"id", p}) // Generate the SQL query for each package.
		res, err := sqldb.Query(query) // Execute the query.
		defer res.Close() // Ensure the result set is closed after the function returns.
		err = res.Err() // Check for any errors during query execution.
		if err != nil {
			log.Panicln(err) // Log and panic on any errors.
		}
		for res.Next() {
			npkg := packages{} // Create a new package instance.
			err := res.Scan(&npkg.Id, &npkg.Name, &npkg.Version, &npkg.ExtraCommand, &npkg.Tag, &npkg.Warning) // Scan the result into the package instance.
			if err != nil {
				log.Fatalln(err) // Log and exit on any errors.
			}
			npkg.Element = element // Associate the element with the package.
			pkgs = append(pkgs, npkg) // Append the package to the slice.
		}
	}
	return pkgs // Return the slice of packages.
}
// queryDatabase executes a SQL query expecting a single row and returns the result as a slice of strings.
// sqldb: The database connection object.
// queryRow: The SQL query string to be executed.
// Returns: A slice of strings representing the query result.
func queryDatabase(sqldb *sql.DB, queryRow string) []string {

	res := sqldb.QueryRow(queryRow)
	var values []string
	err := res.Scan(&values)
	if err != nil {
		log.Println(err)
	}
	return values
}

// generateSQL constructs a SQL SELECT statement with optional WHERE clauses.
// table: The name of the database table.
// columns: A slice of strings representing the column names to be selected.
// arg: A variadic slice of string pairs representing WHERE clause conditions.
// Returns: A string representing the complete SQL SELECT statement.
func generateSQL(table string, columns []string, arg ...[2]string) string {
	cols := strings.Join(columns, ",")
	table = "SELECT " + cols + " FROM " + table
	if len(arg) > 0 {
		table += " WHERE "
		for i, a := range arg {
			table += a[0] + " like '" + a[1] + "'"
			if i+1 < len(arg) {
				table += " and "
			}
		}
	}
	return table
}

// searchDownloads performs a database query to retrieve download statistics.
// sqldb: The database connection object.
// table: The name of the database table.
// columns: A variadic number of strings representing the column names to be selected.
// Returns: A slice of DownloadElements structs containing the query results.
func searchDownloads(sqldb *sql.DB, table string, columns ...string) []DownloadElements {
	query := generateSQL(table, columns)
	runquery, err := sqldb.Query(query)
	defer runquery.Close()
	err = runquery.Err()
	if err != nil {
		log.Fatalln(err)
	}
	var elems []DownloadElements
	var e DownloadElements
	for runquery.Next() {
		if len(columns) > 2 {
			err = runquery.Scan(&e.ID, &e.Version, &e.Counter)
		} else {
			err = runquery.Scan(&e.ID, &e.Counter)
		}
		elems = append(elems, e)
	}
	return elems
}

// stats creates an HTTP handler that serves a statistics page with data from the database.
// sqldb: The database connection object.
// lang: The language code to localize the content.
// Returns: An http.Handler that serves the statistics page.
func stats(sqldb *sql.DB, lang string) http.Handler {
	return http.HandlerFunc(func(res http.ResponseWriter, req *http.Request) {
		Counter := struct{
			ElementsData elements
			VersionStats []DownloadElements
			TotalStats []DownloadElements
			BodyClass string
			Lang string
		}{
			ElementsData: elements{
				Title:          getMsgFromDB(sqldb, "title", lang),
				Header:         getMsgFromDB(sqldb, "header", lang),
				Help:           getMsgFromDB(sqldb, "help", lang),
				Packagename:    getMsgFromDB(sqldb, "packagename", lang),
				Packageversion: getMsgFromDB(sqldb, "packageversion", lang),
				Allow:          getMsgFromDB(sqldb, "allow", lang),
				Warning:        getMsgFromDB(sqldb, "warning", lang),
				Explain:        getMsgFromDB(sqldb, "explain", lang),
			},
			BodyClass: "m",
			VersionStats: searchDownloads(sqldb, "counterd", "program", "version","download_count"),
			TotalStats: searchDownloads(sqldb, "count_all", "program","download_count"),
			Lang: lang,
		}
		templates, err := template.ParseFiles("html/master.html", "html/statsitics.html")
		if err != nil {
			log.Println(err)
		}
		err = templates.ExecuteTemplate(res, "master", Counter)
		if err != nil {
			log.Println(err)
		}
		res.WriteHeader(http.StatusOK)
	})
}

// getPkgIdFromDB retrieves a list of package IDs from the database.
// sqldb: The database connection object.
// Returns: A slice of strings containing package IDs.
func getPkgIdFromDB(sqldb *sql.DB) []string {
	query, err := sqldb.Query("SELECT id FROM packs_all")
	defer query.Close()
	err = query.Err()
	if err != nil {
		log.Println(err)
	}
	var pkgs []string
	var tmpstr string
	for query.Next() {
		err = query.Scan(&tmpstr)
		if err != nil {
			log.Println(err)
		}
		pkgs = append(pkgs, tmpstr)
	}
	// query.Scan(&pkgs)
	if err != nil {
		log.Println(err)
	}
	return pkgs
}

// fullSearchPackagesDB performs a full search of packages in the database.
// sqldb: The database connection object.
// Returns: A slice of packages structs containing the full package details.
func fullSearchPackagesDB(sqldb *sql.DB) []packages {
	pkg_list := getPkgIdFromDB(sqldb)
	var pkgs []packages
	for _, p := range pkg_list {
		query := generateSQL("packs_all", []string{"*"}, [2]string{"id", p})
		res := queryDatabase(sqldb, query)
		var pkg packages
		pkg, _ = ConvertStringsToPackage(res)
		pkgs = append(pkgs, pkg)
	}
	return pkgs
}
func uploadFileForServer(sqldb *sql.DB, lang string) http.Handler{
	return http.HandlerFunc(func(res http.ResponseWriter, req *http.Request) {
		pageDataFromDatabase := elements{
			Title:          getMsgFromDB(sqldb, "title", lang),
			Header:         getMsgFromDB(sqldb, "header", lang),
			Help:           getMsgFromDB(sqldb, "help", lang),
			Packagename:    getMsgFromDB(sqldb, "packagename", lang),
			Packageversion: getMsgFromDB(sqldb, "packageversion", lang),
			Allow:          getMsgFromDB(sqldb, "allow", lang),
			Warning:        getMsgFromDB(sqldb, "warning", lang),
			Explain:        getMsgFromDB(sqldb, "explain", lang),
		}
		data := struct {
			BodyClass string
			ElementsData elements
			Lang         string
		}{
			ElementsData: pageDataFromDatabase,
			BodyClass: "",
			Lang:         lang,

		}
		templates, err := template.ParseFiles("html/master.html", "html/uploadfile.html")
		if err != nil {
			log.Println(err)
		}
		err = templates.ExecuteTemplate(res, "master", data)
		if err != nil {
			log.Println(err)
		}
		// upload(res, req)
		res.WriteHeader(http.StatusOK)
	})
}
func upload() http.Handler {
	return http.HandlerFunc(func(res http.ResponseWriter, req *http.Request){
	file, header, _ := req.FormFile("myFile")
	req.ParseMultipartForm(10000000<<20)
	defer file.Close()
	filename := header.Filename
	tempFile, _ :=os.CreateTemp("Data",header.Filename)
	defer tempFile.Close()
	fileBytes,_:=io.ReadAll(file)
	tempFile.Write(fileBytes)
	fn,_:=os.OpenFile("Data/"+filename, os.O_CREATE, 0666)
	fn.Write(fileBytes)
	fn.Close()
	getParamsFromExif("Data/"+filename)
})}

// index creates an HTTP handler that serves the main page with data from the database.
// sqldb: The database connection object.
// lang: The language code to localize the content.
// Returns: An http.Handler that serves the main page.
func index(sqldb *sql.DB, lang string) http.Handler {
	return http.HandlerFunc(func(res http.ResponseWriter, req *http.Request) {
		pageDataFromDatabase := elements{
			Title:          getMsgFromDB(sqldb, "title", lang),
			Header:         getMsgFromDB(sqldb, "header", lang),
			Help:           getMsgFromDB(sqldb, "help", lang),
			Packagename:    getMsgFromDB(sqldb, "packagename", lang),
			Packageversion: getMsgFromDB(sqldb, "packageversion", lang),
			Allow:          getMsgFromDB(sqldb, "allow", lang),
			Warning:        getMsgFromDB(sqldb, "warning", lang),
			Explain:        getMsgFromDB(sqldb, "explain", lang),
		}
		data := struct {
			BodyClass string
			ElementsData elements
			PackagesData []packages
			Lang         string
			}{
				ElementsData: pageDataFromDatabase,
				BodyClass: "",
				PackagesData: queryPacks(sqldb, &pageDataFromDatabase),
				Lang:         lang,
			}
			templates, err := template.ParseFiles("html/master.html", "html/main.html")
			
			if err != nil {
				log.Println(err)
			}
			err = templates.ExecuteTemplate(res, "master", data)
			if err != nil {
				log.Println(err)
			}
			
				res.WriteHeader(http.StatusOK)
			
		})

}

// public serves static files from the "public" directory.
// Returns: An http.Handler that serves static files.
func public() http.Handler {
	return http.StripPrefix("/public/", http.FileServer(http.Dir("./public")))
}

// main initializes the application, sets up logging, database connection, HTTP routing, and starts the server.
func main() {
	logfilename := "Logs/" + time.Now().Format("2006-01-02--15-04-05") + ".log"
	file, err := os.OpenFile(logfilename, os.O_APPEND|os.O_CREATE, 0777)
	if err != nil {
		os.Exit(12)
	}

	log.SetOutput(file)
	db, _ := sql.Open("sqlite", "file:progs.db")
	mux := http.NewServeMux()
	mux.Handle("/public/", public())
	mux.Handle("/", index(db, "heb"))
	mux.Handle("/en", index(db, "eng"))
	mux.Handle("/stats", stats(db,"eng"))
	mux.Handle("/up", uploadFileForServer(db,"eng"))
	mux.Handle("/upload",upload())
	addr := fmt.Sprintf(":%s", "12312")
	server := http.Server{
		Addr:         addr,
		Handler:      mux,
		ReadTimeout:  15 * time.Second,
		WriteTimeout: 15 * time.Second,
		IdleTimeout:  15 * time.Second,
	}

	if err := server.ListenAndServe(); err != nil {
		log.Fatalf("main: couldn't start simple server: %v\n", err)
	}
	lang := "heb"

	log.Println(getMsgFromDB(db, "title", lang))
}