package main

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"os"

	//"github.com/DataDog/go-sqllexer"
	"log"
	"net/http"
	"query-inter/q"
	"time"
)

func main() {
	//selectQuery := "SELECT MIN(Price) AS SmallestPrice, CategoryID FROM Products GROUP BY CategoryID;"
	PORT := os.Getenv("PORT")

	if PORT == "" {
		log.Panicln("PORT could not be read from env")
	}

	StartServer(PORT)

	//allStatements := q.ExtractSqlStatmentsFromString(selectQuery)
	//fmt.Println(allStatements)

	//lexer := sqllexer.New(selectQuery)
	//for {
	//	token := lexer.Scan()
	//	fmt.Println(token.Value, token.Type)
	//
	//	if token.Type == sqllexer.EOF {
	//		break
	//	}
	//}

	//for _, sql := range allStatements {
	//query := q.ParseSelectStatement(sql)
	//fmt.Print(i)
	//fmt.Println(query)
	//fmt.Println(query.GetFullSql())
	//}

}

func StartServer(port string) {
	http.HandleFunc("/query", HandlePostQuery)
	fmt.Println("Starting Server on 8080")
	fmt.Println("call POST /query with { sql: string }")
	log.Fatal(http.ListenAndServe(":"+port, nil))
}

type QueryRequest struct {
	SQL string `json:"sql"`
}

func HandlePostQuery(w http.ResponseWriter, r *http.Request) {
	body, err := io.ReadAll(r.Body)
	if err != nil {
		http.Error(w, "Error reading request body", http.StatusBadRequest)
		return
	}
	defer r.Body.Close()

	var request QueryRequest
	err = json.Unmarshal(body, &request)
	if err != nil {
		http.Error(w, "Error parsing JSON: "+string(body), http.StatusBadRequest)
		return
	}

	ctx, cancel := context.WithTimeout(r.Context(), 30*time.Second)
	defer cancel()

	var query q.Query
	done := make(chan struct{})

	go func() {
		defer cancel()
		query, err = q.Parse(request.SQL)
		done <- struct{}{}
	}()

	select {
	case <-done:
		// Proceed
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusOK) // Set the HTTP status code

		jsonData, err := q.MarshalSelect(query)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		_, err = w.Write(jsonData)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

	case <-ctx.Done():
		http.Error(w, "Request timed out", http.StatusRequestTimeout)
		return
	}

}