package main

import (
	"database/sql"
	"embed"
	"io"
	"log"
	"net/http"
	"net/url"
	"os"
	"strings"

	"github.com/go-chi/chi"
	"github.com/go-chi/cors"
	"github.com/joho/godotenv"

	"github.com/bootdotdev/learn-cicd-starter/internal/database"

	_ "github.com/go-sql-driver/mysql"
)

type apiConfig struct {
	DB *database.Queries
}

//go:embed static/*
var staticFiles embed.FS

func main() {
	err := godotenv.Load(".env")
	if err != nil {
		log.Printf("warning: assuming default configuration. .env unreadable: %v", err)
	}

	port := os.Getenv("PORT")
	if port == "" {
		log.Fatal("PORT environment variable is not set")
	}

	apiCfg := apiConfig{}

	dbURL := os.Getenv("DATABASE_URL")
	if dbURL == "" {
		log.Println("DATABASE_URL environment variable is not set")
		log.Println("Running without CRUD endpoints")
	} else {
		parsedURL, err := addParseTimeParam(dbURL)
		if err != nil {
			log.Fatal(err)
		}
		db, err := sql.Open("mysql", parsedURL)
		if err != nil {
			log.Fatal(err)
		}
		dbQueries := database.New(db)
		apiCfg.DB = dbQueries
		log.Println("Connected to database!")
	}

	router := chi.NewRouter()

	router.Use(cors.Handler(cors.Options{
		AllowedOrigins:   []string{"https://*", "http://*"},
		AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
		AllowedHeaders:   []string{"*"},
		ExposedHeaders:   []string{"Link"},
		AllowCredentials: false,
		MaxAge:           300,
	}))

	router.Get("/", func(w http.ResponseWriter, r *http.Request) {
		f, err := staticFiles.Open("static/index.html")
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		defer f.Close()
		if _, err := io.Copy(w, f); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
		}
	})

	v1Router := chi.NewRouter()

	if apiCfg.DB != nil {
		v1Router.Post("/users", apiCfg.handlerUsersCreate)
		v1Router.Get("/users", apiCfg.middlewareAuth(apiCfg.handlerUsersGet))
		v1Router.Get("/notes", apiCfg.middlewareAuth(apiCfg.handlerNotesGet))
		v1Router.Post("/notes", apiCfg.middlewareAuth(apiCfg.handlerNotesCreate))
	}

	v1Router.Get("/healthz", handlerReadiness)

	router.Mount("/v1", v1Router)
	srv := &http.Server{
		Addr:    ":" + port,
		Handler: router,
	}

	log.Printf("Serving on port: %s\n", port)
	log.Fatal(srv.ListenAndServe())
}

func addParseTimeParam(input string) (string, error) {
	const dummyScheme = "http://"
	if !strings.Contains(input, dummyScheme) {
		input = "http://" + input
	}
	u, err := url.Parse(input)
	if err != nil {
		return "", err
	}
	q := u.Query()
	q.Add("parseTime", "true")
	u.RawQuery = q.Encode()
	returnUrl := u.String()
	returnUrl = strings.TrimPrefix(returnUrl, dummyScheme)
	return returnUrl, nil
}