package main

import (
	"context"
	"fmt"
	"io"
	"log"
	"net/http"

	"github.com/jackc/pgx/v5/pgxpool"
)

// db connection info
// !MIGHT CHANGE
const (
	host     = "localhost"
	port     = 5432
	user     = "asdfuser"
	password = "asdfpassword"
	dbname   = "asdfdb"
)

var pool *pgxpool.Pool

// initialize connection to db
func connectToDb() (*pgxpool.Pool, error) {
	// this server is intended to be ran on the same system as the db
	dbUrl := fmt.Sprintf("postgresql://%s:%s@%s:%d/%s", user, password, host, port, dbname)
	config, err := pgxpool.ParseConfig((dbUrl))
	if err != nil {
		return nil, fmt.Errorf("unable to parse data URL: %w", err)
	}

	pool, err := pgxpool.NewWithConfig(context.Background(), config)
	if err != nil {
		return nil, fmt.Errorf("unable to create connection pool: %w", err)
	}

	log.Println("Connected to DB :)")
	return pool, nil
}

// take http reqeust body as raw sql and pass to db
func executeSql(w http.ResponseWriter, r *http.Request) {
	// read the request body
	sqlQuery, err := io.ReadAll(r.Body)
	if err != nil {
		http.Error(w, "Failed to read request body", http.StatusBadRequest)
		return
	}
	defer r.Body.Close()

	// execute the sql query without any sanitization
	rows, err := pool.Query(context.Background(), string(sqlQuery))
	if err != nil {
		http.Error(w, "Query execution error", http.StatusInternalServerError)
		return
	}
	defer rows.Close()

	// prepare the response by iterating over the returned rows
	var response string
	for rows.Next() {
		values, err := rows.Values()
		if err != nil {
			http.Error(w, "Error reading query result", http.StatusInternalServerError)
			return
		}
		response += fmt.Sprintf("%v\n", values)
	}

	// send the response to the client
	w.Write([]byte(response))
}

// setup the http server
func serveApi() {
	http.HandleFunc("/executeSql", executeSql)
	log.Println("Unsecure server is running on http://localhost:3001")
	if err := http.ListenAndServe(":3001", nil); err != nil {
		log.Fatalf("Failed to start server: %v", err)
	}
}

func main() {
	var err error
	pool, err = connectToDb()
	if err != nil {
		log.Fatalf("Failed to connect to db: %v", err)
	}
	defer pool.Close()

	serveApi()
}