package main

import (
	"crypto/rand"
	"flag"
	"fmt"
	"log"
	"net/http"
	"os"
	"strings"

	"github.com/imc-vibe/backend/internal/api"
	"github.com/imc-vibe/backend/internal/auth"
	"github.com/imc-vibe/backend/internal/config"
	"github.com/imc-vibe/backend/internal/db"
)

func main() {
	resetAdminPassword := flag.Bool("reset-admin-password", false, "Reset admin password to a random value and exit")
	bind := flag.String("bind", "", "IP address to bind to (default: 0.0.0.0)")
	port := flag.String("port", "", "Port to listen on (default: 8080)")

	flag.Usage = func() {
		fmt.Fprintf(flag.CommandLine.Output(), "Usage: %s [options]\n\nOptions:\n", os.Args[0])
		flag.PrintDefaults()
	}
	flag.Parse()

	cfg := config.Load()

	if *bind != "" {
		cfg.Bind = *bind
	}
	if *port != "" {
		cfg.Port = *port
	}

	database, err := db.Connect(cfg)
	if err != nil {
		log.Fatalf("Failed to connect to database: %v", err)
	}

	if err := database.InitSchema(); err != nil {
		log.Printf("Warning: Could not initialize schema: %v", err)
	}

	if *resetAdminPassword {
		password := generateRandomPassword(16)
		fmt.Printf("Generated password: %s\n", password)

		hash, err := auth.HashPassword(password)
		if err != nil {
			log.Fatalf("Failed to hash password: %v", err)
		}

		if err := database.EnsureAdminUser("admin", hash); err != nil {
			log.Fatalf("Failed to reset admin password: %v", err)
		}

		fmt.Println("Admin password reset successfully.")
		return
	}

	frontendFS := FrontendFileSystem()

	router := http.NewServeMux()

	router.HandleFunc("/api/health", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"status":"ok"}`))
	})

	apiRouter := api.New(database, cfg)
	router.Handle("/api/", apiRouter.Handler())

	router.HandleFunc("/favicon.png", serveStaticFile(frontendFS, "embed/favicon.png"))
	router.Handle("/_app/", http.StripPrefix("/_app/", serveStaticPrefixed(frontendFS, "embed/_app/")))
	router.HandleFunc("/", serveSPA(frontendFS))

	addr := fmt.Sprintf("%s:%s", cfg.Bind, cfg.Port)
	log.Printf("Server starting on http://%s", addr)
	log.Fatal(http.ListenAndServe(addr, router))
}

func generateRandomPassword(length int) string {
	const charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*"
	result := make([]byte, length)
	if _, err := rand.Read(result); err != nil {
		log.Fatalf("Failed to generate random password: %v", err)
	}
	for i := range result {
		result[i] = charset[int(result[i])%len(charset)]
	}
	return string(result)
}

func serveStaticPrefixed(fsys http.FileSystem, prefix string) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		path := prefix + r.URL.Path

		file, err := fsys.Open(path)
		if err != nil {
			http.NotFound(w, r)
			return
		}
		defer file.Close()

		fi, err := file.Stat()
		if err != nil {
			http.NotFound(w, r)
			return
		}

		if fi.IsDir() {
			http.NotFound(w, r)
			return
		}

		contentType := mimeType(path)
		w.Header().Set("Content-Type", contentType)
		http.ServeContent(w, r, fi.Name(), fi.ModTime(), file)
	}
}

func serveStaticFile(fsys http.FileSystem, filename string) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		file, err := fsys.Open(filename)
		if err != nil {
			http.NotFound(w, r)
			return
		}
		defer file.Close()

		fi, err := file.Stat()
		if err != nil {
			http.NotFound(w, r)
			return
		}

		contentType := mimeType(filename)
		w.Header().Set("Content-Type", contentType)
		http.ServeContent(w, r, fi.Name(), fi.ModTime(), file)
	}
}

func serveSPA(fsys http.FileSystem) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		path := r.URL.Path

		if strings.HasPrefix(path, "/api/") {
			http.NotFound(w, r)
			return
		}

		path = "embed/index.html"

		file, err := fsys.Open(path)
		if err != nil {
			log.Printf("Error opening %s: %v", path, err)
			http.Error(w, "Not found", http.StatusNotFound)
			return
		}
		defer file.Close()
		fi, _ := file.Stat()
		w.Header().Set("Content-Type", "text/html; charset=utf-8")
		http.ServeContent(w, r, fi.Name(), fi.ModTime(), file)
	}
}

func mimeType(path string) string {
	switch {
	case strings.HasSuffix(path, ".html"):
		return "text/html; charset=utf-8"
	case strings.HasSuffix(path, ".css"):
		return "text/css"
	case strings.HasSuffix(path, ".js"):
		return "application/javascript"
	case strings.HasSuffix(path, ".json"):
		return "application/json"
	case strings.HasSuffix(path, ".png"):
		return "image/png"
	case strings.HasSuffix(path, ".jpg") || strings.HasSuffix(path, ".jpeg"):
		return "image/jpeg"
	case strings.HasSuffix(path, ".svg"):
		return "image/svg+xml"
	case strings.HasSuffix(path, ".ico"):
		return "image/x-icon"
	case strings.HasSuffix(path, ".woff"):
		return "font/woff"
	case strings.HasSuffix(path, ".woff2"):
		return "font/woff2"
	case strings.HasSuffix(path, ".ttf"):
		return "font/ttf"
	case strings.HasSuffix(path, ".eot"):
		return "application/vnd.ms-fontobject"
	default:
		return "text/plain"
	}
}